Physical Activity Is Associated with Higher Retinal Microvascular Density in Uveal Melanoma and Nevus

Background/Objectives: The aim of the present study was to assess the influence of physical activity on retinal microvascularization in patients with uveal melanoma (UM) and nevus. In addition, vascular differences between tumor and nevus patients as well as the interaction effect of physical activity (PA) and group on retinal microvascular density (MVD) were analyzed. Methods: This cross-sectional, observational clinical study was conducted at the outpatient ophthalmic oncology department at the Center for Integrated Oncology of the University Hospital Cologne (between April 2024 and July 2025). Patients with confirmed uveal melanoma or choroidal nevus were enrolled. Physical activity and retinal MVD via optical coherence tomography angiography were assessed. In addition, regression analyses were performed. Results: A total of 42 participants were enrolled with a mean age of 56.14 (±13.48) years (nevus) and 63.45 (±13.76) years (UM). UM eyes (N = 20) demonstrated significantly reduced MVD in both the superficial and deep layer compared to Nevus (N = 22, all p < 0.001, η2 = 0.155–0.190), while UM eyes showed greater mean vessel length (B = 5.54, p = 0.009, η2 = 0.104). Physical activity was positively associated with MVD in the superficial layer, including vessel area density (B = 1.07, p = 0.022, η2 = 0.133) and vessel length density (B = 0.28, p = 0.028, η2 = 0.119), independent of group. No significant associations were found in the deep layer and no interaction effects between group and PA were detected. Conclusions: Our findings suggest that habitual PA is positively associated with retinal MVD in the superficial layer, independent of diagnostic group, and may partially counteract tumor-induced as well as treatment-related microvascular disruption. As a low-risk and accessible intervention, PA holds promise as a supportive strategy in the oncological management of UM.