目的：观察离焦环总面积(PPRZ)的大小和分布对近视进展的影响。

方法：本回顾性研究于2019至2021年在太原爱尔眼科医院招募137名8-12岁青少年。受试者因屈光不正首次配戴角膜塑形镜，并进行为期1 a的随访观察。为明确入瞳离焦环面积(PPROPZ)和离焦环总面积(PPRZ)，根据PPROPZ与PPRZ比值对受试者进行分组：实验组103眼的PPROPZ与PPRZ比值≥0.2，对照组103眼的比值<0.2。受试者球镜度数介于-6.00 D至-0.75 D之间，逆规散光小于1.00 D，顺规散光小于1.50 D，角膜曲率范围为39.00 D至46.00 D。配戴角膜塑形镜(Ortho-K)时，其最佳矫正视力稳定在0.10 LogMAR(20/25)或更高水平。使用Image J软件测量PPRZ和PPROPZ参数； 通过角膜地形图评估角膜相关指标，并采用光学生物测量仪检测配戴前后1 a的眼轴长度变化。

结果：当PPRZ(P<0.01)或PPROPZ(P<0.001)显著增加时，眼轴增长呈下降趋势。对照组的眼轴增长更快，增长量为(0.37±0.2)mm，而实验组的增长量为(0.21±0.11)mm。此外，水平可见虹膜直径(HVID)越大，眼轴增长速度越慢。相比之下，眼轴增长与角膜表面规则指数(SRI)、角膜表面非对称指数(SAI)、平坦角膜曲率值(K_f)及陡峭角膜曲率值(K_s)均无相关性。

结论：对于具有较大PPROPZ与PPRZ比值的角膜塑形镜配戴者通常眼轴增长减缓。PPRZ和PPROPZ与眼轴增长呈负相关。研究结果为通过角膜塑形镜研究近视控制机制提供了建议和方法。

METHODS:This retrospective study enrolled 137 pre-teens aged 8-12 at Taiyuan Aier Eye Hospital between 2019 and 2021. They were fitted with Ortho-K lenses for the first time due to refractive error, with a one-year follow-up period. To indicate the peripheral plus ring zone overlapping with the pupil zone(PPROPZ)accompanying PPRZ, participants were divided based on the PPROPZ to PPRZ ratio. The experimental group had 103 eyes with a PPROPZ to PPRZ ratio of ≥0.2, and the control group had 103 eyes with a ratio of <0.2. Participants had a spherical diopter in the range of -6.00 D to -0.75 D, against-the-rule astigmatism less than 1.00 D, with-the-rule astigmatism less than 1.50 D, and corneal curvatures of 39.00 D to 46.00 D. They had a stable best corrected visual acuity of 0.10 LogMAR(20/25)or better when wearing orthokeratology(Ortho-K)lenses. PPRZ and PPROPZ were measured using ImageJ; corneal topography assessed corneal-related parameters, and an optical biometer measured the axial length of the eyes pre and post-one years of lens wear.

RESULTS: Changes in axial length elongation were found to decrease when either the PPRZ(P<0.01)or PPROPZ(P<0.001)was increased significantly. The axial length growth was faster in the control group(0.37±0.2 mm)than in the experimental group(0.21±0.11 mm). Furthermore, we found that a larger horizontal visible iris diameter(HVID)corresponded to slower axial growth of the eye. In contrast, axial length growth showed no correlation with surface regularity index(SRI), surface asymmetry index(SAI), flat keratometry value(K_f), steep keratometry value(K_s).

CONCLUSION:For orthokeratology, wearers with larger PPROPZ to PPRZ ratio usually experiences a reduction in axial length growth. The PPRZ and PPROPZ are negatively correlated with the axial length. Our findings provide a recommendation and methods for studying the myopia control mechanism through Ortho-K lenses.