白内障超声乳化术角巩膜缘切口对术后泪膜稳定性的影响

目的探讨角巩膜缘切口对白内障超声乳化术后泪膜变化的影响。方法研究为临床疗效评价的病例对照研究。收集2006年7月—2008年12月行小切口白内障超声乳化及人工晶状体（IOL）植入术的年龄相关性白内障患者128例219眼;年龄61～87岁,平均年龄（66.1±12.1）岁。按信封法随机将患者分为3组,其中角巩膜缘切口组42例69眼,透明角膜切口组45例70眼,巩膜隧道切口组41例80眼。各组资料的人口统计学特征差异无统计学意义（P〉0.05）。在术前第1天,术后第1、2、7、30、90天对各组患者进行干眼症状评分、Schirmer试验（SIt）、泪膜破裂时间（BUT）和角膜荧光素染色（FLS）4项指标的检测。结果角巩膜缘切口组、透明角膜切口组和巩膜隧道切口组在检测的各时间点（F=110.51,P=0.00）干眼症各组临床评分（F=99.45,P=0.01）的差异均有统计学意义。角巩膜缘切口组干眼症临床评分在手术后14d逐渐下降,各时间点的临床评分与术前相比差异均有统计学意义（P〈0.01）,且明显低于透明角膜切口组和巩膜隧道切口组,差异有统计学意义（P〈0.01）。手术后14d角巩膜缘切口组BUT明显低于透明角膜切口组和巩膜隧道切口组,差异有统计学意义（P〈0.01）,但不同时间点间的两两比较差异均无统计学意义（P〉0.05）,而透明角膜切口组手术后14d的BUT值最低。手术后1d角巩膜缘切口组的SIt值达高峰,第1～14天逐渐降低,各组间的差异均有统计学意义（P〈0.01）。手术后1～14d,透明角膜切口组FLS得分与术前相比明显增加,差异有统计学意义（P〈0.05）,且各时间点得分高于角巩膜缘切口组和巩膜隧道切口组,差异有统计学意义（P〈0.05）。角巩膜缘切口组和巩膜隧道切口组FLS在各时间点的差异均无统计学意义（P〉0.05）。结论角巩膜缘切口对泪膜的稳定性影响小,是干眼症高危患者白内障超声乳化术较为理想的选择。

Influence of corneoscleral limbus incision on tear film stability after phacoemulsification

Background Corneoscleral rim incision has less impacts on either the corneal epithelium and conjunctiva or the corneal sensation.But the effects of this operative incision on the stability of tear film after operation is unclear.Objective Purpose of this study was to explore the changes of tear film after phacoemulsification and intraocular lens （IOL） implantation via corneoscleral rim incision.Methods Small incision phacoemulsification and IOL implantation was performed in 219 eyes of 128 patients with age-related cataract from July 2006 to December 2008.The surgery eyes were randomly divided into corneoscleral rim incision group （69 eyes of 42 cases）,corneal transparency incision group （70 eyes of 45 cases）,scleral tunnel incision group （80 eyes of 41 cases）.No significant differences were found in demography of clinical data among these three groups （P0.05）.Dry eye symptoms score,Schirmer test （SIt）,tear film break-up time （BUT） and corneal fluorescein staining in operative eyes were evaluated before surgery and 1 day,2,7 and 30 days after surgery.Written informed consent was obtained from each subject prior to the trial.Results The clinical score of dry eye symptoms was showed to be significantly different among corneoscleral rim incision group,corneal transparency incision group and scleral tunnel incision group （F=99.45,P=0.01） in different time points （F=110.51,P=0.00）.The score was gradually declined from 1 day to 14 days after operation and was stable after that,showing obvious differences in comparison with preoperation （P0.01）,and that in corneoscleral rim incision group was evidently lower than corneal transparency incision group or scleral tunnel incision group（P0.01）.The BUT was significantly less within 14 days after operation than that of preoperation in corneal transparency incision group or scleral tunnel incision group （P0.01）,but no obvious difference was found in corneoscleral rim incision group in different time points （P0.05）,and the BUT value was lowest in corneal transparency incision group from 1 day through 14 days after operation.In corneoscleral rim incision group,Schirmer test was reduced from 1 day through 14 days after operation with the highest value in the first day after operation,showing statistically significant difference in various groups （P0.01）.The corneal fluorescein staining revealed that the score was significantly increased from 1 day through 14 day after operation in comparison with before operation in corneal transparent incision group （P0.05）,and the score was higher than other two groups in these time points （P0.05）.No considerable difference was seen in corneal fluorescein staining score among various time points in corneoscleral rim incision group and scleral tunnel incision group （P0.05）.Conclusion Corneoscleral rim incision does not product adverse influence on the stability of tear film after small incision phacoemulsification and IOL implantation.These results suggest that corneoscleral rim incision is a better select in phacoemulsification cataract surgery for the cataractous eye with a high risk of dry eye.