Abstract
Purpose :
Loss of peripapillary vessel density (VD) has been demonstrated in glaucoma suspects (GS). Our study aimed to determine if reduced VD around the optic nerve head (ONH) was associated with steady-state pattern electroretinogram (ssPERG) parameters, and retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCL-IPL) thicknesses.
Methods :
31 GS (20 eyes) were enrolled in a study at the Manhattan Eye, Ear, and Throat hospital based on normal Humphrey 24-2 visual field tests, suspicious ONHs, and refractive errors < ±5.0 Diopters. Patients underwent ophthalmologic examination, optical coherence tomography (SPECTRALIS OCT), OCT-angiography (CIRRUS Angioplex), and ssPERG (Diopsys NOVA PERG). Retinal VD was measured in three separate areas centered on the ONH using ImageJ vessel analysis plugin. Whole image VD (wiVD) was the full 3x3mm image. Papillary VD (pVD) was a 3mm diameter circular boundary. Circumpapillary VD (cpVD) was a 500μm-wide annulus formed from the area between a 1.5mm and a 2.5mm diameter circle. The optic disc was excluded in cpVD. ImageJ threshold analysis was used to measure the VD of only the large retinal vessels, which were subsequently subtracted from the original wiVD, pVD, and cpVD measurements. Partial correlation and linear regression analyses were conducted.
Results :
After controlling for intraocular pressure (IOP), wiVD (r=0.7, p=0.002), pVD (r=0.732, p<0.001), and cpVD (r=0.633, p=0.006) were positively correlated with MagD/Mag ratio. There were no significant associations with MagD and Mag, nor with RNFL and GCL-IPL thickness. With MagD/Mag ratio as the dependent variable, each VD was entered as a separate independent variable in a linear regression model controlling for IOP and age. WiVD predicted 18.0% variance (F(1,14)= 7.09, B= 0.487, 95%CI: 0.004- 0.042, p= 0.019), pVD predicted 21.2% variance (F(1,14)= 9.16, B= 0.526, 95%CI: 0.007- 0.043, p= 0.009), and cpVD predicted 14.5% variance (F(1,15)=5.535, B= 0.389, 95%CI: 0.002-0.032, p= 0.033).
Conclusions :
This is the first study of the relationship between three measurements of peripapillary VD with RGC dysfunction in GS. All three VD measurements were significantly associated with MagD/Mag ratio, but not with RNFL nor GCL-IPL thickness. These results suggest that in GS, microvascular damage is first reflected in MagD/Mag ratio, prior to affecting MagD, Mag, or measurements of retinal thickness.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.