摘要
Abstract
?AIM:To explore the effect of eccentricity of overnight orthokeratology ( OK) lenses on 2-year eye axial growth and visual quality. ?METHODS:Based on the degree of eccentricity of OK lenses, patients were divided into three groups: a low degree of eccentricity group ( degree of eccentricity ≤0. 5 mm) , a group of moderate eccentricity ( eccentric degree>0. 5-≤1. 0 mm ) and a group with a high degree of eccentricity (eccentric degree >1-≤1.5 mm). The degree of eccentricity of the OK lens, spherical equivalent ( SE) , the uncorrected visual acuity after wearing OK lenses ( UCVA) , axial length before and after wearing OK lenses ( AL) , total higher-order aberrations ( HOA) , comas, and spherical aberrations ( SA ) for 3 mm pupils were analyzed. The difference among the three groups for all parameters was compared using the Kruskal-Wallis H Rank-Sum test. ?RESULTS:The study retrospectively analyzed 75 cases (139 eyes). In the low eccentricity group (53 eyes), the mean age was 11.4±2.4 years, SE was -3.24±1.48 D, and AL was 24.85± 1.01 mm. In the moderate eccentricity group ( 53 eyes ) , the mean age was 11. 4 ± 2. 2 years, SE was-3.22± 1. 29 D, and AL was 25. 15 ± 0. 92 mm. In the high eccentricity group (31 eyes), the mean age was 11.5± 1.9 years, SE was -3.54± 1.43 D, and AL was 24.95± 0.84mm. After two years, there was no significant difference in the changes of the axis among the three groups (P=0.089). The HOA, SA, and coma in the high eccentric group were significantly higher than in the middle eccentric group ( P<0. 05 ) . The HOA, SA, and coma in the high eccentric group were also significantly higher than those in the low eccentric group ( P<0.05) . ?CONCLUSION: For OK lenses, it is unnecessary to strictly require the absolute centralization of the lens position. An unnecessary change of the lenses may delay the eye-axis control. However, the balance between axial control and visual quality should be assessed.关键词
角膜塑形镜/镜片偏心/眼轴/高阶像差/球差/彗差Key words
orthokeratology lens/eccentricity of the lens/axial eye length/higher - order aberrations/spherical aberration/coma
