Pars plana vitrectomy in eyes containing a treated posterior uveal melanoma

PURPOSE: To determine the safety of pars plana vitrectomy in eyes containing a treated posterior uveal melanoma. DESIGN: Interventional case series. METHODS: Retrospective case series of patients with posterior uveal melanoma who underwent pars plana vitrectomy. Complications, vitreous cytology, local tumor control, and metastasis were assessed. RESULTS: Nine patients met study criteria. Tumors were treated with ¹²⁵I plaque radiotherapy (seven patients) or transpupillary thermotherapy (two patients). Vitrectomy was performed for vitreous hemorrhage (five patients), macular pucker (two patients), macular hole (one patient), and rhegmatogenous retinal detachment (one patient). Vitrectomy was performed at a mean of 24.7 months (range, 7-47 months) after melanoma treatment. Dispersion of tumor cells at vitrectomy was not observed in any patients. Melanoma cells were detected in the vitreous aspirate in one of seven cases examined cytologically. This patient had intratumoral and vitreous hemorrhage before plaque radiotherapy, underwent combined vitrectomy/cataract extraction, and developed intraocular tumor dissemination 56 months after vitrectomy. No other patients developed intraocular tumor dissemination. At mean follow-up of 24 months (range, 3-63 months) after vitrectomy, none of the nine patients developed systemic metastasis. CONCLUSIONS: Pars plana vitrectomy rarely may lead to intraocular tumor dissemination, although the risk of this complication is probably low if the tumor has been treated and has responded to therapy before vitrectomy. Vitrectomy should be approached with caution if a vitreous hemorrhage is present, especially if the hemorrhage occurred before tumor treatment, as this may seed tumor cells into the vitreous cavity.