准分子激光角膜切削术后所用高透氧性角膜接触镜细菌培养分析

Bacterial contamination associated with bandage contact lenses after photorefractive keratectomy

目的检测准分子激光屈光性角膜切削术（photorefractivekeratectomy，PRK）后所使用的绷带式高透氧性角膜接触镜的细菌污染发生率以及菌种，为临床提供客观的指导依据。方法50例（100只眼）患者接受PRK手术，手术前取结膜囊分泌物放置于巧克力培养基上，进行细菌学培养。术后给予术眼配戴高透氧性绷带式角膜接触镜（博士伦纯视型及清朗型），常规使用抗炎药物，术后第6—8天摘除角膜接触镜，放置在巧克力培养基上，进行细菌学检测，同时再次取结膜囊分泌物进行细菌学培养。并将接触镜细菌培养阳性与阴性的患者分组对比，分析两组间矫正视力、眼压、角膜厚度等相关影响因素的差异性。结果100片角膜接触镜中，3片（3％）细菌学检测结果呈阳性，其中纯视组1例1片（1％）、清朗组1例2片（2％），检测出的细菌均为表皮葡萄球菌。所有患者术前、术后结膜囊均未监测出细菌，术后均未见眼部感染表现。阳性组和阴性组间，泪液分泌量存在差异，可能与培养阳性有相关。结论PRK术后使用的高透氧性绷带式角膜接触镜具有发生细菌污染的可能，尤其对于泪液分泌量较少的患者，其角膜接触镜发生感染机率较高。手术前后合理用药可有效控制接触镜中细菌的繁殖。

Objective To evaluate the occurrence rate and strains of bacterial contamination on bandage contact lenses after photorefraetive keratectomy （PRK）. Methods In the prospective study,50 patients （ 100 eyes）underwent PRK. Conjunctival sac secre- ta were placed onto a chocolate agar before PRK. All patients accepted bandage contact lenses and anti-inflammatory drug therapy. After PRK, contact lenses and conjunctival sac secreta were also placed onto the chocolate agar. Corrected visual acuity, intraocular pressure and corneal thickness were compared between the contact lenses with and without bacterial contamination. Results Among 100 pieces of cornea contact lens ,3 pieces（ 3% ）were contaminated with bacteria that were staphylococcus epidermis. Of the 3 pieces, 1 piece was a ＂PureVision（ balafilcon A）Visibility Tinted Contact Lense＂ and 2 pieces were ＂SofLens Toric （alphafilcon A）Visibility Tinted Con- tact Lenses＂. No bacteria were found in conjunctival sac secreta before and after operation and no postoperative eye infection was found. There was a difference in tear secretion between the bacterial contamination positive and negative groups. The difference in tear secre- tion may be related to bacterial contamination. Conclusion Bacterial contamination is possible when using bandage contact lenses after PRK, specially for patients with less tear secretion.