'OK' Contact Lenses Work by Flattening Front of Cornea, Not
the Entire Cornea, Suggests Study in Optometry and Vision Science
A contact lens technique called overnight orthokeratology
(OK) brings rapid improvement in vision for nearsighted patients. Now a new study shows that OK treatment works
mainly by flattening the front of the cornea, reports a recent study,
“Posterior Corneal Shape Changes in Myopic Overnight Orthokeratology”,
appearing in the March issue of Optometry and Vision Science, official journal
of the American Academy of Optometry.
The journal is published by Lippincott Williams & Wilkins, a part of
Wolters Kluwer Health.
"This study appears to show that it is only, or
primarily, the very front surface layers of the cornea that are altered by OK
contact lens treatment," comments Anthony Adams, OD, PhD, Editor-in-Chief
of Optometry and Vision Science. The
study was performed by Jeong Ho Yoon, PhD, of University of Choonhae Health
Science, Ulsan, Republic of Korea, and Helen A. Swarbick, PhD, FAAO, of
University of New South Wales, Sydney, Australia.
Overnight Orthokeratology Works—But How?
Orthokeratology is a clinical technique to reduce
nearsightedness (myopia) using specially designed rigid contact lenses to
manipulate the shape of the cornea—the transparent front part that lets light
into the eye. Dr. Adams likens OK
therapy to orthodontic treatment using braces to change the alignment of the
teeth.