圆锥角膜配戴RGPCL后角膜生物力学性能改变

目的观察圆锥角膜患者配戴1年以上RGPCL后的角膜形态、角膜厚度和角膜生物力学性能变化。方法回顾性系列病例研究。选择诊断为中、重度圆锥角膜患者15例（30眼），平均球镜度为（-9.53±3.60）D，平均散光度为（-3.42±2.13）D。为患眼验配RGPCL，采用配对t检验比较初诊和戴镜1年后球镜度和散光度，角膜平坦K值和陡峭K值，角膜厚度值及角膜黏滞性（CH）值和角膜阻力因子（CRF）值的差异。结果戴镜1年以上，患眼角膜陡峭K值从（49.21±4.06）D降低至（47.95±3.16）D（t=3.156，P<0.05），角膜规则指数（SRI）及角膜不规则指数（SAI）分别从戴镜前的0.47±0.15和0.49±0.16降低至0.36±0.14和0.38±0.19（t=2.314、2.253，P<0.05）。角膜散光度由（-3.42±2.13）D减小至（-2.63±1.57）D（t=-5.270，P<0.01）。角膜厚度未见明显改变。角膜生物力学性能指标CH及CRF值分别由（8.26±0.39）mmHg和（7.53±0.56）mmHg上升至（10.23±0.49）mmHg和（9.05±0.58）mmHg（t=-5.954、-5.340，P<0.01）。结论中、重度圆锥角膜配戴RGPCL 1年后角膜生物力学性能指标随角膜形态规则化改变而升高。角膜生物力学性能可作为圆锥角膜配戴RGPCL后疗效及病情转归的重要判定指标。

Corneal biomechanical properties changes in keratoconus eyes induced by rigid gas-permeable contact lenses

ObjectiveTo observe the changes in corneal shape， corneal thickness and corneal biomechanics in keratoconus patients who wore RGPCL for more than 1 year. MethodsIn this retrospective case series study， 15 patients （30 eyes） with moderate or worse keratoconus were recruited. Average spherical and astigmatic powers were -9.53±3.60 D and -3.42±2.13 D， respectively. The RGPCL were fitted for diagnosed keratoconus eyes， and a paired t-test was used to compare corneal parameters between before and after 1 year of lens wear. Measured parameters included spherical and astigmatism power， corneal flat and steep K values， corneal thickness， corneal hysteresis （CH） and the corneal resistance factor （CRF）. ResultsSome changes occurred to keratoconus eyes after 1 year of wear： corneal steep K values decreased from 49.21±4.06 D to 47.95±3.16 D （t=3.156， P<0.05）； the corneal surface regularity index （SRI） and surface asymmetry index （SAI） decreased from 0.47±0.15 and 0.49±0.16 to 0.36±0.14 and 0.38±0.19 （t=2.314， 2.253， P<0.05）； corneal astigmatism decreased from -3.42±2.13 D to -2.63±1.57 D （t=-5.270， P<0.01）； corneal thickness had no significant change； corneal biomechanical CH increased from 8.26±0.39 mmHg to 10.23±0.49 mmHg （t=-5.954， P<0.01）； and corneal biomechanical CRF increased from 7.53±0.56 mmHg to 9.05±0.58 mmHg （t=-5.340， P<0.01）. ConclusionBy following the change in corneal shape after 1 year of RGPCL wear， corneal biomechanical properties have significant increases in eyes with moderate or worse keratoconus. The patient′s condition and corneal biomechanics can be the key indicators for the efficacy of treating keratoconus patients with RGPCLs.