Retinal Vessel Diameter Reductions in Pre-perimetric Glaucoma correlate with Pattern Electroretinogram and Foveal Avascular Zone Area Parameters

Abstract

Purpose : Recent literature suggests that average retinal vessel diameter is decreased in patients with open-angle glaucoma. We performed a prospective, observational cross-sectional study to determine whether changes in retinal vessel diameters were associated with steady state pattern electroretinogram (ssPERG) and Foveal Avascular Zone (FAZ) area parameters in patients with pre-perimetric glaucoma (PPG).

Methods : Five patients (8 eyes) with normal Humphrey 24-2 visual field tests, suspicious optic nerve head findings and with refractive errors < ± 5.0 Diopters were enrolled in the study conducted at Manhattan Eye Ear and Throat Hospital. Participants underwent comprehensive ophthalmological examination and tests on Humphrey Field Analyzer (HFA) , Diopsys NOVA PERG and the Cirrus HD OCT-A Angioplex devices. Average vessel diameter of retinal arteries and veins was calculated using the vessel analysis plug-in on ImageJ. FAZ area was determined using ImageJ. Correlation analyses among vessel diameters, FAZ area and ssPERG parameters [Magnitude (Mag), MagnitudeD (MagD) and MagD/Mag ratio], were assessed to characterize these associations (Pearson's). P values <0.05 considered statistically significant.

Results : Results were gathered from 8 eyes of 5 patients aged 59.90 ± 14.20 years of age, with mean IOP 18.30 ± 4.50 and HFA 24-2 mean deviation 0.21 +/- 0.94. Average vessel diameter was negatively correlated with FAZ area (r=-0.955, p<0.01) and positively correlated with both ssPERG parameters MagD (r= 0.733, p<0.05) and MagD/Mag ratio (r= 0.819, p<0.05). No associations were observed between vessel diameter and Mag. FAZ area was negatively associated with MagD, however, this relationship was not significant (r=-0.347, p=0.055).

Conclusions : To best of our knowledge, this is the first study to confirm the relationship between reductions in average vessel diameter measurements with abnormal ssPERG and enlarged FAZ area parameters in patients with PPG. These results suggest that retinal vascular abnormalities and retinal ganglion cell dysfunction may be present before changes in visual field tests. Future investigations are needed to better understand the relationships between arteriolar and venular diameters, as well as the effects of systemic diseases on vessel diameters.

This is a 2021 ARVO Annual Meeting abstract.