@article{charnock_davidson_keys_gilger_mcmullen_2023, title={Prevalence, differences, and potential correlation to age, sex, breed, coat color, iris color, and geographic location in naturally occurring refractive errors in the normal equine eye from Germany and North Carolina}, volume={26}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1111/vop.13061}, DOI={10.1111/vop.13061}, abstractNote={AbstractPurposeTo evaluate the normal refractive state in horses in NCSU and ECMR and determine the prevalence of naturally occurring refractive errors and their association with breed, age, coat color, iris color, sex, and geographic location.MethodsHorses from NCSU (January 2009–November 2012) and ECMR (January 2013–September 2016) underwent ophthalmic examination and streak retinoscopy. Location, color, breed, sex, and iris color were recorded. Gross and net refractive values for each meridian (horizontal and vertical), spherical refraction, astigmatism for both eyes, and anisometry were recorded, and statistical analyses were performed.ResultsThere is excellent agreement in refraction between the eyes of the same horse (ICC = 0.89). The median net horizontal (H), vertical (V), and spherical refraction for the total population (n = 690) were H: +0.25 D (min. −6.50 D, max. +2.34 D), V: +0.25 D (min. −7.13 D, max. +2.75D), and spherical: +0.25 D (min. −6.82 D, max. +2.17 D), all with interquartile ranges of −0.25 to 0.25 D. Emmetropia (>−0.50 D and <+0.50 D; >−0.75 D and <+0.75 D) was present in 769/1380 eyes (55.7%) and 926/1380 eyes (67.1%), respectively. Anisometropia was present in 86/690 horses (12.5%). Sex, iris color, and location were significantly associated with refraction values, whereas age, breed, and coat color were not.ConclusionsMost eyes evaluated are emmetropic, or shifted myopically, with excellent agreement between eyes of the same horse. Sex, iris color, and geographic location appear to impact refraction in horses.SupportNone.}, number={4}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Charnock, Lauren N. and Davidson, Michael G. and Keys, Deborah A. and Gilger, Brian C. and McMullen, Richard J., Jr.}, year={2023}, month={Jan}, pages={297–305} }
 @article{oh_loew_foster_davidson_english_gervais_herring_mowat_2018, title={Phenotypic characterization of complete CSNB in the inbred research beagle: how common is CSNB in research and companion dogs?}, volume={137}, ISSN={["1573-2622"]}, DOI={10.1007/s10633-018-9653-y}, abstractNote={{"Label"=>"PURPOSE"} Although congenital stationary night blindness (CSNB) has been described in a Japanese beagle dog research colony, certain clinical correlates with human CSNB have not yet been described, nor has an estimate of frequency of the condition been made in inbred and outbred beagle populations. {"Label"=>"METHODS"} A beagle with CSNB obtained from a commercial research dog supplier in the USA and matched control dogs (n = 3) underwent examination, refraction, ocular imaging, assessment of visual navigation ability and detailed electroretinography (ERG). Retrospective review of ERGs in two independent groups of inbred (n = 15 and 537, respectively) and one group of outbred dogs (n = 36) was used to estimate CSNB frequency in these populations. {"Label"=>"RESULTS"} In the affected dog, there were absent dark-adapted b-waves in response to dim-light flashes, severely reduced dark-adapted b-waves in response to bright-light flashes, and normal light-adapted b-waves with a-waves that had broadened troughs. Long-flash ERGs confirmed a markedly reduced b-wave with a preserved d-wave, consistent with cone ON-bipolar cell dysfunction. There was evidence of normal rod photoreceptor a-wave dark adaptation, and rapid light adaptation. In the wider beagle populations, five inbred beagles had a b/a wave ratio of < 1 in dark-adapted bright-flash ERG, whereas no outbred beagles had ERGs consistent with CSNB. {"Label"=>"CONCLUSIONS"} The identified dog had clinical findings consistent with complete type CSNB, similar to that described in the Japanese colony. CSNB appears to be a rare disorder in the wider beagle population, although its detection could confound studies that use retinal function as an outcome measure in research dogs, necessitating careful baseline studies to be performed prior to experimentation.}, number={2}, journal={DOCUMENTA OPHTHALMOLOGICA}, author={Oh, Annie and Loew, Ellis R. and Foster, Melanie L. and Davidson, Michael G. and English, Robert V and Gervais, Kristen J. and Herring, Ian P. and Mowat, Freya M.}, year={2018}, month={Oct}, pages={87–101} }
 @article{young_zheng_davidson_westermeyer_2019, title={Visual outcome in cats with hypertensive chorioretinopathy}, volume={22}, ISSN={["1463-5224"]}, url={https://doi.org/10.1111/vop.12575}, DOI={10.1111/vop.12575}, abstractNote={AbstractPurposeTo investigate factors associated with long‐term visual outcome in cats with hypertensive chorioretinopathy.Animals studiedEighty‐eight client‐owned cats diagnosed with hypertensive chorioretinopathy.ProcedureMedical records from cats with systemic hypertension and associated retinal lesions were reviewed.ResultsMost cats (61%) were blind in both eyes at presentation. Presence of menace response at last follow‐up evaluation was positively correlated with presence of menace response at presentation (P = .0025), time to complete retinal reattachment (P < .0001), and gender (P = .0137). Seventy‐six of 132 eyes (57.6%) that were blind at presentation regained some vision following treatment. At the time of last evaluation, 101/176 eyes (60%) had a positive menace response, while 34/46 (74%) eyes with a follow‐up of >6 months had a positive menace response. Eyes that had a menace response at presentation were 17 and 37 times more likely to have a menace response at last examination compared to eyes blind for less than 2 weeks and eyes blind greater than 2 weeks, respectively. Female cats were overrepresented (62.5% of cases), and male cats were 4.2 times more likely to be visual at time of last examination compared to female cats.ConclusionsWith treatment, the prognosis for long‐term vision in cats with hypertensive chorioretinopathy, even following complete retinal detachment, is good.}, number={2}, journal={VETERINARY OPHTHALMOLOGY}, author={Young, Whitney M. and Zheng, Chaowen and Davidson, Michael G. and Westermeyer, Hans D.}, year={2019}, month={Mar}, pages={161–167} }
 @article{smith_westermeyer_mariani_gilger_davidson_2017, title={Optic neuritis in dogs: 96 cases (1983-2016)}, volume={21}, ISSN={1463-5216}, url={http://dx.doi.org/10.1111/vop.12528}, DOI={10.1111/vop.12528}, abstractNote={AbstractObjectiveTo characterize ocular and neurologic findings, causes, and treatment outcomes of dogs with optic neuritis.ProcedureMedical records from dogs with a diagnosis of optic neuritis at North Carolina State University, College of Veterinary Medicine, Veterinary Hospital between 1983 and 2016 were reviewed.ResultsNinety‐six cases (20 unilateral, 76 bilateral), comprised of 38 males and 58 females with a mean age of 6.1 ± 3.0 years (range 0.5‐13), were identified. Seventy‐four cases were presented for vision loss, and 42 had other concurrent neurologic abnormalities. Funduscopic findings included optic nerve head elevation (n = 92), peripapillary retinal edema or separation (n = 37), retinal hemorrhage or dilation of retinal vasculature (n = 23), and multiple inflammatory foci in the peripapillary region (n = 13). Retrobulbar optic neuritis was diagnosed in four cases. The final diagnoses included the following: multifocal meningoencephalitis of unknown etiology (MUE, n = 35), isolated optic neuritis (I‐ON, n = 42), neoplasia (n = 10), microbial infection (n = 6), orbital inflammation (n = 2), and suspected ivermectin toxicosis (n = 1). Dogs with I‐ON were more commonly male, and medium‐to‐large breed, when compared to dogs with MUE. Follow‐up was available in 72 cases, 50 of which remained blind, 10 had partial visual improvement, and 12 were assessed as having normal vision in the affected eye(s).ConclusionOptic neuritis was most commonly associated with multifocal MUE or was isolated as the sole neurologic finding, with a similar incidence between the two groups. Findings suggest that a clinical syndrome of isolated optic neuritis, distinct from multifocal MUE, occurs in dogs.}, number={5}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Smith, Sara M. and Westermeyer, Hans D. and Mariani, Christopher L. and Gilger, Brian C. and Davidson, Michael G.}, year={2017}, month={Dec}, pages={442–451} }
 @article{mcmullen_davidson_gilger_2013, title={The effect of 1% tropicamide-induced mydriasis and cycloplegia on spherical refraction of the adult horse}, volume={17}, ISSN={1463-5216}, url={http://dx.doi.org/10.1111/vop.12055}, DOI={10.1111/vop.12055}, abstractNote={AbstractObjectivesTo determine the effects of tropicamide 1% on the refractive state of the adult equine globe and identify the most appropriate time period (in relation to mydriasis) to perform streak retinoscopy.Animals studiedEight university‐owned mares of various ages and breeds.ProceduresTopical tropicamide 1% was applied to one randomly selected eye from each of the horses to induce mydriasis and cycloplegia. The contralateral eyes served as controls. Streak retinoscopy and pupillometry were performed prior to, and every 5 min after tropicamide 1% installation for 90 min.ResultsAll values are expressed as mean ± SD. Both horizontal (2.8 ± 0.74 mm) and vertical (7.3 ± 1.29 mm) mean pupil diameters increased significantly (P < 0.04) in the treatment eyes compared with the control eyes (horizontal [0.48 ± 0.85 mm] and vertical [1.06 ± 1.31 mm] pupil diameter). No significant differences in the refractive states of the treatment (horizontal: +0.25 ± 0.43 D and vertical: +0.41 ± 0.37 D) or control (horizontal: +0.34 ± 0.39 D and vertical: +0.41 ± 0.37 D) eyes were identified at any time point. Three of the eight treatment eyes demonstrated blurry or reversing streak reflexes during streak retinoscopy evaluation following the application of topical tropicamide 1%.ConclusionsWhile these reflexes did not significantly influence streak retinoscopy results, their presence may subjectively influence a novice retinoscopist's ability to obtain accurate results. Therefore, optimal streak retinoscopy results may be obtained prior to, or 40‐ to 45‐min following the application of topical tropicamide 1%, once near‐maximal dilation has been achieved.}, number={2}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={McMullen, Richard J., Jr. and Davidson, Michael G. and Gilger, Brian C.}, year={2013}, month={May}, pages={120–125} }
 @article{michau_davidson_gilger_2012, title={Carbon dioxide laser photoablation adjunctive therapy following superficial lamellar keratectomy and bulbar conjunctivectomy for the treatment of corneolimbal squamous cell carcinoma in horses: a review of 24 cases}, volume={15}, ISSN={["1463-5224"]}, DOI={10.1111/j.1463-5224.2011.00977.x}, abstractNote={AbstractObjective To determine the complications and nonrecurrence rates following superficial lamellar keratectomy, bulbar conjunctivectomy, and adjunctive carbon dioxide (CO2) photoablation for corneolimbal squamous cell carcinoma (SCC) in the horse.Study design Retrospective study.Sample population Twenty‐four horses with corneolimbal SCC.Procedure Medical records of horses diagnosed with corneolimbal SCC that was surgically excised and where CO2photoablation was used as an adjunctive therapy from 2000 to 2007 were reviewed. Signalment, prior therapy, tumor location and size, complications, and recurrence of SCC were recorded.Results The Thoroughbred was the most commonly (25%) represented breed. Lesions were >10 mm in diameter in 70.8% of cases. Eight horses (33.3%) had neoplastic cells extending to the deep margin of the keratectomy. All horses were available for follow‐up for an average ± standard deviation of 40.7 ± 25 months. Four horses (16.7%) developed a recurrence of SCC. Three of these four horses underwent repeat keratectomy and CO2photoablation, one each, at 4 months, 1, and 2 years following the initial procedure. One horse underwent enucleation 8 months following the initial procedure.Conclusions and clinical relevance As an adjunctive therapy, CO2photoablation was successful in 87.5% of the horses following a single procedure and in a total of 91.7% following a second therapeutic application. CO2photoablation appears to be effective as an adjunctive therapy following removal of large corneolimbal SCC in the horse and in cases in which all tumor cells were not excised.}, number={4}, journal={VETERINARY OPHTHALMOLOGY}, author={Michau, Tammy M. and Davidson, Michael G. and Gilger, Brian C.}, year={2012}, month={Jul}, pages={245–253} }
 @article{mcmullen_davidson_campbell_salmon_gilger_2010, title={Evaluation of 30- and 25-diopter intraocular lens implants in equine eyes after surgical extraction of the lens}, volume={71}, ISSN={0002-9645}, url={http://dx.doi.org/10.2460/ajvr.71.7.809}, DOI={10.2460/ajvr.71.7.809}, abstractNote={Abstract
Objective—To determine appropriate intraocular lens (IOL) implant strength to approximate emmetropia in horses.
