The best way to diagnose the problem is through an eye examination. Your ophthalmologist will administer eye drops to enlarge (dilate) the pupils temporarily so that they can examine the retina and macula. Usually, you will also undergo an optical coherence tomography (OCT) scan, which will provide a detailed cross-sectional image of the macula, which confirms the diagnosis of an epiretinal membrane. An OCT scan is very fast and convenient. The light beam used for scanning is painless, and unlike X-rays, does not involve any radiation.