Quantitative evaluation of metamorphopsy before and after operation in patients with idiopatic epiretinal membranes using the M-charts™ metamorfopsy book

Purpose: It was aimed to quantitatively evaluate metamorphopsia pre- and postoperatively in patients with idiopathic epiretinal membrane using the M-CHARTS™ metamorphopsy book and to evaluate the relationship between changes in retinal layers in optical coherence tomography (OCT) and metamorphopsia scores. Materials and Methods: This prospective study included patients followed up in Akdeniz University Hospital Ophthalmology Clinic Retina outpatient clinic, diagnosed with idiopathic epiretinal membrane by fundus examination and optical coherence tomography between 2020-2022, and underwent pars plana vitrectomy surgery for epiretinal membrane for one year. Detailed ophthalmologic findings, visual acuities and metamorphopsia scores of all patients were recorded. Central retinal thickness (CRT), retinal nerve fiber layer (RNFL) thickness, ganglion cell layer+inner plexiform layer (GCL+IPL) thicknesses and subfoveal choroidal thickness (SFCT) were evaluated in OCT. The relationship between pre- and postoperative visual acuity, metamorphopsia scores and OCT parameters was investigated. Results: Visual acuity did not differ significantly (p>0.05) in the pre-treatment, post- treatment 1st, 3rd, 6th, and 12th months in the group with and without metamorphopsia score reduction in the eye with iERM. The MV score did not differ significantly (p>0.05) in the 1st,3rd, 6th, and 12th months after treatment in the group with and without metamorphopsia score reduction in the eye with iERM. Retina (ILM-RPE) – Central (S) value did not differ significantly (p>0.05) before and after treatment in the group with and without metamorphopsia score reduction. Retinal (ILM-RPE) – S value at the 3rd, 6th, and 12th months after the treatment was found to be significantly higher (p<0.05) in the group with a decrease in metamorphopsia score than in the group without a decrease in metamorphopsia. In the group with decreased metamorphopsia score, pre-treatment and post-treatment 12th month GHT+IPT(Ganglion Cell Layer+Inner Plexiform Layer) +S value was significantly (p<0.05) higher than the group without metamorphopsia score decrease. Conclusion: Idiopathic epiretinal membrane is a vitreoretinal interface disease that can reduce visual acuity and cause metamorphopsia. Statistically significant preoperative thickness difference in the OCT parameters of the GHT+IPT+S layer in the group with and without a decrease in metamorphopsia scores was associated with the quantitative metamorphopsia complaints of the patients. Anatomical and functional recovery after iERM surgery can continue for years. Keywords: Visual acuity, Metamorphopsia, Optical coherence tomography, Epiretinal membrane