A population-based study of Coats disease in the United Kingdom I: epidemiology and clinical features at diagnosis

Abstract

Aims: coats disease is an uncommon form of retinal telangiectasis. Published case series mostly originate from tertiary referrals centres and may provide a skewed view of disease severity. We conducted a prospective population-based study of Coats disease in the United Kingdom to ascertain the incidence and provide a more representative picture.

Methods: the study was conducted through the British Ophthalmological Surveillance Unit. This first paper reports the features at presentation; gender, mode of presentation, visual acuity, anterior and posterior segment findings, amount of retinal exudation, and disease staging.

Results: a total of 55 eligible cases of Coats disease were identified giving an estimated population incidence of 0.09 per 100.000 of the population. All cases were unilateral and 85% were male. Mean age at presentation was 146 months (median 96 months). The mean age of diagnosis was markedly different with differing mechanisms of presentation. Cases presenting with leucocoria or strabismus presented early whereas subjective visual loss presented much later. A large proportion of eyes (44%) were blind at diagnosis. The great majority of eyes (71%) had 6 or fewer clock hours of retinal exudation. More severe forms/stages of Coats disease were more common in the youngest patients.

Conclusions: compared with published studies of Coats disease, we have found milder disease severity at presentation. This is most likely because of the population-based nature of our study reflecting the full disease spectrum. A large proportion of eyes with Coats have poor visual acuity and disease severity is worse in younger patients.