准分子激光原位角膜磨镶术对青壮年近视患者玻璃体后脱离的影响

目的 探讨准分子激光原位角膜磨镶术（ LASIK）对青壮年近视患者玻璃体后脱离（PVD）的影响.方法 前瞻性系列病例研究.利用光学相干断层扫描（OCT）结合眼部B超对305例（607眼）青壮年近视患者于LASIK术前,术后1 d、1个月、3个月、6个月进行PVD检测,观察术后不同时间点PVD发生率的变化.并对术前OCT证实的PVD阳性眼进行术后黄斑周围四方位PVD高度、范围的检测与量化分析.数据采用x2检验、单因素方差分析、Friedman秩和检验进行处理.结果 LASIK术前及术后1 d、1个月、3个月、6个月,PVD发生率分别为26.5％、31.8％、32.0％、33.2％、34.7％,差异有统计学意义（x2=10.462,P＜O.05）,而术后不同时间点PVD发生率差异无统计学意义.相比术前,上方PVD高度在术后1个月开始增高,差异有统计学意义（F=4.056,P＜0.05）,其他各方位PVD高度术后差异无统计学意义.术后不同时间点之间黄斑区上方、下方、鼻侧、颞侧PVD高度变化差异无统计学意义.术后黄斑区上方、下方、鼻侧、颞侧方位PVD近点距（ND）均有减小（M=321.0、102.8、113.8、228.5,P均＜0.05）,远点距（FD）均有增大（M=276.1、139.8、157.6、204.7,P均＜0.05）.上方、颞侧FD在术后6个月时仍有增大趋势,其他各方位ND、FD变化趋势在术后6个月内趋于稳定.结论 青壮年近视患者LASIK术后短时期内可诱发PVD产生,并能使PVD脱离的高度增高、范围扩大.

Effects of laser in situ keratomileusis on posterior vitreous detachment in young adult myopes

Objective To investigate the incidence,height and extent of posterior vitreous detachment (PVD) after laser in situ keratomileusis (LASIK) in young adult myopes.Methods This was a prospective case-series study.Optical coherence tomography (OCT) combined with B-scan was performed to examine the PVD on 305 myopia patients (607 eyes) before LASIK and 1 day,1 month,3 months, and 6 months after surgery.The incidence of PVD was observed before and after the surgery.The eyes with preoperative PVD, which had been confirmed by OCT,were measured after surgery to examine the height and the extent of PVD (the near distance and the far distance to the fovea centralis of the macula) among various quadrants of the perimacular after surgery.Data were analyzed with a x2 test,a one-way ANOVA, and a Friedman rank test.Results The incidence of PVD at 1 day, 1 month, 3 months, and 6 months after surgery was 31.8％, 32.0％, 33.2％,34.7％, respectively.The incidence of various indicators after surgery was significantly higher than that before surgery (26.5％) (x2=10.462,P＜0.05).The heights of PVD in the superior quadrant began to increase 1 month after surgery (F=4.056,P＜0.05).Though the heights of PVD in the other three quadrants were also heightened increased after surgery, there were no statistically significant differences, compared to preoperative level.The near distances of PVD in the superior, inferior,nasal, and temporal quadrants of the perimacular area were decreased after surgery (M=321.0,102.8,113.8,228.5,P＜0.05),while the furthest distances of PVD in the above four quadrants were increased after surgery (M=276.1, 139.8, 157.6,204.7,P＜0.05).The far distance of PVD in the superior and temporal quadrants had a tendency of continuous increases,while the far distance of PVD in the inferior and nasal quadrants and the near distance tended to stabilization during the 6months after surgery.Conclusion In the short term,LASIK may increase the occurrence of PVD,raise the height of PVD and enlarge the extent of PVD in young adult myopes.