Jinlan Ma1,2, Haoyu Niu2, Xiaolu Ma3, Changjing Han2, Yi Qu4. 1. Department of Health Care, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China. 2. Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China. 3. Department of Ophthalmology, Haidong First People's Hospital, Pingan, China. 4. Department of Health Care, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China. yiqucn@sdu.edu.cn.
Abstract
PURPOSE: To quantify the effect of long-term high-altitude (HA) exposure on retinal and choroidal microcirculation and to relate these changes to high-altitude polycythemia (HAPC), as a proxy for etiopathogenesis of high-altitude related retinopathy (HAR). METHODS: Fifty-one HAPC patients, 50 healthy HA residents, and 43 low altitude (LA) residents were recruited in this study. Optical coherence tomography angiography (OCTA) and enhanced depth imaging (EDI)-OCT images were analyzed. Retinal microvascular metrics included vessel density (VD), skeleton density (SD), fractal dimension (FD), and foveal avascular zone (FAZ). Choroidal microvascular metrics included subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI). All metrics were calculated by ImageJ software and compared among HAPC group, healthy HA group, and LA group. RESULTS: In HAPC group, VD (30.62 ± 3.67%), SD (13.25 ± 1.64%), FD (1.79 ± 0.04), and the CVI (63.01 ± 1.42%) were significant lower and SFCT (403.25 ± 94.3 μm) was significant thicker than healthy HA group (all P < 0.001). FAZ area was comparable between two groups (0.42 ± 0.1 vs. 0.4 ± 0.11 mm2, P = 0.411). However, these metrics were not different between healthy HA group and LA group (all P > 0.05) except for FD was lower in HA group (P < 0.001). Pearson's correlation analyses revealed HGB was negatively related with VD (r = - 0.562, P < 0.001) and positively related with SFCT (r = 0.505, P < 0.001) in healthy HA group; however, no associations between HGB and vascular metrics in HAPC group were detected (all P > 0.05). CONCLUSIONS: Long-term exposure to HA environment induces retinal and choroidal microcirculation disturbance in HAPC patients. However, these changes were not evident in healthy HA residents because of adaptation.
PURPOSE: To quantify the effect of long-term high-altitude (HA) exposure on retinal and choroidal microcirculation and to relate these changes to high-altitude polycythemia (HAPC), as a proxy for etiopathogenesis of high-altitude related retinopathy (HAR). METHODS: Fifty-one HAPC patients, 50 healthy HA residents, and 43 low altitude (LA) residents were recruited in this study. Optical coherence tomography angiography (OCTA) and enhanced depth imaging (EDI)-OCT images were analyzed. Retinal microvascular metrics included vessel density (VD), skeleton density (SD), fractal dimension (FD), and foveal avascular zone (FAZ). Choroidal microvascular metrics included subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI). All metrics were calculated by ImageJ software and compared among HAPC group, healthy HA group, and LA group. RESULTS: In HAPC group, VD (30.62 ± 3.67%), SD (13.25 ± 1.64%), FD (1.79 ± 0.04), and the CVI (63.01 ± 1.42%) were significant lower and SFCT (403.25 ± 94.3 μm) was significant thicker than healthy HA group (all P < 0.001). FAZ area was comparable between two groups (0.42 ± 0.1 vs. 0.4 ± 0.11 mm2, P = 0.411). However, these metrics were not different between healthy HA group and LA group (all P > 0.05) except for FD was lower in HA group (P < 0.001). Pearson's correlation analyses revealed HGB was negatively related with VD (r = - 0.562, P < 0.001) and positively related with SFCT (r = 0.505, P < 0.001) in healthy HA group; however, no associations between HGB and vascular metrics in HAPC group were detected (all P > 0.05). CONCLUSIONS: Long-term exposure to HA environment induces retinal and choroidal microcirculation disturbance in HAPC patients. However, these changes were not evident in healthy HA residents because of adaptation.
Authors: M Dominik Fischer; Andreas Schatz; Immanuel P Seitz; Kai Schommer; Karl U Bartz-Schmidt; Florian Gekeler; Gabriel Willmann Journal: Invest Ophthalmol Vis Sci Date: 2015-07 Impact factor: 4.799
Authors: Wasim A Samara; Abtin Shahlaee; Murtaza K Adam; M Ali Khan; Allen Chiang; Joseph I Maguire; Jason Hsu; Allen C Ho Journal: Ophthalmology Date: 2016-11-23 Impact factor: 12.079
Authors: Alice Y Kim; Damien C Rodger; Anoush Shahidzadeh; Zhongdi Chu; Nicole Koulisis; Bruce Burkemper; Xuejuan Jiang; Kathryn L Pepple; Ruikang K Wang; Carmen A Puliafito; Narsing A Rao; Amir H Kashani Journal: Am J Ophthalmol Date: 2016-09-02 Impact factor: 5.258
Authors: Qisheng You; William R Freeman; Robert N Weinreb; Linda Zangwill; Patricia I C Manalastas; Luke J Saunders; Eric Nudleman Journal: Retina Date: 2017-08 Impact factor: 4.256