Correlation of ganglion cell complex thinning with baseline deep and superficial macular vessel density in glaucoma.

Objective: To investigate the relationship between ganglion cell complex (GCC) thinning and baseline deep and superficial macular vessel density (VD) in glaucoma.

Methods: 97 eyes of 69 primary open-angle glaucoma (POAG) and glaucoma suspect patients from the Diagnostics Innovations in Glaucoma Study with a minimum of 4 visits and 2 years of follow-up after baseline optical coherence tomography angiography (OCTA) examination were included. OCTA 3×3 mm2 macular scans were acquired at each visit and used to calculate superficial and deep parafoveal VD (pfVD) and OCT-based parafoveal GCC (pfGCC) thickness. Association of baseline superficial and deep pfVD with pfGCC thinning rate was evaluated using linear mixed model.

Results: The included subjects had a baseline mean visual field mean deviation (95% CI) of -2.9 (-3.7 to -2.1) dB and a mean follow-up period of 3.6 years. In the univariable model, lower baseline superficial pfVD and higher mean intraocular pressure (IOP) during follow-up were significantly associated with a faster pfGCC thinning rate (p<0.05 for all), while deep pfVD was not (p=0.177). In the multivariable model, faster pfGCC thinning was correlated with higher mean IOP during follow-up (β=-0.05, p=0.002) and lower baseline superficial pfVD (β=-0.04, p=0.011). Eyes with a baseline superficial pfVD in the lowest tertile (≤46%) had significantly faster pfGCC loss compared with eyes with baseline superficial pfVD greater than 46% (p=0.015).

Conclusions: Lower baseline superficial pfVD, but not deep pfVD, was associated with faster pfGCC thinning in glaucoma. Moreover, superficial macular VD may help predict central macula thinning in patients with glaucoma.