Promoting Equitable Access to Glaucoma Screening Using Open-Source Multimodal Imaging Tools

Glaucoma is one of the leading causes of permanent blindness around the world, and it often progresses silently until patients experience serious loss of vision. Detecting the disease at an early stage is crucial for preserving sight, yet standard methods such as measuring intraocular pressure or performing visual field tests frequently fall short in sensitivity and reliability. In this study, we introduce a multimodal imaging strategy that brings together Optos ultra-widefield retinal imaging and optical coherence tomography to improve the identification of early glaucomatous changes. The analysis was conducted entirely with freely available open-source software, specifically IC Measure and ImageJ, showing that accurate measurements of both structural and vascular features can be obtained without the need for expensive proprietary systems. We extracted quantitative parameters from the optic nerve head and peripapillary regions, including cup to disc ratio, peripapillary atrophy, retinal nerve fiber layer thickness and texture, and peripapillary vessel density. When comparing normal, moderate, and severe glaucoma eyes, we observed consistent trends such as larger optic nerve cups, thinning of the retinal nerve fiber layer, and decreased vessel density, all strongly linked to disease severity. These results suggest that combining structural and vascular biomarkers from multimodal imaging can enable earlier and more accessible glaucoma diagnosis, supporting cost-effective screening programs in both advanced and resource-limited healthcare environments.