The relationship between the corneal anterior surface curvature after orthokeratoplasty and myopic diopter

Abstract

Objective To analyse the relationship between corneal anterior surface curvature after orthokeratoplasty and original myopic diopter. Methods The data of 128 eyes of 65 cases with myopic were retrospectively analysed. There were 76 eyes of 38 males and 52 eyes of 27 females. All cases were devided into 2 groups according to diopter. GroupA, 80 eyes of 41 patients with spherical equivalent SE ≤ -3.0 D. And 48 eyes of 24 patients with SE in -3.25 D--6.0 D were included in group B. The follow-up time was 1 month. Results The difference of changes of corneal anterior surface curvature were statistically significant between before and 1, 7, 14 and 30 days after wearing orthokeratoplasty (group A: t=41.86, 63.33, 73.79, 69.33, P<0.05; group B: t=14.89, 24.55, 28.21, 1.71, P<0.05). The difference of changes of clinical diopter were statistically significant (group A: t=23.08, 34.90, 35.15, 38.99, P<0.05 and group B: t=28.50, 46.39, 49.39, 54.72, P<0.05). The correlation between the change of anterior corneal surface curvature (X) and diopter (Y) after orthokeratoplasty was Y=1.018+ 0.875X in group A (r=0.654, P<0.05) and Y=1.235+ 0.942X in group B (r=0.752, P<0.05). Conclusion There are high correlations between corneal anterior surface curvature and diopter after orthokeratoplasty in two groups. The higher of the diopter, the higher of diopter chang corneal anterior surface curvature for 1 D. Key words: Orthokeratoplasty; Corneal anterior surface curvature; Diopter; Correlation coefficient