'Distortion as a Predictor of ERM Surgery Outcome'

Study Overview
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Brief Summary
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Epiretinal membranes (ERM) consist of an abnormal growth of tissue across the retina and are present about 6% of people aged 50 and over. They can cause symptoms of distortion (straight lines appearing bent) or blurred vision. Management options include observation if asymptomatic, or surgery to peel the membrane if symptomatic. Limited data exists regarding how to identify patients who are most likely to benefit from surgery. We propose to measure the effects on distortion (using D chart), visual acuity and vision-related quality of life (using a validated vision-related quality of life questionnaire) of ERM surgery. This will allow us to investigate whether pre-operative D chart score can predict subsequent improvement in quality of life following surgery. We hope the results will help patients and VR surgeons decide whether or not to proceed with ERM surgery. The study will be a prospective case series consisting of patients with symptomatic epiretinal membranes who choose to have epiretinal membrane surgery. The study participants will get standard care with the additional administration of a quality of life questionnaire and measurement of distortion (using a D-chart) at 3 different time points (pre-op, and post-op at 26 and 52 weeks). Recruitment will be in Glasgow, with a possibility of other sites being added on at a later stage.

Detailed Description
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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.

Official Title
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Does Pre-operative D-chart Score Predict Improvement in VFQ-25 Score Following Surgery for Epiretinal Membrane?

Conditions
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Epiretinal Membrane, Distortion, Quality of Life

Intervention / Treatment
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* Procedure: Epiretinal membrane surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Idiopathic epiretinal membrane Patients undergoing vitrectomy and gas surgery, under local or general anaesthetic Able to give informed consent 18 years old and over Exclusion Criteria: Epiretinal membrane secondary to retinal detachment, uveitis or retinal vascular disease Previous vitreoretinal surgery Pre-existing ophthalmic condition which limits the patient's visual acuity (Documented BCVA 6/36 or worse) Pre-existing ophthalmic conditions which cause metamorphopsia (exudative ARMD, central serous retinopathy) VA < 6/60

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Procedure: Epiretinal membrane surgery|Surgery for epiretinal membrane i.e. standard 3-port pars plana vitrectomy and epiretinal membrane and internal limiting membrane peel. Phakic patients will undergo cataract surgery.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VFQ-25 score at final visit (52 weeks after ERM surgery) | Measure of vision-related quality of life using NEI VFQ-25 quality of life questionnaire, 1 year after surgery for epiretinal membrane | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distortion score pre-operatively and at 26 and 52 weeks after ERM surgery | Distortion score calculated using D-chart | 1 year | 
| Best-corrected visual acuity pre-operatively and at 26 and 52 weeks after ERM surgery | Visual acuity measured in ETDRS | 1 year | 
| Vision-related quality of life pre-operatively and at 26 and 52 weeks after ERM surgery | Vision-related quality of life assessed using NEI VFQ-25 quality of life questionnaire | 1 year | 
| Central retinal thickness pre-operatively and at 26 and 52 weeks after ERM surgery | Central retinal thickness obtained from OCT scans done in clinic | 1 year |