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目的:用弥散滤片模拟瞳孔及屈光间质的变化,以比较这些变化对Humphrey视野计(HFA)及倍频视野计(FDT)的影响。方法:测试15位23-39岁正常人的左眼: (1) Snellen视力表; (2) Pelli-Robson(P-R)对比敏感度视力表; (3)白视标白背景自动视野计检查,HFA Model630,采用30-2程序,刺激视标为III; (4) FDT检查,采用N-30程序。每一只眼均经无滤片,1, 2, 3, 4, 5个滤片进行测试,测试顺序为随机。结果:Snellen视力表: 1个滤片只对2名受试者有影响,仅丢失1行; 2个滤片对所有受试者影响甚微,对2名受试者无影响(9名丢失1行,4名丢失2行); 3个滤片对所有受试者效果一样,均丢失3行; 4个滤片可致5名受试者丢失4行,5名受试者丢失5行, 3名受试者丢失6行, 2名受试者丢失7行;5个滤片可致所有受试者丢失全部9行。P-R视力表:3个滤片便可致13名受试者看不到所有字母,2名受试者仅看到1组字母。HFA和FDT的平均偏差值(MD)均随滤片增加而降低,HFA和FDT的图形标准差值(PSD)较小且非常一致。结论:以上结果表明,由弥散滤片所致的照明降低,光散射及瞳孔缩小对HFA及FDT均有明显影响,其视野缺损比较弥散均匀,而屈光间质混浊对FDT的影响比对HFA的影响要大。各组滤片的PSD值比较小且非常一致。
OBJECTIVE: To evaluate the effect of these changes on Humphrey’s (HFA) and octave-field (FDT) by using diffusion filters to simulate the changes of pupil and refraction. Methods: The left eye of 15 normal people aged 23-39 years was tested: (1) Snellen eyesight chart; (2) Pelli-Robson (PR) contrast sensitivity eyesight table; (3) HFA Model 630, using the 30-2 program to stimulate the visual target III; (4) FDT examination using the N-30 program. Each eye were tested without filter, 1, 2, 3, 4, 5 filters. The test sequence was random. RESULTS: The Snellen Eye Chart: 1 filter affected only 2 subjects, losing only 1 line; 2 filters had little effect on all subjects and had no effect on 2 subjects (9 missing 1 row and 4 lost 2 rows); 3 filters were equally effective for all subjects with 3 rows lost; 4 filters resulted in 4 missing for 5 subjects and 5 rows for 5 subjects , Three subjects lost six lines and two subjects lost seven lines; five filters caused all subjects to lose all nine lines. P-R eye chart: three filters will result in 13 subjects can not see all the letters, two subjects only see a set of letters. The mean deviation (MD) of HFA and FDT decreased with the increase of filter, and the pattern standard deviation (PSD) of HFA and FDT was small and very consistent. CONCLUSIONS: The above results show that the reduction of light due to diffusion filters, light scattering and pupil reduction have significant effects on both HFA and FDT, and their visual field defects diffuse evenly, while the influence of refractive mesenchyme on FDT is more pronounced than that of HFA The impact is bigger. The PSD values for each set of filters are small and very consistent.