Glaucoma diagnostic capabilities of macular vessel density on optical coherence tomography angiography: superficial versus deep layers

Background/aims To compare glaucoma diagnostic capabilities of superficial and deep macular vessel density (mVD) parameters in a series of healthy and open-angle glaucoma (OAG) eyes with central visual field (CVF) loss. Methods We consecutively enrolled 113 eyes of 113 patients with OAG and 47 eyes of 47 healthy participants in a retrospective manner. Superficial and deep mVDs were measured at foveal, parafoveal and perifoveal locations on optical coherence tomography (OCT) angiography. The macular ganglion cell-inner plexiform layer thickness (mGCIPLT) was measured on OCT as a reference standard. Glaucoma diagnostic capabilities of superficial and deep mVD parameters were assessed according to the glaucoma stage. Factors associated with the CVF mean sensitivity (MS) were evaluated using linear regression analyses in the OAG eyes. Results Glaucoma diagnostic capabilities of superficial perifoveal and parafoveal mVDs were significantly better than those of deep perifoveal and parafoveal mVDs, regardless of the glaucoma stage (both p<0.05). Both mGCIPLT and superficial parafoveal mVD were significantly associated with CVF MS (β-coefficients=10.567 and 21.147, respectively, both p<0.05), independent of age and glaucoma severity. Conclusion Superficial mVD parameters showed significantly greater glaucoma diagnostic capabilities and better correlation with CVF MS compared with deep mVD parameters.