Effect of the plus power ring zone area on myopia control with orthokeratology lenses
10.3980/j.issn.1672-5123.2025.12.01
- VernacularTitle:配戴角膜塑形镜后离焦环面积的大小对近视防控的影响
- Author:
Weiwei HAO
1
;
Yuru WANG
1
;
Ding JIA
1
Author Information
1. Taiyuan Aier Eye Hospital, Taiyuan 030000, Shanxi Province, China
- Publication Type:Journal Article
- Keywords:
orthokeratology;
myopia prevention and control;
plus power ring zone(PPRZ);
peripheral plus ring zone overlapping with the pupil zone(PPROPZ)
- From:
International Eye Science
2025;25(12):1899-1905
- CountryChina
- Language:Chinese
-
Abstract:
AIM:To observe the effect of the plus power ring zone(PPRZ)area and distribution on myopia progression.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(Kf), steep keratometry value(Ks).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.
