应用相干光断层扫描分析白内障超声乳化术后角膜厚度的变化

Changes in corneal thickness measured with anterior segment optical coherence tomography after phacoemulsification

目的应用前节相干光断层扫描仪(AS-OCT)评估不同核分级白内障通过颞侧透明角膜切口方式进行超声乳化手术后角膜厚度随术后时间延长的变化情况。方法前瞻性系列病例研究。选择年龄相关性白内障患者82例(93只眼),依据晶状体核的混浊程度不同将患者分为3组,Ⅱ级核26例(31只眼),Ⅲ级核29例(31只眼),Ⅳ级核31例(31只眼)。术前1 d、术后1周、1个月及3个月采用AS-OCT扫面角膜中央6×6 mm及切口区域。结果 3组4个不同区域(中央顶点、距顶点3 mm处颞上、距顶点3 mm处鼻下,切口区域)的角膜厚度手术前后变化有统计学差异(F=306.23,288.34,52.17,957.28,P均=0.00)且随时间变化趋势不同(F=59.27,11.62,9.05,25.65,P均=0.00),3组间中央顶点、距顶点3 mm处颞上、切口区域角膜厚度的差异有统计学意义(F=3.59,4.43,39.67,P=0.02,0.01,0.00)。结论白内障患者核越硬,术后角膜厚度增幅越明显;不同部位的角膜术后厚度不同,呈现同一条子午线上梯度性的增厚;3个月后所有部位角膜厚度基本回归于术前水平。

Objective Using anterior segment optical coherence tomography（ AS-OCT） to assess changes in corneal thickness after phacoemulsification with clear corneal incision in patients with different nuclear grades. Methods This is a prospective case series study. Authors analyzed 82 cases（ 93 eyes） of age-related cataract patients. Based on the degree of nucleus opacity,patients were divided into three groups： nuclear grade II ~ grade IV（ each n = 31 eyes）. Corneal thickness was measured using AS-OCT preoperatively and 1 day,1 week,1 month and 3 months postoperatively. Results The corneal thickness differences between four regions of cornea（ corneal vertex,3 mm from vertex at subnasal and superior areas,and incision area） were significant in all groups（ F = 306. 23,288. 34,52. 17,957. 28 for four areas;Pall = 0. 00）. In addition,the difference in thickness between these corneal regions became eminent over time（ F = 59.27,11. 62,9. 05,25. 65 for four areas; Paverage = 0. 00）. Between the three groups of patients,corneal thickness was significantly different at center,3 mm superiotemporal apex,and incision area（ F = 3. 59,4. 43,39. 67 for three groups;P = 0. 02,0. 01,and 0. 00,repsectively）. Conclusions Authors found that the harder was the lens nucleus,the more significant in postoperative corneal thickness increase. These changes were different at various corneal regions,and tended to be increasingly eminent along the corneal radians. All changes in corneal thickness returned to baseline after 3 months.