Ocular consequences of blunt trauma in two species of nocturnal raptors (Athene noctua and Otus scops)

Abstract

To determine the type, prevalence, and prognosis of ocular and periocular lesions in free-living little owls (LO) and scops owls (SO), injured by blunt trauma. Medical records from LO and SO with ocular or periocular lesions secondary to blunt trauma were reviewed. A complete ophthalmic examination was performed in all birds. Short protocol electroretinography (ERG) and ocular ultrasound were performed as dictated by the case. During the study period, a total of 158 LO and 99 SO with blunt trauma were admitted. Among these, 43 LO (27.8%) and 27 SO (27.3%) had ocular or periocular lesions. Bilateral injuries (72.1% LO and 81.5% SO) were more common than unilateral. Common findings in both species were: corneal erosions/superficial ulcers, anterior and posterior uveitis, cataracts, hyphema, posterior synechia, vitreal hemorrhage, and retinal detachment. Electroretinography was performed in 32 LO and eight SO, which had posterior segment lesions or opacity of the transparent media. Normal to nonrecordable b-wave amplitudes were observed. Follow-up was available in 13 LO and 11 SO. Among these, nine LO (14 eyes) and 10 SO (17 eyes) had resolution of the clinical signs following medical treatment. Ocular lesions are common in LO and SO injured by blunt trauma. Electroretinography is a valuable diagnostic tool to assess the severity of retinal dysfunction secondary to blunt trauma and to determine the response to medical treatment. A complete ophthalmic examination is a determining factor in the early management of trauma in these species.