Vessel density and structure in the macular region of non-arteritic anterior ischemic optic neuropathy patients

Abstract

Objective: To explore the correlation between the vessel density and the structure and visual function in patients with non-arteritic anterior ischemic optic neuropathy (NAION) in different stages. Methods: This case-control study included 25 NAION patients (28 eyes)of Peking Union Medical College Hospital from November 2017 to May 2018 and 25 healthy controls(HC) (25 eyes) of matched age and gender. General eye examination, visual field examination, and optical coherence tomography angiography were performed to obtain data of blood flow in the macular area and structure such as ganglion cell complex (GCC) and gross loss of volume (GLV), and focal loss of volume (FLV). All affected eyes were divided into the acute group (≤3 weeks), sub-acute group (4 to 12 weeks), and chronic group (>12 weeks) in line with the course of the disease. The group and regional analyses were made to carry out overall differences of blood flows and structures and the correlations with visual function. Results: There were 25 NAION patients with 28 eyes, 16 males and 9 females, aged (55±9) years. The acute group included 8 patients (8 eyes), and the sub-acute group included 10 patients (10 eyes), while the chronic group comprised 7 patients (10 eyes). The overall macular superficial vessel density of patients with NAION was significantly reduced compared with the HC(42.03%±5.70% vs.49.01%±3.34%, t=-5.546, P<0.01), but the deep vessel density was not significantly reduced (P>0.05). The superficial vessel density of the acute group, sub-acute group, and chronic group was significantly decreased(47.41%±3.51% vs. 41.68%±3.09% vs.38.06%±5.93%, all P<0.05). The GCC thickness in patients with NAION were significantly lower than the HC [(88.5±18.2) μm vs. (102.9±5.4)μm, P<0.05]. The GLV and FLV in patients with NAION were significantly higher than the HC (12.733%±11.216% vs. 0.941%±0.852%, 6.295%±4.291% vs. 0.596%±0.460%, both P<0.05). There was a correlation between the macular superficial vessel density and GCC thickness (r=0.606, P=0.001), FLV(r=-0.552, P=0.002), GLV (r=-0.685, P=0.000) and mean sensitivity (r=0.493, P=0.023). Conclusion: Compared with healthy controls, the macular superficial vessel density in NAION patients decreas along with the course of the disease, and its correlation with structural and visual function is revealed. (Chin J Ophthalmol, 2019, 55:195-202).