I ntraophthalmic artery chemotherapy (IAC) for treatment of retinoblastoma has become popular; it was used initially to salvage eyes with extensive intraocular retinoblastoma. 1 With the success of this treatment, radiotherapy or enucleation has been avoided in many eyes and patients have experienced minimal systemic toxic effects and acceptable local ophthalmic toxic effects. 2 With direct catheterization of the proximal portion of the ophthalmic artery, impressive tumor response was observed even in eyes with advanced retinoblastoma. 1,3 Initial enthusiasm for the use of IAC has been tempered by reports of ocular complications 4,5 and globe retention rates of 50% to 67%, 6 depending on many factors. One of the high-risk characteristics in retinoblastoma is the involvement of the anterior chamber by viable tumor. In most cases enucleation becomes necessary in this scenario, and if seeding is confirmed histopathologically, systemic adjuvant chemotherapy is added. In the present study we describe our experience with anterior segment tumor invasion in enucleated eyes that failed to respond to IAC. Methods A retrospective clinicopathologic review of enucleated eyes with retinoblastoma that had failed to respond to IAC was assembled from the pathology departments at University Col