Background  

To compare visual outcome and ocular complications of transscleral local resection (TSR) with those of iodine-125 plaque brachytherapy (IBT) for uveal melanomas categorised as large because of tumour height.

Methods  

Retrospective study of 87 patients with a uveal melanoma ≤16 mm by largest basal diameter (median, 12.6 vs 14.0 mm for TSR and IBT, respectively) and large by height (median, 11.0 vs 10.6 mm) by the Collaborative Ocular Melanoma Study (COMS) criteria. Thirty-three patients underwent TSR in the United Kingdom and 54 underwent IBT in Finland. Loss of 20/65 and 20/400 vision, local tumour recurrence, cataract, iris neovascularization, glaucoma, maculopathy, optic neuropathy, persistent retinal detachment, and vitreous haemorrhage were analysed using competing risks and logistic regression to control for confounders.

Results  

All patients save one managed with TSR lost 20/70 vision within 3 years. The 2-year cumulative incidence of losing 20/400 vision was 60% (95% CI, 35–75) for TSR and 75% (95% CI, 59–86) for IBT. The 5-year incidence of local tumour recurrence was 41% (95% CI, 17–63) after TSR and 7% (95% CI, 2–17) after IBT. Glaucoma and optic neuropathy were rare after TSR. Cataract, maculopathy, retinal detachment, and vitreous haemorrhage were common after either treatment. The number of patients needed to treat with TSR instead of IBT was four for one additional patient to benefit by avoiding loss of visual acuity 20/400 for at least 2 years, and the corresponding number was three for one additional patient to experience a local recurrence from TSR.

Conclusions  

If TSR is further evaluated as an alternative to IBT in avoiding blindness of an eye with a ciliochoroidal melanoma categorised as large by COMS criteria because of its height, special emphasis must be given to increased risk of local tumour recurrence.