Retinal Function in Children with Retinoblastoma

Abstract

Purpose : Globe salvage for potential vision preservation is a common goal of retinoblastoma (RB) treatment. We used full-field electroretinography (ERG) to test the function of the whole retina in RB patients having a range of tumor severities and undergoing a number of different therapies.

Methods : Serial ERG tests (2-13, median: 6) were performed in both scotopic and photopic conditions on both eyes of each patient. The first test was at age 3 days to 1.4 years (median: 0.65 years). The period of observation ranged from 4 to 25 months (median: 11 months). Scotopic functions were summarized by b-wave saturated amplitude (Vmax) calculated from stimulus/response data. Photopic functions were summarized by amplitude of the b-wave response to the International Society for Clinical Electrophysiology of Vision photopic stimulus, and the amplitude of the response to 30 Hz flickering light. Treatments included intra-arterial, intravenous and intravitreal chemotherapy. Additional therapies included focal laser, cryotherapy and enucleation (13 months after the first ERG) in a patient with unilateral RB (Intraocular Classification of Retinoblastoma group D).

Results : Seven patients, 4 with unilateral RB (1 in group B, 2 in group C, 1 in group D) and 3 with bilateral RB (2 in group A, 4 in group B) had serial examination under anesthesia including ERG testing. Responses from every eye at every test were sufficient for stimulus/response analyses except for the initial test of one RB eye with total retinal detachment at presentation (group D). Throughout the study, in the bilateral RB patients, the eye with the smaller tumor had larger ERG amplitudes. In the unilateral cases, the eye with no tumor had larger responses. No scotopic or photopic response parameter for any eye showed systematic decline with age. During the study, parameter values as a function of age were approximately parallel for the right and the left eye of each patient.

Conclusions : The overall function of the retina — the site of RB disease and the tissue targeted by different treatments — is preserved regardless of disease severity or treatment modality. These full-field ERG results motivate additional studies of the scotopic and photopic visual functions mediated by central and peripheral retina to further characterize the effect of RB and its treatment on the child’s vision.

This is a 2020 ARVO Annual Meeting abstract.