Comparison of Choroidal Thickness in Patients with Diabetes by Spectral-domain Optical Coherence Tomography

PURPOSE To evaluate choroidal thickness in diabetes patients using spectral-domain optical coherence tomography. METHODS We examined 203 eyes of 203 diabetic participants and 48 eyes of 48 healthy controls. The choroidal thickness at the foveal lesion was measured by enhanced-depth imaging optical coherence tomography. The participants were grouped according to diabetic retinopathy grade: no diabetic change, mild-to-moderate or severe non-proliferative, or proliferative diabetic retinopathy. The study parameters included history, age, axial length, intraocular pressure, central retinal thickness, fasting glucose, and blood pressure. RESULTS The subfoveal choroidal thickness was thinner in eyes with non-proliferative or proliferative diabetic retinopathy than in normal eyes (p < 0.01). However, there was no difference between eyes with non-proliferative and proliferative diabetic retinopathy or between eyes with no diabetic change and the controls. Eyes exhibiting macular edema showed no significant difference in choroidal thickness compared with eyes having normal macular contours. CONCLUSIONS The central choroid is thinner when eyes show diabetic changes on the retina. However, the presence of diabetic macular edema or proliferative change is not associated with more pronounced choroidal thinning.