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

Abstract

Background: Identification of ophthalmic diseases that affect vision and/or cause discomfort should be a priority in captive penguins to guarantee their wellness and life quality. Methods: An observational study was conducted. A routine ophthalmologic examination was performed on eighty clinically normal penguins (160 eyes). Results: Ocular lesions were frequent (56% of penguins). Cataracts were the most common (48.8% of penguins). Cortical cataracts (63% of eyes) and posterior subcapsular cataracts (27.4%) were the most common. 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 comparison of ophthalmic findings between them. 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.