Purpose: To determine the impact of subtle differences (most notably in their classification of group E eyes) in two published versions of the ICRB (Philadelphia and the Children's Hospital Los Angeles).
Methods: Analysis of a series of 96 eyes with intra-ocular retinoblastoma.
Results: The disparate criteria of the 2 published ICRB schemas affected group assignment of 5.2% of the eyes (25% of the group E eyes).
Conclusion: Discrepancies need to be reconciled to ensure accurate and uniform application of the ICRB.