Sample Population—16 enucleated globes and 4 adult horses.
Procedures—Lens diameter of 10 enucleated globes was measured. Results were used to determine the appropriate-sized IOL implant for insertion in 6 enucleated globes and 4 eyes of adult horses. Streak retinoscopy and ocular ultrasonography were performed before and after insertion of 30-diopter (D) IOL implants (enucleated globes) and insertion of 25-D IOL implants (adult horses).
Results—In enucleated globes, mean ± SD lens diameter was 20.14 ± 0.75 mm. Preoperative and postoperative refractive state of enucleated globes with 30-D IOL implants was −0.46 ± 1.03 D and −2.47 ± 1.03 D, respectively; preoperative and postoperative difference in refraction was 2.96 ± 0.84 D. Preoperative anterior chamber (AC) depth, crystalline lens thickness (CLT), and axial globe length (AxL) were 712 ± 0.82 mm, 11.32 ± 0.81 mm, and 40.52 ± 1.26 mm, respectively; postoperative AC depth was 10.76 ± 1.16 mm. Mean ratio of preoperative to postoperative AC depth was 0.68. In eyes receiving 25-D IOL implants, preoperative and postoperative mean refractive error was 0.08 ± 0.68 D and −3.94 ± 1.88 D, respectively. Preoperative AC depth, CLT, and AxL were 6.36 ± 0.22 mm, 10.92 ± 1.92 mm, and 38.64 ± 2.59 mm, respectively. Postoperative AC depth was 8.99 ± 1.68 mm. Mean ratio of preoperative to postoperative AC depth was 0.73.
Conclusions and Clinical Relevance—Insertion of 30-D (enucleated globes) and 25-D IOL implants (adult horses) resulted in overcorrection of refractive error.}, number={7}, journal={American Journal of Veterinary Research}, publisher={American Veterinary Medical Association (AVMA)}, author={McMullen, Richard J. and Davidson, Michael G. and Campbell, Nigel B. and Salmon, Jacklyn H. and Gilger, Brian C.}, year={2010}, month={Jul}, pages={809–816} }
 @book{engagement_2010, title={Integrating learning, discovery, and engagement through the scholarship of engagement}, journal={Technical Report- Not held in TRLN member libraries}, institution={Raleigh, NC: NCSU Office of Extension, Engagement, and Economic Development}, author={Engagement, Task Force}, year={2010} }
 @article{pena_naranjo_klauss_fondevila_leiva_roura_davidson_dubielzig_2008, title={Histopathological features of ocular leishmaniosis in the dog}, volume={138}, ISSN={["0021-9975"]}, DOI={10.1016/j.jcpa.2007.09.004}, abstractNote={Canine leishmaniosis (CL) can present with multiple clinical signs and ocular disease is reported to occur in almost 25% of affected dogs. The purpose of the present study was to characterize the nature of inflammation within the eyes of dogs with leishmaniosis and to determine whether parasites were present in these lesions. Eyes from 60 dogs with confirmed leishmaniosis that died or were humanely destroyed over a 4 year period were included in the study. Sections of formalin-fixed globes were stained with haematoxylin and eosin (HE) and subjected to immunohistochemistry using a Leishmania-specific antibody. Clinically evident ocular signs were present in 15 of 60 dogs (13 bilaterally and 2 unilaterally). Thirty-five of 60 dogs received some form of anti-protozoal treatment. In 36 of 120 eyes (30%) a granulomatous inflammatory infiltrate was found and in 32 of 120 eyes (26.6%) the parasite was identified immunohistochemically within the globe. Ocular tissues affected, in order of frequency, were conjunctiva and limbus, ciliary body, iris, cornea, sclera and iridocorneal angle, choroid and the optic nerve sheath. Different microscopical patterns were defined in each of these structures. Leishmania organisms and associated inflammation can be found in different ocular tissues, accounting for some of the ocular clinical signs described for this disease.}, number={1}, journal={JOURNAL OF COMPARATIVE PATHOLOGY}, author={Pena, M. T. and Naranjo, C. and Klauss, G. and Fondevila, D. and Leiva, M. and Roura, X. and Davidson, M. G. and Dubielzig, R. R.}, year={2008}, month={Jan}, pages={32–39} }
 @misc{brown_atkins_bagley_carr_cowgill_davidson_egner_elliott_henik_labato_et al._2007, title={Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats}, volume={21}, DOI={10.1111/j.1939-1676.2007.tb03005.x}, abstractNote={Consensus Statements of the American College of Veterinary Internal Medicine (ACVIM) provide veterinarians with guidelines regarding the pathophysiology, diagnosis, or treatment of animal diseases. The foundation of the Consensus Statement is evidence‐based medicine, but if such evidence is conflicting or lacking, the panel provides interpretive recommendations on the basis of their collective expertise. The Consensus Statement is intended to be a guide for veterinarians, but it is not a statement of standard of care or a substitute for clinical judgment. Topics of statements and panel members to draft the statements are selected by the Board of Regents with input from the general membership. A draft prepared and input from Diplomates is solicited at the ACVIM Forum and via the ACVIM Web site and incorporated in a final version. This Consensus Statement was approved by the Board of Regents of the ACVIM before publication.}, number={3}, journal={Journal of Veterinary Internal Medicine}, author={Brown, S. and Atkins, C. and Bagley, R. and Carr, A. and Cowgill, L. and Davidson, M. and Egner, B. and Elliott, J. and Henik, R. and Labato, M. and et al.}, year={2007}, pages={542–558} }
 @article{billson_miller-michau_mould_davidson_2006, title={Idiopathic sclerosing orbital pseudotumor in seven cats}, volume={9}, ISSN={["1463-5224"]}, DOI={10.1111/j.1463-5224.2005.00436.x}, abstractNote={AbstractObjective To review the clinical presentation and histopathologic findings on a series of cats with orbital fibrotic disease and compare the data to that of humans with sclerosing orbital pseudotumor.Animals A retrospective study was undertaken, which identified tissue samples from seven cats between 1997 and 2002 with a history of orbital mass effect and pathology characterized by fibrous tissue proliferation.Procedure Information was obtained from medical records for affected cats, including age, sex, clinical signs, management, and outcome, with histopathology re‐examined.Results Six of seven cats presented with unilateral orbital involvement that progressed to bilateral orbital disease despite treatment. Onset was insidious, evolving over weeks to months and was associated with fixation of orbital structures. Owners of six of the cats opted for euthanasia because of disease progression and pain. Histopathology of affected orbital tissue included extensive fibrosis with encapsulation of normal tissues without characteristics of neoplasia.Conclusions Clinical findings and histopathology of globes and orbital tissues in cats bore many similarities to idiopathic sclerosing orbital pseudotumor in humans. In cats, the prognosis for the globe appears to be poor but an elucidation of the pathogenesis and earlier diagnosis coupled with more aggressive treatment modalities as indicated in humans may be beneficial.}, number={1}, journal={VETERINARY OPHTHALMOLOGY}, author={Billson, FM and Miller-Michau, T and Mould, JRB and Davidson, MG}, year={2006}, pages={45–51} }
 @article{mahmoud_peng_d proia_davidson_deramo_fekrat_2006, title={Recombinant tissue plasminogen activator injected into the vitreous cavity may penetrate the retinal veins of a porcine model of vascular occlusion}, volume={90}, ISSN={["1468-2079"]}, DOI={10.1136/bjo.2005.089037}, abstractNote={Aim: To determine if recombinant tissue plasminogen activator (rtPA) injected into the vitreous cavity can penetrate the retinal vessels of porcine eyes with or without vascular occlusion. Methods: Eight eyes (group I) of four pigs underwent clamping of the optic nerve flush with the globe for 90 minutes. One hour after reperfusion, one eye of each pig was injected with 75 μg of rtPA, and the fellow eye was injected with balanced salt solution (BSS). Eyes were processed for immunohistochemistry. Four additional eyes (group II) of two pigs were subjected to the same injections, but without optic nerve clamping. Results: After reperfusion, the clinical picture was similar to that of a central retinal vein occlusion. Immunoperoxidase staining showed rtPA only in the retinal veins but not the retinal arteries in all eyes injected with rtPA in both groups I and II. Those eyes also showed intense rtPA staining at the level of the internal limiting membrane (ILM). No staining was seen at the level of the ILM or inside the retinal vessels in the BSS injected eyes. Immunofluorescence staining showed intense staining at the level of the ILM, but not inside the retinal vessels in the rtPA-injected eyes. Conclusions: rtPA may penetrate the retinal veins, but not the arteries of porcine eyes with and without vascular occlusion. The ILM may play a part in preventing rtPA penetration.}, number={7}, journal={BRITISH JOURNAL OF OPHTHALMOLOGY}, author={Mahmoud, T. H. and Peng, Y-W and D Proia, A. and Davidson, M. and Deramo, V. A. and Fekrat, S.}, year={2006}, month={Jul}, pages={911–915} }
 @article{breitschwerdt_blann_stebbins_munana_davidson_jackson_willard_2004, title={Clinicopathological abnormalities and treatment response in 24 dogs seroreactive to Bartonella vinsonii (berkhoffii) antigens}, volume={40}, ISSN={["0587-2871"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1842839032&partnerID=MN8TOARS}, DOI={10.5326/0400092}, abstractNote={Bartonella vinsonii (B. vinsonii) subspecies berkhoffii is a recently recognized cause of endocarditis, myocarditis, and granulomatous disease in dogs. In an effort to elucidate other potential disease manifestations, the case records of 24 dogs that were seroreactive to B. vinsonii (berkhoffii) antigens were studied retrospectively. Diagnoses included immune-mediated hemolytic anemia, neutrophilic or granulomatous meningoencephalitis, neutrophilic polyarthritis, cutaneous vasculitis, and uveitis. Repeated B. vinsonii (berkhoffii) antibody titers became negative after treatment. This study indicates that a diverse spectrum of disease manifestations and clinicopathological abnormalities can be detected in dogs that are seroreactive to B. vinsonii (berkhoffii) antigens.}, number={2}, journal={JOURNAL OF THE AMERICAN ANIMAL HOSPITAL ASSOCIATION}, author={Breitschwerdt, EB and Blann, KR and Stebbins, ME and Munana, KR and Davidson, MG and Jackson, HA and Willard, MD}, year={2004}, pages={92–101} }
 @article{levy_liang_ritchey_davidson_tompkins_tompkins_2004, title={Failure of FIV-infected cats to control Toxoplasma gondii correlates with reduced IL2, IL6, and IL12 and elevated IL10 expression by lymph node T cells}, volume={98}, ISSN={["0165-2427"]}, DOI={10.1016/j.vetimm.2003.11.002}, abstractNote={Increased susceptibility to intracellular pathogens in HIV-infected individuals and FIV-infected cats is attributed to a defective T-helper 1 (Th1) immune response. However, little is known about specific cytokine responses to secondary pathogens. To address this question, control and FIV-infected cats were challenged with Toxoplasma gondii, and lymph node cells analyzed for cytokine mRNA expression. Twenty-four weeks post-FIV infection, prior to T. gondii challenge, IL2 and IL12 mRNAs were depressed, whereas IL10 and IFNγ mRNAs were increased in CD4+ and CD8+ subsets. Following T. gondii challenge, control cats showed increased expression of IL2, IFNγ, IL10, IL12, and IL6 mRNAs. In contrast, IL2, IL6, IFNγ, and IL12 mRNAs were suppressed in FIV–T. gondii co-infected cats, whereas IL10 remained at the high prechallenge levels. IFNγ and IL10 mRNAs were produced by both CD4+ and CD8+ cells in FIV–T. gondii cats. Elevated IL10 may suppress a Th1 cytokine response to T. gondii challenge.}, number={1-2}, journal={VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY}, author={Levy, JK and Liang, YH and Ritchey, JW and Davidson, MG and Tompkins, WA and Tompkins, MB}, year={2004}, month={Mar}, pages={101–111} }
