Overnight wear of ortho-k contact lenses may slow the progression of myopia.
Orthokeratology — the fitting of special gas permeable contact lenses for the temporary treatment of myopia — may also reduce the progression of myopia in children, according to a new study.
Researchers in Japan studied how overnight wear of ortho-k lenses might affect eyeball elongation in children, which is a cause of myopia progression. Measurement of the axial (front-to-back) length of eyes before and after a two-year period of overnight ortho-k was compared with measurements in age-matched children who wore only eyeglasses (the control group).
A total of 92 children (184 eyes) completed the study, with 42 in the ortho-k group and 50 in the eyeglasses group. The average age for both groups was about 12 years at the beginning of the study. All, including those in the eyeglasses group, were eligible for orthokeratology.
At the beginning of the study, no significant differences existed between the two groups in the amount of myopia (about -2.57 diopters) and axial length of eyes (about 24.7 mm). At the end of the study, the increase in mean axial length of eyes in the eyeglasses group (0.61 mm) was significantly greater than that in the ortho-k group (0.39 mm).
The study authors concluded that overnight ortho-k suppressed the elongation of the eyes, suggesting that this treatment can slow the progression of myopia to a certain extent. Data showing that gas permeable lenses can slow the progression of myopia was presented at this year’s annual meeting of the Association for Research in Vision and Ophthalmology (ARVO).
A full report of the study appears in this month’s issue of the journal Investigative Ophthalmology & Visual Science.