Volume : 1
Issue : 1
Online ISSN : 2395-1451
Print ISSN : 2395-1443
Article First Page : 29
Article End Page : 34
Objective: To provide a descriptive analysis of spectral domain optical coherence tomography (SD-OCT) based morphologic patterns of diabetic macular edema (DME) and to study the association of alteration in macular thickness parameters with severity of diabetic retinopathy.
Method: Twenty consecutive cases each of diabetes mellitus without retinopathy, non-proliferative diabetic retinopathy, proliferative diabetic retinopathy (based on ETDRS classification) and 20 healthy controls were recruited. Best corrected visual acuity (BCVA) was assessed using logMAR scale. All the study subjects were subjected to SD-OCT imaging using macular cube 512x128 protocol. Central subfield thickness (CST) (μm) and cube average thickness (CAT) (μm) were documented. Cases with CAT more than 250 μm were sub classified based on morphology. Statistical analysis was done. Results: Significant increase in CST and CAT and decrease in BCVA was found between the study groups (p < 0.001, p < 0.001, p<0.0001, respectively).Significant negative correlation of BCVA was found with CST (r=0.4, p<0.05) and CAT (r=0.2, p<0.001).Forty cases with CAT above 250 μm were further classified: diffuse retinal thickening (n=60%, 24/40); cystoid macular edema (n=25%, 10/40); serous retinal detachment (n=15%, 6/40).
Conclusion: Significant increase in CST and CAT on SD-OCT is associated with increase in severity of diabetic retinopathy and decrease in BCVA. Cube average thickness provides a global perspective of defining DME within the macular cube.
Keywords: diabetic retinopathy; spectral domain optical coherence tomography; central subfield thickness; cube average thickness; macular edema, serous retinal detachment.