The following is a summary of “Evaluation of macular retinal oximetry across different levels of diabetic retinopathy: a cross sectional study,” published in the January 2025 issue of Ophthalmology by Smith et al. 

Researchers conducted a retrospective study to evaluate retinal oxygen saturation and vessel density in the macula of controls and subjects with type 2 diabetes (DM), both with (DMR) and without (DMnR) retinopathy, and to assess regional changes in retinal oxygen saturation.  

They analyzed data from 70 subjects (28 controls, 26 DMnR, and 16 DMR, with 8 having mild/moderate Nonproliferative diabetic retinopathy (NPDR) and 8 with severe NPDR/ Proliferative diabetic retinopathy (PDR)). Participants were categorized based on glycosylated hemoglobin A1c and fundus photography. Retinal oximetry was performed within a 300–400 μm region at 4 diagonal locations (superior nasal, superior temporal, inferior nasal, inferior temporal) 3.1 degrees from the fovea center, adjacent to the Foveal avascular zone (FAZ). Optical coherence tomography angiography (OCTA) was done and corrected for refractive error. Photoshop and ImageJ were used to measure superficial capillary plexus vascular density (SCP). Oximetry and OCTA vessel density were analyzed both overall and regionally.  

The results showed the average retinal oxygen saturation was highest in DMR (P = 0.008). The average OCTA density was lower in DMR than in the controls (P = 0.01) but not when compared to the DMnR subjects (P = 0.07). A significant negative correlation was found between average oxygen saturation and SCP vascular density for all subjects (P = 0.02). Longer duration of DM was positively linked with oxygen saturation (P = 0.01) and negatively with OCTA SCP vascular density (P = 0.009). The retinal location had no differential impact.  

Investigators concluded that the first investigation of the association between macular oxygen saturation and SCP vascular density across varying stages of diabetic retinopathy, potentially providing a novel approach for monitoring disease progression in patients with DM. 

Source: bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-025-03850-1