Retinal microvasculature and choriocapillaris impairments according to the stage of dry age‐related macular degeneration

BACKGROUND: We aimed to analyse the retinal microvasculature and choriocapillaris according to the dry age-related macular degeneration (AMD) stage and to identify factors associated with their microvasculatures. METHODS: Patients were divided into four groups: normal controls, early, intermediate and advanced AMD groups. The vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris was compared using optical coherence tomography angiography among the groups. Linear regression analysis was performed to identify factors associated with the VD. RESULTS: The VDs of the SCP were 22.1 ± 5.7, 19.1 ± 5.4, 18.0 ± 6.4 and 12.2 ± 6.4% (p < 0.001); the VDs of the DCP were 22.4 ± 4.5, 20.7 ± 4.3, 18.1 ± 5.3 and 14.6 ± 5.8% (p < 0.001); the VDs of the choriocapillaris were 29.4 ± 3.7, 26.4 ± 4.8, 24.5 ± 4.9 and 24.2 ± 3.7% (p < 0.001) in the control, early, intermediate, and advanced groups, respectively. AMD stage and age were significantly associated with the VDs of all layers, and the VDs of the SCP and DCP were associated with visual acuity (both p < 0.001). Additionally, hypertension was associated with the VDs of the DCP (p = 0.027) and choriocapillaris (p = 0.024). CONCLUSIONS: The retinal microvasculature and choriocapillaris tended to become more impaired as the AMD stage progressed. Age was significantly associated with the microvasculature impairments of all layers, and hypertension was significantly associated with impairments of the DCP microvasculature and choriocapillaris.