Anterior Segment Seeding in Eyes With Retinoblastoma Failing to Respond to Intraophthalmic Artery Chemotherapy.

IMPORTANCE Anterior chamber seeding following intraophthalmic artery chemotherapy is rarely reported. OBJECTIVES To describe clinicopathologic observations in eyes in which intraophthalmic artery chemotherapy for retinoblastoma failed and to report anterior chamber involvement. OBSERVATIONS A retrospective case series of 12 enucleated eyes (11 patients) with retinoblastoma refractory to intraophthalmic artery chemotherapy between March 1, 2010, and October 31, 2013, at University College London Institute of Ophthalmology and the Retinoblastoma Service, Royal London Hospital. Data analysis was conducted from June 1, 2014, to March 1, 2015. The International Classification of Retinoblastoma groups were B in 1 eye (8%), C in 4 eyes (33%), and D in 7 eyes (58%). Systemic chemotherapy with vincristine sulfate, etoposide, and carboplatin had failed in 10 patients (91%) and 6 eyes (50%) received additional local treatments. In 6 eyes (50%) anterior chamber invasion was clinically detectable. On histopathologic examination, 4 eyes (33%) had no viable retinal tumor; the remainder had poorly differentiated tumor (6 eyes [50%]) or moderately differentiated tumor (2 eyes [17%]). Anterior segment involvement occurred in the ciliary body and/or ciliary muscle (7 eyes [58%]), iris (6 eyes [50%]), and cornea (4 eyes [33%]). CONCLUSIONS AND RELEVANCE Intraophthalmic artery chemotherapy can fail in eyes with retinoblastoma. In contrast to previous reports on outcomes following intraophthalmic artery chemotherapy, our series shows involvement of the anterior segment of the eye, including the ciliary body, iris, and cornea. Careful case selection and follow-up are advised.