Wallace David K, Freedman Sharon F, Zhao Zheen
Departments of Ophthalmology and Pediatrics, Duke University, Durham, North Carolina, USA.
Trans Am Ophthalmol Soc. 2009 Dec;107:47-52.
The primary indication for laser treatment in retinopathy of prematurity (ROP) is plus disease, or abnormal dilation and tortuosity of arterioles and venules. ROPtool is a computer program that traces retinal blood vessels and measures their width and tortuosity. Our purpose was to gain insight into the evolution of plus disease by applying ROPtool to RetCam images from eyes of infants who had serial photographs taken during their ROP screening period.
Serial images were collected from eyes of 62 infants screened for ROP as part of another study. Fifty-nine images of one eye of 7 infants who developed plus disease were selected and analyzed by ROPtool. The average tortuosity of the most tortuous blood vessel and the average width of the most dilated vessel in each quadrant were calculated for each image.
Tortuosity increased from an average of 7.72 units at the first examination to 24.44 units at the examination with maximum tortuosity, or an increase of 217% over a mean time period of 6.2 weeks. Two eyes had an increase in tortuosity of more than 500% from the first examination. Vessel width increased from an average of 8.60 units at the first examination to 11.03 units at the examination with maximum blood vessel width, or an increase of 28% over a mean time period of 5.1 weeks.
ROPtool can measure changes in retinal vascular dilation and tortuosity in individual eyes over time. As plus disease develops, changes in tortuosity are sometimes very large, whereas changes in vessel width tend to be more subtle. Quantification of plus disease over time may help to improve our understanding of its mechanism and to monitor disease progression or response to treatment.
早产儿视网膜病变（ROP）激光治疗的主要指征是增值性病变，即小动脉和小静脉异常扩张和迂曲。ROPtool是一个计算机程序，可追踪视网膜血管并测量其宽度和迂曲度。我们的目的是通过将ROPtool应用于在ROP筛查期间拍摄了系列照片的婴儿眼睛的RetCam图像，来深入了解增值性病变的演变情况。
作为另一项研究的一部分，从62名接受ROP筛查的婴儿眼中收集了系列图像。选择了7名发生增值性病变的婴儿一只眼睛的59张图像，并通过ROPtool进行分析。计算每张图像中每个象限最迂曲血管的平均迂曲度和最扩张血管的平均宽度。
迂曲度从首次检查时的平均7.72单位增加到迂曲度最大时检查的24.44单位，即在平均6.2周的时间段内增加了217%。两只眼睛的迂曲度从首次检查起增加超过了500%。血管宽度从首次检查时的平均8.60单位增加到血管宽度最大时检查的11.03单位，即在平均5.1周的时间段内增加了28%。
ROPtool可以测量单只眼睛视网膜血管扩张和迂曲度随时间的变化。随着增值性病变的发展，迂曲度的变化有时非常大，而血管宽度的变化往往更细微。对增值性病变随时间进行量化可能有助于增进我们对其机制的理解，并监测疾病进展或对治疗的反应。
