[Clinical study on the reduction of ocular surface bacteria in pre-operative cataract surgery patients by cleansing the eyelid margins].

Objective: To explore the clinical significance of ocular surface bacteria inhibition by cleaning eyelid margins before surgery in cataract patients. Methods: Case-control study. Thirty-five patients (45 eyes) with age-related cataracts who were proposed to receive treatment of Phacoemulsification combined with cataract extraction and intraocular lens implantation at Peking University 3(rd) hospital were included. The experimental group consisted of 9 males and 15 females with the average age of (69.8±11.5). The control group consisted of 6 males and 15 females with the average age of (61.8±16.2). In the experimental group, bacteria samples from the conjunctival sac and eyelid margins were collected at three times separately and were cultured for identification: first sampling was taken prior to application of any type of antimicrobial measures; second sampling was taken after application of lid scrub twice daily for 7 days to cleanse their eyelid margins by the patients;the last sampling was taken after patients' application of Levofloxacin antibiotic eye drops 3 times per day continuously for 3 days prior to surgery. In the control group, bacteria samples from the conjunctival sac and eyelid margins were collected at two times separately and were cultured for identification: first sampling was taken before application of any antimicrobial measures;second sampling was taken after patients' application of only Levofloxacin antibiotic eye drops successively for 3 days before surgery. Then the results of bacteria culture of the two groups above were compared. Results: In the experimental group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 83.3% (20/24), 70.8% (17/24), 45.8% (11/24), respectively; according to the bacteria cultures results of the second sampling (tanken after application of lid scrub for cleaning the eyelid margins for 7 days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 58.3% (14/24), 45.8% (11/24), 25% (6/24), respectively;According to the bacteria cultures results of the third sampling (taken after application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 20.8% (5/24), 20.8% (5/24), 4.2% (1/24), respectively. In the experimental group, we compared the bacterial positive rate of the samples taken after patients' application of antibiotics for 3 days to the bacterial positive rate of the samples taken prior to application of any antibacterial measures to have found that the total positive rate, the positive rates of common bacteria and rare bacteria decreased significantly (P<0.05) and the difference in between are of statistical significance. In the control group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures, the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 81% (17/21), 66.7% (14/21), 19% (4/21), respectively;According to the bacteria cultures results of the second sampling (taken after the application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 38.1% (8/21), 14.3% (3/21), 33.3% (7/21) respectively. When comparing the experimental group to the control group, the experimental group yielded significantly better results than the control group for the rate of reduction of rare bacteria in the eyelid margin after using antibiotics for 3 days. This is due to the lid scrub being used with the antibiotics. The difference are of statistical significance (χ(2)=6.518, P=0.017). There was no statistically significant difference between the experimental and control group in terms of the total positive rate as well as the positive rate of common bacteria and rare bacteria in the conjunctival sac. Conclusions: The cleaning of the eyelid and eyelid margin with lid scrub prior to cataract surgery combined with antibiotics eye drops will achieve excellent antibacterial effects for common and rare bacteria in the eyelid and conjunctival sac. The antibacterial effect of using lid scrub with antibiotic eye drops is more favorable than that of using antibiotic eye drops only. However, the lid scrub eyelid hygiene products cannot replace preoperative antibiotics independently. (Chin J Ophthalmology, 2018, 54: 445-451).目的： 探讨睑缘清洁对白内障患者术前睑缘和结膜囊细菌抑制作用的临床意义。 方法： 病例对照研究。收集2017年9月至10月于北京大学第三医院拟行超声乳化白内障吸除联合人工晶体植入术的年龄相关性白内障患者35例（45只眼）。将患者分为两组，试验组19例（21只眼）其中男性9例，女性15例，年龄（69.8±11.5）岁；对照组16例（21只眼），其中男性6例，女性15例，年龄（61.8±16.2）岁。试验组在采取抗菌措施前、采用清洁棉片（含辛二醇、聚胺丙基双胍等）清洁眼睑及睑缘7 d后、左氧氟沙星滴眼液连续使用3 d后3个时间点对术眼睑缘、结膜囊分别取材进行细菌培养及鉴定。对照组在未行任何抗菌措施前及左氧氟沙星滴眼液连续使用3 d后2个时间点对术眼睑缘、结膜囊分别取材进行细菌培养及鉴定。将两组细菌培养鉴定结果进行对比。计量资料采用两独立样本t检验进行统计学比较；计数资料组内比较采用McNemar检验，组间比较采用χ(2)检验或Fisher精确检验。 结果： 试验组在使用抗菌措施前对睑缘进行细菌培养，培养总阳性率、常见菌及非常见菌阳性率分别为83.3%（20/24）、70.8%（17/24）、45.8%（11/24）；清洁睑缘7 d后，阳性率分别为58.3%（14/24）、45.8%（11/24）、25.0%（6/24）；抗生素滴眼液滴眼3 d后阳性率分别为20.8%（5/24）、20.8%（5/24）、4.2%（1/24）；试验组抗生素滴眼液滴眼3 d后较使用抗菌措施前睑缘培养总阳性率、常见菌阳性率、非常见菌阳性率均有明显下降，差异均有统计学意义（P=0.000，0.002，0.006）。对照组在使用抗菌措施前阳性率分别为81.0%（17/21）、66.7%（14/21）、19.0%（4/21），抗生素滴眼液滴眼3 d后阳性率分别为38.1%（8/21）、14.3%（3/21）、33.3%（7/21）。对睑缘非常见菌抑菌效果比较，试验组抗生素滴眼液滴眼3 d后明显优于对照组抗生素滴眼液滴眼3 d后，差异有统计学意义（χ(2)=6.518，P=0.017）。试验组与对照组结膜囊细菌培养、常见菌、非常见菌培养结果差异均无统计学意义。 结论： 白内障摘除手术前眼睑与睑缘清洁联合抗生素滴眼液对睑缘和结膜囊有良好的抑菌效果，对于非常见菌的抑菌作用优于单纯使用抗生素滴眼液；睑缘清洁不能替代抗生素。（中华眼科杂志，2018，54：445-451）.