Abstract
Purpose :
To evaluate choroidal vascularity index (CVI) and choroidal thickness (CT) in subjects with non neovascular age related macular degeneration (NNVAMD) and reticular pseudodrusen (RPD) compared with healthy individuals
Methods :
In this IRB approved prospective case control study, we included 70 eyes of 39 subjects with NNVAMD (including 31 eyes of 17 subjects with RPD) and 32 eyes of 17 healthy individuals. Choroidal imaging was performed in all subjects using spectral domain optical coherence tomography (SDOCT; Spectralis, Heidelberg Engineering Inc., Germany) using a macular volume protocol (20x20 degree; 6mm B-scans, 512 A-scans x 97-B-scans, 9x averaging). The inner and outer borders of the choroid in each B-scan of the macular volume were manually segmented using previously-described 3D-OCTOR software in order to compute mean CT (in microns). The luminal and stromal portions of the choroid were then auto-segmented using binarization (dark pixels considered to be vessels, bright pixels considered as stroma) of OCT B-scans and segmentation of binarized choroid layer were achieved using a previously reported validated automated software. CVI (%) was calculated as ratio of luminal area to total choroidal area within the central B-scan. Mean values for these choroidal parameters were compared between eyes with NNVAMD without RPD, NNVAMD with RPD, and healthy individuals using the student t-test.
Results :
The CVI in NNVAMD with RPD eyes was significantly higher compared to healthy individuals (49.95 ± 4.80 vs. 47.32 ± 4.73, p = 0.01). Choroidal thickness was significantly lower in NNVAMD with RPD eyes than in healthy individuals (138.79 ± 49.79 vs. 189.21 ± 37.24, p <0.001). CVI was also significantly higher in subjects with NNVAMD with RPD when compared to NNVAMD without RPD (p = 0.03). In contrast, CVI (p = 0.84) and CT (p = 0.84) were not significantly different in NNVAMD eyes (CVI = 47.57 ± 5.70, CT = 191.15 ± 27.41) compared to healthy individuals.
Conclusions :
NNVAMD eyes with RPD had a higher choroidal vascularity index and thinner choroid than eyes with NNVAMD eyes without RPD and healthy individual eyes. Choroidal vascularity index may be a parameter warranting further study in eyes with NNVAMD, RPD, and related disorders.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.