Orthokeratology : Compendium of latest research

back

Seven-year retrospective analysis of the myopic control effect of orthokeratology in children: a pilot study

This Hong Kong Study reviewed the clinical records of over 200 short-sighted children attending a local opticians over a prior period of seven years and for a sub-group of 70 children divided into those who had undergone Overnight Vision Correction (OVC) treatment with an average commencement age of 9 and those who had worn spectacles with an average commencement age of 10. After seven years, the children wearing overnight ortho-k corrective contact lenses were shown to have only a modest increase in their short-sight of just over one-third of a diopter whilst those wearing spectacles showed an increase in their short-sight of more than two diopters. This significant difference - albeit based on a retrospective study rather than a controlled clinical trial - still confirms the superior performance of OVC in slowing down or halting the further development of short-sight in children. 

Objectives: To investigate retrospectively the difference in myopia progression, over about 7 years, between two groups of Hong Kong Chinese myopic children who wore overnight orthokeratology lenses or single-vision spectacles.

Methods: A total of 238 records of children wearing overnight orthokeratology lenses or single-vision spectacles from Eye'ni optical shop (Hong Kong) between January 1999 and December 2009 were reviewed. Refractive and central corneal curvature data with 6-year or a longer follow-up period of 70 patients were retrieved: 34 children (15 boys and 19 girls, aged 9.2 ± 1.8 years) wore orthokeratology lenses and 36 (20 boys and 16 girls, aged 10.2 ± 2.0 years) wore spectacles. Myopic progression was determined as the change of myopia from the baseline to the final visit.

Results: No statistically significant differences (P . 0.05) in age, central flat corneal curvatures, baseline refractive error, or follow-up period were observed between the two groups. Average myopic progression of the overnight orthokeratology contact lens cohort (-0.37 ± 0.49 D) was significantly less (P , 0.001) than of the single-vision spectacle group (-2.06 ± 0.81 D) over about 7 years.

Conclusion: Our preliminary 7-year data support the claim that overnight orthokeratology contact lenses may be a feasible clinical method for myopic progression control. Prospective and randomized investigations are warranted to overcome the limitations of this retrospective study.

Alan Kwok-hei Mok, Cindy Sin-Ting Chung Eye'ni,;Department of Anatomy,LiKaShing Faculty of Medicine, TheUniversity of Hong Kong, Hong Kong,People's republic of China 

Read full article at Clinical Optometry

Contact iGO
Follow us on...
2014 (c) iGO Optical Ltd. Registered in England and Wales Company No. 5729682 Registered office: The Granary, Manor Park, Warkworth, Banbury OX17 2AG UK
Made by: Web design and web development