Abstract
Purpose :
Vascular factors have been shown to be responsible in the pathogenesis of Normal Tension Glaucoma (NTG). This cross-sectional study examined the ability of vessel density (VD) to predict variance across pattern electroretinogram (PERG) parameters, average retinal nerve fiber layer thickness (avRNFLT) and average ganglion cell-inner plexiform layer thickness (avGCL + IPLT) in NTG suspects with Obstructive Sleep Apnea (OSA).
Methods :
Four pre-perimetric glaucoma subjects (7 eyes) with normal Humphrey 24-2 visual field tests, normal intraocular pressure (IOP) levels and suspicious optic nerve head were consecutively recruited at Manhattan Eye, Ear and Throat Hospital. Participants underwent Diopsys NOVA PERG and Cirrus Optical Coherence Tomography tests. Patients with documented OSA diagnosis were included. After controlling for Age (Step 1), hierarchical multiple linear regression analysis was used to determine the ability of IOP (Step 2) and VD (Step 3) to predict variance in dependent variables (Magnitude [Mag], MagnitudeD [MagD], MagnitudeD/Magnitude ratio [MagD/Mag ratio], avRNFLT and avGCL+IPLT).
Results :
In prediction of Mag and MagD, after controlling for Age, VD explained 70.1% and 72.8% of variance (B= 0.149 [95% CI: 0.037, 0.262], p=0.024) (B= 0.134 [95% CI: 0.031, 0.237], p=0.026), respectively. IOP was not significant. In the prediction of MagD/Mag ratio, Age and IOP explained 62.3% and 29.3% of variance (B= 0.003 [95% CI: 0.000, 0.006], p=0.035) (B= 0.008 [95% CI: 0.002, 0.014], p=0.020), respectively. VD was not significant.
In prediction of avRNFLT, after controlling for Age, IOP and VD explained 76.9% and 11.0% of variance (B= -2.730 [95% CI: -4.316, -1.143], p=0.009) (B= 0.652 [95% CI: 0.079, 1.225], p=0.036), respectively.
In prediction of avGCL+IPLT, after controlling for Age, IOP and VD explained 69.3% and 6.00% of variance (B= -1.466 [95% CI: -2.115, -0.816], p=0.003) (B=-0.274 [95% CI:-0.480, -0.068], p=0.024), respectively.
Conclusions :
In NTG suspects with OSA, VD was a significant predictor for Mag and MagD, demonstrating the importance of healthy microvasculature for normal retinal ganglion cell function. We report combined effects of VD and IOP on avRNFLT and avGCL+IPLT, emphasizing the need to further investigate this relationship, IOP diurnal fluctuations and IOP nocturnal elevations in OSA.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.