Investigation of fellow eye of unilateral retinal detachment in Shih-Tzu
Fonte: Yoshiki Itoh, Seiya Maehara, Ayako Yamasaki, Keiko Tsuzuki and Yasuharu Izumisawa
Fundo de olho normal em um Shih-Tzu de 1 ano. Foto: Dra. Daniela Pereira
Abstract: Objective: To investigate disease in the fellow eye, and consider the relation to rhegmatogenous retinal detachment (RRD) in Shih-Tzus. Animals studied The fellow eyes of 49 Shih-Tzus (27 male, 22 female; median age: 6.8 years) with unilateral RRD diagnosed by funduscopy or ultrasonography at Rakuno Gakuen University Teaching Animal Hospital were assessed in this study. Procedures: Ophthalmic examinations (including menace response, pupillary light reflex, slit-lamp biomicroscopy, and funduscopy) were performed in the subjects. Electroretinography was performed in 12 eyes that developed retinal degeneration. Maximum follow-up period was 42 months. Results: Cataracts and vitreous opacity were observed in 26 (53%) and 32 eyes (65%), respectively, by slit-lamp biomicroscopy. Retinal degeneration with various degrees of hyper-reflectivity of the tapetal fundus and/or attenuation of retinal vessels was observed in 35 eyes (71%) on funduscopy. A reduction of amplitude in rod, standard combined and 30 Hz flicker electroretingram was detected in 5 (42%), 10 (83%), and 6 eyes (50%), respectively. During the follow-up period, RRD was detected in six eyes. Conclusion: Retinal degeneration was frequently detected by funduscopy and electroretingrams in the fellow eye in Shih-Tzus with RRD. In our subjects, vitreous degeneration was also observed frequently. It has been reported that peripheral retinal degeneration is one of the causes of RRD associated with vitreous degeneration in humans. We assume that primary retinal degeneration with secondary vitreous degeneration is one of the causes of RRD in Shih-Tzus.