Beckman C, Bond-Taylor L, Lindblom B, Sjöstrand J
Department of Clinical Neuroscience, University of Göteborg, Sweden.
Br J Ophthalmol. 1995 Oct;79(10):900-4. doi: 10.1136/bjo.79.10.900.
AIMS/BACKGROUND: The study aimed to determine the influence of increased intraocular light scatter on the contrast in scanning laser ophthalmoscope (SLO) images and to examine to what extent SLO images can visualise the fundus through media opacities due to cataract.
Intraocular light scatter was estimated from measurements of letter contrast sensitivity before and after cataract surgery in five eyes. SLO images were obtained before and after surgery using confocal apertures of 1, 2, 4, and 10 mm, at laser wavelengths of 633 and 780 nm. Visibility of the fundus was determined by measurements of retinal contrast. SLO images were compared with standard fundus photographs.
SLO images obtained before surgery revealed details of the retina that were unresolvable in the fundus photographs because of light scattering. By using one of the three smallest apertures, image contrast was further improved. However, no simple relations between aperture size, estimated light scatter, and image contrast could be found.
SLO imaging was found to be superior to fundus photography for viewing the retina in eyes with cataract. Owing to the inhomogeneous nature of cataracts, the optimal choice of confocal aperture and laser wavelength is not simple and must be individualised.
目的/背景：本研究旨在确定眼内光散射增加对扫描激光检眼镜（SLO）图像对比度的影响，并研究SLO图像在多大程度上能够透过白内障导致的介质混浊看清眼底。
通过测量5只眼睛白内障手术前后的字母对比敏感度来估计眼内光散射。在手术前后，使用1、2、4和10毫米的共焦孔径，在633和780纳米的激光波长下获取SLO图像。通过测量视网膜对比度来确定眼底的可见度。将SLO图像与标准眼底照片进行比较。
手术前获得的SLO图像显示出眼底照片中因光散射而无法分辨的视网膜细节。使用三个最小孔径之一可进一步提高图像对比度。然而，未发现孔径大小、估计的光散射和图像对比度之间存在简单关系。
发现SLO成像在观察白内障患者的视网膜方面优于眼底摄影。由于白内障的不均匀性质，共焦孔径和激光波长的最佳选择并不简单，必须个体化。
