Fig. 2.

Representative scans with CT measurements on Cirrus HD-OCT high-definition 1-line raster scans. Perpendicular lines were drawn from posterior edge of RPE to choroid/sclera junction using Cirrus HD-OCT software. Choroidal thickness was measured in the fovea and at 500-μm intervals nasal and temporal to the fovea with the measurements expressed as micrometers (red lines). Note that the choroid is thickest at center, thinner temporally, and thinnest nasally. A. Representative scan from a normal subject; (B) representative scan from a patient with mild non-proliferative diabetic retinopathy; (C) representative scan from a patient with moderate nonproliferative diabetic retinopathy and diabetic macular edema; (D) representative scan from a patient with treated proliferative diabetic retinopathy, note that there is a disruption in the photoreceptor inner/outer segment junction probably because of the retinal ischemia.