Purpose: To evaluate Optical coherence tomographic (OCT) biomarkers in participants diagnosed with diabetes, diabetic retinopathy (DR) and diabetic macular edema (DME) and co relation with disease severity.
Methods: Demographics, visual acuity, SD-OCT, and colour fundus photographs of 110 individuals with diabetes, DR and DME (200 eyes) evaluated between December 2020 and October 2022 were analysed to evaluate disease severity corelation. Features captured on SD-OCT and thickness metrics. On SD-OCT we analysed the OCT scans (Macular cube 6 mm x 6 mm) for central subfield thickness and biomarkers: disorganization of the inner retinal layers (DRIL), presence of hyperreflective dots and foci and their location, intraretinal cystoid abnormalities and shape and presence of septae within the, integrity of the external limiting membrane and ellipsoid zone.
Results: 101 patients (200 eyes) were evaluated; 66 eyes had (33%) moderate NPDR, followed by 38 eyes (19%) with mild NPDR, 29 eyes (15%) with severe NPDR, 14 eyes (7%) very severe NPDR. Biomarkers like DRIL, Hyperreflective foci, ELM and EZ disruption (p = 0.001) and intraretinal cystoid spaces (p = 0.003) correlated positively with disease severity and negatively with VA.
Conclusion: SD-OCT imaging biomarkers can be utilised as an efficient tool in understanding the disease severity and inter individual differences in visual acuity when there is no difference in ETDRS-based grading of DR that is evident clinically.