Skip to main content

A clinical method for predicting the success of orthokeratology treatment phase I

1 February 1995


Orthokeratology (OK) is a method of fitting rigid contact lenses in a progression in order to change the cornea's radius of curvature, resulting in an improvement in uncorrected visual acuity. The usefulness of OK for most patients will depend on both the magnitude of myopia reduction and the amount of time he or she must wear a "retainer lens" to maintain that change. This study is an attempt to create a simple and clinically practical procedure to predict which patients will require the least amount of retainer lens wear while maintaining optimal visual acuity, and is divided into two phases.

Phase I of this study was devoted to an assessment of the efficacy and duration of refractive changes induced by short-term OK lens wear and whether or not different individual refractive errors respond differently to the OK lens effect. Statistical analysis revealed a significant difference between subjects' RE changes. That is, patient refractive errors did respond differently from each other when subjected to the OK lenses.

In Phase II, ten patients from Phase I were selected to receive the OK treatment. After patients have achieved minimal wear time of their OK retainer lenses, a comparison of the retainer lens wearing time and the initial changes in refractive condition found in Phase I will be statistically correlated. We hypothesize that those patients whose refractive condition changed the least in the two hours post OK lens removal will require the least amount of retainer lens wear at the end of the OK procedure. Phase II is currently under way, with completion anticipated sometime in 1995.


Files are restricted to Pacific University. Sign in to view.