 @article{wilkie_davidson_2004, title={Preface}, volume={7}, ISSN={["1463-5216"]}, DOI={10.1111/j.1463-5224.2004.04045.x}, abstractNote={Veterinary OphthalmologyVolume 7, Issue 5 p. 283-283 Preface David A. Wilkie, David A. Wilkie College of Veterinary Medicine, The Ohio State UniversitySearch for more papers by this authorMichael Davidson, Michael Davidson College of Veterinary Medicine, North Carolina State UniversitySearch for more papers by this author David A. Wilkie, David A. Wilkie College of Veterinary Medicine, The Ohio State UniversitySearch for more papers by this authorMichael Davidson, Michael Davidson College of Veterinary Medicine, North Carolina State UniversitySearch for more papers by this author First published: 16 August 2004 https://doi.org/10.1111/j.1463-5224.2004.04045.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume7, Issue5September 2004Pages 283-283 RelatedInformation}, number={5}, journal={VETERINARY OPHTHALMOLOGY}, author={Wilkie, DA and Davidson, M}, year={2004}, pages={283–283} }
 @article{michau_breitschwerdt_gilger_davidson_2003, title={Bartonella vinsonii subspecies berkhoffi as a possible cause of anterior uveitis and choroiditis in a dog}, volume={6}, ISSN={["1463-5224"]}, DOI={10.1111/j.1463-5224.2003.00310.x}, abstractNote={AbstractA 2‐year old, neutered, female spaniel mixed breed was referred to the North Carolina State University Veterinary Teaching Hospital for evaluation of bilateral anterior uveitis. The dog was febrile and, in addition to anterior uveitis, multifocal hyporeflective lesions were present in the tapetal fundus of both eyes. The antibody titer forBartonella vinsoniisubspeciesberkhoffiwas positive (1 : 512). Aqueous paracentesis was performed for PCR in an attempt to detectB. vinsoniiin the eye but was unsuccessful. The ocular manifestations ofBartonellainfection in humans are currently expanding as more sensitive serologic and PCR techniques are being developed to identifyBartonellaspp. In addition to optic neuritis and neuroretinitis, retinochoroidal lesions are one of the most common manifestations ofB. henselaeinfection, and are frequently accompanied by vitreous or anterior segment inflammation. Diagnosis of aBartonellainfection in humans can be made on serology alone, in conjunction with ocular examination findings. The ultimate proof ofB. vinsonii (berkhoffi)as a direct cause of ocular disease would be detection of the infectious agent in the eye. However, it is unknown at this time whetherBartonellacauses ocular disease primarily, secondarily via an autoimmune reaction, or both. Due to the difficulties associated with culture ofBartonellaspp. and the limitations of PCR, serology is currently the most useful tool for screening dogs for possibleBartonellaspp. infection. In the case presented here, even though the PCR was negative, the clinical signs of anterior uveitis and choroiditis might reasonably be associated withB. vinsonii (berkhoffi)seroreactivity, which was repeatable on three separate occasions. Clinical improvement was also accompanied by a post‐treatment decrease inB. vinsonii (berkhoffi)seroreactivity, potentially supporting resolution ofBartonellainfection in this dog. This is the first reported case of a possible association between uveitis, choroiditis andBartonellainfection in the dog, without clinical manifestations of other organ or tissue involvement. Future studies based on PCR analysis of intraocular fluids may clarify the involvement ofB. vinsonii (berkhoffi)in dogs with intraocular inflammatory disease. Furthermore, performing fluorescein angiography in dogs with elevatedBartonellatiters may also prove useful in the identification and characterization of lesions.}, number={4}, journal={VETERINARY OPHTHALMOLOGY}, author={Michau, TM and Breitschwerdt, EB and Gilger, BC and Davidson, MG}, year={2003}, month={Dec}, pages={299–304} }
 @article{michau_proulx_rushton_olivry_dunston_gilger_davidson_2003, title={Intraocular extramedullary plasmacytoma in a cat}, volume={6}, ISSN={["1463-5224"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037629973&partnerID=MN8TOARS}, DOI={10.1046/j.1463-5224.2003.00277.x}, abstractNote={AbstractAn 8‐year‐old, castrated male Domestic Short‐haired cat was referred for evaluation of a possible intraocular neoplasm following previous ocular trauma. The eye was blind, and uveitis and an iridal mass were noted on examination. An enucleation was performed and the mandibular lymph node excised. Histopathologic examination revealed neoplastic proliferation of plasma cells in the iris and lymph node. No other evidence of disseminated disease was detected. This is the first case reported of an intraocular extramedullary plasmacytoma in the cat. The variation in clinical manifestations and potential association with multiple myeloma are not known at this time. Disseminated metastasis from a primary plasmacytoma of the uveal tract could also involve the bone marrow and be indistinguishable from multiple myeloma. Early enucleation, as in trauma‐associated sarcomas, may be indicated to prevent metastasis. Periodic systemic evaluation for evidence of multiple myeloma should be performed.}, number={2}, journal={VETERINARY OPHTHALMOLOGY}, author={Michau, TM and Proulx, DR and Rushton, SD and Olivry, T and Dunston, SM and Gilger, BC and Davidson, MG}, year={2003}, month={Jun}, pages={177–181} }
 @article{haupert_grossniklaus_sharara_davidson_syed_fekrat_2003, title={Optimal laser power to rupture Bruch's membrane and the retinal vein in the pig}, volume={34}, ISSN={["1938-2375"]}, DOI={10.3928/1542-8877-20030301-08}, abstractNote={* BACKGROUND AND OBJECTIVE: For laserinduced chorioretinal venous anastomosis to become a viable treatment option for perfused central retinal vein occlusion, laser parameters must be refined to more reliably create venous anastomoses while minimizing complications. The aim of this study was to determine the lowest argon laser power at which Bruch's membrane and the retinal vein are ruptured in 100% of attempts in the porcine eye.
          * MATERIALS AND METHODS: Testing was performed on 6 eyes of 3 Yorkshire Cross pigs, using an argon green laser. The spot size was 50 urn and the duration was 0.2 seconds for all applications. Twelve laser powers were tested, from 0.5 to 6 W, increasing by increments of 0.5 W. Light microscopy was used to determine the frequency of rupture of Bruch's membrane and the retinal vein for each power.
          * RESULTS: The rupture rate of Bruch's membrane was 0% at 0.5 W, 5% at 1.0 W, 20% at 1.5 W, 70% at 2.0 W, and 100% for all powers from 2.5 to 6.0 W. The rupture rate of the retinal vein was 0% at 0.5 W, 5% at 1.0 W, 30% at 1.5 W, 60% at 2.0 W, 80% at 2.5 W, and 100% for all powers from 3.0 to 6.0W.
          * CONCLUSION: Argon green laser powers of at least 2.5 and 3.0 W were necessary to rupture Bruch's membrane and the retinal vein, respectively, with a 100% success rate in the porcine eye. Because patients with central retinal vein occlusion have secondary retinal edema and may have lenticular opacity, higher laser powers may be required to achieve a 100% rupture rate of these structures.
          [Ophthalmic Surg Lasers Imaging 2003;34:122-127.]}, number={2}, journal={OPHTHALMIC SURGERY LASERS & IMAGING}, author={Haupert, CL and Grossniklaus, HE and Sharara, N and Davidson, MG and Syed, A and Fekrat, S}, year={2003}, pages={122–127} }
 @article{sobol_foley_nyska_davidson_wilson_2003, title={Regulated over-expression of DNA polymerase beta mediates early onset cataract in mice}, volume={2}, ISSN={["1568-7864"]}, DOI={10.1016/S1568-7864(03)00026-0}, abstractNote={Base excision repair (BER) is a tightly coordinated mechanism for repair of DNA base damage (via alkylation and oxidation) and base loss. From E. coli to yeast to human cells, subtle alterations in expression of BER proteins lead to mutagenic or genome instability phenotypes. DNA polymerase beta (beta-pol), the major BER polymerase, has been found to be over-expressed in human tumor tissues and more recently it has been shown that over-expression of beta-pol results in a mutator and genome instability phenotype. These previous reports imply that beta-pol over-expression is deleterious and suggests that such an imbalance may cause an overall functional deficiency in the BER pathway. In the present study, we have developed a bicistronic tetracycline-responsive transgenic system to over-express beta-pol in mice. We find that over-expression of beta-pol in the lens epithelium results in the early onset of severe cortical cataract, with cataractogenesis beginning within 4 days after birth. In utero and post-natal suppression of transgenic Flag-beta-pol expression by doxycycline administration completely prevents cataract formation through adulthood, yet cataract is subsequently observed following removal of doxycycline and re-expression of the transgene. Cataract development accompanies increased expression of cyclooxygenase-2 in the lenticular fibers of the lens, implicating oxidative stress in the development of this cataractous phenotype. Although the mechanism for the transgene mediated cataractogenesis is not clear at this time, it is nevertheless intriguing that increased expression of beta-pol leads to such a phenotype. These results suggest that either a beta-pol expression imbalance negatively affects overall fidelity and/or BER capacity or that beta-pol has a role in lens epithelial cell differentiation.}, number={5}, journal={DNA REPAIR}, author={Sobol, RW and Foley, JF and Nyska, A and Davidson, MG and Wilson, SH}, year={2003}, month={May}, pages={609–622} }
 @article{michau_schwabenton_davidson_gilger_2003, title={Superficial, nonhealing corneal ulcers in horses: 23 cases (1989-2003)}, volume={6}, ISSN={["1463-5216"]}, DOI={10.1111/j.1463-5224.2003.00309.x}, abstractNote={AbstractObjective  To characterize superficial, nonhealing corneal ulcers in the horse and to assess the affect of age, breed, sex, inciting cause of the ulcer, and treatment on healing time of these ulcers.Design  Retrospective study.Animals  Twenty‐three horses with superficial, nonhealing corneal ulcerations.Procedure  Medical records from 1989 to 2003 of horses diagnosed with superficial, nonhealing corneal ulcers were reviewed. Signalment, duration of clinical signs, ophthalmic abnormalities, treatment and response to treatment were recorded. Horses were treated, in addition to medical therapy, using debridement, debridement and grid keratotomy, superficial keratectomy, and superficial keratectomy with conjunctival graft placement.Results  Mean age ± SD of horses was 13.7 ± 5.8 years. The mean time of presence of the corneal ulceration was 38.9 ± 21.3 days. Mean time to complete re‐epithelialization of the corneal ulcers after treatment was 20 ± 14.7 days. Horses treated with debridement alone, grid keratotomy and superficial keratectomy healed in a mean time of 15.3 ± 14.6 days, 16 ± 12.6 days, and 22.8 ± 6.7 days, respectively.Conclusions and clinical relevance  Horses treated with a single debridement at initial evaluation healed in a significantly shorter time period than horses treated with grid keratotomy or superficial keratectomy. The latter two procedures may be beneficial in the treatment of nonhealing ulceration in horses, but the results of this study suggest that these procedures should only be performed following failure of the ulcer to heal after epithelial debridement.}, number={4}, journal={VETERINARY OPHTHALMOLOGY}, author={Michau, TM and Schwabenton, B and Davidson, MG and Gilger, BC}, year={2003}, month={Dec}, pages={291–297} }
