T.P.54 Epiretinal membrane: A reversible cause for visual disability in myotonic dystrophy

Abstract

<h2>Abstract</h2> Myotonic dystrophy type 1 is a multisystem disorder that affects skeletal and smooth muscle as well as the eye, heart, endocrine system, and central nervous system. In the eye it commonly causes ptosis and cataracts and has been associated with retinal pigmentary changes. In a case control study of 30 patients not selected for eye symptoms and 28 age matched controls, we performed a comprehensive screen of the eye including optical coherence tomography of macula and retinal nerve fibre layer, visual acuity and colour vision, pupil assessment, visual fields, slit lamp, intra ocular pressure, dilated fundal examination and retinal photography. We also assessed patients' CTG repeat size, age, 6min walk and motor impairment rating scale (MIRS). We examined 59 eyes in 30 patients (one patient had recent eye surgery and was unable to be examined in that eye) and 56 eyes in 28 controls. Twenty-six eyes (44%) in 18 (60%) myotonic dystrophy patients showed evidence of epiretinal membranes (ERM) compared with just 4 (7%) eyes in 4 controls (14%); <i>p</i><0.0001 and <i>p</i><0.001 respectively (two tailed Fisher's exact test). Most of these were asymptomatic at this time but three of the ERMs amongst the myotonic patients were impairing vision (visual acuity 6/15) and one patient was referred for retinal peel operation. About half the patients with ERM also had retinal pigmentary changes as well (compared with four controls). There was no association between the presence of ERM and motor disability as measured by MIRS or 6min walk test, nor with CTG repeat length. There was a trend towards patients with ERM being older (average age 48years vs 40years <i>p</i>=0.14). Epiretinal membrane is a treatable cause of visual disability in myotonic dystrophy and should be specifically looked for in patients with impaired vision even when they do not have other signs of advanced disease.