Abstract
Purpose :
The association of lesions in spectral domain optical coherence tomography (SD-OCT) with the morphology of abnormal vessels in neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) is not clear. Recently, optical coherence tomography angiography (OCTA) enabled the visualization of vessels in detail. Using OCTA, we quantified the morphologic characteristics of type I neovascularization (NV) in nAMD and branched vascular network (BVN) in PCV, and analyzed the association with the anatomical features in SD-OCT.
Methods :
Patients treated with at least 3 ranibizumab or aflibercept injections were included. The anatomical characteristics analyzed by SD-OCT at baseline and after 3 injections were as follow; height and width of intraretinal fluid (IRF) and subretinal fluid (SRF), and pigment epithelial detachment (PED). Using OCTA, we obtained the images of type 1 NV and BVN, and binarized them to calculate the areas of type I NV and BVN. Then the binarized images were skeletonized to calculate total length of the vessels. In addition, mean vessel thickness was calculated by dividing the vessel area by the total vessel length. The fractal dimension was calculated to measure the complexity of the vascular network. Pearson correlation coefficient was calculated for statistical analysis.
Results :
In total 36 eyes (21 type 1 NV, 15 BVN), the increased area and length of abnormal vessel were associated with greater width of baseline PED (r=0.43, P=0.01; r=0.36, P=0.03), short height of baseline PED (r=-0.36, P=0.03; r=0.33, P=0.04) and poor response of PED height after 3 anti-VEGF treatment (r=0.35, P=0.03; r=0.33, P=0.04). High fractal dimension was associated with short height of baseline PED (r=-0.41, P=0.01) and poor response of PED height after 3 anti-VEGF treatment (r=0.45, P=0.01). The number of ranibizumab injections was more frequent when the fractal dimension was higher (r=0.35, P=0.03), while the number of aflibercept injections was more frequent when the vessel thickness higher (r=0.34, P=0.04).
Conclusions :
Using OCTA, various morphologic features of type 1 NV in nAMD and BVN in PCV could be quantified. The area, length and fractal dimension of the abnormal vessels were related to the anatomical status of PED and the number of anti-VEGF injections.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.