Claesson M, Klarén L, Beckman C, Sjöstrand J
Department of Ophthalmology, University of Göteborg, Sweden.
Acta Ophthalmol (Copenh). 1994 Feb;72(1):27-32. doi: 10.1111/j.1755-3768.1994.tb02732.x.
The benefits of Nd:YAG laser capsulotomy on visual performance were evaluated in 13 patients with after-cataract following extracapsular cataract extraction. Besides clinical evaluation we measured: visual acuity, letter contrast sensitivity with and without the presence of a circular glare source (glare angle: 8 degrees). Finally, the patients were asked to evaluate their subjective glare problems. In all patients, visual acuity had decreased markedly compared to measurements 2 months after cataract surgery. Before capsulotomy we observed impaired letter contrast sensitivity and increased intraocular light scatter compared to normals. Following capsulotomy, VA and contrast sensitivity both improved by a factor of 2. The subjective glare problems diminished, although most patients showed minor decreases in intraocular light scatter. The limited glare induced loss of letter contrast sensitivity, present before capsulotomy, remained after treatment. Our study indicates that after-cataract impairs resolution and contrast sensitivity without necessarily causing a marked increase in light scatter as measured at a large angle.
对13例囊外白内障摘除术后发生后发性白内障的患者,评估了钕:钇铝石榴石激光晶状体囊切开术对视觉性能的益处。除临床评估外,我们还测量了:视力、有无圆形眩光光源(眩光角度:8度)时的字母对比敏感度。最后,要求患者评估其主观眩光问题。与白内障手术后2个月的测量结果相比,所有患者的视力均显著下降。在晶状体囊切开术前,我们观察到与正常人相比,字母对比敏感度受损,眼内光散射增加。晶状体囊切开术后,视力和对比敏感度均提高了2倍。主观眩光问题减轻,尽管大多数患者的眼内光散射略有降低。晶状体囊切开术前存在的由有限眩光引起的字母对比敏感度损失在治疗后仍然存在。我们的研究表明,后发性白内障会损害分辨率和对比敏感度,而不一定会导致如大角度测量时明显的光散射增加。