Purpose: To study the oxygen-saturation profiles in RP and macular dystrophies and compare them with age-matched healthy controls.
Methods: In a cross-sectional prospective study, 62 subjects with RP, 23 with macular dystrophies, and 78 controls were enrolled, and retinal oximetry was performed with the Oxymap T1 retinal oximeter. The images were analyzed for oxygen saturation and diameter of retinal vessels.
Results: All parameters showed a significant difference among the three groups. Patients with RP showed significantly lower diameters (98.4 μm and 136.9 μm arteriolar and venous) (P < 0.001), higher saturations (102.3% and 59.1%) (P < 0.001; 0.06), and higher arterio-venous saturation difference (AVSD) (43%) (P < 0.001) compared with the other two groups. Macular dystrophies showed higher global arteriolar values (96.7%) and AVSD (41.6%) but comparable venous values (54.9%) to the control group (90.6%, 57.4%, and 33.3%).
Conclusions: Oximetry is sensitive in quantifying hemodynamic changes in retinal dystrophies. It is still unclear whether these hemodynamic changes are a cause or a result of the disease process.