Relationship between variations in posterior vitreous detachment and visual prognosis in idiopathic epiretinal membranes

PURPOSE To clarify the relationship between variations in posterior vitreous detachments (PVDs) and visual prognoses in idiopathic epiretinal membranes (ERMs). METHODS In this retrospective, observational, and consecutive case series, we observed variations in PVDs in 37 patients (mean age, 65.7±11.0 years) with ERMs and followed them for 2 years. Three PVD types were found biomicroscopically: no PVD, complete PVD with collapse (C-PVD with collapse), and partial PVD without shrinkage, with persistent vitreous attachment to the macula through the premacular hole of the posterior hyaloid membrane (P-PVD without shrinkage [M]). The best-corrected visual acuity (BCVA) was measured and converted to the logarithm of the minimum angle of resolution (logMAR) BCVA at the first visit and 2 years later. RESULTS No PVD was observed in 16 of the 37 eyes (mean age, 61.3±11.3 years), C-PVD with collapse in 11 of the 37 eyes (mean age, 69.1±9.9 years), and P-PVD without shrinkage (M) in 10 of the 37 eyes (mean age, 69.3±10.9 years). The logMAR BCVA at the first visit was the worst in the P-PVD without shrinkage (M) group (0.22±0.35) compared with the no-PVD group (-0.019±0.07; P<0.01) and the C-PVD group (0.029±0.08; P<0.05). The logMAR BCVA 2 years later was also worst in the P-PVD without shrinkage (M) group (0.39±0.35) compared with the no-PVD group (0.04±0.13) and the C-PVD with collapse group (0.03±0.09; P<0.05 for both comparisons). The change in the logMAR BCVA over the 2-year follow-up period was worst in the P-PVD without shrinkage (M) group (0.17±0.23) compared with the no-PVD group (0.06±0.14) and the C-PVD with collapse group (0.0009±0.09; P<0.05 for both comparisons). CONCLUSION Cases with an ERM with a P-PVD without shrinkage (M) had a worse visual prognosis than those with an ERM with no PVD and C-PVD with collapse.