A Meta-analysis of Central Corneal Thickness Changes With Overnight Orthokeratology.

OBJECTIVES: To assess the change of central corneal thickness (CCT) in the treatment of orthokeratology in patients with myopia. METHODS: A systematic search of all relevant studies published through April 2014 was conducted, and 95% confidence intervals (CI) of CCT change were calculated. Random or fixed-effects models were used according to heterogeneity. Publication bias of the articles was evaluated using funnel plots and Begg test. RESULTS: A total of 10 studies with 239 patients (339 eyes) from clinical studies were included. Central corneal thickness reduced significantly from 1 day to 1 week by 5.73 µm (95% CI, 1.75-9.70 µm; P=0.005), and a significant mean reduction of 5.89 µm also occurred from 1 day to 1 month (95% CI, 3.50-8.29 µm; P<0.001). No significant reduction was found between 1 week and 1 month (P=0.32). CONCLUSIONS: Our meta-analysis demonstrated that most reduction of CCT occurred during the first week and remained thinner for 1 month. Further randomized controlled trials with larger sample sizes, standardized outcome measurements, and different follow-up periods are warranted to find the precise change.