Scotopic and photopic ERGs, and best-corrected visual acuity (BCVA) were checked before and shortly after silicone oil removal in eyes that had previously undergone vitrectomy and silicone oil injection for complex retinal detachment. Pre- and postoperative ERG a- and b-wave amplitudes were compared.
Twenty-eight eyes of 28 patients including 20 male and 8 female subjects with mean age of 39.3 ± 0.06 (range, 12 to 85) years were studied. Mean interval from primary vitreoretinal surgery to silicone oil removal was 21.04 ± 0.52 (range, 7 to 39) months. Mean duration from silicone oil removal to second ERG was 13.04 ± 1.75 (range, 10 to 16) days. Before silicone oil removal, mean a-wave amplitudes in maximal combined response, rod response and cone response ERGs were 27.4 ± 19.9, 7.2 ± 4.5 and 5.5 ± 3.4 μv, respectively. These values increased to 48.8 ± 31.9, 15.1 ± 14.4 and 17.4 ± 22.2 μv, respectively after silicone oil removal (P < 0.001). Mean b-wave amplitudes in the same order, were 69.41 ± 51, 41.2 ± 30.4 and 25.1 ± 33.9 μv before silicone oil removal, increasing to 165.6 ± 102.5, 81.7 ± 53.7 and 44.7 ± 34.1 μv respectively, after silicone oil removal (P < 0.001). Mean BCVA significantly improved from 1.10 ± 0.34 at baseline to 1.02 ± 0.33 logMAR after silicone oil removal (P < 0.001).