Abstract
Purpose :
To determine the efficacy of corneal crosslinking (CXL) in stabilizing corneal shape molded by orthokeratology (Ortho-K) in rhesus monkeys.
Methods :
Two rhesus monkeys wore bilateral Ortho-K lenses based on the standard protocol for the treatment of myopia in humans. One monkey wore Ortho-K lenses continuously for 24 hours, while the other monkey wore them overnight only for 7 consecutive days. After removal of the Ortho-K lenses, each monkey underwent standard corneal crosslinking in one eye while using the fellow eye as a control. Slit-lamp microscopy, corneal topography and retinoscopy refraction measurements were conducted in follow-up examinations at 1-week intervals for a period of approximately 1 month. Differences between CXL treatment eyes and control eyes were observed.
Results :
Central corneal flattening was achieved after wearing Ortho-K lenses for 24h and 7 days, and subsequently a gradual regression of corneal shape was observed in all eyes with or without CXL treatment. In the 7-day Ortho-K lens group, the control eye regressed to original corneal shape by 6 days, while the CXL eye regressed completely by 14 days. In the 24h Ortho-K lens group, the control eye regressed completely by 8 days, while the CXL eye maintained a certain degree of corneal flattening at 27 days post-operatively. For both monkey wearing lens for 24h and 7 days, the refraction change during regression showed similar trends between the control and CXL treatment eye.
Conclusions :
The corneal CXL technique appears to slow regression of Ortho-K in the normal cornea to a limited extent, however this effect does not appear to be sustained in the long term according to the current protocol.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.