Full-field electroretinography under general anesthesia in retinoblastoma

To investigate the electrical responses of the retina in retinoblastoma (RB), by recording full-field electroretinography (ERG) under general anesthesia.The ERG was recorded using Ephios hand-held portable ERG system, according to International Standards for Clinical Electrophysiology of Vision. Forty-eight eyes of 43 cases and 33 eyes of 33 controls were enrolled. The cases were classified based on international intraocular retinoblastoma classification (IIRC). Forty-eight eyes of cases were divided into 30 cases with active RB and 18 cases with regressed RB.The amplitudes of a- and b-waves were decreased as compared to controls in all subgroups. The implicit times of all RB patients from group A to C differed statistically from controls (p value0.05) except for single-flash rod response. The ERG waveforms in group E eyes were non-recordable. The comparison of ERG parameters between active and regressed groups (IIRC groups A and B) was statistically insignificant. Single case follow-up of unilateral RB after systemic chemotherapy showed improvement in amplitudes compared to baseline parameters.Reduced amplitudes and delayed implicit times were noted in advanced disease. The ERG of RB cases did not follow any specific pattern of waveform. ERG appears to be a dynamic parameter to observe changes following treatment for RB. Although ERG is not a diagnostic test for RB, it can be used as a complementary test to assess the residual retinal function in RB eyes.