 @article{pizzirani_davidson_gilger_2003, title={Transpupillary diode laser retinopexy in dogs: ophthalmoscopic, fluorescein angiographic and histopathologic study}, volume={6}, ISSN={["1463-5216"]}, DOI={10.1046/j.1463-5224.2003.00299.x}, abstractNote={AbstractObjective  To evaluate the ophthalmoscopic, fluorescein angiographic and light microscopic effects of diode laser retinopexy application in the tapetal and nontapetal fundus in the dog, and to ascertain appropriate laser power settings for production of photocoagulative lesions in these two regions.Animals studied  Three adult female Beagle dogs.Procedures  Laser burns were applied to selected areas in the fundus with an indirect headset delivery system using settings varying from 100 to 200 milliWatts (mW) and from 100 to 600 milliSeconds (mS) with total delivered energy ranging between 15 and 100 milliJoules (mJ). The dogs were then monitored by ophthalmoscopic examination and fluorescein angiography at regular intervals for 7–28 days. Histopathologic studies were performed at 7, 14 and 28 days after laser application.Results  The diode laser produced ophthalmoscopically visible lesions in the nontapetal fundus with all laser settings used, and the appearance of these lesions corresponded to the energy levels used, and degree of pigment in the lased region. Gray‐white colored lesions with minimal subsensory retinal edema were seen with settings as low as 100 mWatts/150 mSeconds. In the tapetal fundus, laser burns were more difficult to produce, less repeatable, and required higher energy levels. Laser burns appeared as bronze, dark green or black discolorations of the tapetum with varying degrees of subsensory retinal edema. Lesions were more reproducible and were achieved with lower settings in the tapetal area of the tapetal/nontapetal junction. Ophthalmoscopically, depigmentation and repigmentation of the RPE (nontapetal fundus) and degenerative changes in the overlying retina (tapetal fundus) developed in the laser burns over the 28‐day study period. Fluorescein angiographic studies showed disruption of the blood–retinal barrier at the level of the RPE and fluorescein leakage into the subsensory retinal space was seen in most lesions at 24 h, was minimal at 3 days, and had resolved by 7 days. Histologically, grayish‐white lesions in the nontapetal fundus, and bronze to small black lesions in the tapetal fundus were typically characterized by outer retinal necrosis and RPE migration. Gliosis was considered minimal, was confined to the retina, and no inflammatory cells were seen. Peripheral intense white lesions (nontapetum) and lesions with a black center (tapetal fundus) were characterized by more extensive panretinal and choroidal necrosis. Most of the nontapetal lesions and a few in the tapetal fundus showed the formation of a central retinal detachment.Conclusions  The diode laser effectively produces lesions suitable for retinopexy in both the nontapetal, pigmented fundus and the tapetal fundus, although variably so in the latter region. Initial laser settings of 100–150 mW/200 mS for the pigmented fundus, and 150 mW/200–300 mS for the peripheral tapetal fundus are recommended, and the clinician should gradually increase time interval settings to achieve a grayish‐white lesion in the nontapetum, and a bronze to slightly black lesion in the tapetal fundus. If possible, retinopexy should be applied to the peripheral tapetal area or tapetal/nontapetal junction.}, number={3}, journal={VETERINARY OPHTHALMOLOGY}, author={Pizzirani, S and Davidson, AG and Gilger, BC}, year={2003}, month={Sep}, pages={227–235} }
 @article{michau_gilger_maggio_davidson_2003, title={Use of thermokeratoplasty for treatment of ulcerative keratitis and bullous keratopathy secondary to corneal endothelial disease in dogs: 13 cases (1994-2001)}, volume={222}, ISSN={["0003-1488"]}, DOI={10.2460/javma.2003.222.607}, abstractNote={Abstract
				
					Objective—To evaluate the outcome of thermokeratoplasty
for treatment of ulcerative keratitis and bullous
keratopathy secondary to corneal endothelial disease
in dogs.
				
					Design—Retrospective study.
				
					Animals—13 dogs.
				
					Procedures—Medical records from 1994 to 2001 for
dogs evaluated because of ulcerative keratitis and
bullous keratopathy and treated with thermokeratoplasty
were reviewed.
				
					Results—There were 7 spayed females, 5 castrated
males, and 1 sexually intact male, ranging from 6 to
16 years of age. Ten dogs had endothelial degeneration,
and 3 dogs had breed-related endothelial dystrophy.
All dogs had bullous keratopathy, characterized
by microbullae formation that was detected via biomicroscopy.
Recurrent or nonhealing corneal ulcers
were detected unilaterally in 5 dogs and bilaterally in
8 dogs. Mean ± SD duration from thermokeratoplasty
until ulcerations were healed for all dogs was 2.2 ±
1.1 weeks. All dogs that underwent thermokeratoplasty
for nonhealing corneal ulceration secondary to
endothelial disease and corneal edema had epithelial
wound healing and resolution of corneal ulceration.
Mean duration of treatment (ie, topical treatment
required until resolution of ulceration) was significantly
less after thermokeratoplasty than duration of
treatment (with multiple treatments) prior to referral.
				
					Conclusions and Clinical Relevance—It may be
necessary to perform thermokeratoplasty of the
entire cornea to prevent recurrence of ulcerations
in areas that have not been treated with thermokeratoplasty.
(J Am Vet Med Assoc 2003;222:
607–612)}, number={5}, journal={JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Michau, TM and Gilger, BC and Maggio, F and Davidson, MG}, year={2003}, month={Mar}, pages={607–612} }
 @article{colitz_davidson_gilger_2002, title={Bilateral proliferative keratitis in a Domestic Long-haired cat}, volume={5}, ISSN={["1463-5216"]}, DOI={10.1046/j.1463-5224.2002.00221.x}, abstractNote={AbstractA 9‐year‐old, female spayed, Domestic Long‐haired cat was presented with bilateral, progressive, pink−white corneal opacities. The referring veterinarian had diagnosed feline herpesvirus‐1 (FHV‐1) keratitis though diagnostics for FHV‐1 had not been performed and treatment with antibiotics and antivirals did not improve the condition. Histopathology showed neutrophils, plasma cells and lymphocytes, but no eosinophils or mast cells. Routine diagnostics did not find an underlying cause, but Southern blot analysis for FHV‐1 was positive. The cat responded to topical corticosteroids and cyclosporine when used consistently.}, number={2}, journal={VETERINARY OPHTHALMOLOGY}, author={Colitz, CMH and Davidson, MG and Gilger, BC}, year={2002}, month={Jun}, pages={137–140} }
 @article{massa_gilger_miller_davidson_2002, title={Causes of uveitis in dogs: 102 cases (1989-2000)}, volume={5}, ISSN={["1463-5216"]}, DOI={10.1046/j.1463-5224.2002.00217.x}, abstractNote={AbstractUveitis is one of the most common ocular diseases and one of the most common causes of blindness in dogs. The purpose of this retrospective study was to correlate the signalment, history, clinical signs and ophthalmic findings of dogs with uveitis with the underlying etiology. We conducted a retrospective study of 102 dogs presented to the NCSU‐VTH from 1989 to 2000 with clinical signs of uveitis. Medical records of dogs presented for uveitis were reviewed. Dogs were included in the study only if a complete diagnostic work‐up database was collected, if sufficient follow‐up was documented, and if the uveitis was not secondary to trauma or a hypermature cataract. The mean age ± SD of all dogs in this study was 6.2 ± 3.6 years. There were 33 intact and 16 castrated males, and 14 intact and 27 neutered females. Fourteen breeds were represented, with the Golden Retriever (n = 14) most common. Fifty‐nine dogs (58%) were diagnosed with idiopathic/immune‐mediated uveitis, neoplasia was diagnosed in 25 dogs (24.5%) and 18 dogs (17.6%) were diagnosed with infectious causes of uveitis. Aqueous flare was the most common clinical sign, occurring in 88 dogs (86%). The most common infectious organisms associated with uveitis in the dogs of this study wereEhrlichia canis(n = 7). Lymphosarcoma (n = 17) was the most common neoplasm. In ≈ 60% of dogs presenting for uveitis an underlying cause was not found, and a diagnosis of immune‐mediated or idiopathic uveitis was made. However, ≈ 25% of dogs had ocular and/or systemic neoplasia (with 17% of cases having lymphosarcoma) and 18% with an underlying infectious cause for uveitis. Because of the high percentage of systemic disease associated with uveitis in dogs, extensive diagnostic testing is recommended before instituting symptomatic anti‐inflammatory therapy.}, number={2}, journal={VETERINARY OPHTHALMOLOGY}, author={Massa, KL and Gilger, BC and Miller, TL and Davidson, MG}, year={2002}, month={Jun}, pages={93–98} }
 @article{colitz_lewbart_davidson_2002, title={Phacoemulsification in an adult Savannah monitor lizard}, volume={5}, ISSN={["1463-5216"]}, DOI={10.1046/j.1463-5224.2002.00233.x}, abstractNote={AbstractAn adult male Savannah monitor lizard (Varanus exanthematicus) was presented for bilateral lens opacities that had progressed rapidly over the previous 2 months. A diagnosis of bilateral mature cataracts was made and phacoemulsification cataract extraction was performed. Surgery restored vision and normal activity to the patient.}, number={3}, journal={VETERINARY OPHTHALMOLOGY}, author={Colitz, CMH and Lewbart, G and Davidson, MG}, year={2002}, month={Sep}, pages={207–209} }
 @article{jurk_thibodeau_whitney_gilger_davidson_2001, title={Acute vision loss after general anesthesia in a cat}, volume={4}, ISSN={["1463-5216"]}, DOI={10.1046/j.1463-5224.2001.00170.x}, abstractNote={AbstractA 6‐year‐old, male castrated, domestic shorthair cat presented with a 2‐week history of blindness following general anesthesia. Behavioral changes, lethargy, inappetence and neurological deficits were also noted. Ophthalmic evaluation revealed blindness, normal pupillary light response and dazzle response, but no other abnormalities. Serodiagnostic testing for common infectious agents was negative and a cerebrospinal fluid analysis was normal. History and postmortem examination following euthanasia revealed cerebrocortical necrosis most consistent with anesthesia related hypoxia.}, number={2}, journal={VETERINARY OPHTHALMOLOGY}, author={Jurk, IR and Thibodeau, MS and Whitney, K and Gilger, BC and Davidson, MG}, year={2001}, month={Jun}, pages={155–158} }
 @article{moodie_hashizume_houston_hoopes_demidenko_trembly_davidson_2001, title={Postnatal development of corneal curvature and thickness in the cat}, volume={4}, ISSN={["1463-5224"]}, DOI={10.1046/j.1463-5216.2001.00198.x}, abstractNote={Abstract Objective  To evaluate the postnatal development of central corneal curvature and thickness in the domestic cat. Animals studied  Six Domestic Short‐haired (DSH) kittens starting at 9 weeks of age and 6 adult cats. Procedures  Kittens were evaluated biweekly to monthly for a 12‐month period, starting at age 9 weeks. Corneal development was monitored by hand‐held keratometry and ultrasound biomicroscopy. Standard regression analysis using a nonlinear least squares method was used to generate a formula that would predict corneal curvature as a function of age. Results  Mean keratometry (K) values for the 9‐week‐old cats were 54.51 (±1.02) diopters (D) and these values steeply declined over the next 3 months to 44.95 (±0.90) D. Thereafter, K‐values gradually decreased to reach a plateau by 12–15 months of age of 39.90 (±0.42) D. Because K‐values still appeared to be slightly diminishing at this point, six other > 2‐year‐old cats were evaluated by keratometry and were found to have K‐values of 38.99 (±0.81). Two to four diopters of astigmatism was common in young kittens whereas adult cats had a low mean degree of astigmatism (< 1 D). A formula that predicted keratometry values in diopters (K) as a function of age in weeks (w) was established as follows: K = 39.83 + 26.87 exp(−0.074 w). The central cornea increased in thickness primarily during the first 4 months of life with 9 week‐old kittens having values of 0.379 (±0.012) mm; 16‐week‐old kittens, 0.548 (±0.021) mm and 67 week‐old cats, 0.567 (±0.012) mm. Conclusions  The maturation process of the feline cornea proceeds over the first 1–2 years of life to attain an adult status that is characterized by a roughly spherical state of approximately 39 D corneal curvature, substantially flatter than the human cornea, and a central thickness similar to the human cornea. Research studies of the refractive or optical properties of the cornea in which cats are used as experimental animals should be conducted on animals greater than 18 months of age.}, number={4}, journal={VETERINARY OPHTHALMOLOGY}, author={Moodie, KL and Hashizume, N and Houston, DL and Hoopes, PJ and Demidenko, E and Trembly, BS and Davidson, MG}, year={2001}, pages={267–272} }
