Myopia control using toric orthokeratology (TO-SEE study)

Connie Chen, Sin Wan Cheung, Hie Hua Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

190 Citations (Scopus)


Purpose. This nonrandomized clinical study aimed to investigate the effectiveness of toric orthokeratology (ortho-k) for myopia control in myopic children with moderate-to-high astigmatism. Methods. We enrolled 80 subjects (aged 6-12 years; ortho-k, 43; control, 37) with myopia of 0.50 to 5.00 diopters (D), and with-the-rule astigmatism of -1.25 to -3.50 D, and unremarkable ocular and general conditions. Data collection, including visual acuity, subjective and objective refraction, axial length, corneal topography, and biomicroscopy examination, was performed every 6 months during the 24-month study period. Results from the right eye or the eye with higher astigmatism were reported. Results. A total of 35 ortho-k and 23 control subjects completed the study successfully. Subjects in both groups demonstrated axial elongation (P < 0.001). The average axial elongation at the end of study was 0.31 ± 0.27 and 0.64 ± 0.31 mm in the ortho-k and control groups, respectively (P < 0.001). At the end of 24 months, axial elongation in ortho-k subjects was 52% slower than that in the control group. Axial elongation was correlated significantly with the initial age of the subjects (P = 0.02) and treatment assigned (P = 0.04), but not with sex, initial myopia, initial refractive cylinder, or initial corneal toricity (P > 0.08). Conclusions. Toric ortho-k lenses can slow axial elongation effectively in myopic children with moderate-to-high astigmatism. ( number, NCT00978692.)
Original languageEnglish
Pages (from-to)6510-6517
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Issue number10
Publication statusPublished - 10 Oct 2013


  • Astigmatism
  • Myopia
  • Myopia control
  • Orthokeratology
  • Toric design

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience


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