Measuring Subjective Quality of Vision and Metamorphopsia Before and After Epiretinal Membrane and Macular Hole Surgery

Metamorphopsia is a visual symptom in which straight lines appear distorted, for example a vertical window blind may appear wavy which can affect quality of vision. Metamorphopsia is a common symptom in retinal conditions such as epiretinal membranes (ERM) and macular holes. There is a lack of studies analysing the prevalence of ERM in the UK and Europe.

Both of the conditions have shown to be a higher risk factor with age. With an aging population it is likely these numbers will increase. Currently the only treatment option is surgery (vitrectomy) or conservative management to monitor the condition. It would therefore be beneficial to find a tool that would inform the surgeon of a patient's quality of vision and how this impacts their life. A patient's severity of metamorphopsia reveals more precise information on the progression of the disease than visual acuity alone (Nomoto et al. 2013) therefore gaining a better understanding can help aid clinical decisions.

Current clinical practice is to monitor metamorphopsia with an Amsler chart, a grid with lines; the patient is then asked to draw where they can see distortion. They are used to detect metamorphopsia but are unable to quantify and provide an accurate measurement of the severity of metamorphopsia and quality of vision

The Quality of Vision questionnaire (QoV) (McAlinden et al. 2010) is a modern tool developed to specifically measure subjective quality of vision. The Metamorphopsia questionnaire (Arimura et al. 2011) has been developed to provide a measurement of subjective metamorphopsia in macular disease. Both have been psychometrically validated and are in use in a number of clinical trials worldwide.

It would be valuable to investigate the role of each questionnaire in identifying quality of vison and metamorphopsia pre- and post-surgery for ERM and macular holes to establish if there are changes to patient responses. We would compare this to visual acuity and optical coherence tomography (OCT) images pre- and post-surgery to see if changes correspond to the questionnaire responses. If a questionnaire can measure metamorphopsia and its impact on quality of vision in ERM and macular holes, this would assist in clinical decision making.