Supplementary Material for: Evaluation of the effects of vitrectomy with primary epiretinal membrane peel on optical quality using double-pass aberrometry

Introduction: We performed a prospective, single-center, cohort study in order to evaluate the effects of vitrectomy with epiretinal membrane (ERM) peel on optical quality in patients with primary ERM. Methods: Thirty patients treated for primary ERM by vitrectomy with ERM peel were included from our tertiary university hospital ophthalmology department. The main study outcome was variation in optical quality parameters measured using the HD Analyzer™ between pre-operative and two-month post-operative evaluations in operated eyes. Optical quality parameters comprised point spread function (PSF) width at 10% and 50%, objective scatter index (OSI), and modulation transfer function (MTF) cutoff. Contralateral non-operated eyes were used as an internal control for measurement reproducibility. Results: Mean PSF width at 10% (42.22 vs 27.37 arc/min; p = 0.0002) and mean OSI (3.32 vs 2.32; p = 0.0003) were significantly improved between pre- versus post-operative evaluations. Mean PSF width at 50% and mean MTF cutoff showed no changes. Subgroup analysis according to crystalline lens status gave similar results demonstrating that improvements in mean PSF width at 10% and OSI were not lens-related. Non-operated eyes showed no changes in any of the parameters analyzed. Conclusion: Reduced light scattering measured by OSI indicates improved optical quality following vitrectomy with ERM peel among patients with primary ERM. OSI measurement could thus be a new parameter of interest in the pre-operative assessment of primary ERM and other pre-vitrectomy assessments.