THE CORNEAL RESHAPING INHIBITS MYOPIA PROGRESSION (CRIMP) STUDY: A RETROSPECTIVE STUDY OF THE EFFECT OF ORTHOKERATOLOGY ON PROGRESSIVE MYOPIA

Title THE CORNEAL RESHAPING INHIBITS MYOPIA PROGRESSION (CRIMP) STUDY: A RETROSPECTIVE STUDY OF THE EFFECT OF ORTHOKERATOLOGY ON PROGRESSIVE MYOPIA
Author, Co-Author Russell Lowe, Laura Downie
Topic
Year
2010
Day
Friday
Program Number
105931
Room
Third Floor Foyer
Affiliation
Private Practitioner
Abstract PURPOSE: The aim of this retrospective study was to determine whether overnight corneal reshaping therapy, also known as orthokeratology, was effective in attenuating the rate of childhood myopic refractive error development compared with a carefully matched spectacle-wearing control group over a period of investigation up to 10 years.

METHODS: Thirty-two subjects (n = 64 eyes) were investigated per group. Treatment groups were matched for baseline age, gender, ethnicity, refractive error and visual acuity. At baseline, all subjects were aged < 18 years (range: 5.4- 17.7 years), and exhibited manifest spherical myopic refractive error > -0.50 DS (range: -0.75 to -9.50 DS). The minimum period of evaluation for each subject was two years (range: 2.0- 10.1 years; mean ± SEM: controls: 5.0 ± 0.3 years, orthokeratology: 5.1 ± 0.3 years, p > 0.05). Five (16%) of the orthokeratology treated patients undertook a wash out regression trial to enable full evaluation of their refractive status after 4.2 ± 0.5 (mean ± SEM) years of treatment.

RESULTS: The orthokeratology-treated eyes showed a statistically significant (p < 0.05) lower rate of myopic refractive error development compared with the control eyes, (controls: -0.29 ± 0.05 D/yr vs. orthokeratology: -0.04 ± 0.02 D/yr). A sub-population (n = 43) of orthokeratology eyes demonstrated an apparent total arrest of myopic progression throughout the evaluation period. Further analysis identified two significant (p < 0.05) characteristics associated with refractive stability: symmetry in the vertical meridian of the baseline corneal topography and superior uncorrected visual acuity scores throughout treatment.


CONCLUSIONS: This retrospective study provides long-term evidence to support the notion that orthokeratology treatment may regulate the rate of progression of childhood myopia.
Affiliation of Co-Authors Private Practitioner
Outline