LASEK术后角膜接触镜的细菌学检测

目的 检测准分子激光上皮瓣下角膜磨镶术(LASEK)后所使用的绷带式角膜接触镜的细菌污染菌种和位置.方法 前瞻性调查研究.20例(35眼)接受LASEK手术的患者于术后即刻配戴绷带式角膜接触镜,常规使用抗炎药物,术后第6天使用无菌镊摘除角膜接触镜,并采用无菌剪将角膜接触镜剪成两半,分正反面放置在巧克力培养基上,进行细菌学检测和药物敏感性实验.结果 35片角膜接触镜中,5片(14％)细菌学检测结果呈阳性,其中4片细菌生长位置为角膜接触镜的内侧面,1片生长于角膜接触镜的外侧面.检测出的细菌有甲氧西林敏感的凝固酶阴性葡萄球菌、甲氧西林耐药的凝固酶阴性葡萄球菌、棒状杆菌和微球菌.检测到的菌种对左氧氟沙星和妥布霉素敏感.所有患者均未见明显眼部感染表现.结论 LASEK术后使用的角膜接触镜具有发生细菌污染的可能,尤其在角膜接触镜的内侧面,可能与手术造成局部适宜细菌生长的微环境有关,手术前后合理用药、术中保护角膜瓣活性有利于降低感染的风险.

Study of bacterial contamination associated with bandage contact lenses after laser subepithelial keratectomy

Objective To evaluate the locations and agents of the bacterial contamination of bandage disposable soft contact lenses after laser subepithelial kerateetomy （LASEK）. Methods It was a prospective investigative study. Bandage disposable soft contact lenses were collected with sterile forceps from 35 eyes of 20 consecutive patients treated for myopia with LASEK. Immediately after collection, each lens was cut into two parts with sterile scissors and placed onto chocolate agar with the outer surface of one piece placed down and the inner surface of the other piece placed down. The lenses were analyzed for bacterial colonization and the inner and outer surfaces were evaluated. Results Five （14%） positive cultures were found on the bandage contact lenses. Four of them appeared on the inner surface of the lens; one of them appeared on the outer surface. Methicillin-sensitive, coagulase-negative staphylococci （MSSCoN）, methicillin-resistant, coagulase-negative staphylococci （MRSCoN）, corynebacterium and micrococcus were isolated in the positive cultures. All of the microorganisms were sensitive to the administered antibiotics levofloxaxin and tobramycin. No clinical findings of infection were noted. Conclusion Bacterial contamination is possible when using bandage contact lenses after LASEK, especially on the inner surface of the lens. The reason may be related to the procedure of keeping the epithelial flap in place which could develop a local environment suitable for bacterial colonization and potential infection.