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.
Keywords: Electrophysiology; Retina; Treatment Surgery.
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