August 1, 2025
By Kevin Chan, OD, MS, FAAO, IACMM
Photo Credit: Getty Images
The article written by Fan et al. investigates a plethora of risk factors and biometric variables that affect the success of orthokeratology in patients with low myopia. It also further elucidates current strategies to optimize treatment outcomes for patients in this subgroup.
Clinical Relevance and Significance
Children with incipient or low myopia (defined as −0.50D to −3.00D in this research) are generally an overlooked group of patients whose myopia risks and progression are often mistaken by parents, or underestimated as ‘not bad enough’ in the eye care community. Meanwhile, it is also well documented that the younger the onset of myopia, the greater the progression of myopia during development. For that, children who are treated withOrthoK are likely to have slower myopia progression, particularly with a potentially greater effect when initiated at a younger age. Nevertheless, little evidence is known as to which biometric factors or variables would likely influence the effectiveness of OrthoK treatment for patients with incipient or low myopia. This research aims to help elucidate the key biometric factors that can identify patients at greater risks of rapid axial length progression, and thereby develop effective management strategies for OrthoK-treated individuals with low myopia.
Study Methodology and Statistical Analysis
- A 12-month retrospective study examining 380 children in OrthoK treatment.
- Data analysis was conducted in the Optometry Center at Peking University People’s Hospital between January 2021 and December 2022.
- Sample randomization was made to minimize correlative effects of laterality between the eyes. A sample of 191 right eyes and 189 left eyes were included in this study.
- Inclusion criteria:
- Best-corrected monocular visual acuity greater than, or equal to, 20/20;
- Children of Chinese descent aged 8 to 15 years;
- Spherical Equivalent Refraction (SER) −0.50D and −5.75D;
- Subgroup 1 – ‘Low’ myopia: −0.50D to −3.00D
- Subgroup 2 – ‘Moderate’ myopia: −3.25D to −5.75D
- Refractive astigmatism less than 1.50D;
- Slow axial length (AL) threshold: ≤0.20 mm/year
- Exclusion criteria:
- History of ocular or systemic conditions, such as connective tissue disorders, Down syndrome, and Marfan syndrome;
- Modification of prescription during OrthoK lens wear;
- Discontinuation of OrthoK lens use during the study period
- Study groups:
- Low myopia with slow AL elongation
- Low myopia with rapid AL elongation
- Moderate myopia with slow AL elongation
- Moderate myopia with rapid AL elongation
- Univariate and multivariate binary logistic regression were used to analyze the correlations of rapid axial length elongation and a myriad of risk factors (e.g. age, gender, mean K, parental myopia, daily near work time, dietary habits)
- Multinomial logistic regression was used to further differentiate the effects of biometric factors among different study groups (p<0.05)
Sound Clinical efficacy by OrthoK for Low Myopes
The authors reported that there was clinically significant axial length changes found between the low and moderate myopia groups (0.24±0.21 mm vs. 0.14 ± 0.165 mm, P<0.0001). In particular, the low myopia group showed a greater 12-month AL growth compared to the moderate myopia group.
Notable findings of the study:
- Children with low myopia treated with OrthoK alone were nearly 2.95 times more likely to exhibit greater AL elongation than OrthoK-atropine combined for the same group.
- Some of the factors associated with poorer treatment outcomes included female gender, flatter mean K and having two myopic parents.
- Those who consumed diets rich in white meats, e.g. fish, duck, were 16.67 (1/0.06) times more likely to have a slower AL growth than children with low myopia who consumed a normal diet.
Contemporary Management Strategies for Low Myopia
The authors in this research outline a multi-faceted management approach, including:
- Comprehensive assessment via corneal topography and tear function evaluation.
- Individualized lens design selection to accommodate unique corneal shapes and refractive needs.
- Despite its seemingly innocuous nature toward myopia progression, the authors asserted that children with low myopia indeed warrant a more proactive surveillance and assertive clinical approach by practitioners. In particular, OrthoK combined with atropine treatment can be clinically more effective for those with low myopia at an early age.
- Increased intake of white meat likely yields slower progression of myopia. This association was suggested to be attributable to a low, unsaturated fat diet.
Study Limitations
- Questionnaire-based study design was using parent-reported data, which can be subject to recall bias. Validation of the questionnaire is warranted.
- Data collection methods were widely varied (particularly for the behavioral factors); therefore, accuracy and reproducibility can be subject to skewed results.
Expand the Applications of OrthoK and Atropine for Children with Low Myopia
The study advocated for the application of OrthoK for children with low myopia. Meanwhile, for those at-risk children, it is also crucial to identify patient and parental demographics, as well as corneal characteristics and near-work habits. In addition, a combined treatment approach via OrthoK and atropine eye drops is likely to yield greater efficacy than OrthoK as monotherapy for children with low myopia. Moreover, environmental and behavioral modifications for at-risk children are emphasized despite low, allegedly ‘safe,’ myopia status.
Abstract
Factors Influencing Ortho-K Treatment in Low Myopia and Management Approaches
Fan, Yuzhuo PhD; Li, Xuewei PhD; Chen, Sitong MSc; Li, Yan MSc; Zhao, Mingwei MD; Wang, Kai MD
Purpose
This study aimed to identify the key demographic, biometric, and behavioral factors that impact the treatment effect of Ortho-K in low myopia and to discover the management ideas for low myopes undergoing Ortho-K treatment.
Methods
A 12-month retrospective study examined 380 individuals who received Ortho-K treatment. Stratification and multinomial logistic regression were conducted to identify biometric features and behavioral indicators associated with Ortho-K treatment outcomes in low myopes.
Results
The 12-month axial length growth was significantly longer in the low myopia group than in the moderate myopia group (P<0.0001). Multivariate logistic regression analysis showed that Ortho-K only was 2.23 times more likely to have rapid axial growth than Ortho-K combined with 0.01% atropine in patients with low myopia (P=0.01; odds ratio [OR]=2.23; 95% confidence interval [CI], 1.19–4.20). Multinomial logistic regression analyses showed that in patients with low myopia, female sex (P<0.0001; OR=0.4; 95% CI, 0.22–0.72), young age (P=0.01; OR=0.79; 95% CI, 0.66–0.93), flatter K mean (P=0.004; OR=0.74; 95% CI, 0.61–0.91), and having two myopic parents (P=0.03; OR=0.18; 95% CI, 0.05–0.71) were associated with worse treatment outcomes. A diet rich in white meats, such as fish and duck (P=0.01; OR=0.06; 95% CI, 0.01–0.54), was protective behavioral factors associated with slower axial length growth in children with low myopia.
Conclusions
Patients with low myopia who exhibit one or more of the demographic and biometric risk factors (young age, female, flat mean K, and two myopic parents) require heightened attention in clinic settings because of their increased risk of myopia progression. Ortho-K combined with 0.01% atropine may achieve better efficacy than Ortho-K only in low myopes. A diet rich in white meat is protective and controlled behavioral factors for these patients.
