Aim To report retinal function outcomes after ophthalmic artery chemosurgery (OAC) for advanced retinoblastoma (RB) in eyes with minimal pretreatment retinal function.

Methods For 72 advanced RB eyes with baseline electroretinograms (ERGs) indistinguishable from noise (‘extinguished’) or flicker ERG amplitudes <25 µV (‘poor’), ERGs were obtained before OAC and at 3 months, 1 year and 2 years after OAC. Presence of baseline retinal detachments (RDs) and their subsequent resolution or persistence was also noted.

Results At 3 months, 1 year and 2 years post-OAC, ‘extinguished’ eyes showed 9/15, 4/11 and 2/6 detectable ERGs, respectively, and ‘poor’ eyes showed 19/55, 14/30 and 8/18 ERGs exceeding 25 μV, respectively. Correlations between baseline and post-OAC ERGs were poor; however, good correlation (R²) existed between ERGs post-OAC at 3 months and 1 year (0.749), at 3 months and 2 years (0.773) and at 1 year and 2 years (0.771). Overall, 49/70 eyes presented with RD; 29 RDs resolved 3 months post-OAC, with an average ERG change of +20.6 μV. Eyes with persistent RD had an average ERG change of −2.2 μV. No eyes underwent ≥25 μV change without RD resolution.

Conclusions Minimal baseline ERGs do not preclude significant recovery of retinal function after OAC. Good correlation exists between ERG outcomes at 3 months and those at subsequent follow-ups, suggesting that ERG amplitudes at 3-month post-OAC can prognosticate longer term retinal function, and that improvement is durable. For eyes presenting with RD, RD resolution is necessary but not sufficient for significant (≥25 μV) increases in ERG amplitudes.