The dynamic influence of induced decentered orthokeratology lenses on higher-order wavefront aberrations

Objective To evaluate the status of orthokeratology decentration and dynamic changes in higher-order aberrations with different pupil diameters and to discuss its effect on visual quality.Methods This was a prospective clinical study.Thirty myopic subjects (30 right eyes) were fitted with overnight orthokeratology lenses.The mean age was 23.6±2.3 years and the initial mean spherical equivalent (SE) refractive error was-2.61±0.83 D.All subjects underwent corneal topography measurements and wavefront aberration measurements before orthokeratology and 1 week,1 month and 3 months after orthokeratology.The decentration (distance and angle) of the center of the flattened corneal area after orthokeratology was calculated relative to the pupil center.The higher-order aberrations under 3 mm and 6 mm pupil diameters were evaluated.Data were analyzed using pearson correlation,repeated measured ANOVA.Results The decentrations at 1 week,1 month,and 3 months after orthokerato1oty were 0.53±0.26 mm,0.54±0.32 mm and 0.60±0.35 mm,respectively.The decentration was mainly located in the superior temporal quadrant.There were no statistically significant differences in the decentration measurements at different timepoints after orthokeratology.The location and magnitude of decentration had no correlation with initial SE or astigmatism.Total higher-order aberrations,third order,fourth order,combined coma,and spherical-like aberrations under 3 mm and 6 mm pupil diameters significantly increased after orthokeratology treatment (P＜0.05).However,there were no statistically significant differences in wavefront aberrations at different timepoints after orthokeratology.The aberrations under a 6 mm pupil diameter had increased significantly compared to a 3 mm pupil diameter (P＜0.05) after orthokeratology treatment.The magnitude of decentration in the horizontal or vertical direction was positively correlated with the coma in the corresponding direction.However,no correlations were found between the total magnitude of decentration and other higher-order aberrations.Conclusion The decentration from orthokertology present throughout the entire process,but it is very subtle and became stable after 1 week.Decentration increase higher-order aberrations. Key words: Orthokeratology;  Myopia;  Decentration;  Pupil diameter;  Higher-order aberrations