Assessment of choroidal neovascularization perfusion : a pilot study with laser speckle flowgraphy

Abstract

Purpose: The purpose of this study was to quantify perfusion in the area of choroidal neovascularization (CNV) using laser speckle flowgraphy (LSFG) before and after intravitreal anti-vascular endothelial growth factor (VEGF) injection. Methods: Retrospective case series. Fifteen eyes of 15 patients with treatment-naïve CNV due to age-related macular degeneration (AMD) and with available LSFG images were included. The main outcome was the mean blur rate (MBR) quantified as a measure of perfusion within the CNV area observed on indocyanine green angiography. Twelve patients had available longitudinal data until one month after the injection, used to evaluate changes in perfusion, central macular thickness (CMT), visual acuity, and ocular perfusion pressure. Reproducibility of LSFG measurements was investigated at each time point from two images taken within five minutes. Results: Intraclass correlation coefficients for LSFG measurements were higher than 0.8 indicating excellent reproducibility. There was a significant decrease in perfusion after one week (-26.4±14.4%;P=0.027), whereas, after one month, perfusion was no longer significantly different from baseline (P=0.121). CMT showed a progressive decrease over the follow-up period. Changes in perfusion were strongly correlated with changes in CMT after one week, but not thereafter. Conclusions: This pilot study suggests a method to select a region in the CNV area to quantify perfusion using LSFG. MBR could represent a parameter possibly related to regrowth of the CNV after anti-VEGF treatment. Large-scale studies are needed to assess the usefulness of LSFG in defining re-treatment criteria for neovascular AMD.