 @article{davidson_2001, title={Towards a better canine intraocular lens}, volume={4}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1046/j.1463-5224.2001.00175.x}, DOI={10.1046/j.1463-5224.2001.00175.x}, abstractNote={Veterinary OphthalmologyVolume 4, Issue 1 p. 1-1 Towards a better canine intraocular lens Michael G. Davidson, Michael G. Davidson Raleigh, North Carolina, USASearch for more papers by this author Michael G. Davidson, Michael G. Davidson Raleigh, North Carolina, USASearch for more papers by this author First published: 21 December 2001 https://doi.org/10.1046/j.1463-5224.2001.00175.xCitations: 8Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume4, Issue1March 2001Pages 1-1 RelatedInformation}, number={1}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Davidson, Michael G.}, year={2001}, month={Mar}, pages={1–1} }
 @article{gilger_wilkie_davidson_allen_2001, title={Use of an intravitreal sustained-release cyclosporine delivery device for treatment of equine recurrent uveitis}, volume={62}, ISSN={["0002-9645"]}, DOI={10.2460/ajvr.2001.62.1892}, abstractNote={AbstractObjective—To evaluate the use of an intravitreal sustained-release cyclosporine (CsA) delivery device for treatment of horses with naturally occurring recurrent uveitis.Animals—16 horses with recurrent uveitis.Procedures—Horses with frequent recurrent episodes of uveitis or with disease that was progressing despite appropriate medication were selected for this study. Additional inclusion criteria included adequate retinal function as determined by use of electroretinography, lack of severe cataract formation, and no vision-threatening ocular complications (eg, retinal detachment, severe retinal degeneration, and posterior synechia). Sustained-release CsA delivery devices (4 µg of CsA/d) were implanted into the vitreous through a sclerotomy at the pars plana. Reexaminations were performed 1, 3, 6, and 12 months after implantation, then continued annually. Ophthalmic changes, number of recurrent episodes of uveitis, and vision were recorded.Results—The rate of recurrent episodes after device implantation (0.36 episodes/y) was less than prior to surgery (7.5 episodes/y). In addition, only 3 horses developed episodes of recurrent uveitis after surgery. Vision was detected in 14 of 16 affected eyes at a mean follow-up time of 13.8 months (range, 6 to 24 months).Conclusions and Clinical Relevance—This intravitreal sustained-release CsA delivery device may be a safe and important tool for long-term treatment of horses with chronic recurrent uveitis. (Am J Vet Res2001;62:1892–1896)}, number={12}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Gilger, BC and Wilkie, DA and Davidson, MG and Allen, JB}, year={2001}, month={Dec}, pages={1892–1896} }
 @article{davidson_2000, title={Dorzolamide}, volume={22}, number={4}, journal={Compendium on Continuing Education for the Practicing Veterinarian}, author={Davidson, M. G.}, year={2000}, pages={340–342} }
 @article{davidson_morgan_mcgahan_2000, title={Effect of surgical technique on in vitro posterior capsule opacification}, volume={26}, ISSN={["0886-3350"]}, DOI={10.1016/S0886-3350(99)00451-4}, abstractNote={Purpose: To compare the effect of different cataract extraction surgical techniques on residual lens epithelial cell (LEC) density and cell regrowth rates using an in vitro model of posterior capsule opacification (PCO). Setting: Comparative Ophthalmology Research Laboratories, North Carolina State University, Raleigh, North Carolina, USA. Methods: Lens capsule explants were prepared from freshly enucleated canine globes after extracapsular cataract extraction (ECCE), phacoemulsification, or phacoemulsification followed by capsule vacuuming. Initial cell density on the capsule and cell proliferation were determined by phase contrast microscopy. The effects of the surgical technique on time to confluent growth of the cells across the posterior lens capsule were determined. Results: Residual cell density on the remaining anterior capsule immediately after lens removal was 31.6% ± 19.3%, 16.1% ± 8.9%, and 7.7% ± 5.7% in the ECCE, phacoemulsification, and phacoemulsification/capsule-vacuuming groups, respectively. Time to confluence (range 5.0 to 6.3 days) was not significantly different among the 3 groups when the lens capsules were cultured in serum-supplemented media. The confluence rate was significantly longer (by approximately 5 to 7 days) in the phacoemulsification/capsule-vacuuming group than in the other 2 groups when the capsules were cultured in serum-free media. Conclusions: Phacoemulsification with and without anterior and equatorial capsular vacuuming led to less initial LEC density in the capsular bag than ECCE. However, because cell proliferation rates among the 3 groups were only marginally affected, near 100% removal of LEC at the time of cataract extraction may be necessary to prevent PCO.}, number={10}, journal={JOURNAL OF CATARACT AND REFRACTIVE SURGERY}, author={Davidson, MG and Morgan, DK and McGahan, MC}, year={2000}, month={Oct}, pages={1550–1554} }
 @article{davidson_wormstone_morgan_malakof_allen_mcgahan_2000, title={Ex vivo canine lens capsular sac explants}, volume={238}, ISSN={["0721-832X"]}, DOI={10.1007/s004170000158}, abstractNote={{"Label"=>"BACKGROUND", "NlmCategory"=>"BACKGROUND"} Lens capsular sac explants from human cadaver eyes were used to investigate posterior capsular opacification (PCO). The purpose of this study was to characterize a similar model using canine tissue and to determine whether transferrin (Tf), transforming growth factor beta-2 (TGF-beta2), and insulin-like growth factor-1 (IGF-1) are secreted by lens epithelial cells (LEC) of these ex vivo sacs. {"Label"=>"METHODS", "NlmCategory"=>"METHODS"} The lens from canine eyes was removed by extracapsular cataract extraction, the lens sac dissected free, pinned to a petri dish, and cultured in either serum-supplemented or serum-free medium. Morphologic characteristics and growth rate to confluence on the posterior capsule were studied by phase-contrast microscopy. Vimentin, alpha smooth muscle actin, and panTGF-beta expression by LEC were determined by immunohistochemistry. Tf, TGF-beta2, and IGF-1 levels were measured by ELISA in the supernatant of sacs cultured in serum-free medium. {"Label"=>"RESULTS", "NlmCategory"=>"RESULTS"} The mean time to confluence of LEC onto the posterior capsule was 5.4+/-1.1 days (n=22) and 14.7+/-3.7 days (n=14) for sacs in serum-supplemented and serum-free medium, respectively. Following development of confluence, explants displayed opacification and light scatter from cellular proliferation and capsular contraction. Confluent LEC expressed vimentin, alpha smooth muscle actin, and TGF-beta2, and both Tf and TGF-beta2 were secreted into the culture supernatant. {"Label"=>"CONCLUSION", "NlmCategory"=>"CONCLUSIONS"} Canine lens sac explants have characteristics virtually identical to those of human origin, and appear to be a useful alternative tissue source for this model when human cadaver eyes are unavailable. Tf and TGFbeta-2, but not IGF-1, are secreted by LEC in explanted lens sacs and may influence the proliferation and metaplasia of LEC during the development of PCO.}, number={8}, journal={GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY}, author={Davidson, MG and Wormstone, M and Morgan, D and Malakof, R and Allen, J and McGahan, MC}, year={2000}, month={Aug}, pages={708–714} }
 @article{colitz_malarkey_dykstra_mcgahan_davidson_2000, title={Histologic and immunohistochemical characterization of lens capsular plaques in dogs with cataracts}, volume={61}, ISSN={["0002-9645"]}, DOI={10.2460/ajvr.2000.61.139}, abstractNote={AbstractObjective—To determine histologic and immunohistochemical characteristics of the multifocal adherent plaques that commonly develop on the internal surfaces of the anterior and posterior lens capsules in dogs with cataracts.Sample Population—31 anterior and 4 posterior capsular specimens collected during lens extraction surgery in dogs with cataracts.Procedure—Specimens were evaluated, using light and transmission electron microscopy. Immunohistochemical techniques were used to localize cytokeratin, vimentin, α-smooth muscle-specific actin, fibronectin, tenascin, and transforming growth factor- β (TGF-β) within plaques.Results—Histologically, plaques comprised elongated spindle-shaped cells that formed a placoid mass. Cells were embedded in an extracellular matrix containing collagen fibrils, often with duplicated or split basement membranes. Immunohistochemically, normal lens epithelial cells and cells within plaques stained for vimentin. Most cells and some areas of the extracellular matrix within plaques stained for TGF-β and α-smooth muscle-specific actin. Fibronectin and tenascin were also detected in the extracellular matrix.Conclusions and Clinical Relevance—Canine lens capsular plaques are histologically and immunohistochemically similar to posterior capsule opacification and subcapsular cataracts in humans, which suggests that the canine condition, like the human conditions, is associated with fibrous metaplasia of lens epithelial cells. Transforming growth factor-β may play a role in the genesis of capsular plaques. Because severity of plaques was correlated with stage of cataract development, earlier surgical removal of cataracts may be useful to avoid complications associated with plaque formation. (Am J Vet Res2000;61:139–143)}, number={2}, journal={AMERICAN JOURNAL OF VETERINARY RESEARCH}, author={Colitz, CMH and Malarkey, D and Dykstra, MJ and McGahan, MC and Davidson, MG}, year={2000}, month={Feb}, pages={139–143} }
 @article{pena_roura_davidson_2000, title={Ocular and periocular manifestations of leishmaniasis in dogs: 105 cases (1993-1998)}, volume={3}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1046/j.1463-5224.2000.00106.x}, DOI={10.1046/j.1463-5224.2000.00106.x}, abstractNote={The purpose of this retrospective study was to determine the prevalence, type, and prognosis of ocular lesions associated with leishmaniasis in dogs. One hundred and five dogs (24.4% of all cases of leishmaniasis diagnosed during the study period) had ocular or periocular leishmaniasis, and 16 dogs (15.2% of ocular cases) had only ocular lesions and systemic signs were not apparent. Anterior uveitis was the most common manifestation and other prevalent findings included blepharitis and keratoconjunctivitis. Several distinct variations of eyelid lesions were seen including a dry dermatitis with alopecia, diffuse blepharedema, cutaneous ulceration, and discrete nodular granuloma formation. In some cases with keratoconjunctivitis, corneal lesions clinically resembled nodular granulomatous episclerokeratitis. Twenty‐seven of the 34 cases with ocular lesions had improvement in signs following systemic antiprotozoal and topical anti‐inflammatory therapy, although many cases with anterior uveitis required long‐term topical therapy. Response of ocular signs correlated highly with overall, systemic response to therapy. Ophthalmic manifestations of systemic leishmaniasis are common in the dog, and this disease should be considered in the differential diagnosis of most adnexal and anterior segment ocular inflammatory lesions in dogs in endemic areas.}, number={1}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Pena, M.T. and Roura, X. and Davidson, M.G.}, year={2000}, month={Mar}, pages={35–41} }
