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

Jessie Charm, Hie Hua Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)


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.
Original languageEnglish
Pages (from-to)164-170
Number of pages7
JournalContact Lens and Anterior Eye
Issue number4
Publication statusPublished - 1 Aug 2013


  • High myopia
  • Myopia control
  • Orthokeratology
  • Study design

ASJC Scopus subject areas

  • Ophthalmology
  • Optometry


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