Rebound tonometry intraocular pressure reference values for conscious adult Egyptian vultures (Neophron percnopterus).

Objective: To obtain standard reference values of intraocular pressure measured with rebound tonometry in conscious healthy Egyptian vultures (Neophron percnopterus).

Methods: 17 Egyptian vultures presented for a routine health check, involving a full physical examination, blood film examination, Hct, manual total leukocyte count, and plasma biochemistry. 15 animals considered healthy and with no signs of stress underwent an ophthalmic examination, including observation of facial symmetry, adnexa, and direct fundoscopy to screen for ocular disease. Healthy animals, with no evidence of ocular disease and no signs of stress, were included in the study. The birds were manually restraint in an upright position for rebound tonometry of the right and left eyes.

Results: Mean and SD of intraocular pressure were 27.33 ± 3.54 mm Hg for the right eye and 27.00 ± 4.11 mm Hg for the left eye. There was no statistical difference when comparing the right and left eyes. The combined mean ± SD for both eyes was 27.2 ± 3.76 mm Hg.

Conclusions: Rebound tonometry was well tolerated in all animals included in the study. The results of intraocular pressure with rebound tonometry can be used as reference values during the ophthalmological examination of Egyptian vultures.

Clinical relevance: The investigation of vision threatening diseases in Egyptian vultures may necessitate rebound tonometry as part of a comprehensive ophthalmologic examination. Rebound tonometry values obtained from anesthetized Egyptian vultures, or Egyptian vultures restrained in lateral, dorsal, or sternal positions, may differ from those reported here.