超声乳化白内障吸除术后泪膜的变化

目的　了解超声乳化白内障吸除术对泪膜的影响。方法　随机抽取行超声乳化白内障吸除术的老年性白内障患者 6 8例 (79只眼 ) ,分别于术前 ,术后 1、2、7、14、30及 180d行泪膜破裂时间(breakuptime ,BUT)、基础泪液分泌试验 (SchirmerⅠtest,SⅠt)、角膜荧光素染色、干眼仪检查及下睑中央泪河高度检查。结果　与术前相比 ,术后 1及 2d ,BUT明显缩短 ,SⅠt、下睑中央泪河高度、角膜荧光素染色程度及干眼仪检查等级明显增高 (P <0 0 1) ;术后 7d时SⅠt,14d时下睑中央泪河高度 ,30d时BUT、角膜荧光素染色程度和干眼仪检查等级恢复至术前水平 ,与术前比较差异无显著意义(P >0 0 5 )。术后 30d ,19 3%的患眼泪膜未能恢复至术前水平 ;术前泪膜正常的患者中 1/9发生干眼。术后 1、7、14及 30d ,术前BUT <10s的术眼BUT <5s的发生率高于术前BUT≥ 10s的术眼(P <0 0 5 ) ;术后 14、30及 180d ,术前角膜荧光素染色评分 >2分的术眼术后角膜荧光素染色评分 >2分的发生率高于术前角膜荧光素染色评分≤ 2分的术眼 (P <0 0 5 ) ;术后 14d ,术前干眼仪检查等级≥Ⅲ级的术眼术后干眼仪检查等级≥Ⅲ级的发生率高于术前干眼仪检查等级 <Ⅲ级的术眼(P <0 0 5 )。结论　超声乳化白内障吸除术可影响泪膜的稳定性 ,使部分患

Tear film changes after phacoemulsification

OBJECTIVE: To evaluate tear film changes after phacoemulsification. METHODS: This prospective randomized study involved 68 consecutive patients with age-related cataract (79 eyes) who underwent phacoemulsification. Tear break-up time, Schirmer I test (S I t) value, corneal fluorescein staining, tear film pattern by DR-1 tear interfermetry and the height of tear meniscus were measured preoperatively and 1 day and 2, 7, 14, 30, 180 days postoperatively. RESULTS: At 1 day and 2 days postoperatively, the mean tear break-up time reduced greatly, and the number of patients who showed III to V tear film pattern, the mean S I t value, the height of tear meniscus and fluorescein staining scores increased significantly (P < 0.001 for day 1, P < 0.005 for day 2). S I t value at 7 days postoperatively (P = 0.831) and the height of tear meniscus at 14 days returned to their preoperative values (P = 1.000). The tear break-up time, corneal fluorescein staining scores and the grades of tear film pattern all recovered at 30 days postoperatively (P > 0.05). At 30 days postoperatively, 19.3% of patients showed shorter tear break-up time and less S I t value than that of preoperative day. In addition, 1/9 of the patients with normal preoperative tear film experienced dry eye at 30 days postoperatively. The cases with tear break-up time < 10 seconds compared to patients with tear break-up time >/= 10 seconds were more easily to show tear instability postoperatively (relative risk 13.5, 8.25, 20.0, 39.0, 8.6, 3.9 at 1 day and 2, 7, 14, 30, 180 postoperative days, respectively). CONCLUSION: Phacoemulsification significantly alters the tear break-up time, S I t value, corneal fluorescein staining, tear film pattern and the height of tear meniscus. Some patients with normal tear film may experience dry eye after surgery. Patients with preexisting tear break-up time < 10 seconds are easily at risk of experiencing the tear film instability postoperatively.