青少年配戴角膜塑形镜偏心量对眼轴影响的临床研究

目的 观察青少年配戴角膜塑形(orthokeratology,OK)镜引起的偏心量对眼轴的影响.方法 选取重庆爱尔麦格眼科医院符合入选标准、完成OK镜验配并坚持戴镜12个月的青少年患者162例(右眼为观察眼),按年龄分为低龄组(8 ～11岁)和高龄组(12 ～ 15岁),每组81例.在戴OK镜后3和12个月,观察角膜地形图和眼轴,分析两组的偏心程度和偏心发生率,以及偏心量对眼轴的影响.结果 在戴OK镜后3个月,低龄组低、中和重度偏心的发生率分别为27.16％、49.38％和23.46％,高龄组低、中和重度偏心的发生率分别为19.75％、56.79％和23.46％;在戴OK镜后12个月时,低龄组低、中和重度偏心的发生率分别为30.86％、45.68％和23.46％,高龄组低、中和重度偏心的发生率分别为19.75％、56.79％和23.46％,两组间在不同时间点的低、中、重度偏心发生率比较,差异无统计学意义(P＞0.05);中度偏心的发生率相对较高.计算戴OK镜前与戴OK镜12个月后的眼轴差值及近视球镜差值,两组间比较无统计学差异(P＞0.05).戴镜1年后的眼轴[低龄组(24.97±0.55)mm,高龄组(24.99 ±0.65)mm]与戴镜前[低龄组(24.83 ±0.53) mm,高龄组(24.85 ±0.64) mm]分别进行组内比较,差异有统计学意义(P＜0.05).戴镜1年后的近视球镜与戴镜前分别进行组内比较,差异无统计学意义(P＞0.05).在8 ～15岁,发生重度偏心的戴OK镜人群,其眼轴增长较低度和中度偏心的戴OK镜人群明显,差异有统计学意义(P＜0.05).结论 8～15岁青少年配戴OK镜12个月,偏心的发生率无年龄相关性.戴镜3个月后,偏心量基本稳定.戴镜12个月时,重度偏心的青少年眼轴增长显著大于低度、中度偏心组.早期发现、及时纠正有助于近视进展的防治.

Influence of decentration caused by orthokeratology lenses on ocular axis in adolescents

Objective To investigate the effect of decentration caused by orthokeratology (OK) lens wearing on ocular axis in adolescents.Methods A total of 162 adolescents wearing OK lenses for 12 months from Aier Mega Eye Hospital of Chongqing were divided into group 1 (8-11 years old,n =81) and group 2 (12-15 years old,n =81).Corneal topography and axis oculi of the right eye were measured at the 3rd and 12th months after wearing OK lenses.The incidence and degree of decentration,and the influence of decentration on ocular axis were analyzed.Results At 3 months after OK lens wearing,the incidences of mild,moderate and severe decentration were 27.16％,49.38％ and 23.46％ in group 1 and were 19.75％,56.79％ and 23.46％ in group 2,respectively;At 12 months,the incidences were 30.86％,45.68％ and 23.46％ in group 1 and 19.75％,56.79％ and 23.46％ in group 2,respectively.At each time point,no significant difference was found between the two groups in the incidences of mild,moderate or severe decentration (P ＞ 0.05).A relative high incidence of moderate decentration was noted in both groups.The adolescents in the two groups showed no significant differences in the changes in axis oculi or myopic differential value after wearing OK lenses for 12 months;but in both groups,the ocular axis significantly increased after wearing OK lens for 12 months,from 24.83 ± 0.53 mm to 24.97 ± 0.55 mm in group 1 (P ＜ 0.05) and from 24.85 ± 0.64 mm to 24.99 ± 0.65 mm in group 2 (P ＜ 0.05).The myopia sphere showed no obvious changes in either of the groups at one year of OK lens wearing (P ＞ 0.05).In the adolescents aged 8-15 years,the ocular axis length increased significantly in those with severe decentration as compared with those with mild and moderate decentration (P ＜0.05).Conclusion In adolescents at 8-15 years,age is not related with the incidence of decentration after wearing OK lens for 12 months,and the degree of decentration became relatively stable after wearing the lens for 3 months.After wearing the lens for 12 months,the length of the ocular axis increased significantly in adolescents with severe decentration as compared with those with mild and moderate decentration,suggesting the benefit of early detection and correction of severe decentration for prevention and treatment of myopia.