长期配戴RGP对角膜屈光力及散光的影响

Effects of long-term wearing rigid gas permeable contact lens on corneal refractive power and astigmatism

目的观察长期配戴硬性透气性角膜接触镜（RGP）后，角膜屈光力及散光的变化。方法前瞻性临床研究。选取2013年1月至2015年12月来我院眼科就诊验配RGP的患者共53例（106只眼），除屈光不正外无任何眼病。根据其角膜散光的大小分为A组（角膜散光〈2．00D）19例（38只眼），B组（角膜散光2．00。4．00D）17例（34只眼），C组（角膜散光〉4．00D）14例（28只眼）。各组患者戴镜前及戴镜24个月后停戴3d、停戴3周时进行角膜地形图检查，比较陡峭子午线角膜屈光力（Ks）、平坦子午线屈光力（1〈f）及柱镜度数（Cyl）的前后变化。对相关数据进行配对t检验及单因素方差分析。结果戴镜24个月并停戴3d时，三组Ks、Cyl数值均较戴镜前有统计学意义的降低（P〈0．05），Kf数值较戴镜均前无明显变化（P〉0．05）。A组、B组、C组的Ks减小量依次增加，分别为（0．146±0．454）D、（0．365±0．383）D、（0．790±0．518）D（F=13．338，P〈0．001），A组与B组．A组与C组，B组与C组之间差异有统计学意义（P=0．022，P〈0．001，P=0．002）；Cyl的降低数值亦逐渐增加，分别为（O．165±0．451）D、（0．372±0．403）D、（0．741±0．574）0（F=10．099，P〈0．001）A组与B组，A组与C组．B组与C组之间差异均有统计学意义（P=0．036，P〈0．001，P=-0．008）。各组停戴3周后的Ks、酣结果与停戴3d时的结果接近，差异均无统计学意义（19〉0．05）。结论长期配戴RGP，角膜散光会降低，角膜散光越大降低越多．角膜散光的减小主要与Ks值的降低有关。

OBJECTIVE To observe changes of corneal refractive power and astigmatism after long-term wearing rigid gas permeable contact lens（RGPCL）. METHODS This was a prospective study. From January 2013 to December 2015, 53 patients （ 106 eyes） without eye disorders except ametropia, that visited our hospital for RGPCL were included. According to the corneal astigmatism value, the patients were divided into 3 groups ： corneal astigmatism value less than 2. 00D in group A （19 patients, 38 eyes）, between 2. 00D and 4, 0D in group B （17 patients, 34 eyes）, more than 4. 0D in group C （14 patients, 28 eyes）]. All patients were examined by corneal topography before wearing RGPCL and 3 days after 24 months wearing as well as 3 weeks after 24 months wearing. The flatkeratometry （Kt）, the steepkeratometry （Ks） and the cylinder （Cyl） values were recorded. The recorded data were analyzed with paired t-test and one-way analysis of variance. RESULTS The third day after 24 months wearing RGPCL, in all groups, the Ks and the Cyl experienced a statistically significant decrease （P 〈 0.05） while the Kf had no significant change （P 〉 0.05） . The Ks of A group, B group and C group reduced increasingly in sequence as 0.146±0.454D, 0.365±0.383D, 0.790±0.518D （F = 13.338, P〈 0.001）. And differences between group A and group B, group A and group C, group B and group C were statistically significant （19=0.022, P〈0.001, P=0.002）; same happened to Cyl as 0.165±0.451D, 0.372±0.403D, 0.741±0.574D （F=10.099, P〈0.001 ）. And differences between group A and group B, group A and group C, group B and group C were statistically significant （P=0.036, P〈0.001, P=0.008）. Comparison between the 3rd day and the 3rd week after 24 months wearing showed no difference in terms of Ks, Kf and Cyl （P 〉 0.05）. CONCLUSIONS The study showed that the corneal astigmatism can be decreased with long-term wearing RGPCL, in addition, worse corneal astigmatism reduced more sharply. The reduction of corneal astigmatism was mainly related to decrease of Ks value.