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.