High myopia-partial reduction orthokeratology (HM-PRO): study design

Cont Lens Anterior Eye. 2013 Aug;36(4):164-70. doi: 10.1016/j.clae.2013.02.012. Epub 2013 Mar 18.


Purpose: To report the study design and preliminary results of a pilot study, High Myopia-Partial Reduction Orthokeratology study.

Methods: Children with myopia of 6.00D or above and who satisfied the recruitment criteria were randomly assigned to partial reduction orthokeratology (PR ortho-k) and spectacle-wearing control groups. The myopia of the PR ortho-k children were partially reduced using custom made 4-zone ortho-k lenses of target 4.00D. Residual refractive errors were corrected with single vision spectacles. Control subjects were fully corrected with single vision spectacles. PR ortho-k subjects were also required to return for assessment after the first overnight lens wear, and one week and one month after lens wear.

Results: Fifty-two eligible subjects were randomly assigned to PR ortho-k group (n=26) and control group (n=26). The median age of each group was 10.00 years. The median (range) subjective myopia of the right eye at baseline was 6.41D (5.00-8.00D) and 6.22D (6.00-8.00D) for PR ortho-k and spectacle groups, respectively (p>0.05). Nineteen (79%) PR ortho-k subjects achieved successful lens fit at the one month visit and the median myopic reduction was 3.75D in the right eye. The incidence of (mild) corneal staining in PR ortho-k subjects reduced from 30% at the first overnight lens wear to 16% at the 1-month visit. Corneal pigmented arc was observed in 32% of PR ortho-k subjects at the 1-month visit.

Conclusions: PR ortho-k was successfully applied to high myopic children with no significant changes in ocular health/best corrected visual acuity after one month of lens wear.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Contact Lenses
  • Eyeglasses*
  • Female
  • Humans
  • Male
  • Myopia / diagnosis*
  • Myopia / rehabilitation*
  • Orthokeratologic Procedures / instrumentation*
  • Orthokeratologic Procedures / methods*
  • Pilot Projects
  • Research Design
  • Single-Blind Method
  • Treatment Outcome