Unilateral Glaucoma as a Clinical Indicator of Iris and Ciliary Body Melanoma

Background Iris and ciliary body melanomas are rare but potentially life-threatening tumors that are difficult to distinguish from benign nevi. Earlier diagnosis improves outcomes, but reliable clinical indicators are limited. Glaucoma has been observed in conjunction with iris or ciliary body melanoma, but its prevalence and clinical significance at a population level is not well established. Objective To determine the prevalence of glaucoma in iris and ciliary body melanoma compared with nevus and to assess whether unilateral glaucoma may serve as a diagnostic indicator of melanoma. Methods This retrospective cohort study used the IBM MarketScan Research Database, which contains de-identified longitudinal healthcare claims data from commercially insured patients in the United States. Patients with iris or ciliary body melanoma or nevus were identified by International Classification of Diseases, Tenth Revision (ICD-10) diagnostic codes. Outcomes included the prevalence of glaucoma prior to treatment in melanoma versus nevus, age-stratified prevalence of glaucoma, and rates of glaucoma surgery. Odds ratios (ORs) with 95% CIs were calculated to compare groups. Results A total of 17,978 patients were included (112 with melanoma, 17,866 with nevus). Glaucoma prevalence prior to treatment was significantly higher in the melanoma cohort than nevus cohort (11.6% vs 1.3%; OR, 10.1; 95% CI, 5.1-18.4; P < 0.001). This pattern persisted across all age groups, with the greatest relative difference observed in patients aged 20-39 years (10.9% vs 0.7%; OR, 14.2; 95% CI, 1.5-63.0; P = 0.01). Among patients with glaucoma, surgery was required more frequently in the melanoma cohort (18.9%) than nevus cohort (15.0%). Conclusion Unilateral glaucoma is significantly more common in eyes with iris and ciliary body melanoma than in those with iris and ciliary body nevus in this claims-based cohort, and melanoma patients are more likely to require surgical management. Unilateral glaucoma may serve as an important early clinical indicator of melanoma, although further clinical correlation is necessary. Incorporating glaucoma status into diagnostic criteria could improve recognition, prompt referral and biopsy, and reduce delays in treatment.