Primary orbital polymethylmethacrylate implant following primary enucleation for retinoblastoma: a study of 321 cases.

: To evaluate the outcome of primary orbital polymethylmethacrylate (PMMA) implant following the primary enucleation for retinoblastoma. : Retrospective study of 321 retinoblastoma patients who underwent unilateral enucleation and PMMA implant for retinoblastoma by myoconjunctival technique. Outcome measures included implant centration and extrusion. : The mean age at the time of enucleation of patients with retinoblastoma was 35 months (median, 30 months; range, <1 to 449 months). After primary enucleation, primary orbital PMMA implant was used in all cases. The mean diameter of implant was 18 mm (median, 18 mm; range, 12-20 mm) and the mean horizontal diameter of the socket conformer was 24 mm (median, 24 mm; range, 18 mm-26 mm). Post-enucleation and implant, seven (2%) patients underwent orbital external beam radiotherapy owing to microscopic extrascleral tumor extension or tumor infiltration of optic nerve transection. Over a mean follow-up period of 40 months (median, 34 months; range, 4-129 months), implant migration was noted in 28 (9%) patients, implant extrusion in 9 (3%), and implant exposure in 5 (2%), and contracted socket in 5 (2%) patients including grade 1 contraction in 3 (1%), grade 2 in 1 (<1%), and grade 4 in 1 (<1%) patient. Implant exchange for an improved prosthesis fit was performed in 4 (1%) cases. Stable customized ocular prosthesis was achieved in all but one patient. : Primary orbital PMMA implant following primary enucleation for retinoblastoma is associated with minimal complications and provides acceptable cosmetic outcomes.