Assessment of Choroidal Neovascularization Perfusion: A Pilot Study With Laser Speckle Flowgraphy

Abstract

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. Translational Relevance: LSFG technology to quantify perfusion could provide useful biomarkers for therapeutic management of CNV.

Measuring optic nerve head perfusion to monitor glaucoma: a study on structure–function relationships using laser speckle flowgraphy

“…The devices are equipped with an eyetracking system and with targets for internal and external fixation, so as to improve the acquisition in eyes with poor fixation. The technique showed high reproducibility in previous clinical studies (Aizawa et al 2011;Shiga et al 2014;Luft et al 2016;Calzetti et al 2018;Calzetti et al 2020b). All participants were asked to abstain from coffee, tea and alcohol intake within six hours of LSFG examination, as these substances are known to potentially affect MBR (Okuno et al 2000).…”

“…2018; Calzetti et al. 2020b). All participants were asked to abstain from coffee, tea and alcohol intake within six hours of LSFG examination, as these substances are known to potentially affect MBR (Okuno et al.…”

Reduced blood flow by laser speckle flowgraphy after 125I-plaque brachytherapy for uveal melanoma

“…One limitation of our study is that the anti-VEGF agents frequently given after 125 I-plaque brachytherapy [ 32 – 34 ] decrease retinal blood flow. In fact, several recent studies have deployed LSFG and reported reduced retinal perfusion, but which resolved by 2 months after injection [ 29 , 35 , 36 ]. Of note, in our cohort, only 1 patient was treated with bevacizumab less than 2 months before imaging.…”

Short-term changes in retinal and choroidal relative flow volume after anti-VEGF treatment for neovascular age-related macular degeneration

“…This could be useful to determine whether the changes seen are related to the therapy or to random measurement errors. Third, we did not evaluate the correlations with visual function or other relevant biomarkers, such as those provided by OCT-A, and did not measure MBR of the neovascular area, which was proposed as a potential biomarker of MNV perfusion 37 . Lastly, it is known that intravitreal injections have a direct effect on intraocular pressure (IOP), which could interfere with retinal or choroidal blood flow.…”