Equine retinal detachment in the United Kingdom: 23 cases (2010–2020)

Abstract

Background: Few reports describe the aetiology, presentation and diagnosis of retinal detachment in horses. Equine recurrent uveitis (ERU) and trauma are the most common causes of equine retinal detachment in the United States, but no studies have characterised the disease within the United Kingdom. Objectives: To describe clinical presentation, aetiology and diagnostic examination findings of horses with retinal detachment within a UK-based population. Study design: Retrospective case series. Methods: Medical records of horses presented to a single UK referral centre between 2010 and 2020 were reviewed. Horses were diagnosed with retinal detachment by clinical examination and/or ultrasonography, and details of clinical presentation, aetiology and examination findings were recorded. Results: A total of 23 horses were included. There were 13 geldings and 10 mares with a median age of 9 at presentation (range 4 days to 17 years). Warmbloods were the most common breed (n = 8). Unilateral cases (n = 21) were more common than bilateral (n = 2). ERU was the most common aetiology (n = 10) followed by trauma (n = 8). Three cases presented post-intraocular surgery, one congenital and one secondary to primary glaucoma. Ultrasound confirmed diagnosis in 23 (100%) cases, but only nine could be visualised by direct ophthalmoscopy. Cataracts, posterior synechiae and vitreal debris were found commonly in both the ipsilateral and contralateral eye affected. Main limitations: Small sample size. Single-centre retrospective study which may not be representative of the entire UK population. Histological confirmation of cases was not obtained. Conclusions: Causes of retinal detachment in the studied population are like those previously reported in the USA and most cases presented with complete detachment. Ocular ultrasound is useful in the diagnosis of retinal detachment when the fundus cannot be directly assessed. The presence of retinal detachment should be considered in non-visual eyes presenting with cataracts, vitreal debris and posterior synechiae.