Residual corneal flattening after discontinuation of long-term orthokeratology lens wear in asian children.
OBJECTIVE
Most patients treated with orthokeratology (OK) in Asia are children. The effects of long-term OK on corneal curvature among children after lens wear discontinuation have not previously been reported.


METHODS
This study investigated 28 subjects, aged 10.4 +/- 2.5 years at commencement of OK lens wear, who had been treated with OK for 50.2 +/- 27.4 months. Corneal curvature was measured with a Canon RK3 autokeratometer before commencement of OK and again approximately 2 weeks (17.3 +/- 8.6 days) after discontinuation of OK lens wear. Data were analyzed using paired Student t tests, with a critical P value of 0.05.


RESULTS
Compared with baseline, residual flattening of the cornea was found after cessation of OK lens wear, averaging 0.07 +/- 0.04 mm in the flat meridian (P<0.001) and 0.02 +/- 0.07 mm in the steep meridian (P=0.07). This was confirmed by power vector analysis of curvature data, with a significant reduction in M (-0.27 +/- 0.23 diopter (D); P<0.001), and a slight increase in J0 (0.17D +/- 0.36D; P=0.02). A trend toward greater residual corneal flattening was found among subjects with more pretreatment myopic refractive error (P=0.04).


CONCLUSIONS
Corneal curvature may not necessarily return completely to baseline after discontinuation of long-term OK lens wear in children. Intermittent temporary discontinuation of OK lens wear and close monitoring of corneal recovery are recommended during long-term OK treatment.
Wu
Richard
R
University of New South Wales, Sydney, Australia.
Stapleton
Fiona
F
Swarbrick
Helen A
HA
D000293:Adolescent; D044466:Asian People; D002648:Child; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D006801:Humans; D009216:Myopia / Q000208:ethnology / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy*; D054158:Orthokeratologic Procedures; D012029:Refraction, Ocular; D013997:Time Factors