 @article{maggio_defrancesco_atkins_pizzirani_gilger_davidson_2000, title={Ocular lesions associated with systemic hypertension in cats: 69 cases (1985-1998)}, volume={217}, ISSN={["0003-1488"]}, DOI={10.2460/javma.2000.217.695}, abstractNote={AbstractObjective—To characterize clinical and clinicopathologic findings, response to treatment, and causes of systemic hypertension in cats with hypertensive retinopathy.Design—Retrospective study.Animals—69 cats with hypertensive retinopathy.Procedure—Medical records from cats with systemic hypertension and hypertensive retinopathy were reviewed.Results—Most cats (68.1%) were referred because of vision loss; retinal detachment, hemorrhage, edema, and degeneration were common findings. Cardiac abnormalities were detected in 37 cats, and neurologic signs were detected in 20 cats. Hypertension was diagnosed concurrently with chronic renal failure (n = 22), hyperthyroidism (5), diabetes mellitus (2), and hyperaldosteronism (1). A clearly identifiable cause for hypertension was not detected in 38 cats; 26 of these cats had mild azotemia, and 12 did not have renal abnormalities. Amlodipine decreased blood pressure in 31 of 32 cats and improved ocular signs in 18 of 26 cats.Conclusions and Clinical Relevance—Retinal lesions, caused predominantly by choroidal injury, are common in cats with hypertension. Primary hypertension in cats may be more common than currently recognized. Hypertension should be considered in older cats with acute onset of blindness; retinal edema, hemorrhage, or detachment; cardiac disease; or neurologic abnormalities. Cats with hypertensioninduced ocular disease should be evaluated for renal failure, hyperthyroidism, diabetes mellitus, and cardiac abnormalities. Blood pressure measurements and funduscopic evaluations should be performed routinely in cats at risk for hypertension (preexisting renal disease, hyperthyroidism, and age > 10 years). Amlodipine is an effective antihypertensive agent in cats.(J Am Vet Med Assoc2000;217:695–702)}, number={5}, journal={JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Maggio, F and DeFrancesco, TC and Atkins, CE and Pizzirani, S and Gilger, BC and Davidson, MG}, year={2000}, month={Sep}, pages={695–702} }
 @article{davidson_2000, title={Orbital fibroma in a horse}, volume={3}, ISBN={1463-5216}, number={2}, journal={Veterinary Ophthalmology}, author={Davidson, M. G.}, year={2000}, pages={213} }
 @article{davidson_2000, title={Toxoplasmosis}, volume={30}, ISSN={["0195-5616"]}, DOI={10.1016/S0195-5616(00)05006-3}, abstractNote={Toxoplasmosis in dogs and cats can cause chorioretinitis, anterior uveitis, or both. Ocular lesions are a common manifestation of generalized toxoplasmosis. The prevalence of toxoplasmosis as a cause of idiopathic anterior uveitis in cats is not clear, although there is a significant association between exposure to T. gondii and feline anterior uveitis. The pathogenesis of ocular toxoplasmosis may be different in humans and cats, and the anterior uveitis may represent a type of immune-mediated inflammation. A diagnosis is made by observing compatible clinical findings and obtaining supportive findings on serologic tests. Despite improved diagnostic techniques, including determination of IgM class antibodies and PCR testing, definitive diagnosis of ocular toxoplasmosis remains a challenge. Topical anti-inflammatory therapy should be used in cats with anterior uveitis, a positive serum titer, and no concurrent systemic signs. Systemic clindamycin should be given to cats with ocular and systemic signs and to cats with suggestive serology and idiopathic anterior uveitis that fails to respond to topical therapy alone.}, number={5}, journal={VETERINARY CLINICS OF NORTH AMERICA-SMALL ANIMAL PRACTICE}, author={Davidson, MG}, year={2000}, month={Sep}, pages={1051-+} }
 @article{beam_correa_davidson_1999, title={A retrospective-cohort study on the development of cataracts in dogs with diabetes mellitus: 200 cases}, volume={2}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1046/j.1463-5224.1999.00073.x}, DOI={10.1046/j.1463-5224.1999.00073.x}, abstractNote={The objective of the study was to determine the incidence and estimated median time to cataract formation in dogs with diabetes mellitus. The animals studied were 200 dogs with diabetes mellitus which were referred to a university teaching hospital between 1985 and 1995. Medical records from dogs with a diagnosis of diabetes mellitus were reviewed and, where necessary, further follow‐up information was gathered from the referring veterinarian. Incidence rate and median time to diabetic cataract formation was calculated using survival‐analysis techniques in a retrospective cohort study design. Among the 200 dogs in the study population, 23 had cataracts at the time of diabetes diagnosis that were presumed to be related to other disease processes. Of the remaining 177 dogs, 132 had documented cataract development with features suggestive as being secondary to diabetes. Twenty‐three dogs did not have obvious cataracts at the time of their last examination while 22 dogs did not have cataracts at the time they were lost to follow‐up. These 55 cases contributed to the statistical models as noncases of cataracts until the last date for which an examination was available. Half of the population had developed cataracts by the 170th day postdiagnosis of diabetes mellitus, while 75% and 80% of the population developed cataracts by 370 days and 470 days, respectively. The results of this study suggest that the majority of dogs with diabetes will develop cataracts within 5–6 months from the time of diagnosis of the disease, and that approximately 80% of dogs will develop cataracts within 16 months of diagnosis.}, number={3}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Beam, S and Correa, MT and Davidson, MG}, year={1999}, month={Sep}, pages={169–172} }
 @article{breitschwerdt_papich_hegarty_gilger_hancock_davidson_1999, title={Efficacy of Doxycycline, Azithromycin, or Trovafloxacin for Treatment of Experimental Rocky Mountain Spotted Fever in Dogs}, volume={43}, ISSN={0066-4804 1098-6596}, url={http://dx.doi.org/10.1128/AAC.43.4.813}, DOI={10.1128/aac.43.4.813}, abstractNote={ABSTRACT
          
            Dogs were experimentally inoculated with
            Rickettsia rickettsii
            (canine origin) in order to compare the efficacies of azithromycin and trovafloxacin to that of the current antibiotic standard, doxycycline, for the treatment of Rocky Mountain spotted fever. Clinicopathologic parameters, isolation of rickettsiae in tissue culture, and PCR amplification of rickettsial DNA were used to evaluate the response to therapy or duration of illness (untreated infection control group) in the four groups. Concentrations of the three antibiotics in plasma and blood cells were measured by high-performance liquid chromatography. Doxycycline and trovafloxacin treatments resulted in more-rapid defervescence, whereas all three antibiotics caused rapid improvement in attitudinal scores, blood platelet numbers, and the albumin/total-protein ratio. Based upon detection of retinal vascular lesions by fluorescein angiography, trovafloxacin and doxycycline substantially decreased rickettsia-induced vascular injury to the eye, whereas the number of ocular lesions in the azithromycin group did not differ from that in the infection control group. As assessed by tissue culture isolation, doxycycline resulted in the earliest apparent clearance of viable circulating rickettsiae; however, rickettsial DNA could still be detected in the blood of some dogs from all four groups on day 21 postinfection, despite our inability to isolate viable rickettsiae at that point. As administered in this study, trovafloxacin was as efficacious as doxycycline but azithromycin proved less efficacious, possibly due to the short duration of administration.
          }, number={4}, journal={Antimicrobial Agents and Chemotherapy}, publisher={American Society for Microbiology}, author={Breitschwerdt, E. B. and Papich, M. G. and Hegarty, B. C. and Gilger, B. and Hancock, S. I. and Davidson, M. G.}, year={1999}, month={Apr}, pages={813–821} }
 @article{davidson_1999, title={Etodolac}, volume={21}, number={6}, journal={Compendium on Continuing Education for the Practicing Veterinarian}, author={Davidson, M. G.}, year={1999}, pages={494–495} }
 @article{gerardi_colitz_dubielzig_davidson_1999, title={Immunohistochemical analysis of lens epithelial-derived membranes following cataract extraction in the dog}, volume={2}, ISSN={1463-5216 1463-5224}, url={http://dx.doi.org/10.1046/j.1463-5224.1999.00071.x}, DOI={10.1046/j.1463-5224.1999.00071.x}, abstractNote={The objective of the study was to characterize the morphologic and immunohistochemical features of lens epithelial‐derived proliferative membranes from the anterior segment of canine globes. These features were correlated with those previously identified for diseases resulting from lens epithelial cell (LEC) proliferation including posterior capsular opacification, traumatic subcapsular cataract, and subcapsular plaques associated with hypermature cataracts. Sixteen canine globes were removed as a result of glaucoma or other complications following cataract extraction. Light microscopic and immunohistochemical analysis was performed on sections from formalin‐fixed, paraffin‐embedded globes. The tissues were stained with a variety of antibodies for cellular markers for LECs, growth factors or other cellular constituents relevant to cellular metaplasia and proliferation. The membranes were composed of monolayers or multilayers of spindle‐shaped cells on the external surfaces of the anterior and posterior lens capsule, ciliary processes, iris leaflets, and iridocorneal angle, and they could be seen extending from an obvious monolayer of LEC within the capsular sac. Variably, scattered pigment cells, presumably of uveal origin, were concurrently present. Cellular components of the membranes stained positive for vimentin, transforming growth factor‐beta, basic fibroblast growth factor, and smooth muscle actin. An amorphous eosinophilic extracellular matrix consisting predominately of collagen was associated with the membranes. Proliferative anterior segment membranes following cataract surgery were morphologically and immunohistochemically similar to cellular and matrix components of posterior capsular opacification and capsular plaques seen with hypermature cataracts, both of which result from metaplasia and proliferation of LEC. The presence of these LEC‐derived membranes in association with secondary glaucoma suggests that exuberant proliferation of LEC outside the confines of the lens capsular sac may cause pathologic alterations in the eye following cataract surgery in the dog.}, number={3}, journal={Veterinary Ophthalmology}, publisher={Wiley}, author={Gerardi, JG and Colitz, CMH and Dubielzig, RR and Davidson, MG}, year={1999}, month={Sep}, pages={163–168} }
 @article{gilger_rose_davidson_roberts_miller_1999, title={Low-Dose Oral Administration of Interferon-alpha for the Treatment of Immune-Mediated Keratoconjunctivitis Sicca in Dogs}, volume={19}, ISSN={1079-9907 1557-7465}, url={http://dx.doi.org/10.1089/107999099313433}, DOI={10.1089/107999099313433}, abstractNote={This preliminary study was designed to evaluate the effectiveness and dosage of oral use of interferon-alpha (IFN-alpha) in the treatment of naturally occurring, immune-mediated, canine keratoconjunctivitis sicca (KCS). Dogs with chronic immune-mediated KCS were selected from the two clinic populations. All medication, except topical artificial tears, was discontinued at least 2 weeks prior to beginning the clinical trial. IFN-alpha was administered orally once daily to the dogs by their owners as the sole therapy for the KCS. Examinations of the dogs were performed every 2 weeks for the duration of the trial (12 weeks). Each dog was given either two or three separate, escalating doses (20, 40, 80 IU of the IFN-alpha. A favorable response was observed in 55% (11/20) of all dogs treated. Clinical findings of those dogs that responded included increased wetting of the eyes, decreased mucus discharge, and fewer signs of discomfort. There was a nearly significant difference (p = 0.08) in pretreatment mean Schirmer's tear test (STT) between the dogs that responded (6.4 +/- SEM 0.62 mm/min) and those that did not respond (4.7 +/- SEM 0.69 mm/min) to the orally administered IFN-alpha. Seven of 11 dogs with favorable outcomes had an increased STT of at least 5 mm/min after treatment with oral IFN-alpha and the group had a post-treatment STT (10.5 +/- SEM 1.4 mm/min) significantly greater than baseline (p = 0.0004). The post-treatment STT of the dogs that did respond was significantly greater (p < 0.01) than the post-treatment mean STT of dogs that did not respond. All dogs that responded did so with the 20 or 40 IU dose of IFN-alpha. No side effects were noted and all dogs tolerated the treatment well.}, number={8}, journal={Journal of Interferon & Cytokine Research}, publisher={Mary Ann Liebert Inc}, author={Gilger, Brian C. and Rose, Patricia D. and Davidson, Michael G. and Roberts, Steven M. and Miller, Thomas}, year={1999}, month={Aug}, pages={901–905} }
