Risk factors for macular complications in large solitary peripheral retinal capillary haemangiomas: a multimodal imaging study.

PURPOSE To characterise the clinical and multimodal imaging features of large solitary peripheral retinal capillary haemangiomas (RCHs) and identify risk factors for distinct macular complications. METHODS In this cross-sectional study, eyes with a large (>1.5 mm) solitary peripheral RCH were included and stratified into three groups according to macular status: RCH with macular sparing (RCH-MS), with macular exudation (RCH-ME) and with macular traction (RCH-MT). Demographic, clinical and multimodal imaging data were collected and compared. Univariable and multivariable regression analyses were performed to assess risk factors. RESULTS Among 69 eyes, 16 were classified as RCH-MS, 33 as RCH-ME and 20 as RCH-MT. Compared with RCH-MS, RCH-ME and RCH-MT exhibited significantly worse visual acuity. Multivariable analysis revealed that RCH-MT was associated with greater tumour-to-foveola distance (OR 1.347, 95% CI 1.024 to 1.771) and higher prevalence of fibrovascular proliferation overlying the RCH (OR 14.371, 95% CI 1.622 to 127.301). Feeding artery dilation was significantly associated with RCH-ME (OR 17.392, 95% CI 2.121 to 142.627) and worse visual acuity (β=0.374, 95% CI 0.023 to 0.724). Feeding artery beading was inversely associated with RCH-ME (OR 0.057, 95% CI 0.006 to 0.552) and correlated with better visual outcome (β=-0.472, 95% CI -0.894 to -0.051). CONCLUSIONS The macular status of large solitary peripheral RCHs is influenced by tumour location, fibrovascular proliferation and feeding artery characteristics. These findings highlight the predictive value of multimodal imaging for macular involvement and visual outcomes and provide insights into the mechanisms underlying RCH-associated macular exudation and traction.