Imaging Evidence of Diabetic Choroidopathy In Vivo: Angiographic Pathoanatomy and Choroidal-Enhanced Depth Imaging

PURPOSE: To describe the pathoanatomy of diabetic choroidopathy (DC) in pre-diagnosed diabetic retinopathy (DR) cases and to provide angiographic and optical evidence for DC using indocyanine green angiography (ICGA) and enhanced depth imaging spectral-domain optical coherence tomography (EDI SD-OCT). METHODS: A retrospective analysis of 80 eyes from 40 DR patients was conducted. In Group One, choroidal vascular abnormalities were evaluated by comparing angiographic findings from simultaneous ICGA with those from fundus fluorescein angiography (FFA). In Group Two, EDI SD-OCT was used to evaluate the subfoveal choroidal thickness (SFCT) and define the choroid boundary in order to acquire the bilateral and symmetric choroidal area (CA). Data were then analyzed by Image Pro Plus 6.0. RESULTS: In Group One, choroidal abnormalities that were evident using ICGA but not FFA included early hypofluorescent spots in 47 eyes (75.81%), late hyperfluorescent spots in 37 eyes (59.68%), and late choroidal non-perfusion regions in 32 eyes (51.61%). In particular, a significant difference between proliferative DR (PDR) in 17 of 23 eyes (73.91%) and non-PDR in 16 of 39 eyes (41.03%) was observed in late choroidal non-perfusion regions. Eighteen of 31 eyes (58.06%) also exhibited “inverted inflow phenomena.” In Group Two, both the SFCT and CA of eyes with diabetic macular edema and serous macular detachment were significantly greater than those in the other eyes. The CA in panretinal photocoagulation (PRP) treated cases was also greater than that in non-PRP treated cases. CONCLUSIONS: Early hypofluorescent spots, late choroidal non-perfusion regions, inverted inflow phenomena, higher SFCT, and larger CA are qualitative and quantitative indexes for DC. Moreover, the late choroidal non-perfusion region is a risk factor for DC with DR. Our study suggests that the supplemental use of ICGA and EDI SD-OCT with FFA is a better choice for DR patients.