The consequences of avian ocular trauma: histopathological evidence and implications of acute and chronic disease.

Abstract

OBJECTIVE: To present a description and categorization of the histopathological lesions in avian ocular trauma. ANIMAL STUDIED: Seventy-five birds diagnosed with ocular trauma at to the Comparative Ocular Pathology Laboratory of Wisconsin. PROCEDURES: Histological slides were reviewed, and the type of trauma was classified by cause into either (i) blunt trauma or (ii) penetrating trauma and by duration into (i) acute or (ii) chronic. RESULTS: Blunt trauma was the most common source of trauma, and the most frequent lesions were observed in the retina (91%), with 71% of retinas having a tear or detachment and 46% of retinas showing chronic degenerative changes. Damage to the iris/ciliary body was present in 77% of cases. Corneal (17%) and lens (31%) lesions were relatively low. Acute traumatic events had a higher prevalence of readily identifiable discrete retinal tears/detachments (64%). Nearly all cases of chronic trauma exhibited chronic retinal lesions (93.7%), as well as a greater percentage of cartilage/bone lesions (71.4%), irido/cyclodialysis (51.9%), lenticular lesions (72.7%), and corneal damage (83.3%). However, the incidence of iridocyclodialysis was roughly equivalent for acute and chronic blunt trauma. CONCLUSIONS: Ocular trauma can lead to profound acute and chronic lesions within the eye. Here, we provide insight into understanding ocular damage caused by trauma, which may help future studies suggest new therapeutic options and provide insight regarding the releasability of avian wildlife.