Anterior segment changes produced in response to long-term overnight orthokeratology

Curr Eye Res. 2013 Aug;38(8):862-70. doi: 10.3109/02713683.2013.790977. Epub 2013 Apr 30.


Purpose: To evaluate the effect of overnight orthokeratology (OK) on anterior chamber depth (ACD), posterior radius of corneal curvature (PRCC) and axial length (AL) over one year.

Methods: In this prospective longitudinal study, measurements were made in 34 right eyes of 34 subjects at baseline, 15 days, 1 and 12 months after starting OK treatment. ACD and PRCC measurements were obtained using a Pentacam system and AL was measured using an IOL-Master. ACD and PRCC were measured along the horizontal and vertical meridians at 1 mm intervals. These measurements were expressed as the distance from the center in the nasal (N), temporal (T), superior (S) and inferior (I) directions.

Results: A significant reduction in ACD was observed in both meridians during treatment. PRCC flattened significantly in the (T) direction after 15 d (1 mm, p < 0.05), at the corneal center after 15 d (p < 0.01), in the (T) direction after 1 month (1 mm, p < 0.05), in the (S) direction after 12 months (1 mm p < 0.05), in the (N) direction after 12 months (1 mm p < 0.05), in the (N) and (T) directions after 12 months (3 mm, p < 0.05) and in the (T) direction after 12 months (4 mm p < 0.05), at the corneal center after 12 months (p < 0.01). AL was significantly reduced during treatment (p < 0.05).

Conclusions: A long period of OK reduces ACD and AL and changes PRCC.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Anterior Chamber*
  • Axial Length, Eye
  • Contact Lenses*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Myopia / therapy*
  • Orthokeratologic Procedures / methods*
  • Photography / methods
  • Photography / standards
  • Prospective Studies
  • Reproducibility of Results
  • Statistics, Nonparametric
  • Treatment Outcome
  • Visual Acuity
  • Young Adult