Macular Vessel Density, GCC Thickness Important to Evaluate for Glaucoma Progression

Vahid Mohammadzadeh, MD

New research published in Ophthalmology suggests rates of macular vessel density (VD) and ganglion cell complex thinning (GCC) are associated with central visual field loss over time in eyes with early glaucoma.

“Assessment of both macular VD and GCC thickness should be considered for evaluation of glaucoma progression,” wrote study investigator Vahid Mohammadzadeh, MD, Department of Ophthalmology, UCLA Jules Stein Eye Institute.

Mohammadzadeh and a team of colleagues investigated the relationship of longitudinal changes in macular vessel density from optical coherence tomography (OCT) angiography and in ganglion cell complex (GCC) from OCT with central VF in this patient population.

The observational cohort consisted of 95 eyes.Of the eyes, 37 were preperimetric and 58 were early glaucoma ( 10–2VF mean deviation [MD], ≥ –6 decibels) They had an average follow-up of 3.8 years and an average of 5.3 visits.

The investigators matched whole-image VD (wiVD) and whole-image GCC (wiGCC) and parafoveal scans, as well as localized regions of interest, hemiretinae of whole images, and superior, inferior, temporal, and nasal sectors of parafoveal maps with central VF location. Additionally, they calculated age-adjusted rates of change of VD, GCC, mean sensitivity of VF locations, and 10-2 VF MD using linear mixed-effects models, as well as normalized rates of change for comparison of change rates in wiVD and wiGCC.

The main outcomes for the trial were the structure–function (SF) correlations of VD and GCC with central VF measurement change rates and the comparison of different correlations of structure–function relationships after bootstrapping the difference of the correlation coefficients.

Investigators observed vessel density loss and GCC thinning exhibited significant correlations with central VF damage, globally and with most localized regions of interest. Data show the structure–function correlation between wiVD and 10–2 VF MD change rates was 0.42 (95% confidence interval [CI], 0.24 - 0.58). Meanwhile, the correlation was 0.27 (95% CI, 0.08 - 0.45) between wiGCC and 10–2 VF MD change rates (all P <.05).

Moreover, in contrast to GCC thinning, investigators found VD loss in the parafoveal sectors exhigited significant correlations with central VF damage in inferior and temporal sectors. They noted the differences in the relationship of structure-function with central VF damage were not significant between VD loss and GCC thinning.

The data additionally show the mean normalized change rates of wiVD (–7.40%/year [95% CI, –7.71 to 7.09]) was faster compared to that of wiGCC (–2.39%/year [95% CI, –2.94 to 1.84]; P <.05).

The abstract, “Longitudinal Structure–Function Relationship between Macular Vessel Density and Thickness and Central Visual Field in Early Glaucoma,” was published in Ophthalmology Glaucoma.