Objective: The aim of the present study was to provide ophthalmic reference values under normal physiological conditions for Aegypius monachus (cinereous vulture).
Procedures: Thirty-two eyes of sixteen adult captive cinereous vultures were used for this study. Tear tests and tonometry in conscious and anesthetized states, neuro-ophthalmic tests, measurement of corneal diameter, slit-lamp biomicroscopy, ophthalmoscopy, and funduscopy were performed.
Results: Schirmer tear test (STT) value was 11.4 ± 2.6 and 11.5 ± 2.8 mm/min in the right (OD) and left eye (OS), respectively. Phenol red thread test (PRT) values were 22.3 ± 2.1 mm/15 s OD and 22.8 ± 3.0 mm/15 s OS. The results showed a strong correlation between STT and PRT in both eyes. Intraocular pressure (IOP) values were 32.8 ± 6.9 mm Hg OD and 31.9 ± 7.1 mm Hg OS with TonoVet and 20.7 ± 4.5 mm Hg OD and 19.5 ± 4.1 mm Hg OS with Tono-Pen. There were significant differences in IOPs between rebound and applanation tonometry in both OD and OS. Tear production and IOP values showed significant reductions with general anesthesia in both tear tests and both tonometry (P < .001). Horizontal corneal diameter (mm) was 15.56 ± 0.96 OD and 15.56 ± 0.96 OS. Vertical diameter (mm) was 14.13 ± 0.96 OD and 14.06 ± 1.06 OS. The horizontal diameter was significantly longer than vertical diameter (P < .001).
Conclusions: Ocular morphologic information and normal reference range values for various ophthalmic measurements were obtained in clinically healthy cinereous vultures, which can facilitate accurate diagnosis and better management of ophthalmic diseases in cinereous vultures.
Keywords: Schirmer tear test; applanation tonometry; cinereous vulture; general anesthesia; phenol red thread tear test; rebound tonometry.
© 2019 American College of Veterinary Ophthalmologists.