Myopia control using toric orthokeratology (TO-SEE study)

Invest Ophthalmol Vis Sci. 2013 Oct 3;54(10):6510-7. doi: 10.1167/iovs.13-12527.


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.).

Keywords: astigmatism; myopia; myopia control; orthokeratology; toric design.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Astigmatism / complications
  • Astigmatism / physiopathology
  • Astigmatism / therapy
  • Child
  • Contact Lenses*
  • Cornea / pathology*
  • Cornea / physiopathology
  • Corneal Topography
  • Equipment Design
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Myopia / complications
  • Myopia / physiopathology
  • Myopia / therapy*
  • Orthokeratologic Procedures / methods*
  • Refraction, Ocular / physiology*
  • Treatment Outcome
  • Visual Acuity

Associated data