 @article{colitz_davidson_mcgahan_1999, title={Telomerase activity in lens epithelial cells of normal and cataractous lenses}, volume={69}, ISSN={["0014-4835"]}, DOI={10.1006/exer.1999.0739}, abstractNote={Telomerase is a ribonucleoprotein responsible for maintaining telomere length, preventing chromosomal degradation and recombination, and repairing DNA strand breaks. These activities are believed to be important in preventing cell senescence. Telomerase activity is normally found in germinal, neoplastic and stem cells, but not any ocular tissue studied to date. The epithelium of the crystalline lens is comprised of a population of cells with diverse mitotic potential including the germinative epithelium which contains cells with the potential for unlimited replicative capacity, equatorial cells which terminally differentiate into lens fibers, and the central epithelium which are considered to be quiescent and nonreplicative under normal circumstances. We speculated that the germinative region of lens epithelial cells might have telomerase activity, and that dysregulation of its activity might be associated with cataractogenesis. We investigated these hypotheses in lens capsule specimens from normal and cataractous dogs and from cultures of canine lens epithelial cells using standard assays for telomerase activity and telomere length. Telomerase activity was found in normal canine lens epithelial cells in the central, germinative and equatorial regions of the anterior lens capsule at equivalent levels. Similar findings were made in feline and murine lens epithelial cells, indicating that the presence of telomerase activity in the lens was not species specific. Lens fiber cells, corneal epithelium and endothelium and nonpigmented ciliary epithelium were telomerase negative. Telomerase activity and telomere lengths were significantly greater in lens epithelia from cataractous lenses when compared with normal lenses. Since telomerase activity is associated with an immortal phenotype, the presence of telomerase activity in the lens epithelial cells may function to prevent conversion to senescence. It was, therefore, difficult to explain why these cells cannot be passaged more than four times in culture. We found that telomerase activity and telomere lengths gradually decreased with increased passages until telomerase activity was no longer present at passage two. Consistent with these findings, there were no senescent cells present on the lens capsule when the lens was initially dissected for culture, but an increasing number of cells were senescent with each passage, correlating well with the loss of telomerase activity. Telomerase activity is likely important in the germinative epithelium to maintain its proliferative potential and prevent cell senescence. Telomerase may function in the quiescent, central lens to maintain telomeres damaged by oxidative stress and ultraviolet light exposure, thereby preventing accelerated loss of these elements which triggers cell senescence. It remains to be determined if the increase in telomerase activity in lens epithelial cells from cataractous lenses is a primary dysregulation that may have a role in the development of the cataract, or is secondary to cataract formation.}, number={6}, journal={EXPERIMENTAL EYE RESEARCH}, author={Colitz, CMH and Davidson, MG and McGahan, MC}, year={1999}, month={Dec}, pages={641–649} }
 @article{levy_ritchey_rottman_davidson_liang_jordan_tompkins_tompkins_1998, title={Elevated interleukin-10-to-interleukin-12 ratio in feline immunodeficiency virus-infected cats predicts loss of type 1 immunity to Toxoplasma gondii}, volume={178}, ISSN={["0022-1899"]}, DOI={10.1086/515632}, abstractNote={Similar to human immunodeficiency virus, feline immunodeficiency virus (FIV) induces immunodeficiency and enhanced susceptibility to secondary pathogens. To explore cytokine alterations in lentivirus immunodeficiency, constitutive mRNA expression was measured in lymph nodes of healthy and FIV-infected cats before and after challenge with Toxoplasma gondii. Cytokine mRNA expression was similar in control and FIV-infected cats during the first 10 weeks after infection. At 16 weeks, interferon (IFN)-gamma, tumor necrosis factor-alpha, and interleukin (IL)-10 mRNA were increased in FIV-infected cats. Challenge with T. gondii induced an increase in IL-2, IFN-gamma, and IL-12 in the lymph nodes of control cats, whereas IFN-gamma and IL-10 but not IL-2 or IL-12 increased in the lymph nodes of FIV-T. gondii coinfected cats. These results indicate that FIV immunodeficiency may derive from a failure to generate an IL-12-dependent type 1 response and that an elevated level of IL-10 mRNA expression is a predictor of lentivirus immunodeficiency.}, number={2}, journal={JOURNAL OF INFECTIOUS DISEASES}, author={Levy, JK and Ritchey, JW and Rottman, JB and Davidson, MG and Liang, YH and Jordan, HL and Tompkins, WA and Tompkins, MB}, year={1998}, month={Aug}, pages={503–511} }
 @article{gilger_davidson_colitz_1998, title={Experimental implantation of posterior chamber prototype intraocular lenses for the feline eye}, volume={59}, number={10}, journal={American Journal of Veterinary Research}, author={Gilger, B. C. and Davidson, M. G. and Colitz, C. M. H.}, year={1998}, month={Oct}, pages={1339–1343} }
 @article{davidson_english_1998, title={Feline ocular toxoplasmosis}, volume={1}, DOI={10.1046/j.1463-5224.1998.00033.x}, abstractNote={Ocular infection withToxoplasma gondiiis a well‐recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive forT. gondii, are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed.}, number={2}, journal={Veterinary Ophthalmology}, author={Davidson, M. G. and English, R. V.}, year={1998}, pages={71} }
 @article{gilger_davidson_howard_1998, title={Keratometry, ultrasonic biometry, and prediction of intraocular lens power in the feline eye}, volume={59}, number={2}, journal={American Journal of Veterinary Research}, author={Gilger, B. C. and Davidson, M. G. and Howard, P. B.}, year={1998}, pages={131–134} }
 @article{lee_meyer_sullivan_davidson_swanson_hellyer_1998, title={Respiratory depressant and skeletal muscle relaxant effects of low-dose pancuronium bromide in spontaneously breathing, isoflurane-anesthetized dogs}, volume={27}, ISSN={["0161-3499"]}, DOI={10.1111/j.1532-950X.1998.tb00159.x}, abstractNote={Objective—To assess and compare the respiratory depressant and skeletal muscle relaxant effects of two low doses of a nondepolarizing neuromuscular blocker, pancuronium bromide. To determine if a “low dose” of pancuronium bromide can produce selective skeletal muscle relaxation in extraocular muscles sufficient to perform intraocular surgery while sparing or minimizing depression of muscles of ventilation.Study Design—Blinded, randomized crossover, placebo controlled study. Animals—Six healthy, adult mongrel dogs weighing 20.8 ±1.9 kg.Methods—Spontaneously breathing, isoflurane‐anesthetized dogs received 0.02 mg/kg pancuronium bromide, intravenously (IV), (high dose [HD]), 0.01 mg/kg pancuronium bromide, IV, (low dose [LD]), or saline placebo IV in a blinded, randomized crossover study. Indices of patient ventilation including tidal volume (Vt), respiratory rate (RR), and minute ventilation (VE) were recorded throughout the study period. Serial arterial blood gas analyses were performed at timed intervals. Neuromuscular blockade of skeletal muscle was assessed at timed intervals with train‐of‐four stimulus/response ratios. Eye position scores, based on the degree of ocular rotation from a neutral gaze axis, were assigned by an ophthalmologist who was blinded to the treatment given.Results—Vt and VE in HD dogs decreased by 82% from baseline after administration of pancuronium bromide. Similarly, Vt and VE in LD dogs decreased 40% and 55%, respectively. Decreased ventilation in HD dogs corresponded with significant (P< .05) neuromuscular blockade, as indicated by train‐of‐four ratio less than 75% between 0 and 60 minutes. Eye position scores in HD and LD dogs were suitable for intraocular surgery between 0 and 60 minutes. Eye position scores in five of six control dogs were unsuitable for intraocular surgery at any time period.Conclusions—LD dogs experienced only transient, mild to moderate respiratory depression compared with HD dogs, which experienced prolonged, moderate to severe respiratory depression. Both LD and HD dogs acquired and maintained eye position scores suitable for intraocular surgery between 0 to 60 minutes. A “low dose” of pancuronium bromide, which would provide adequate extraocular muscle relaxation while minimizing ventilatory depression, was not identified.Clinical Relevance—All patients receiving any dose of neuromuscular blocking agents should be closely monitored and receive ventilatory assistance as needed.}, number={5}, journal={VETERINARY SURGERY}, author={Lee, DD and Meyer, RE and Sullivan, TC and Davidson, MG and Swanson, CR and Hellyer, PW}, year={1998}, pages={473–479} }
 @article{davidson_geoly_gilger_mclellan_whitley_1998, title={Retinal degeneration associated with vitamin E deficiency in hunting dogs}, volume={213}, number={5}, journal={Journal of the American Veterinary Medical Association}, author={Davidson, M. G. and Geoly, F. J. and Gilger, B. C. and McLellan, G. J. and Whitley, W.}, year={1998}, month={Sep}, pages={645–651} }
 @article{allen_davidson_nasisse_fleisher_mcgahan_1998, title={The lens influences aqueous humor levels of transforming growth factor-beta 2}, volume={236}, ISSN={["0721-832X"]}, DOI={10.1007/s004170050083}, abstractNote={{"Label"=>"BACKGROUND", "NlmCategory"=>"BACKGROUND"} Transforming growth factor-beta 2 (TGF-beta 2) is a pluripotent cytokine which has been suggested to play a number of roles in ocular physiologic and pathologic states. Intraocular fluid (i.o.f.) levels of TGF-beta 2 are quite high. Although the sources of ocular TGF-beta are not completely defined, the retinal pigment epithelium, the epithelium of the ciliary body and trabecular meshwork cells all secrete it. In this study we utilized canine lens and rabbit ciliary pigmented epithelial cell cultures to quantitate the in vitro secretion of TGF-beta 2. In addition, the effects of aphakia or the presence of cataractous lenses on IOF TGF-beta 2 levels were determined. {"Label"=>"METHODS", "NlmCategory"=>"METHODS"} Lens and ciliary body epithelial cell culture supernatants and aqueous humors were assayed for total TGF-beta 2 levels by ELISA and bioassay. {"Label"=>"RESULTS", "NlmCategory"=>"RESULTS"} TGF-beta 2 accumulated in the media bathing lens epithelial cell cultures (0.7 +/- 0.03 ng/ml at day 2) and ciliary pigmented epithelial cell cultures (0.8 +/- 0.06 ng/ml at day 2) in a time-dependent manner. Surprisingly, aqueous humor from aphakic rabbit eyes contained significantly higher levels of TGF-beta 2 than their contralateral phakic controls. Furthermore, aqueous humor from canine eyes with cataracts also contained significantly higher levels of TGF-beta 2 than normal eyes. {"Label"=>"CONCLUSIONS", "NlmCategory"=>"CONCLUSIONS"} These results suggest that the lens secretes TGF-beta 2 and that the presence and status of the lens may influence IOF TGF-beta 2 levels.}, number={4}, journal={GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY}, author={Allen, JB and Davidson, MG and Nasisse, MP and Fleisher, LN and McGahan, MC}, year={1998}, month={Apr}, pages={305–311} }
