Abstract:

Objective: To observe the changes of ocular biometric parameters in childrenwith low to moderate myopia after wearing orthokeratology lenses. Methods: A total of 80 children with low to moderate myopia at the Ophthalmology Department of Ruijin Hospital were enrolled. Children were randomly divided into 2 groups: orthokeratology lens group (n=40) and spectacles (n=40) group. Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness (LT) of children in the 2 groups were measured by Lenstar 900 at baseline, 6 months and 12 months after wearing orthokeratology lenses or spectacles, and differences in data between the 2 groups were analyzed with independent t tests. Results: There were no statistically significant differences in AL, CCT, ACD, and LT between the 2 groups at baseline. The incremental AL in the orthokeratology group was lower than that in the spectacles group at both 6 months [(0.08±0.08) mm vs (0.16±0.13) mm, t=-4.859, P<0.001] and 12 months [(0.18±0.11) mm vs (0.35±0.14) mm, t=-3.723, P<0.001). For children in the orthokeratology group, after six monthsof lens wearing, the CCT and ACD decreased by 4.65 μm and 0.02 mm (t=-6.205, P<0.001; t=-3.699, P<0.001), respectively, while LT increased by 0.02 mm (t=3.133, P<0.001), which were significantly different from those of spectacles group. After twelve months of lens wearing, the CCT and ACD decreased by 5.03 μm and 0.01 mm (t=-9.456, P<0.001; t=-3.171, P<0.001), respectively, and the LT increased by 0.04 mm (t=4.125, P<0.001), which were significantly different from those of spectacles group. During the follow-up, slight punctate exfoliation of corneal epithelium occurred in 3 children in orthokeratology lens group,with an incidence of 7.5%. Conclusions: Orthokeratology wearing could slow down axial elongation in children with low to moderate myopia, decrease CCT and ACD, and increase LT. For children wearing lens, adverse effects of punctate exfoliation of corneal epithelium should be paid attention to.

Key words: Orthokeratology, Spectacles, Myopia, Axial length, Central corneal thickness, Anterior chamber depth, Lens thickness