Rapid Vessel Density Loss Linked to Faster Rate of Visual Field Loss

Robert N. Weinreb, MD

Rapid vessel density loss was associated with a higher concurrent and subsequent rates of visual field loss during an extended period in patients with suspected glaucoma and primary-open angle glaucoma (POAG).

After dividing the eyes into fast and slow optical coherence tomography angiography (OCTA), these findings in a recent cohort study found a signficantly greater rate of visual field mean deviation loss was faster for fast OCTA progressors during a 4-year follow-up period.

“This finding is clinically relevant if subsequent prospective studies confirm that fast progressors identified by OCTA are at higher risk of functional loss and may need more intensive observation and treatment,” wrote study author Robert N. Weinreb, MD, Shiley Eye Institute, University of California, San Diego.

Study participants were enrolled in the Diagnostic Innovations in Glaucoma Study and were followed up for a mean of 4.0 years from January 2015 - February 2020, with data analysis for the current study undertaken in March 2021.

Investigators noted all study participants underwent annual comprehensive ophthalmologic evaluation including:

• Best-corrected visual acuity
• Slitlamp biomicroscopy
• Goldmann applanation tonometry
• Gonioscopy
• Dilated fundus examination
• stereoscopic optic disc photography
• Ultrasonographic pachymetry

Study inclusion included an age older than 18 years, open angles of gonioscopy, best-corrected visual acuity of 20/40 or better, and refraction within ±5.0 diopters spherical and within ±3.0-diopters cylinder at study entry.

The rate of vessel density loss was calculated from macular whole-image vessel density values from 3 optical coherence tomography angiography scans and the rate of visual field loss was calculated from visual field mean deviation during the entire follow-up period after the first optical coherence tomography angiography visit. Linear mixed-effects models estimated the rates of change.

A total of 124 eyes from 82 patients were assessed in the study (mean age, 69.2 years; 41 female, 50% and 41 male, 50.0%).

Data show the annual rate of vessel density change was -0.80% (95% CI, -0.88% to -0.72%) during a mean initial follow-up of 2.1 years (95% CI, 1.9 - 2.3 years). The eyes with annual rates of vessel density loss of -0.75% or greater (n = 62) were categorized as fast progressors, while eyes with annual rates of less than -0.75% (n = 62) were categorized as slow progressors.

Those considered fast OCTA progressors had a faster mean annual rate of vessel density loss (-1.14%; 95% CI, -1.22% to -1.05%) compared with the slow progressors (-0.47%; 95% CI, -0.53% to -0.41%).

For the slow OCTA progressors, the annual rate of visual field loss was -0.15 dB (95% CI, -0.29 to -0.01 dB) compared to -0.43 dB (95% CI, -0.58 to -0.29 dB) for the fast optical coherence tomography angiography progressors (difference, -0.28 dB; 95% CI, -0.48 to -0.08 dB; P = .006).

Additionally, in a multivariable model, the fast OCTA progressor group was associated with the faster overall rate of visual field loss after adjusting to include concurrent visual field mean deviation rate (-0.17 dB; 95% CI, -0.33 to -0.01 dB; P = .04).

Investigators noted limitations of the study included the relatively small sample size and the variation across patients on “the preexisting course of glaucoma-tous change and progression during the initial visits.”

“Taking the limitations of this investigation into account, the results support the use of OCTA for monitoring the rate of vessel density loss to assess visual field progression in patients with glaucoma,” investigators wrote.

The study, “Association of Initial Optical Coherence Tomography Angiography Vessel Density Loss With Faster Visual Field Loss in Glaucoma,” was published in JAMA Ophthalmology.