Mlinar Tinkara, Debevec Tadej, Kapus Jernej, Najdenov Peter, McDonnell Adam C, Ušaj Anton, Mekjavic Igor B, Jaki Mekjavic Polona
Department of Automatics, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
Jozef Stefan International Postgraduate School, Ljubljana, Slovenia.
Front Physiol. 2023 Feb 28;14:1026987. doi: 10.3389/fphys.2023.1026987. eCollection 2023.
Technological advances have made high-altitude ski slopes easily accessible to skiers of all ages. However, research on the effects of hypoxia experienced during excursions to such altitudes on physiological systems, including the ocular system, in children is scarce. Retinal vessels are embryologically of the same origin as vessels in the brain, and have similar anatomical and physiological characteristics. Thus, any hypoxia-related changes in the morphology of the former may reflect the status of the latter. To compare the effect of one-day hypoxic exposure, equivalent to the elevation of high-altitude ski resorts in North America and Europe (∼3,000 m), on retinal vessel diameter between adults and children. 11 adults (age: 40.1 ± 4.1 years) and 8 children (age: 9.3 ± 1.3 years) took part in the study. They spent 3 days at the Olympic Sports Centre Planica (Slovenia; altitude: 940 m). During days 1 and 2 they were exposed to normoxia (FO = 0.209), and day 3 to normobaric hypoxia (FO = 0.162 ± 0.03). Digital high-resolution retinal fundus photographs were obtained in normoxia (Day 2) and hypoxia (Day 3). Central retinal arteriolar equivalent (CRAE) and venular equivalents (CRVE) were determined using an Automated Retinal Image Analyser. Central retinal arteriolar and venular equivalents increased with hypoxia in children (central retinal arteriolar equivalent: 105.32 ± 7.72 µm, hypoxia: 110.13 ± 7.16 µm, central retinal venular equivalent: normoxia: 123.39 ± 8.34 µm, hypoxia: 130.11 ± 8.54 µm) and adults (central retinal arteriolar equivalent: normoxia: 105.35 ± 10.67 µm, hypoxia: 110.77 ± 8.36 µm; central retinal venular equivalent: normoxia: 126.89 ± 7.24 µm, hypoxia: 132.03 ± 9.72 µm), with no main effect of group or group*condition interaction. A main effect of condition on central retinal arteriolar and venular equivalents was observed (central retinal arteriolar equivalent:normoxia: 105.34 ± 9.30 µm, hypoxia: 110.50 ± 7.67 µm, < 0.001; central retinal venular equivalent: normoxia: 125.41 ± 7.70 µm, hypoxia: 131.22 ± 9.05 µm, < 0.001). A 20-hour hypoxic exposure significantly increased central retinal arteriolar and venular equivalents in adults and children. These hypoxia-induced increases were not significantly different between the age groups, confirming that vasomotor sensitivity of the retinal vessels to acute hypoxia is comparable between adults and prepubertal children.
技术进步使各个年龄段的滑雪者都能轻松抵达高海拔滑雪场。然而，关于儿童前往此类海拔高度旅行期间所经历的缺氧对包括眼部系统在内的生理系统影响的研究却很匮乏。视网膜血管在胚胎学上与脑血管起源相同，且具有相似的解剖学和生理学特征。因此，前者形态上任何与缺氧相关的变化都可能反映后者的状况。为比较相当于北美和欧洲高海拔滑雪胜地海拔高度（约3000米）的一日缺氧暴露对成人和儿童视网膜血管直径的影响。11名成年人（年龄：40.1±4.1岁）和8名儿童（年龄：9.3±1.3岁）参与了该研究。他们在奥林匹克体育中心普拉尼卡（斯洛文尼亚；海拔：940米）度过了3天。在第1天和第2天，他们处于常氧环境（FO = 0.209），第3天处于常压缺氧环境（FO = 0.162±0.03）。在常氧（第2天）和缺氧（第3天）状态下获取了数字化高分辨率视网膜眼底照片。使用自动视网膜图像分析仪测定中央视网膜动脉当量（CRAE）和静脉当量（CRVE）。儿童（中央视网膜动脉当量：常氧：105.32±7.72微米，缺氧：110.13±7.16微米，中央视网膜静脉当量：常氧：123.39±8.34微米，缺氧：130.11±8.54微米）和成年人（中央视网膜动脉当量：常氧：105.35±10.67微米，缺氧：110.77±8.36微米；中央视网膜静脉当量：常氧：126.89±7.24微米，缺氧：132.03±9.72微米）的中央视网膜动脉和静脉当量在缺氧时均增加，且无组别主效应或组别*条件交互作用。观察到条件对中央视网膜动脉和静脉当量有主效应（中央视网膜动脉当量：常氧：105.34±9.30微米，缺氧：110.50±7.67微米，<0.001；中央视网膜静脉当量：常氧：125.41±7.70微米，缺氧：131.22±9.05微米，<0.001）。20小时的缺氧暴露显著增加了成人和儿童的中央视网膜动脉和静脉当量。这些缺氧诱导的增加在各年龄组之间无显著差异，证实视网膜血管对急性缺氧的血管运动敏感性在成人和青春期前儿童之间具有可比性。
