'Distortion as a Predictor of ERM Surgery Outcome'

Epiretinal membranes consist of a proliferation of fibrocellular tissue along the inner aspect of the retina. Over time, this membrane can result in anterior-posterior traction and cause disruption of the retinal architecture, which can lead to symptoms of blurred vision, or distorted vision (with straight lines appearing bent or wavy). Patients with ERM now constitute one of the most common referrals to the vitreoretinal service. Management of epiretinal membrane includes observation or surgery for severely symptomatic membranes. The surgery consists of vitrectomy and epiretinal +/- inner limiting membrane peel. Currently there is limited evidence to help identify which patients with an epiretinal membrane are the most likely to benefit from this operation, which makes it more difficult for patients to be able to weigh up the benefits and risks of proceeding with this elective procedure. Our study will measure the effects on distortion (using D chart), visual acuity and quality of life of ERM surgery. Hence it will allow us to investigate whether the pre-op D chart score can predict subsequent improvement in quality of life following surgery. This will provide vitreoretinal surgeons and patients with an evidence base regarding the success of this elective procedure and offer realistic expectations regarding surgical outcomes. Ultimately, we hope that the results of this study will facilitate the decision of whether or not to proceed with ERM surgery. We plan to recruit patients with an epiretinal membrane who choose to undergo surgery at the time of their clinic appointment within the vitreoretinal service. In addition to standard care, the study participants will undergo measurements of distortion (using a D-chart, duration 5-10 minutes) and fill in a quality of life questionnaire. These measurements will be taken before the operation and at six and twelve months following the operation. The aims of the study are: * To investigate the sustained effect of epiretinal membrane surgery on distortion (using D-chart), visual acuity and vision-related quality of life (using NEI VFQ-25 questionnaire) * To determine the relationship between pre-operative distortion score and post-operative vision-related quality of life score following ERM surgery Our study will have a larger number of participants with a longer period of follow up (52 weeks) than comparable studies. It will be the first epiretinal membrane study that measures distortion using the D-chart, which we believe to be superior to existing tests (such as the M-chart) which have been used in similar studies.