Study of retinal microvascular perfusion alteration and structural damage at macular region in primary open-angle glaucoma patients

Abstract

Objective: To investigate the alteration of retinal microcirculation and structural damage at macular region and evaluate their associations in primary open angle glaucoma (POAG) eyes. Methods: Cross-sectional study. Fifty-nine POAG patients (male/femal=35/24) were recruited from July 2015 to December 2015 in Eye, Ear, Nose and Throat Hospital of Fudan University. Twenty-eight eyes of early-stage POAG group (EG), 11 eyes of moderate-stage POAG group (MG) and 20 eyes of severe-stage POAG group (SG) were enrolled in this study. All patients underwent complete ophthalmological examinations and the general information was collected. The macular perfusion parameters (flow index & vessel area density) and the global/hemimacular retina thickness were derived from the 3D angio-retina and retina map procedures in the single optic coherence tomography (OCT) system with split-spectrum amplitude decorrelation angiography (SSADA) algorithm, respectively. One-way ANOVA analysis was conducted to compare the macular perfusion parameters, retinal thickness and visual field defects among three groups. Pearson partial regression analysis was used to calculate the correlations between different variables. Results: The mean flow index and vessel area density of MG eyes were 0.05±0.01 and 60.8%±7.9%, which were significantly lower than those indexes (0.06±0.01; 71.9%±4.6%) in EG eyes (t=5.11, P=0.001; t=5.05, P<0.01). The full and inner retinal layer thicknesses of MG eyes were (270.3±24.6) μm and (98.4±13.3) μm, which were obviously thinner than those indexes (293.0±12.0 μm, 113.0±7.4 μm) in EG eyes (t=3.60, P<0.01; t=4.06, P<0.01). However, there was no significant alteration of macular perfusion parameters and retinal thickness between MG and SG eyes. Furthermore, there was a significantly positive correlation between macular perfusion (flow index/vessel area density) and the macular retina thickness (full/inner thickness) (R=0.35-0.71, All P<0.01). Conclusions: The microvascular perfusion and retinal thickness in MG eyes were lower than those in EG eyes. There was significant positive association between the retinal microvascular perfusion and structural damage. Furthermore, the association between microvascular perfusion and inner inferior retinal thickness is the strongest. (Chin J Ophthalmol, 2017, 53: 98-103).