Relationship between diabetic macular edema and choroidal layer thickness

PurposeTo investigate the relationship between diabetic macular edema (DME) and the choroidal layer thickness in diabetic patients.MethodsThis is a retrospective observation study. Three hundred eighteen eyes of 159 diabetes mellitus (DM) patients and age-matched 100 eyes of 79 healthy controls were enrolled. DME was defined as over 300 μm in the central retinal subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid sector. The central choroidal thickness (CCT), as well as inner and outer layers were determined based on enhanced depth imaging (EDI)–OCT. Diabetic patients with/without systemic diabetic treatments (DT) at the start of this study was defined as DT+ and DT–, respectively. The number of eyes examined was 62 and 256 eyes in DME+and DME–groups, respectively. DM patients were further subdivided into 4 groups with/without DME and DT; DME+DT+(35 eyes), DME–DT+(159 eyes), DME+DT–(27 eyes), and DME–DT–group (97 eyes). Multiple comparisons on CCT layers including control and each DM group were statistically examined.ResultsThe total CCT layer was 254±83, 283±88, and 251±70 μm in the control, DME+, and DME–group, respectively. A total CCT layer in DME+was significantly thicker than the DME–group (P P P ConclusionsThe total and outer CCT layers of diabetic eyes were significantly thickened in the DME+DT–as compared with the DME–DT+group, suggesting that CCT may be related to the pathology of DME.