EVALUATION OF THE OCULAR PARAMETERS AND LESIONS IN A FLOCK OF AQUARIUM-HOUSED AFRICAN BLACK-FOOTED PENGUINS (SPHENISCUS DEMERSUS).

Abstract

African black-footed penguins (Spheniscus demersus) are one of the most common penguin species exhibited in zoos and aquariums. Ophthalmic literature published in this species is limited to intraocular pressure (IOP) and corneal thickness. The objective of this research was to evaluate IOP (rebound tonometry; dog setting), tear production, corneal fluorescein staining, and ocular lesions from 48 eyes of 24 penguins (aged 4.29-29.58 yr) at Ripley's Aquarium of the Smokies. Statistical analysis revealed that tear production (12.68 ± 4.59 mm/min [mean ± SD], with a modified half strip in 25 eyes) was not affected by sex or weight or between left and right eyes. Schirmer tear measurements were observed to decrease with age (P = 0.008). IOP (29.81 ± 4.88 mm Hg [mean ± SD]) was not affected by sex, weight, or age or between left and right eyes. Faint corneal fluorescein uptake was observed in four eyes, indicating stippled-to-patchy erosions on the corneal epithelium. Cataracts were the most common ocular lesion (50%; 12/24 penguins) and mostly incipient anterior subcapsular. Increased age (P = 0.024) was determined to be a risk factor for cataracts. Other ocular lesions observed in this group were corneal fibrosis, diffuse chemosis, and perilimbal corneal conjunctivalization. This study contributes to species-specific ocular reference intervals for African black-footed penguins and characterizes their most common ocular lesions.