Determination and comparison of retinal variations in Honamlı and Saanen goat breeds by funduscopic examination

Objective: This study was conducted to determine the retinal variations of healthy Honamlı and Saanen goat breeds by funduscopic examination and compare the findings. Material and Methods: The study material consisted of 60 one-year-old female goats, including 30 Honamlı and 30 Saanen individuals. Following physical and ophthalmic examinations, retinal variations were identified using a fundus camera. The still images obtained were transferred to a computer. On these images, the following features were identified: the color and pattern of the tapetal and non-tapetal areas; the shape, color, and position of the optic disc; the presence of the Bergmeister's papilla; the number of arteries and veins emerging from the optic disc; and the distribution of rostral and ventral arteries and veins originating from the optic disc. The measurements of the tapetal and non-tapetal areas, as well as the area and diameter of the optic disc, were evaluated on a pixel basis. Results: The tapetal area color was predominantly observed as blue-yellow-green in both Honamlı and Saanen goat breeds. The non-tapetal area appeared black in both breeds. The shape of the optic disc was identified as either oval or round in both groups. The optic disc color was mostly light orange in both breeds. In the majority of cases, the optic disc was located within the tapetal region, near the tapetal-non-tapetal junction, in both Honamlı and Saanen goats. The presence of the Bergmeister papilla was observed at a high rate in both breeds. The number of arteries emerging from the optic disc ranged from 3 to 6, and the number of veins ranged from 2 to 3 in both breeds. Rostral arteries ranged from 2 to 4, and ventral arteries ranged from 1 to 3 in both Honamlı and Saanen goats. In both breeds, typically one rostral and one ventral vein were observed. There was no statistically significant difference between the two breeds in terms of tapetal area, non-tapetal area, optic disc area, and optic disc diameter measurements. Conclusion: It was concluded that the findings obtained from ophthalmic, ultrasonographic, and fundus examinations in Honamlı and Saanen goat were close to each other. Keywords: Eye, Fundus, Goat, Imaging, Retina.