Of 24 consecutive eyes in 24 patients with retinoblastoma treated with IAC, the mean age at the time of first diagnosis was 20.2 (0.5-60) months and at the time of IAC it was 38.9 (14-120) months. The patients included 22 Iranian, 1 Iraqi and 1 Azeri patient. There were 14 boys (59.9%) and 10 girls (41.6%). The disease was unilateral in 14 (58.3%), bilateral in 10 (41.7%), and familial in five (20.8%) patients at the time of diagnosis. IAC was performed as the primary treatment in six eyes (25%) and secondary treatment (after failed systemic chemotherapy or recurrences) in 18 (75%). All our six naive cases had unilateral involvement. Of the 18 secondary cases, four eyes (16.7%) had bilateral disease and two (8.3%) patients had an enucleation of the fellow eye (
Figure 1). The eyes were classified as international classification of retinoblastoma group B (n= 1, 4.2%), group C (n = 2, 8.3%), group D (n =18, 75%), and group E (n = 3, 12.5%) at the first visit. On the initial examination, the mean tumor base was 14.4 mm (range, 2-21 mm), the mean thickness was 8.1 mm (range, 2.5-13 mm) and the mean volume was 1712.7 mm
3 (range, 60-4788 mm
3). There was a mean of 1.4 tumors per eye (range 1-7). Vitreous seeds were visible in 19 eyes (79.2%), subretinal seeds in 10 (41.7%), anterior chamber seeds in two (8.3%), subretinal fluid in 19 (79.2%), cataract in two (8.3%), feeding vessels in 19 (79.2%), iris neovascularization in one (4.2%), and neovascular glaucoma in none. The mean follow-up was 17.6 months (median, 14.6; range, 3-57 months) after IAC. Each patient was visited every month until complete regression.