Abstract
Purpose:
The pathogenesis and clinical features of diabetic retinopathy (DR) are primarily attributed to retinal vascular damage; however, evidence suggests that choroidal angiopathy may co-exist. Recent studies reveal a reduction in choroidal thickness in eyes with DR, when compared to age-matched healthy eyes. This study aimed to analyze the morphology and the vascular layers of the choroid in eyes with DR, using spectral-domain optical coherence tomography (SD-OCT).
Methods:
A cross sectional retrospective review identified 33 patients with DR (33 eyes) and 24 age-matched healthy subjects (24 eyes), who underwent high-definition 1-line raster scanning with Cirrus HD-OCT at New England Eye Center, Boston between February 2010 and June 2012. Patients were classified clinically into 3 groups; non-proliferative DR without macular edema (NPDR group, 9 eyes), proliferative DR (PDR group, 10 eyes) and diabetic macular edema (DME group, 14 eyes). Two independent raters experienced in analyzing OCT images, evaluated the choroid for morphological changes and performed analysis of its vascular layers.
Results:
The choroid-scleral interface had an irregular contour in 8 of 9 (89%) eyes with NPDR, 9 of 10 (90%) eyes with PDR and 13 of 14 (93%) eyes with DME, when compared to 0 of 33 (0.0%) healthy eyes. The thickest point of choroid was displaced from under the fovea, and focal choroidal thinning was observed in eyes with DR. Mean sub-foveal choroidal thickness and mean sub-foveal medium choroidal vessel layer/choriocapillaris layer thickness were significantly reduced in eyes with PDR (p<0.05) and DME (p<0.05), when compared to healthy eyes.
Conclusions:
Choroidal morphology is altered in eyes affected with moderate to severe DR. Sub-foveal choroidal thickness and sub-foveal medium choroidal vessel layer/choriocapillaris layer thickness is significantly reduced in eyes with PDR and DME. This is the first study, describing morphological features of the choroid and analysis of its vascular layers in eyes with DR, using SD-OCT. Further studies involving prospective correlation of increasing severity of DR with the morphological alteration and changes in the vascular layers of the choroid, may provide a better insight into the choroidal angiopathy associated with DR, and its effect on disease progression.
Keywords: 499 diabetic retinopathy •
550 imaging/image analysis: clinical