Electrophysiological changes after 360° retinotomy and macular translocation for subfoveal choroidal neovascularisation in age related macular degeneration

Abstract

Aim - To evaluate electrophysiological changes after 360° retinotomy and macular translocation for subfoveal choroidal neovascularisation in patients with age related macular degeneration (AMD). Methods - A consecutive series of 32 patients suffering from subfoveal choroidal neovascularisation secondary to AMD underwent 360° retinotomy and macular translocation. The ERG served as the main parameter of the study and was recorded 1 day before the translocation surgery and no earlier than 4 weeks after the silicone oil removal. Results - The scotopic ERG amplitudes were significantly reduced after translocation surgery. Depending on the applied flash luminance the mean b-wave amplitude reduction of the scotopic ERG varied between 67% (0.2 cd.s/m2) and 74% (0.03 cd.s/m2). The a-waves and b-waves of the saturating light response decreased significantly by 46% and 59%, respectively. The photopic a-wave and b-wave amplitudes were significantly lower after the translocation surgery resulting in a mean reduction of 27% and 43%, respectively. Conclusions - Although macular translocation may provide the potential of preserving and even restoring vision in patients with subfoveal choroidal neovascular membranes secondary to AMD the present study indicates that a significant electrophysiological decrease is caused by surgical procedures associated with this technique. Further research is necessary to clarify if certain modifications of the surgical procedure are able to substantially reduce the neuroretinal trauma.