Effect of Orthokeratology Lens on Contrast Sensitivity Function and High-Order Aberrations in Children and Adults

Objectives: Overnight orthokeratology (OOK) lenses are used to temporarily decrease myopic refractive error and improve uncorrected vision. Overnight orthokeratology lenses significantly increase ocular and corneal high-order aberrations (HOAs) and compromise contrast sensitivity function (CSF) to a degree correlated with myopic correction achieved. In Taiwan, OOK lenses are mainly used in children for myopia control. However, information regarding its effects in this population remains limited. This study discusses the change in HOAs and CSF after 28 nights of OOK lens use in children compared with that in adults. Methods: In total, 46 children (9-18 years) and 26 adults (>18 years) who visited Ophthalmology Department of Mackay Memorial Hospital from October to December 2013 were enrolled. Contrast sensitivity and ocular/corneal total high-order, coma, and spherical aberrations (SA) were tested before OOK treatment. After 28 days of overnight use, CSF and topography were reexamined, and data were collected and analyzed using t test and Pearson correlation coefficients. Results: In total, 23 eyes of 23 children and 14 eyes of 14 adults were evaluated. The treatment resulted in a significant increase in ocular total HOA, coma, and SA in both groups. However, CSF declined more in adults than children. Conclusion: Our study revealed that OOK lenses decrease CSF to a greater extent in adults than that in children despite no significant differences in the change of ocular HOAs between both subject groups. We proposed children may have better neural adaptation to compensate for optical aberrations induced by OOK lens use.