Clinical observation of S-Curve design for orthokeratology correcting myopia in adolescents

Objective To observe and evaluate the effect of S-Curve design for orthokeratology on correction of refractive error for adolescents with high myopia (-6.00D＜equivalent sphere lens≤-8.00D) and low corneal curvature (39.00D≤flat K＜41.00D).Methods In this study,90 teenagers (90 eyes) with myopia were included.They were divided into three groups,high myopia group (30 eyes),low corneal curvature group (30 eyes) and general design for orthokeratology group (30 eyes).High myopia group and low corneal curvature group were corrected by S-Curve design for orthokeratology,general design for orthokeratology group were corrected by general design for orthokeratology.All patients were fitted with overnight orthokeratology for 8-10h.UCVA,diopter,corneal curvature,axial length (AL) were measured at pre-wear and 1 day,1 week,1 month,3 months,6 months after orthokeratology.Data were analyzed with a paired t test and randomized block ANOVA.Results UCVA of three groups increased significantly at 6-month visit (t =2.012,t =3.134,t =4.221; P ＜0.01),general design for orthokeratology group became stable after 1-month lens wearing,the other two groups got stable UCVA at 3-month following.Refraction (equivalent sphere lens) of all wearers decreased at 1-week visit (t =5.053,t =7.235,t =8.123; P ＜0.01),general design for orthokeratology group decreased more quickly.Corneal curvature of all wearers decreased at 1-week visit (t =5.245,t =14.332,t =11.223; P ＜0.01),general design for orthokeratology group decreased fastest within the first week and almost did not change after l-month lens wearing.High myopia group and low corneal curvature group decreased fastest within the first month and reached the stable level at 3-month visit.The changes of AL did not show significant differences among three groups at 6 months after wearing orthokeratology lenses (F =52.123,P ＞0.05).Conclusions S-Curve design for orthokeratology can correct myopia and reduce myopia progression for adolescents with high myopia and low corneal curvature effectively and safely. Key words: Orthokeratology; Myopia