摘要
目的 评价晶状体后照明计算机数码摄像技术检查白内障患者晶状体混浊及其程度的可靠性 ,探讨白内障患者晶状体后照明数码图像的特征。方法 将白内障后照明测试仪 (cataractscreener,CT S)与计算机内置的图像采集卡相连 ,对 33例 (6 4只眼 )正常人及白内障患者的晶状体进行数码摄像 ,观察CT S数码摄像技术检测的图像与裂隙灯显微镜下观察晶状体混浊程度的一致性及其干扰因素的特征。应用PhotoShop阈值分割法及自行编制的Matlab程序定量分析不同检查者CT S图像上晶状体混浊的面积。结果 CT S数码摄像技术检测白内障患者晶状体皮质、后囊膜下混浊的图像较裂隙灯显微镜清晰。CT S数码摄像技术检测晶状体混浊的特异性及皮质与后囊膜下型白内障的敏感性分别为 94 %及 90 % ;对核性白内障患者的检测 ,裂隙灯显微镜优于CT S数码摄像技术。 3位不同检查者摄取CT S图像的晶状体混浊相对面积变异系数为 2 2 3%～ 10 86 %。CT S图像特征 :晶状体皮质混浊为线状、楔形或聚集成簇状排列的斑块状阴影 ,晶状体后囊膜下混浊为成片的空泡状或颗粒状阴影。结论 CT S图像具有较高检查者间的一致性 ,可客观记录晶状体皮质及后囊膜下混浊程度 ,为白内障的定量研究奠定基础 ,但不适用于核性白内障的筛查与评价。
Objective To evaluate the reliability of digital photography with retroillumination for lens as a tool to assess the degree of lens opacity, and to study the morphological features of some lens diseases using the digital images. Methods The cataract screener (Neitz CT-S) was connected to a computer capable of acquiring digital images of lens. The digital lens retroillumination and slit lamp images were collected in 64 eyes. Three independent separate examiners took three sets of different CT-S digital photographs in four cataract subjects. The area of lens opacification in the images was measured and analyzed using threshold adjustment in PhotoShop software and a customized program in Matlab software. Results The distinct digital images of lens cortical opacity, posterior subcapsular opacity and other lens diseases were obtained with CT-S computer digital photography, which images were much better than slit lamp sectional digital images. The sensitivity and specificity of measuring lens opacification with CT-S digital images were 90% and 94% respectively. However, the digital lens retroillumination images were not as sensitive as the slit lamp images for nuclear cataracts. The variation coefficients of lens opacity area in the three sets of CT-S digital images in the same subject, which were taken by the independent examiners, were from 2.23% to 10.86%. The cortical opacification in CT-S digital images was linear, cuniform or clustered aggregate shadow configuration. The posterior subcapsular opacification was discal vacuolar or granular appearance. Conclusions The reproducibility of the CT-S digital images taken by the independent examiners is excellent. This technique can objectively show cortical or posterior subcapsular opacities, but nuclear cataracts.
出处
《中华眼科杂志》
CAS
CSCD
北大核心
2003年第5期278-282,共5页
Chinese Journal of Ophthalmology
