Abstract
Purpose :
Decrease in retinal vessel diameters (VD) has been well established in glaucoma, but no such relationships were reported in glaucoma suspects (GS) yet. This study hypothesized that decreased VD had a significant relationship with changes in steady-state pattern electroretinography (ss-PERG) and in the ganglion cell layer - inner plexiform layer (GCL-IPL) in GS.
Methods :
Thirty-one eyes (20 patients) were enrolled in the study at Manhattan Eye Ear and Throat Hospital, based on normal Humphrey 24-2 visual field test, suspicious optic nerve head, and glaucoma stage 0. Each subject underwent full ophthalmologic examination, optical coherence tomography (OCT), OCT-angiography (OCTA), and ss-PERG. The OCTA images were analyzed in ImageJ. A linear regression analysis was used.
Results :
In the linear regression model controlling for age, race, spherical equivalent (SE), and central corneal thickness (CCT), VD explained a 4.7% variance in Magnitude (Mag) (p = 0.169), 9.2% variance in MagnitudeD (MagD) (p = 0.021), and 16.9% variance in MagD/Mag ratio (p = 0.009).
After controlling for age, signal strength, and CCT, the linear regression model with GCL-IPL as the dependent variable found VD significantly associated with the average GCL-IPL (AvGCL-IPL) (p = 0.006), minimum GCL-IPL (MinGCL-IPL) (p = 0.002), superior sector (S) (p = 0.007), superonasal sector (SN) (p = 0.014), inferior sector (p = 0.023), and inferonasal (IN) sector (p = 0.014). In an identical linear regression model, Mag was significantly associated with S (p = 0.005), SN (p = 0.047), superotemporal (ST) sector (p = 0.01), and IN sector (p = 0.02). MagD had a significant relationship with AvGCL-IPL (p = 0.015), MinGCL-IPL (p = 0.006), superior sector (p = 0.003), ST (p = 0.009), and IN (p = 0.05). MagD/Mag ratio was significantly associated with the AvGCL-IPL (p=0.003), MinGCL-IPL (p < 0.001), and S (p = 0.046).
Conclusions :
Retinal VD reductions were significantly associated with a decrease in MagD and MagD/Mag ratio as well as with specific GCL-IPL parameters in GS. These findings add evidence to the vascular theory of glaucoma indicating the possible presence of a breakdown of neurovascular coupling in GS, where high demands of retinal ganglion cells in energy are not met by adequate blood supply.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.