Corneal ulceration with prolonged healing following Nd:YAG laser cyclophotocoagulation in dogs is a frequent complication. It is hypothesized that these corneal ulcerations may be a form of neurotrophic keratitis due to laser-induced damage to corneal innervation. Fifteen clinically normal dogs had the neodymium:yttrium aluminum garnet(Nd:YAG) laser cyclophotocoagulation performed on the left eye. Each treated eye received 100 Joules of laser energy. Corneal touch threshold (CTT) and Schirmer I tear tests (STT) were performed before the surgery and on days 1,3,5,7,9,11, and 13 post-laser treatment. Applanation tonometry was performed before surgery and twice daily for 14 days post-laser treatment. Eyes were enucleated after 14 days and corneal nerves were stained using a gold chloride technique. Major nerve bundles entering the cornea were quantitated by quadrant, using camera lucida reproductions. Nerve bundle diameters were measured using NIH image computer software on computer-scanned images. Statistical methods included repeated values for analysis of variance for CTT, STT and IOP, and a paired t-test for nerve diameters and bundles. All laser treated eyes had significantly higher CTTs (P<0.05) compared to control eyes for all measurements. Six out of fifteen dogs had evidence of ulcerative keratitis. Intraocular pressure was significantly lower in laser treated eyes compared to control eyes in the a.m. on days 2-9,and 14, and in the p.m. on days 2-11 using a Bonferroni-corrected alpha level (P<0.0039). A significant decrease of one nerve bundle per corneal quadrant was found between the laser treated and control eyes. There was no significant difference in STT or nerve bundle diameters between laser treated and control eyes. Nd:YAG laser cyclophotocoagulation effectively reduces IOP while increasing CTT. The procedure also causes a significant decrease in the number of major nerve bundles entering the cornea, but has no effect on the diameter of those bundles. These findings support the hypothesis that nerve damage and corneal hypoesthesia are etiologic factors in ulcerative keratitis following Nd:YAG laser cyclophotocoagulation. / Master of Science

Orientador: Cláudia Valéria Seullner Brandão / Resumo: O estudo objetivou descrever valores de referência para importantes testes diagnósticos oftalmológicos, como sensibilidade corneal, produção lacrimal, pressão intraocular, espessura corneal e microbiota conjuntival em saguis de tufo preto (Callithrix penicillata) saudáveis e sem alterações oculares. Foram utilizados 13 saguis de tufo preto, totalizando 26 olhos, provenientes do CEMPAS da Faculdade de Medicina Veterinária e Zootecnia - UNESP, Botucatu, São Paulo, Brasil. Os saguis foram submetidos a contenção química com anestesia dissociativa à base de cetamina e midazolam, para realização dos exames. Os resultados obtidos para sensibilidade corneal com estesiômetro Cochet-Bonnet foi de 5,8 ± 0,6cm; produção lacrimal com ponta de papel absorvente endodôntica estéril de 13 ± 3mm/min; pressão intraocular com tonômetro de rebote Tonovet Plus Icare® de 22,2 ± 2,9mmHg; espessura corneal 340,7 ± 25,5µm; e predomínio de bactérias Gram-positivas nas amostras de microbiota conjuntival. Não houve diferença significativa considerando lateralidade e sexo dos animais (P>0,05). Os resultados obtidos nos testes diagnósticos oftalmológicos poderão auxiliar médicos veterinários oftalmologistas a diagnosticar e tratar doenças oculares em saguis de tufo preto, além de contribuir para pesquisas na área de visão. / Abstract: The study aimed to describe reference values for important ophthalmic diagnostic tests, such as corneal sensitivity, tear production, intraocular pressure, corneal thickness and conjunctival microbiota in black tufted marmosets (Callithrix penicillata). Thirteen black tuft marmosets were used, totaling 26 eyes, followed by CEMPAS by the Faculty of Veterinary Medicine and Zootechnics - UNESP, Botucatu, São Paulo, Brazil. The procedures were used for chemical containment with dissociative anesthesia based on ketamine and midazolam, to perform the exams. The results obtained for corneal sensitivity with a Cochet-Bonnet esthesiometer were 5.8 ± 0.6 cm; tear production with sterile endodontic absorbent paper tip of 13 ± 3mm / min; intraocular pressure with Tonovet Plus Icare® rebound tonometer of 22.2 ± 2.9mmHg; corneal thickness 340.7 ± 25.5 µm; and predominance of Gram-positive bacteria in conjunctival microbiota. There was no significant difference considering the laterality and sex of the animals (P> 0.05). The results obtained in ophthalmological diagnostic tests can help veterinary ophthalmologists to diagnose and treat eye diseases in the black tufted marmosets, in addition to contributing to research in the field of vision. / Mestre