Different characteristics of retinal damage between chronic hypertension and hypertensive retinopathy

The purpose of this study was to identify how chronic hypertension (HTN) and hypertensive retinopathy (HTNR) have different effects on retinal damage including inner retinal thinning and microvasculature impairment. The subjects were divided into three groups: controls, HTN patients without HTNR (HTN group), and patients with relieved HTNR (HTNR group). The ganglion cell-inner plexiform layer (GC-IPL) thickness, vessel density (VD), and GC-IPL/VD ratio were compared among the groups. A total of 241 eyes were enrolled; 101 in the control group, 92 in the HTN group, and 48 in the HTNR group. The mean GC-IPL thicknesses were 83.5 ± 5.7, 82.1 ± 6.2, and 75.9 ± 10.7 μm in each group, respectively (P < 0.001). The VD was 20.5 ± 1.3, 19.6 ± 1.4, and 19.5 ± 1.6 mm(−1) in each group, respectively (P = 0.001). The GC-IPL/VD ratio was 4.10 ± 0.33, 4.20 ± 0.40, and 3.88 ± 0.56 in each group, respectively (P < 0.001). In the HTNR group, HTN duration (B = 0.054, P = 0.013) and systolic blood pressure (SBP) (B = −0.012, P = 0.004) were significantly associated with the GC-IPL/VD ratio. In conclusion, inner retinal reduction and retinal microvasculature impairment were observed in patients with HTN and HTNR, and the GC-IPL/VD ratio of HTNR patients was significantly lower than that of HTN patients, indicating more prominent damage to the inner retina than microvasculature in HTNR patients. Additionally, the GC-IPL/VD ratio was significantly associated with SBP in HTNR patients, so more strict BP control is required in HTNR patients.