Background/aims We have previously introduced electroretinography (ERG) as a proxy for visual function to monitor for retinal toxicity due to intra-arterial chemotherapy for retinoblastoma in young children. In this paper, we report ERG results for patients with retinoblastoma receiving initial treatment with systemic chemotherapy.

Methods Inclusion criteria were patients presenting with retinoblastoma at <3 months of age or <6.0 kg in weight, with large tumours not amenable to local laser treatment, cryotherapy or plaque brachytherapy. Patients received intravenous carboplatin 18.7 mg/kg every 3–5 weeks, contingent on recovery of blood counts, until they had grown sufficiently to receive intra-arterial chemotherapy. ERG was performed during examination under anaesthesia at monthly intervals, using contact lens electrodes and a hand-held ganzfeld stimulator. 30-Hertz flicker responses are reported.

Results Four patients were treated for bilateral retinoblastoma. All eyes responded well to systemic chemotherapy. 30-Hertz flicker ERGs improved during treatment in all eyes, significantly in six of eight eyes, and at least in one eye of each patient.

Conclusion Effective systemic chemotherapy for retinoblastoma in children who are too small for intra-arterial chemotherapy is compatible with significant increases in ERG amplitudes, even in eyes presenting with extinguished ERGs. ERG signals may increase independent of resolution of retinal detachment.