方法：连续配戴角膜塑形镜1a以上的青少年近视患者40例80眼，平均年龄13.68±2.32岁，戴镜前平均等效球镜-3.61±1.48D，夜间戴镜8～10h，观察戴镜前和戴镜后1wk； 1，3，6，12mo的屈光度、角膜曲率、角膜表面规则指数(SRI)、泪膜破裂时间(BUT)、泪液基础分泌量、角膜上皮荧光素染色的情况。

结果：戴镜后12mo与戴镜前相比，屈光度明显降低，平均等效球镜从-3.61±1.48D下降为-1.39±1.31D，差异有显著统计学意义(P<0.01)； 角膜曲率明显变平坦，平均K值从42.29±1.55D下降为40.13±1.41D，差异有显著统计学意义(P<0.01)； SRI升高，从0.34±0.01增加到0.37±0.01，差异有显著统计学意义(P<0.01)； BUT减少，从10.39±2.25s下降到7.26±1.77s，差异有显著统计学意义(P<0.01)； 以上指标均在戴镜1wk后趋于稳定，戴镜后1，3，6，12mo各指标与戴镜后1wk相比，差异均无统计学意义(P>0.05)。泪液基础分泌量戴镜前后各时间点比较，差异均无统计学意义(P>0.05)。戴镜后角膜上皮染色病例数增加，以Ⅰ级为主，戴镜后1wk； 1，3，6，12mo角膜染色Ⅰ级分别为15眼(18.8%)，9眼(11.3%)，13眼(16.3%)，9眼(11.3%)，12眼(15.0%)。戴镜后各时间点，角膜荧光素染色Ⅰ级者的BUT均比0级者显著降低(P<0.05)。

结论：夜戴型角膜塑形镜可使近视度下降，角膜变平坦，不影响泪液的基础分泌，但泪膜稳定性下降，应注意定期随访。

METHODS: The diopter, corneal curvature, corneal surface regularity index(SRI), tear break-up time(BUT), Schirmer I test, and corneal fluorescent(FL)were recordedon 40(80 eyes)adolescent myopia patients(mean age 13.68±2.32 years), who had worn OK contact lensfor more than 1 year, with mean spherical equivalent refraction -3.61±1.48D before wearing OK contact lens. These indexes were tested and recorded before the patients' wearing OK contact lens and 5 times(1wk and 1, 3, 6, 12mo after the first wearing)during the patients' overnight wearing OK contact lens for 8～10 hours per day.

RESULTS: Compared with pre-wearing, at post-wearing OK contact lens 12mo, the mean spherical equivalent refraction was apparently decreased from -3.61±1.48D to -1.39±1.31D(P<0.01). The corneal curvature was significantly flattened from 42.29±1.55D to 40.13±1.41D(P<0.01). Mean SRI was increased from 0.34±0.01 to 0.37±0.01(P<0.01). Mean BUT was decreased from 10.39±2.25s to 7.26±1.77s(P<0.01). These indexes were stable at 1wk after wearing OK contact lens overnight and had no significant differences during the following(1, 3, 6, 12mo after wearing)tests(P>0.05). There were no significant differences on Schirmer Ⅰ test during the 12mo of OK wearing(P>0.05). The cases of corneal fluorescent staining increased were mainly grade I, and the number of corneal staining grade I at 1 wk and 1, 3, 6, 12 mo after wearing were 15 eyes(18.8%), 9 eyes(11.3%),13 eyes(16.3%), 9 eyes(11.3%), and 12 eyes(15.0%). BUT of corneal staining grade I wasdecreased significantly, compared with the BUT of corneal staining grade 0 during the 12mo of OK wearing(P<0.05).

CONCLUSION: OK contact lens can significantly decrease the degree of myopia and K value of corneal curvature without changing tear volume. However, tear film stability weakens, which needs regular follow-up.