The incidence of myopia in adolescents is gradually increasing, and orthokeratology has achieved effective effects in controlling the progress of myopia, but the effects are mixed. The retrospective study included 30 monocular orthokeratology (ortho-k) lens-treated adolescents to explore the true effectiveness of ortho-k lenses and 36 binocular ortho-k lenses-treated adolescents to study the influencing factors of ortho-k lenses. After 12 months, among 30 adolescents treated with monocular ortho-k lenses, the average axial elongation in the ortho-k group was significantly less than that in the control group (P = 0.002). After 24 months, among 36 adolescents treated binocular ortho-k lenses, the axial elongation in the different initial age groups and different initial myopia groups were significantly different (all P < 0.05). Axial elongation correlated negatively with initial myopia during follow-up periods. In adolescents with myopia, axial elongation can be controlled effectively using an ortho-k lens. Younger children with initial higher myopia will benefit more than older children with initial lower myopia.

Background To investigate which baseline factors are predictive for axial length growth over an average period of 1 years in a group of adolescents wearing orthokeratology (OK) contact lenses.Methods In this retrospective study, the clinical records of 189 new OK wearers (378 eyes) between 2014 and 2018 at Xiangya Hospital of Central South University were reviewed. The primary outcome measure was axial length change from baseline to the time of 1 year. Independent variables included baseline measures of age at initiation of OK wear, refractive error (spherical equivalent), corneal thickness, corneal curvature. (1) Age group, 8 ~ 10 years old is the first group, 10 ~ 13 years old is the second group, ≥13 years old is the third group; (2) Myopia degree group, ≥-3.00D is the first group, -3.00 ~ -6.00D is the second group, <-6.00D is the third group; (3) corneal thickness group, ≤550μm is the first group,> 550μm is the second group; (4) corneal curvature group, ≤42.0D is The first group, 42.0 ~ 44.0D is the second group,> 44.0D is the third group.Results ANOVA was used to analyze the difference between the baseline axial length of each group and the axial length for 1 year after continuous wearing of orthokeratology: (1)The mean axial difference between different age groups are 0.251mm, 0.033mm,and 0.112mm, and the difference of the three groups is not statistically significant (F=2.279，P=0.104). By pairwise comparison, only the difference between the first group and the third group is statistically significant (P=0.041); (2) The mean axial difference between different myopia degree groups are 0.173mm, 0.109mm and -0.008mm, and the difference of the three groups is statistically significant (F=8.340，P=0.000 ). By pairwise comparison, the difference between the first group and the second group is statistically significant (P=0.000) and the difference between the first group and the third group is statistically significant(P=0.016); (3) The mean axial difference between different corneal thickness groups and corneal curvature groups is not statistically significant.Conclusions OKs are effective in controlling axial length elongation and myopic progression in adolescents, particularly in younger children with higher myopia.