Gifford Paul, Swarbrick Helen A
School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia.
Optom Vis Sci. 2013 Apr;90(4):306-13. doi: 10.1097/OPX.0b013e318287328e.
To investigate the time course of refractive and corneal topographic changes in overnight hyperopic orthokeratology (OK) for emmetropic presbyopes.
Sixteen adult emmetropic presbyopic subjects were fitted with rigid hyperopic OK lenses (BE Enterprises, Brisbane, Australia/Capricornia, Slacks Creek, Australia) targeted to correct +2.00 D, in one eye only. The fellow eye acted as a non-lens-wearing control. Thirteen subjects completed the study. Lenses were worn overnight for a 7-day period, and changes in subjective refraction and corneal topography were measured in the morning on lens removal (A.M.) and 8 hr after lens removal (P.M.).
There were statistically significant changes from baseline in all variables at all visits in lens-wearing eyes. Hyperopic OK caused a -1.00 (0.33) D shift in best vision sphere refraction at Day1 A.M., and -1.11 (0.61) D, at Day7 A.M., with -0.91 D of best vision sphere change from baseline still apparent by Day7 P.M. (mean [SD]). This led to an improvement in monocular near visual acuity (VA) from Jaeger 10.8 (2.4) at baseline to Jaeger 4.6 (2.5) at Day1 A.M., Jaeger 3.2 (2.3) at Day7 A.M., and Jaeger 3.9 (3.0) at Day7 P.M. Binocular distance VA did not change from baseline. The central cornea steepened, and the mid-peripheral nasal cornea flattened at lens removal after one night of wear. There was no significant difference in central corneal steepening between A.M. visits, but there was longer retention of effect by Day7 P.M. Nasal paracentral corneal flattening also showed a greater effect and longer retention of effect by Day7.
Hyperopic OK induced central corneal steepening and paracentral corneal flattening, which led to a monovision myopic shift in refraction that was sufficient to provide functional correction of near vision. Lack of change in binocular distance VA indicates that hyperopic OK offers a viable option for providing monovision correction in emmetropic presbyopia.
研究正视型老花眼患者夜间远视角膜塑形术（OK）后屈光和角膜地形图变化的时间进程。
16名成年正视型老花眼受试者仅一只眼睛佩戴硬性远视OK镜片（BE企业，澳大利亚布里斯班/澳大利亚斯拉克斯克里克摩羯座公司），目标矫正度数为+2.00D。另一只眼睛作为未佩戴镜片的对照。13名受试者完成了研究。镜片佩戴过夜7天，在早晨取下镜片时（上午）和取下镜片8小时后（下午）测量主观验光和角膜地形图的变化。
佩戴镜片眼睛的所有变量在所有随访时与基线相比均有统计学显著变化。远视OK在第1天上午使最佳视力球镜验光发生-1.00（0.33）D的偏移，在第7天上午为-1.11（0.61）D，到第7天下午最佳视力球镜仍有-0.91D的变化（均值[标准差]）。这导致单眼近视力（VA）从基线时的Jaeger 10.8（2.4）改善到第1天上午的Jaeger 4.6（2.5）、第7天上午的Jaeger 3.2（2.3）和第7天下午的Jaeger 3.9（3.0）。双眼远视力与基线相比无变化。佩戴一夜后取下镜片时，中央角膜变陡，鼻侧中周边角膜变平。上午随访时中央角膜变陡无显著差异，但到第7天下午效果持续时间更长。鼻侧旁中央角膜变平在第7天时也显示出更大的效果和更长的效果持续时间。
远视OK引起中央角膜变陡和旁中央角膜变平，导致屈光发生单眼近视性偏移，足以提供近视力的功能性矫正。双眼远视力无变化表明远视OK为正视型老花眼提供单眼矫正提供了一个可行的选择。
