Changes in Anterior and Posterior Corneal Curvature after Wearing Overnight Orthokeratology Lenses

Purpose: To examine the changes in anterior and posterior corneal curvature after three months of wearing overnight orthokeratology lenses (OK lens).Methods: Thirty-two healthy children were recruited for a three-month period of orthokeratology treatment and data from their right eyes were analyzed. Flat K of anterior corneal surface was measured by autorefracter. The mean K of anterior and posterior cornea readings were taken by Pentacam based on rotating Scheimpflug imaging. These measurements were taken before OK lens wear and three months after OK lens wear.Results: In our study, the anterior K readings measured by autorefracter and Pentacam were both significantly reduced after a three-month period of overnight lens wear, but the posterior Sim K readings were similar to the baseline results. The reduction in central corneal thickness was also significant after three months of overnight lens wear.Conclusion: Flattening of the anterior cornea and reduction of the central corneal thickness were observed after overnight wearing of OK lenses for three months in children. No changes were noted in the posterior corneal surface. Thus, the main effect of myopia reduction came from changes in the anterior corneal surface.