Minimally Invasive Iris Melanoma Resection and Cataract Surgery

Purpose To compare the outcomes of minimally invasive iris melanoma resection (MIMR) with or without combined cataract surgery (CS) in patients with circumscribed iris melanoma, with the goal of developing evidence-based guidance for surgical management. Method This retrospective, multicenter case series included 89 patients treated at Copenhagen University Hospital (Denmark, DK) and Cole Eye Institute, Cleveland Clinic (USA). Danish patients underwent combined MIMR and CS with iris diaphragm, while US patients underwent MIMR only. Outcomes included visual acuity, anterior chamber stability, induced astigmatism, cataract progression, and surgical complications. Tumour-related outcomes were tumor size, local recurrence, and development of metastasis. Statistical analyses were performed using R, with p<0.05 considered significant. Results Median age and follow-up differed between cohorts: 76 years and 13 months (range, 12–38) in the Danish cohort, compared with 58 years and 47 months (range, 1–145) in the American cohort (p<0.001). All tumors were classified as AJCC T1. Visual acuity improved significantly after combined MIMR + CS (mean change –0.15 logMAR, p = 0.005) and decreased slightly after MIMR alone (+0.06 logMAR, p = 0.004). Combined surgery induced a small but significant increase in median corneal astigmatism (–0.45 D, p<0.001), while standalone MIMR did not result in significant refractive change. Cataract progression after MIMR necessitated surgery in 16% of cases over a median follow-up of 47 months (range 1-145 months). Complications were infrequent and manageable, with no sustained hypotony or intraoperative hyphema. Stable anterior segment anatomy enabled effective iris reconstruction in both approaches. The median tumor size was 1 clock hour (range, 0.25–3.5). Tumor recurrence occurred in 3 cases (3.4%), all recurrences were T1a lesions and occurred in the MIMR only cohort. No metastatic events were observed during follow-up. Conclusions Both standalone and combined minimally invasive iris melanoma resection (MIMR) demonstrated excellent safety, with low complication rates (<5%). No metastatic events were observed, and tumor recurrence occurred in only 3.4% of cases. In the combined MIMR + cataract surgery cohort, early visual recovery was superior, whereas standalone MIMR preserved lens status and induced minimal astigmatic change. These outcomes reflect distinct patient profiles—older cataractous versus younger phakic eyes—highlighting the importance of individualized surgical planning. Given its strong local control and low systemic risk, MIMR represents a safe and effective surgical option for localized iris melanoma, with combined procedures preferred when cataract coexists or is expected to progress.