Electroretinogram changes after scleral buckling surgery of retinal detachment

Objective To observe changes in visual function after a single scleral buckling surgery for rhegmatogenous retinal detachment (RD) by using ERG (electroretinogram). Methods One eye from 56 patients with rhegmatogenous RD was chosen. Forty-three corresponding normal fellow eyes from these patients were chosen as controls. Single scleral buckling surgery was carried out and a full-field ERG was performed before the surgery, and 1 and 6 months after surgery. Results The mean amplitude of ERG decreased and the latency (except for the a-wave) was delayed in the eye with a retinal detachment, and wavelets of the oscillatory potential decreased or were completely lacking. One month after surgery, the amplitudes of the a and b waves were noticeably improved (except for the 30 Hz flicker responses), but the latency (except for the a-wave) was still delayed. The ratio of b/a (mixed response) increased 1 month after surgery, with no further changes thereafter. The amplitude of the scotopic b wave was 58.1% of the control eyes, while the 30 Hz flicker responses was only 45.8% of controls; the difference between the two responses was significant (P < 0.001). The number of oscillatory potential wavelets increased, but the total amplitude of the oscillatory potentials did not exhibit any obvious changes during the follow-up period (P = 0.20). In the 41 patients whose detachment involved the macula preoperatively, the amplitude of the 30 Hz flicker responses improved significantly after surgery (P = 0.037). Six months after the operation, the wave amplitudes were not significantly different from 1 month after surgery, but there was a tendency toward a decrease in the latency. Conclusions After reattachment of the retina, visual function showed dramatic improvement 1 month after the surgery. The postreceptoral responses recovered more than the a-wave. The rod system recovered more quickly and completely than the cone system during the follow-up period. The incomplete recovery observed by using ERGs indicates that there is irreversible damage that likely occurs following retinal detachment and surgery.