Purpose
Two angiographic subtypes of occult choroidal neovascularization (CNV), fibrovascular pigment epithelial detachment (FVPED) and late leakage of undetermined source (LLUS), have been well-described. The purpose of this study is to define and compare the optical coherence tomographic (OCT) correlates of these angiographic subtypes.
Methods
We retrospectively analyzed 17 consecutive patients with previously untreated occult with no classic choroidal neovascularization who had both fluorescein angiography (FA) and volume spectral domain (SD) OCT images obtained on the same visit. Planimetric grading was performed on the FA images by certified reading center CNV graders to precisely outline boundaries of the FVPED and/or LLUS lesion for each cases. SDOCT images were graded in a masked fashion and inner retinal pigment epithelial (RPE) and inner choroidal boundaries were manually segmented on all B-scans in order to generate a PED thickness map. FA images were registered with the OCT fundus image and PED thickness was correlated with the angiographic lesion present at each location in the fundus.
Results
Point-by-point comparison revealed that PED thickness was significantly different in areas of FVPED versus LLUS. Whereas the mean PED thickness in areas of FVPED was 65.78 ± 46.87 µ , it was only 13.13 ± 9.17 µ in areas on LLUS (p < 0.001). Aside from differences in PED thickness, there were no apparent morphologic differences on OCT between areas of LLUS and FVPED, including internal reflectivity and RPE integrity.
Conclusions
Although they appear to be distinct angiographic subtypes, LLUS and FVPED appear to differ only based on the thickness or height of the RPE elevation, with areas of LLUS representing much shallower elevations of the RPE.
Keywords: 412 age-related macular degeneration •
453 choroid: neovascularization