State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
Center for Eye Research Australia; Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia.
Sci Rep. 2020 Feb 11;10(1):2357. doi: 10.1038/s41598-020-59157-2.
Orthokeratology (Ortho-K) works to reshape cornea and is the only non-surgical way to enable vision without corrective aids. However, its effect is only temporary, and successful stabilization requires ongoing Ortho-K wear to maintain the reshaping effect. Corneal crosslinking (CXL) is a commonly-used technique in clinical practice to stabilize corneal shape in keratoconic eyes. However, whether or not CXL can stabilize corneal shape after Ortho-K in normal cornea has not been reported. Therefore, this proof-of-concept study using 2 rhesus monkeys aimed to determine the efficacy of the combined procedure. One monkey wore Ortho-K bilaterally for 24 hours, and the other from 6 pm to 8 am for 7 days. The left eyes of both monkeys underwent CXL after Ortho-K while the contralateral eye served as control. Results showed a gradual regression of corneal shape in all eyes with or without CXL. However, eyes underwent CXL regressed more slowly than the control eyes. The control eyes and the CXL treatment eye in the 7-day Ortho-K monkey regressed completely at last, while the CXL treatment eye in the 24 h Ortho-K monkey maintained a corneal flattening of -1.48 D 27 days after procedure. These findings suggest CXL can slow the regression of Ortho-K for a short duration, but cannot sustain its effect according to the current protocol.
角膜塑形术（Ortho-K）通过重塑角膜来实现视力矫正，是一种无需借助矫正辅助工具即可实现视力矫正的非手术方法。然而，其效果是暂时的，要想成功稳定视力，需要持续佩戴角膜塑形镜来维持角膜的重塑效果。角膜交联术（CXL）是临床实践中一种常用的技术，用于稳定圆锥角膜患者的角膜形状。然而，在正常角膜中，CXL 是否能稳定角膜塑形术后的角膜形状尚未有报道。因此，本研究使用两只恒河猴进行了概念验证试验，旨在确定联合治疗的效果。一只恒河猴双眼佩戴角膜塑形镜 24 小时，另一只从下午 6 点到次日早上 8 点连续佩戴 7 天。所有猴子的双眼在佩戴角膜塑形镜后均接受 CXL，对侧眼作为对照。结果显示，所有接受或不接受 CXL 的眼睛的角膜形状都逐渐出现回退。然而，接受 CXL 的眼睛回退速度比对照组慢。在佩戴 7 天角膜塑形镜的恒河猴中，对照组和接受 CXL 治疗的眼睛最终完全回退，而在佩戴 24 小时角膜塑形镜的恒河猴中，接受 CXL 治疗的眼睛在术后 27 天仍保持-1.48 D 的角膜平坦度。这些发现表明，CXL 可以在短时间内减缓角膜塑形术的回退，但根据目前的方案，不能维持其效果。
