Changes in Focal Macular ERGs after Macular Translocation Surgery with 360° Retinotomy

PURPOSE. To evaluate the short- and long-term changes of focal macular electroretinograms (fmERGs) after macular translocation with 360° retinotomy. METHODS. This was a retrospective study. fmERGs were recorded in 19 eyes of 19 consecutive patients who underwent macular translocation with 360° retinotomy for choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD; 17 eyes) or polypoidal choroidal vasculopathy (2 eyes). The changes in the fmERGs, recorded before, shortly after (6-12 months; mean 8.3 months), and more than 18 months (18-30 months; mean 22.4 months) after surgery from 12 eyes, were analyzed. A 15° stimulus centered on the fovea was used to elicit the fmERGs. RESULTS. The mean logarithm of minimum angle of resolution (logMAR) was 1.06 ± 0.07 (20/230) before surgery, 0.78 ± 0.08 (20/121) early after surgery (n = 19), and 0.64 ± 0.07 (20/87) late after surgery (n = 12). These improvements in visual acuity were significant (P = 0.0074, P = 0.0050, respectively). Before surgery, the amplitudes of all components of the fmERGs were markedly reduced in all eyes. The mean b-wave amplitude in 17 AMD eyes recorded early after surgery was significantly larger (P = 0.0262), and the mean a-wave amplitude was also increased but not significantly (P = 0.1180). The mean amplitudes of the a- and b-waves in 10 AMD eyes recorded after 18 months were significantly larger than those before the surgery (P = 0.0218, and P = 0.0284). The mean implicit time of the b-wave in 17 AMD eyes decreased early after surgery, and a further decrease was detected at the later testing time. CONCLUSIONS. These results indicate that macular function is partially recoverable after macular translocation in some patients.