Purpose: To investigate the safety and efficacy of intravitreal injection of melphalan for retinoblastoma.
Methods: A retrospective chart review of all patients who were administered intravitreal injections of melphalan for retinoblastoma between 1990 and 2011. A total of 264 eyes of 250 patients were included. All ocular adverse events, systemic prognosis, ocular prognosis, and visual acuity were investigated.
Results: The total number of intravitreal injections administered was 1,067; each eye received between one and 25 injections. A postoperative subconjunctival tumor developed in one eye. None of the eyes suffered infections or uveitis, and all other adverse events including chorioretinal atrophy displayed incidences of less than 1.5 %. At 5 postoperative years, the cumulative incidence of cataract surgery was 3.1 % among the eyes that were treated without ocular hyperthermia. Distant metastasis or intracranial invasion occurred in 11 patients, all of whom had high-risk pathological factors for metastasis such as optic nerve invasion, but refused to receive adjuvant chemotherapy. Sixty-eight percent of the eyes achieved complete vitreous seed remission, but recurrence occurred in 19 % of these eyes after 10.0 ± 4.9 months. In addition, 47 and 27 % of the eyes without primary macular tumors retained visual acuity of >0.5 and >1.0, respectively.
Conclusions: The risk of extraocular tumor spreading following intravitreal injections is low, and other adverse events are rare. Sixty-eight percent of the treated eyes achieved complete vitreous seed remission, and about half of them retained practical levels of vision. The intravitreal injection of melphalan is a safe and effective treatment for vitreous seeds.