Biophotonic imaging technology offers a non-invasive solution for objectively and quantitatively staging diabetic retinopathy (DR) and detecting pre-DR before structural damage occurs. Integrating this technology into clinical practice enables more accurate staging, early risk management, and prediction of treatment outcomes, ultimately reducing DR-related structural damage. The platform featured a novel physics-based retinal oximetry algorithm, built on Saccadic-Phase Spatial Frequency Domain Imaging (SP-SFDI). This technology measured an oxygen saturation analogue (αSO2) in tissue with high resolution, detecting oxygenation changes <3% using two snapshots capturing phase shifts in spatially modulated light. Its first application, BioxyDR™, focused on measuring αSO2 in the superficial retinal vasculature for accurate DR staging and early detection. For clinical validation, the study included 63 DR patients, 60 diabetes mellitus (DM) patients without DR (DM no DR), and 18 controls (no DM, no known ocular diseases). Retinal venous αSO2 significantly differed (p = 0.007) between controls and patient groups, including proliferative (PDR) and non-proliferative DR (NPDR). 100% of controls and DR patients were correctly classified per standard-of-care (SOC) criteria. Among DM no DR patients, 8 were classified as pre-DR, and 7 (87%) developed DR within 18 months. Notably, all patients classified as not pre-DR (100%) remained DR-free. Initial studies across various ocular diseases showed distinct classifications based on venous and arterial αSO2. Taken together, these findings suggest that venous αSO2 measured with SP-SFDI may serve as a biomarker for DR progression, with higher αSO2 levels indicating greater disease severity. αSO2 also shows promise as a metric for staging pre-DR.
© 2025. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.