Superficial Parafoveal Vessel Density May Predict Rate of Parafoveal Ganglion Cell Complex Thinning in Glaucoma

Decreased superficial parafoveal vessel density (pfVD) may be associated with an increased rate of parafoveal ganglion cell complex (pfGCC) thinning in patients with glaucoma, according to a study published in the British Journal of Ophthalmology.

Researchers established this association by conducting an analysis of 97 eyes of 69 patients with primary open-angle glaucoma and glaucoma suspects (35 women, 34 men, 35.1% glaucoma suspects, 48.5% early glaucoma, 16.5% moderate to advanced glaucoma) from the Diagnostic Innovations in Glaucoma Study (DIGS) (Clinical Trials Identifier: NCT00221897). They defined glaucoma suspects as having elevated intraocular pressures (IOP) of 22 mm Hg or higher, or an optic disc with observable neuroretinal rim changes, and classified primary open-angle glaucoma (POAG) as having repeatable abnormal standard automated perimetry tests. Investigators assessed pfGCC thinning rate through optical coherence tomography angiography (OCT-A) with an average follow-up of 3.6 years.

At baseline, mean superficial pfVD was 47.6% (95% CI, 46.8%-48.5%), deep pfVD was 51.7% (95% CI, 51.0%-52.4%), and global pfGCC was 95.4 (95% CI, 92.9-97.8) μm.

Researchers noted that the rate of pfGCC thinning correlated with baseline superficial pfVD (β=-0.03, P =.026)) but not deep pfVD (P =.177).

A multivariate analysis revealed that significant contributors to an increased rate in pfGCC thinning were higher mean IOP at follow-up (β, -0.05; P =.002) and lower baseline superficial pfVD (β, -0.04; P =.011).

Eyes with superficial pfVD ≤46% had a faster thinning rate at baseline (mean, -1.19 μm/year) in both univariate (P =.047) and multivariate analyses (P =.015) compared with pfVD >46%.

Researchers noted no difference in pfGCC thinning rate when stratifying for glaucoma severity (β, -0.28; P =.071).

“Although lower baseline superficial macular vessel density (VD), but not deep VD, was associated with a faster ganglion cell complex (GCC) thinning in glaucoma patients, this association was not strong,” according to the investigators. “Moreover, baseline superficial macular VD predicted subsequent central macula GCC thinning and progression of glaucoma.”

This study was limited by the poor quality of a third of the images included in the analysis and a small sample size of participants with moderate to advanced glaucoma.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or clinical research organizations. Please refer to the original article for a full list of disclosures.

Reference

Wu J-H, Moghimi S, Nishida T, et al. Correlation of ganglion cell complex thinning with baseline deep and superficial macular vessel density in glaucoma. Br J Ophthalmol. Published online January 31, 2022. doi:10.1136/bjophthalmol-2021-320663