矢量分析法比较近视伴较高散光青少年配戴球面和环曲面角膜塑形镜后的临床疗效

The use of vector analysis to evaluate the changes in corneal astigmatism with general and toric orthokeratology lenses

目的 矢量分析法比较近视伴较高散光的青少年儿童患者分别配戴球面角膜塑形镜和环曲面角膜塑形镜后角膜散光的改变及临床效果。方法 前瞻性观察研究。收集2013年3月至2014年6月到广州军区武汉总医院眼科就诊的青少年儿童24例（47眼），其中球面角膜塑形镜组（简称球面组）14例（27眼），环曲面角膜塑形镜组（简称环曲面组）10例（20眼）。在配戴1 d、1周、1个月、3个月时观察患者的裸眼视力（UCVA）、角膜散光改变以及主观感觉、并发症等。2组间的比较采用独立样本t检验。结果 配戴前球面组、环曲面组近视度分别为（-3.80±1.43）、（-3.98±1.53）D；角膜散光J0分别为（-1.11±0.23）、（-1.18±0.29）D；角膜散光J45分别为（0.11±0.21）、（0.05±0.51）D。2组差异均无统计学意义。随着戴镜时间的延长，2组的UCVA呈逐步上升状态；戴镜1 d、1周、1个月时，2组间差异无统计学意义；戴镜3个月时，环曲面组（5.05±0.06）高于球面组（4.93±0.05），差异有统计学意义（t=-3.55，P〈0.05）。角膜散光J0在配戴后各时间点差异均有统计学意义（t=-4.83、-1.56、-2.38、-1.03，P〈0.05）。角膜散光J45在配戴后各时间点差异均无统计学意义。球面组中4例有重影、视力模糊等不适症状，环曲面组无一例报告有明显视觉不适症状。结论 近视伴较高散光患者配戴普通球面角膜塑形镜虽然也可以获得较好的UCVA，但是降低角膜散光的能力及镜片稳定性低于环曲面角膜塑形镜。

Objective To use vector analysis to evaluate the effectiveness of general and toric orthokeratology lenses for changes in corneal astigmatism in myopic children with moderate-to-high astigmatism. Methods This was a prospective study. Fourteen patients, 27 eyes （Spherical group）, were fitted with spherical orthokeratology lenses and 10 patients, 20 eyes （Toric group）, were fitted with toric orthokeratology lenses. Data collection was performed 1 day, 1week, 1 month, 3 months after orthokeratology fitted and included visual acuity, corneal topography, axial length and biomicroscopy examinations. Changes in corneal toricity were evaluated using vector analysis. Data were compared between the two groups using independent t test. Results The median subjective myopia of Spherical group and Toric group at base line was -3.80±1.43 D and -3.98±1.53 D （P〉0.05）. The corneal J0 vector values were -1.11±0.23 D and -1.18±0.29 D （P〉0.05） and the J45 vector values were 0.11±0.21 D and 0.05±0.51 D （P〉0.05）, respectively. After wearing orthokeratology lenses for 1 day, 1 week, 1 month and 3 months, the UCVAs improved steadily in both groups, the differences between the two groups were insignificant in 1 day, 1 week, 1 month, but with significant difference in 3 months （4.93±0.05 vs. 5.05±0.06）. The differences of corneal J0 vector values between the two groups were significant for all the time ponits （t=-4.83, -1.56, -2.38, -1.03, P〈0.05）. The differences of corneal J45 vector values between the two groups were insignificant. There were 4 and zero patients in Spherical group and Toric group who reported visual disturbance symptoms. Conclusion Both spherical and toric orthokeratology lenses can improve UCVA in myopic children with moderate-to-high astigmatism. However, the toric design can be effective for improving contact lens fitting and enhancing the effect of corneal reshaping.