后发性白内障切开孔径大小对视野的影响

目的　探讨治疗后发性白内障 2mm和 4mm不同切开孔径对视野的影响 ,并分析其相关因素。方法　将 4 0例白内障摘除人工晶状体植入术后晶状体后囊膜Ⅱ级混浊患者随机均分为 2mm切开孔径组和 4mm切开孔径组 ,行掺钕钇铝石榴石激光晶状体后囊膜切开术后 1 5个月检查中心 30°和周边 6 0°视野。以 2 1例白内障摘除人工晶状体植入术后晶状体后囊膜透明患者 (透明组 )为对照 ,对各组视野检查指标结果进行分析。结果　 2mm切开孔径组视野检查的平均偏差为 - 8 6 5± 3 96 ,样本标准差为 5 71± 2 6 0 ,中心 10°总光敏感度值为 2 89 30± 4 3 6 3,周边 6 0°总光敏感度值为 5 5 8 2 0±197 2 7,与透明组比较 ,差异均有非常显著意义 (P <0 0 0 1)。 4mm切开孔径组视野检查的平均偏差为- 4 0 8± 2 73,样本标准差为 3 0 5± 2 13,中心 10°总光敏感度值为 336 5 4± 34 32 ,周边 6 0°总光敏感度值为 94 5 95± 2 4 4 74 ,与透明组比较 ,差异均无显著意义 (P >0 0 5 )。结论　治疗后发性白内障 2mm切开孔径虽可获得较佳视力 ,但对视野影响较大 ,表现为弥漫性光敏感度下降和视岛不规则局限性压陷 ;而 4mm切开孔径对视野的影响较小 ,为较佳的晶状体后囊膜切开直径。

Effect of the different diameter of posterior capsulotomy on visual field

OBJECTIVE: The purpose of this study is to determine the influence of two different diameter of posterior capsulotomy on visual field. METHODS: Forty patients with posterior capsule opacification (PCO) of grade II after phacoemulsification and intraocular lens implantation were randomly divided into two groups. 20 cases received laser capsulotomy with 2 mm diameter. Other 20 cases received laser capsulotomy with 4 mm diameter. One and half months after laser capsulotomy, vision field of every patient was examined using the automated perimetry for central 30 degrees and peripheral 60 degrees. Visual field in 21 patients with a transparent posterior capsule after cataract surgery was also evaluated by the same automated perimetry. RESULTS: There were significant reductions in the total visual field sensitivity, the mean deviation (MD) and the pattern standard deviation (PSD) in 2 mm diameter capsulotomy group compared with 4 mm diameter capsulotomy group (P < 0.001). There were no significant difference in visual field between 4 mm capsulotomy group and the transparent posterior capsule group (P > 0.05). CONCLUSIONS: Better visual acuity could be obtained after laser capsulotomy with 2 mm capsulotomy, however the generalized sensitivity reduction and irregular localized depression of visual island might occurred. 4 mm diameter capsulotomy may be a better choice in laser capsulotomy in patients with PCO.