Retinal reattachment and ERG recovery after ophthalmic artery chemosurgery for advanced retinoblastoma in eyes with minimal baseline retinal function

Abstract

Purpose : To report retinal function outcomes after ophthalmic artery chemosurgery (OAC) for advanced retinoblastoma (RB) in eyes with minimal pre-treatment retinal function.

Methods : ERG recordings were obtained for 70 eyes of children with advanced RB prior to OAC and at 3 months, 1 year and 2 years after OAC initiation. Inclusion criteria were baseline ERGs indistinguishable from noise (“extinguished” eyes) or flicker ERG amplitudes < 25 μV (“poor” eyes). Presence of retinal detachment (RD) prior to OAC and subsequent resolution or persistence of RD at 3 months after OAC were 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 22/55, 13/30 and 10/17 ERGs exceeding 25 μV respectively. Of the 70 eyes examined, 49 presented with RD. Twenty-nine RDs had resolved by 3 months after initiation of OAC, with an average ERG amplitude change of +20.6 μV, whereas eyes with persistent RD had a corresponding average ERG amplitude change of –2.2 μV; this difference was statistically significant (p < 0.001, Student’s t-test). No eyes underwent ≥ 25 μV change without resolution of RD. Correlation between baseline ERGs and amplitudes post-OAC at follow-up visits of 3 months, 1 year and 2 years was poor, with R² = 0.127, 0.108 and 0.215 respectively. However, there was good correlation between ERG amplitudes measured at 3 months and 1 year after OAC (R² = 0.749), at 3 months and 2 years after OAC (R² = 0.771) and at 1 year and 2 years (R² = 0.771).

Conclusions : Poor, even extinguished, baseline ERGs do not preclude significant recovery of retinal function after OAC. For eyes presenting with RD, resolution of the RD with OAC is a necessary, but not sufficient, condition for a significant (≥ 25 μV) increase in ERG amplitudes; conversely, all eyes that exhibited significant ERG increases were eyes with baseline RD that resolved with OAC. Finally, correlation between baseline and final ERG outcomes in this cohort is very weak, but good correlation exists between ERG outcomes at 3 months and those at subsequent follow-up visits. This suggests that ERG amplitudes at 3-months post-OAC predict retinal function over the subsequent two years, and that the improvement is durable.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.