Meehan R T, Taylor G R, Rock P, Mader T H, Hunter N, Cymerman A
Department of Internal Medicine, University of Texas Medical Branch, Galveston.
Ophthalmology. 1990 Jul;97(7):875-81. doi: 10.1016/s0161-6420(90)32500-9.
The width of retinal arteries and veins was measured by digital image analysis using an automated vessel-tracking software program. Mean coefficients of variations in vessel width of less than 3% were easily achieved from digitized 35-mm retinal photographs taken with a table-top or hand-held fundus camera. Retinal images were analyzed from seven subjects exposed to sea level or altitudes equivalent to 10,000 (3048 m), 17,500 (5334 m), and 25,000 (7620 m) ft and nine subjects exposed to sea level and 14,110 ft (4300 m). At each altitude, retinal veins dilated more than did arteries (5 +/- 1 versus 0 +/- 1% at 10,000 ft and 28 +/- 9% versus 9 +/- 2% at 25,000 ft; veins versus arteries, respectively). However, widths of retinal arteries and veins were reduced in nine subjects tested after 15 minutes, 24 hours, and 48 hours of 10 degrees head-down tilt; and values varied inversely with intraocular pressures (IOP). Hand-held retinal fundus photography and digital image analysis were found to provide a sensitive and objective method for detecting and quantifying retinal vascular responses in humans exposed to novel environments.
使用自动血管追踪软件程序通过数字图像分析测量视网膜动脉和静脉的宽度。从用台式或手持式眼底相机拍摄的数字化35毫米视网膜照片中，很容易实现血管宽度变异系数平均值小于3%。对7名暴露于海平面或相当于10000英尺（3048米）、17500英尺（5334米）和25000英尺（7620米）高度的受试者以及9名暴露于海平面和14110英尺（4300米）的受试者的视网膜图像进行了分析。在每个高度，视网膜静脉比动脉扩张得更多（在10000英尺时分别为5±1%和0±1%，在25000英尺时分别为28±9%和9±2%；分别为静脉与动脉）。然而，在9名受试者中，在头向下倾斜10度15分钟、24小时和48小时后进行测试，视网膜动脉和静脉的宽度减小；并且这些值与眼内压（IOP）呈反比。发现手持式视网膜眼底摄影和数字图像分析为检测和量化暴露于新环境中的人类视网膜血管反应提供了一种灵敏且客观的方法。