 @article{davidson_harned_grimes_duncan_wormstone_mcgahan_1998, title={Transferrin in after-cataract and as a survival factor for lens epithelium}, volume={66}, ISSN={["1096-0007"]}, DOI={10.1006/exer.1997.0413}, abstractNote={The Fe-transport protein, transferrin (Tf), is synthesized and secreted by whole lenses and cultured lens epithelial cells. Because of Tf's central role in cell growth and proliferation, its participation in lens cell proliferation following cataract extraction was explored using a rabbit model of after-cataract. Varying amounts of the central anterior lens capsule were removed (0, 35, or 80%) following extraction of the lens. The Tf content of and secretion by after-cataract lens capsular sacs containing regenerated lens tissue was determined ex vivo at 0, 3, 5, 7 and 9 weeks post-surgery. In all cases Tf content of and secretion by the lens sacs was higher than that of their contralateral controls (whole lenses). Tf secretion was up to 5-fold higher and metabolic labeling studies indicated secretion of newly synthesized Tf. The sacs contained up to 10 times the concentration of Tf as the control lenses. Human lens after-cataract capsular bags also secreted Tf. The function of Tf as a survival factor was tested on cultured lens epithelial cells. Cells cultured in serum-free medium had a survival rate of only 20-34% if the medium was changed each day. If the medium was never changed during this period, the survival rate was 43-52%, suggesting secretion of essential growth factors by these cells. Addition of 200 microg ml-1 Tf to the medium during each daily change increased survival to levels attained when the medium was not changed. Addition of Tf antibodies to the culture medium during each daily change decreased cell survival to 14%. Apparently Tf acts as a survival factor for lens epithelia and its synthesis is up-regulated in after-cataract lens sacs. These factors suggest that Tf may play an important role in the pathogenesis of lens epithelial cell proliferation and after-cataract formation following cataract surgery.}, number={2}, journal={EXPERIMENTAL EYE RESEARCH}, author={Davidson, MG and Harned, J and Grimes, AM and Duncan, G and Wormstone, IM and McGahan, MC}, year={1998}, month={Feb}, pages={207–215} }
 @article{sullivan_davidson_nasisse_glover_1997, title={Canine retinopexy: a determination of surgical landmarks, and a comparison of cryo application and diode laser methods}, volume={7}, number={2}, journal={Veterinary and Comparative Ophthalmology}, author={Sullivan, T. C. and Davidson, M. G. and Nasisse, M. P. and Glover, T. L.}, year={1997}, pages={89–95} }
 @article{nadelstein_wilcock_cook_davidson_1997, title={Clinical and histopathologic effects of diode laser transscleral cyclophotocoagulation in the normal canine eye}, volume={7}, number={3}, journal={Veterinary and Comparative Ophthalmology}, author={Nadelstein, B. and Wilcock, B. and Cook, C. and Davidson, M. G.}, year={1997}, pages={155–162} }
 @article{davidson_1997, title={Clinical retinoscopy for the veterinary ophthalmologists}, volume={7}, number={2}, journal={Veterinary and Comparative Ophthalmology}, author={Davidson, M. G.}, year={1997}, pages={128–137} }
 @article{hawkins_davidson_meuten_rottman_al._1997, title={Cytologic identification of Toxoplasma gondii in bronchoalveolar lavage fluid of experimentally infected cats}, volume={210}, number={5}, journal={Journal of the American Veterinary Medical Association}, author={Hawkins, E. C. and Davidson, M. G. and Meuten, D. J. and Rottman, J. B. and al.}, year={1997}, pages={648–650} }
 @article{gilger_davidson_nadelstein_nasisse_1997, title={Neodymium yttrium aluminum garnet laser treatment of cystic granula iridica in horses: Eight cases (1988 1996)}, volume={211}, number={3}, journal={Journal of the American Veterinary Medical Association}, author={Gilger, B. C. and Davidson, M. G. and Nadelstein, B. and Nasisse, M.}, year={1997}, pages={341–343} }
 @article{breitschwerdt_davidson_hegarty_papich_grindem_1997, title={Prednisolone at anti-inflammatory or immunosuppressive dosages in conjunction with doxycycline does not potentiate the severity of Rickettsia rickettsii infection in dogs.}, volume={41}, ISSN={0066-4804 1098-6596}, url={http://dx.doi.org/10.1128/AAC.41.1.141}, DOI={10.1128/aac.41.1.141}, abstractNote={Dogs were experimentally inoculated with Rickettsia rickettsii to determine if anti-inflammatory or immunosuppressive dosages of prednisolone, when administered in conjunction with an antirickettsial antibiotic (doxycycline), induced therapeutically relevant pathophysiological consequences that ultimately influence disease outcome. Although the duration of rickettsemia was prolonged in dogs receiving immunosuppressive, but not anti-inflammatory, corticosteroids, concurrent administration of doxycycline and corticosteroids conferred no other detected detrimental effects. Treatment with doxycycline or doxycycline in conjunction with prednisolone resulted in decreased R. rickettsii-specific antibody titers; however, examination of appropriately timed acute- and convalescent-phase serum samples would have facilitated an accurate diagnosis of Rocky Mountain spotted fever (RMSF) in all 16 dogs. We conclude that the concurrent use of anti-inflammatory or immunosuppressive doses of prednisolone in conjunction with doxycycline, early in the course of experimental RMSF, confers no clinically relevant detrimental effects and that additional studies might be indicated to detect possible beneficial effects in cases of severe or potentially fulminant RMSF. However, because the illness induced in these dogs was of mild to moderate severity, the results of this study should definitely not be construed as supporting the safety or efficacy of prednisolone for treatment of severe canine or human RMSF.}, number={1}, journal={Antimicrobial Agents and Chemotherapy}, publisher={American Society for Microbiology}, author={Breitschwerdt, E B and Davidson, M G and Hegarty, B C and Papich, M G and Grindem, C B}, year={1997}, month={Jan}, pages={141–147} }
 @article{drost_berry_breitschwerdt_davidson_1997, title={THORACIC RADIOGRAPHIC FINDINGS IN DOGS INFECTED WITH RICKETTSIA RICKETTSII}, volume={38}, ISSN={1058-8183 1740-8261}, url={http://dx.doi.org/10.1111/j.1740-8261.1997.tb00852.x}, DOI={10.1111/j.1740-8261.1997.tb00852.x}, abstractNote={Sixteen beagle dogs were injected intradermally withRickettsia rickettsii.The dogs were divided into four groups (n=4):1) infected, non‐treated withdoxycycline;3) infected, treated with doxycycline and an anti‐inflammatory dose of corticosteroid;4) infected, treated with ocular fluoresein angiograhphy was performed on days 6, 10, 17 post‐inoculatin.A mild interstitial lung opacitywas noted in4/16 dogs on day 6, 5/16 on day 10 and 17 post‐inculatin. Increased retinal vascular permeability was noted n 8/16 dogs on day 6,3/16 on day 10 and 1/16 on day 17 post‐inoculation. Correlatin between the presence of radiographic and retinal lesions was not signigicant (p=0.08). Elevan, naturally infected, dogs with thoracic radiographs and an final diagnosis of RMSF were also evluated. Four of the 11 dogs had an unstructu4red inteerstitial pattern. Dogs with acute, experimentally‐infected or naturally‐occurring RMSF may have subtle pulmonary changes characterized by an unstructured interstitial patteern.}, number={4}, journal={Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound}, publisher={Wiley}, author={Drost, Wm Tod and Berry, Clifford R. and Breitschwerdt, Edward B. and Davidson, Michael G.}, year={1997}, month={Jul}, pages={260–266} }
 @article{davidson_lappin_english_tompkins_1993, title={A feline model of ocular toxoplasmosis}, volume={34}, number={13}, journal={Investigative Ophthalmology and Visual Science}, author={Davidson, M. G. and Lappin, M. R. and English, R. V. and Tompkins, M. B.}, year={1993}, pages={3653} }
 @article{davidson_rottman_english_lappin_tompkins_1993, title={Feline immunodeficiency virus predisposes cats to acute generalized toxoplasmosis}, volume={143}, number={5}, journal={American Journal of Pathology}, author={Davidson, M. G. and Rottman, J. B. and English, R. V. and Lappin, M. R. and Tompkins, M. B.}, year={1993}, pages={1486} }
 @article{davidson_murphy_nasisse_hellkamp_olivero_brinkmann_campbell_1993, title={Refractive state of aphakic and pseudophakic eyes of dogs}, volume={54}, number={1}, journal={American Journal of Veterinary Research}, author={Davidson, M. G. and Murphy, C. J. and Nasisse, M. P. and Hellkamp, A. S. and Olivero, D. K. and Brinkmann, M. C. and Campbell, L. H.}, year={1993}, pages={174} }
 @article{davidson_nasisse_breitschwerdt_thrall_page_jamieson_english_1991, title={Acute blindness associated with intracranial tumors in dogs and cats: Eight cases (1984-1989)}, volume={199}, number={6}, journal={Journal of the American Veterinary Medical Association}, author={Davidson, M. G. and Nasisse, M. P. and Breitschwerdt, E. B. and Thrall, D. E. and Page, R. L. and Jamieson, V. E. and English, R. V.}, year={1991}, pages={755} }
 @article{davidson_baty_1991, title={Anaphylaxis associated with intravenous sodium fluorescein administration in a cat}, volume={1}, number={2}, journal={Veterinary and Comparative Ophthalmology}, author={Davidson, M. G. and Baty, K. T.}, year={1991}, pages={127} }
 @article{davidson_nasisse_english_wilcock_jamieson_1991, title={Feline anterior uveitis: A study of 53 cases}, volume={27}, number={1}, journal={Journal of the American Animal Hospital Association}, author={Davidson, M. G. and Nasisse, M. P. and English, R. V. and Wilcock, B. P. and Jamieson, V. E.}, year={1991}, pages={77} }
 @article{davidson_nasisse_jamieson_english_olivero_1991, title={Phacoemulsification and intraocular lens implantation: A study of surgical results in 182 dogs}, volume={1}, number={4}, journal={Veterinary and Comparative Ophthalmology}, author={Davidson, M. G. and Nasisse, M. P. and Jamieson, V. E. and English, R. V. and Olivero, D. K.}, year={1991}, pages={233} }
 @article{davidson_nasisse_jamieson_english_olivero_1991, title={Traumatic anterior lens capsule disruption}, volume={27}, number={4}, journal={Journal of the American Animal Hospital Association}, author={Davidson, M. G. and Nasisse, M. P. and Jamieson, V. E. and English, R. V. and Olivero, D. K.}, year={1991}, pages={410} }
 @article{davidson_nasisse_kornegay_1990, title={INTERMEDIATE FILAMENT COMPLEMENT OF THE NORMAL AND GLIOTIC CANINE RETINA}, volume={103}, ISSN={["0021-9975"]}, DOI={10.1016/S0021-9975(08)80169-7}, abstractNote={Intermediate filament expression of various cell types in the adult canine normal and gliotic retina was determined by an immunoperoxidase method of using monoclonal antibodies on aldehyde-fixed tissues. In the normal retina, vimentin was present in astrocytes in the nerve fibre layer, horizontal cell processes, and Muller cell fibres from the internal limiting membrane to the outer nuclear layer. Neurofilamentous axons were noted in the nerve fibre, inner plexiform layer, and outer plexiform layer, although the degree of staining intensity varied among the three molecular weight neurofilament antisera used. Glial fibrillary acidic protein (GFAP) staining was confined to the nerve fibre and ganglion cell layer; this was interpreted as representing fibrous astrocytes. Astrocyte density varied according to retinal topography with an increased number around retinal blood vessels and in the peripapillary retina. Quantitative, but not qualitative differences in staining for vimentin and the neurofilaments were noted in degenerative, gliotic retinas. In common with several other mammalian species previously studied, the canine Muller cells accumulate or express GFAP under pathological con ditions involving a gliotic response.}, number={2}, journal={JOURNAL OF COMPARATIVE PATHOLOGY}, author={DAVIDSON, M and NASISSE, M and KORNEGAY, J}, year={1990}, month={Aug}, pages={125–134} }
 @article{davidson_nasisse_rusnak_corbett_english_1990, title={SUCCESS RATES OF UNILATERAL VS BILATERAL CATARACT-EXTRACTION IN DOGS}, volume={19}, ISSN={["0161-3499"]}, DOI={10.1111/j.1532-950X.1990.tb01176.x}, abstractNote={Postoperative results of 113 unilateral and 77 bilateral extracapsular cataract extractions (EC‐CEs) in dogs were evaluated retrospectively. Restoration or improvement of functional vision was achieved in 79.6% of the eyes in dogs with unilateral extraction and 85.7% of the eyes in dogs with bilateral extractions at weeks 4 to 6. Complications occurring 6 weeks to 9 months after lens extraction lessened the surgical success rate in both groups. Twenty‐six percent of the dogs in which bilateral lens removal was performed suffered complications resulting in surgical failure in one eye. When using the criterion that one or both treated eyes had functional vision, a short‐term success rate of 98.7% was found for bilateral extractions.}, number={3}, journal={VETERINARY SURGERY}, author={DAVIDSON, MG and NASISSE, MP and RUSNAK, IM and CORBETT, WT and ENGLISH, RV}, year={1990}, pages={232–236} }