Characterisation of cataracts and other ophthalmic findings in various species of captive penguins.

BACKGROUND: The identification of ophthalmic diseases that affect vision and/or cause discomfort should be a priority in captive penguins to improve their overall health and quality of life. METHODS: A routine ophthalmological examination was performed on 80 clinically normal penguins (160 eyes), and any lesions observed were recorded. RESULTS: Ocular lesions were frequent (56% of penguins), with cataracts being the most common (48.8% of penguins). Cortical cataracts (63% of eyes) and posterior subcapsular cataracts (27.4%) were the most commonly occurring. All maturation stages were found; incipient cataracts (52.1% of eyes with cataracts) were predominant, while Morgagnian cataracts (8.2%) were the least frequent. A correlation existed between lenticular changes and increasing age. Uveitis was present in 43.8% of eyes with cataracts, and ectropion uveae was the predominant clinical sign. Other ocular findings included blepharitis (3.8% of all eyes), corneal leukoma (5.6%) and posterior lens subluxation (7.5%). LIMITATIONS: The small number of birds of some species prevented the comparison of ophthalmic findings between species. CONCLUSION: This study corroborates the high prevalence of ocular lesions in captive penguins. Cataracts were frequent and age related. Most cataracts were cortical, and the predominant maturation stage was incipient. Lens-induced uveitis was a common finding. Lowered intraocular pressure was related to cataract formation.