Abstract
Purpose :
Previous studies have demonstrated that macular vessel density (mVD), circumpapillary optic nerve head vessel density (cp ONH VD), and foveolar avascular zone (FAZ) by means of optical coherence tomography – angiography (OCT-A) are risk factors for glaucoma. The goal of this study was to ascertain whether there was relationship between these vascular predictors and PERG uncoupled parameters in glaucoma suspects (GS).
Methods :
14GS subjects (20 eyes) were enrolled in a prospective research study at the Manhattan Eye, Ear, and Throat Hospital (MEETH) in New York City as part of a longitudinal glaucoma study. All three vascular predictors (mVD, cp ONH VD, and FAZ) were measured on an OCT-A 3x3 scan using ImageJ software and major vessels were subtracted from the VD measurements. Using a linear regression model, we assessed the relationship between magnitude (Mag), magnitudeD (MagD), and MagD/Mag ratio. For this model in step 1, age and spherical equivalence were entered as covariates, mVD was entered in step 2, cp ONH VD in step 3, and FAZ was entered in step 4.
Results :
Linear regression analysis revealed that FAZ explained 14.9% of the variance in Mag (F(1,8)=6.194, B=-1.612, 95% CI: -3.106,-0.118, p=0.038) and 10.4% of the variance in MagD (F(1,8)=7.668, B=-1.522, 95% CI: -2.789, -0.254, p=0.024). Also, the analysis revealed that mVD explained 36.2% of the variance in the ratio (F(1,10)=23.855, B = 0.021, 95% Cl: 0.012, 0.031, p < 0.001) and cp ONH VD explained 6.2% of the variance in the ratio (F(1,9)= 6.245, B = 0.010, 95% Cl: 0.001. 0.019, p=0.034).
Conclusions :
To the best of our knowledge, this is the first report describing the relationship between uncoupled PERG parameters and microvascular risk factors for glaucoma in GS subjects. We report that FAZ is a significant predictor for Mag and MagD variance, whereas mVD and cp ONH VD significantly predict variance in the ratio. We hypothesize that the macular microvascular structural damage (FAZ) affects Mag and MagD more significantly, while the functional change in the posterior pole and macular region areas (assessed by VDs) is mostly affected by transient and reversible endothelial dysfunction driven by the imbalance of nitric oxide and endothelin-1. Further studies are needed to clarify these relationships.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.