Sleep Quality is Associated with Axial Length Elongation in Myopic Children Receiving Orthokeratology: A Retrospective Study

PURPOSE: To identify potential demographic and lifestyle factors associated with progression of myopia with orthokeratology (ortho-k) treatment via follow-up of axial length (AL). METHODS: In this retrospective observational study, demographics, ocular parameters, near-work distance, outdoor activities, and sleep quality were analyzed in 134 children with myopia aged 8~15 years using ortho-k and a follow-up for one year. RESULTS: Compared with the slow progression group, the participants in the fast progression group were younger in age (10.55 ±1.70 years vs 9.90 ±1.18 years, P = 0.009), demonstrated higher spherical equivalent (SE) value (−2.52 ±0.63 diopters (D) vs −3.05 ±0.89 D, P < 0.001), shorter near-work distance (P = 0.010), and poorer sleep quality (Pittsburgh sleep quality index [PSQI], 4.79 ±1.29 vs 3.81 ±1.38, P < 0.001) in the one-year follow-up. Furthermore, multivariate linear regression analyses showed that baseline age (B =−0.020, P = 0.020), SE (B = 0.0517, P < 0.001), and total PSQI (B=0.026, P = 0.001) were associated with axial elongation. Advanced logistic regression analyses demonstrated that shorter average near-work distance (P = 0.034), higher SE value (P = 0.023), and poorer sleep quality (P = 0.003) were associated with fast axial elongation. CONCLUSION: Sleep quality is one of the key factors associated with axial elongation in children with myopia after using ortho-k for one year. Further studies are required to confirm this observation and expand its practical applications.