CRT角膜塑形镜短期内镜片参数调整原因及调整效果分析

Reasons and Effects of the Lens Parameters Adjustment in Corneal Refractive Therapy in the Short Term

目的:探讨Paragon角膜屈光矫治类(CRT)角膜塑形镜配戴早期镜片参数调整原因,并分析调整参数后的效果。方法:回顾性系列病例研究。从2018年4月至2021年5月在北京大学人民医院眼视光中心验配CRT角膜塑形镜的患者中,随机选取符合纳入标准的近视患者65例(90眼)的眼部参数进行分析。比较镜片调整前后的镜片参数,分析镜片参数调整的原因,进一步通过自行编写的Matlab程序,计算调整镜片参数前后的角膜塑形镜形成的治疗区面积(TZA)、治疗区偏位(TZD)、治疗区内加权泽尼克离焦系数(C_(weighted defocus))等变量。根据镜片参数调整原因将患者分为视力不良组、角膜点染组和TZA大组,对总体及各组内调整前后TZA、TZD和C_(weighted defocus)的比较行配对t检验分析。结果:在纳入的90眼中,因角膜点染调整镜片参数28眼(31%),因原镜片的TZA大而调整镜片参数41眼(46%),因视力不良调整镜片参数21眼(23%)。调整镜片参数前后矢高变化量为(6.59±30.85)μm。TZA调整前(12.88±3.69)mm^(2),调整后(11.77±3.17)mm^(2),变化量为(-1.11±3.01)mm^(2);TZD调整前(0.63±0.31)mm,调整后(0.57±0.29)mm,变化量为(-0.07±0.28)mm,TZA、TZD调整前后差异均有统计学意义(t=-3.50,P=0.001;t=-2.29,P=0.024)。C_(weighted defocus)调整前(0.44±0.20)D/mm^(2),调整后(0.49±0.19)D/mm^(2),变化量为(0.03±0.20)D/mm^(2),差异无统计学意义(t=1.16,P=0.190)。结论:CRT镜片参数调整主要原因为TZA过大、角膜点染和视力不良。参数调整后镜片偏位改善,TZA缩小。

Objective:To explore the causes for early adjustment of lens parameters in Paragon corneal refractive therapy(CRT)fitting,and analyze the effects of adjustment.Methods:This was a retrospective study.All participants were recruited from patients who were fitted with CRT lenses in the Optometry Center of Peking University People's Hospital from April 2018 to May 2021.The ocular parameters of 65 myopic patients(90 eyes)who met the inclusion criteria were randomly selected.In this study,the adjustment of the parameters was compared and the reason for the adjustment was analyzed.A customized Matlab program was used to calculate the change of treatment zone area(TZA),treatment zone decentration(TZD),and weighted Zernike defocus coeficient(C_(weighted defocus))aferthe adjustment.All subjects weredivided into three groups according to the causes of adjustments:poor visual acuity group,corneal staining group,and large treatment zone group.Paired t-test was conducted in the overall and each group.Results:Among all 90 eyes included in the study,the cases of adjustment due to corneal staining accounted for 28 eyes(31%),due to large treatment zone accounted for 41 eyes(46%),due to poor visual acuity accounted for 21 eyes(23%).The variation of sagittal height before and after adjustment of lens parameters in all cases was 6.59±30.85μm.TZA was 12.88±3.69 mm^(2)and 11.77±3.17 mm^(2)before and after adjustment,with a change of-1.11±3.01 mm^(2)(f=-3.50,P=0.001).TZD was 0.63±0.31 mm and 0.57±0.29 mm before and after adjustment,with a change of-0.07±0.28 mm(t=-2.29,P=0.024).The difference of TZA and TZD was statistically significant beween the before and aferadjustment.C_(weighted defocus) was O.44±0.20D/mm and 0.49±0.19 D/mm^(2)before and after adjustment,respectively,with a change of 0.03±0.20 D/mm^(2).While the change of Cweighedfoeus showed no statistically significant difference(1.16,P-0.190).Conclusions:The main reasons for parameter adjustment of CRT lenses were large treatment zone,corneal staining and poor visual acuity.The large treatment zone accounted for the highest proportion.After adjusting the lens parameters,the decentration and the area of treatment zone were reduced.