Effect of orthokeratology on the remodeling of the anterior corneal surface and the delaying of eye axis growth in children.
Authors: zhang siqi , zhu huailin , zhang lan , gao mingjun , liu changyang , zhao qi 
Published: August 2023

Abstract
Purpose
Our study aims to analyze the effect of orthokeratology (OK) lenses on the development of myopia and eye axis growth in children while also evaluating the corneal reconstruction that occurs as a result. The study seeks to explore the correlation between the flat K of the central cornea and the changes in the axial length resulting from the use of OK lenses.
Methods
This study focused on patients aged 8–15 years old who were wearing OK lenses and receiving treatment at the pediatric outpatient clinic of the Second Affiliated Hospital of Dalian Medical University. The patients underwent various examinations, including slit lamp examination, visual acuity, computerized optometry, intraocular pressure, biometric measurement, and corneal topography examination before treatment and at 1 month, 3 months, and 6 months after treatment. All patients were divided into four groups according to age: younger group (8–11 years); older group (12–15 years) and initial degree of myopia: (low-grade myopia group (-1.00 D < SE < 3.25D); medium myopia group (-3.25 D < SE < 6.00D). The study followed the inclusion and exclusion criteria. Statistical analysis was conducted using SPSS software, and the expected results were discussed and analyzed.
Results
After wearing OK lenses, all four groups achieved good visual acuity at the 1-, 3-, and 6-month follow-ups. By the 6th month, both the LL and LM groups, as well as the HL and HM groups, achieved a standard visual acuity of approximately 1.0. There were noticeable differences in the initial eye-axis lengths among the four groups (P < 0.001). Specifically, the LM group had greater eye-axis lengths than the LL group (P < 0.001), while the HM group had greater eye-axis lengths than the HL group (P < 0.001). However, there were no significant differences in the amount of change in the ocular axis at 1, 3, and 6 months between the groups. There was a statistically significant difference in the amount of change in the corneal flat K-value at 1, 3, and 6 months between the groups (P1 = 0.001, P3 = 0.001, and P6 = 0.004, 0.05) but not in the amount of change in the e-value (P1 = 0.205, P3 = 0.252, > 0.05, not statistically significant); regression analysis of the amount of change in the k-value and the amount of change in the e-value revealed no statistically significant differences
Conclusion
The results show that the shaping effect of OK glasses on the cornea does not correlate significantly with the age and initial myopia of the child and that the rate of delayed axial growth with appropriate OK glasses is consistent across children of different ages and initial myopia; changes in flat K and e values do not accurately predict each individual. Axial growth of the eye may be impacted by changes in e-values due to the shaping action of orthokeratology lenses. According to our theory, axial development may be lessened, and the shift in morphology from the center to the peripheral zone of the cornea will be more obvious with a larger corneal e-value change.