Baerveldt shunts in the treatment of glaucoma secondary to anterior uveal melanoma and proton beam radiotherapy.

INTRODUCTION: Melanoma of the iris and ciliary body may be associated with secondary glaucoma. Treatment with proton beam radiotherapy (PBRT) to the anterior segment can also elevate intraocular pressure (IOP), resulting in uncontrolled glaucoma, often requiring enucleation. This is the first prospective study of Baerveldt aqueous shunts in irradiated eyes with anterior uveal melanoma (AUM; affecting the iris or ciliary body).

METHODS: Thirty-one eyes with uncontrolled IOP following anterior segment PBRT treatment for AUM were prospectively recruited to undergo Baerveldt shunt implantation. Postoperative examinations were performed on day 1; weeks 1, 3, 6, 9; months 3, 6, 9, 12 and annually thereafter. Surgical success was defined as IOP 21 mm Hg or less and 20% reduction from baseline. All complications were recorded.

RESULTS: Mean follow-up was 15.7 months (SD ± 8.3 months). Mean interval from irradiation to shunt implantation was 2.5 years. Mean preoperative IOP was 31.0 (± 10.3) mm Hg; mean IOP at last visit was 15.0 (± 5.0) mm Hg; mean pre-operative glaucoma medications were 3.3 (± 1.3); postoperatively 0.7 (± 1.3) glaucoma medications. Surgical success rate was 86% using glaucoma medications. Four eyes had minor postoperative complications, none of which were sight threatening. There were no local tumour recurrences or systemic metastases. There were no enucleations caused by ocular hypertension.

CONCLUSIONS: Baerveldt shunts were effective in lowering IOP, with few complications, in eyes treated with total anterior segment irradiation for AUM.