The Role of Peripheral Defocus in the Mechanism of Orthokeratology for Myopia Control

doi:10.3870/j.issn.1672-0741.25.08.029

Abstract

Abstract: In recent years,the increasing prevalence and early onset of myopia have made its control a pressing public health priority.Orthokeratology(OK lenses)is regarded as one of the key effective strategies for myopia management,although its exact mechanisms of action remain incompletely understood.The predominant hypothesis is that orthokeratology modifies the relative optical power of the cornea,thereby inducing peripheral retinal defocus and associated choroidal changes,which together contribute to slowing axial elongation.Grounded in peripheral defocus theory,this article reviews alterations in retinal peripheral defocus and the choroidal response following orthokeratology,discusses methods for assessing retinal peripheral defocus,examines factors influencing the magnitude of defocus,and explores its correlation with myopia control outcomes.The objective of this study is to clarify the mechanism through which orthokeratology effectively mitigates myopia progression.

Key words: orthokeratology, peripheral retinal defocus, peripheral choroidal thickness

CLC Number:

R778.11

Fang Dengqin, Xiang Yan. The Role of Peripheral Defocus in the Mechanism of Orthokeratology for Myopia Control[J]. Acta Medicinae Universitatis Scientiae et Technologiae Huazhong, 2026, 55(1): 134-139.

References

[1] Troilo D,Smith E L,Nickla D L,et al.IMI-report on experimental models of emmetropization and myopia[J].Invest Ophthalmol Vis Sci,2019,60(3):M31-M88.
[2] Wu H,Zhang G,Shen M,et al.Assessment of choroidal vascularity and choriocapillaris blood perfusion in anisomyopic adults by SS-OCT/OCTA[J].Invest Ophthalmol Vis Sci,2021,62(1):8.
[3] Read S A,Fuss J A,Vincent S J,et al.Choroidal changes in human myopia:insights from optical coherence tomography imaging[J].Clin Exp Optom,2019,102(3):270-285.
[4] Wallman J,Wildsoet C,Xu A,et al.Moving the retina:choroidal modulation of refractive state[J].Vision Res,1995,35(1):37-50.
[5] Smith E L,Hung L F,Huang J,et al.Effects of optical defocus on refractive development in monkeys:Evidence for local,regionally selective mechanisms[J].Invest Ophthalmol Vis Sci,2010,51(8):3864-3873.
[6] Lam A K C,Hon Y,Leung S Y Y,et al.Association between long-term orthokeratology responses and corneal biomechanics[J].Sci Rep,2019,9(1):12566.
[7] Li T,Chen Z,She M,et al.Relative peripheral refraction in myopic children wearing orthokeratology lenses using a novel multispectral refraction topographer[J].Clin Exp Optom,2023,106(7):746-751.
[8] Gifford K L,Gifford P,Hendicott P L,et al.Stability of peripheral refraction changes in orthokeratology for myopia[J].Contact Lens Anterior Eye J,2020,43(1):44-53.
[9] Zheng X H,Shi H L,You J X,et al.A study on the distribution characteristics of peripheral retinal defocus in children and adolescents[J].Chin J Ophthalmol,2024,60(4):337-342.
[10] Li Z,Jin X,Gui M,et al.The influence of orthokeratology on peripheral refraction during accommodation[J].BMC Ophthalmol,2025,25(1):161.
[11] Wen K,Wu Y,Yang B,et al.Novel quantitative analysis of relative peripheral refraction changes in orthokeratology and their relationship with one-year axial elongation[J].Photodiagnosis Photodyn Ther,2025,55:104739.
[12] Lian Y,Lu W,Xu A,et al.The correlation between modifications to corneal topography and changes in retinal vascular density and retinal thickness in myopic children after undergoing orthokeratology[J].Front Med,2023,10:1166429.
[13] Lau J K,Wan K,Cheung S W,et al.Weekly changes in axial length and choroidal thickness in children during and following orthokeratology treatment with different compression Factors[J].Transl Vis Sci Technol,2019,8(4):9.
[14] Wu H,Peng T,Zhou W,et al.Choroidal vasculature act as predictive biomarkers of long-term ocular elongation in myopic children treated with orthokeratology:A prospective cohort study[J].Eye Vis,2023,10(1):27.
[15] Zhao M,Lam A K,Ying M T,et al.Hemodynamic and morphological changes of the central retinal artery in myopic eyes[J].Sci Rep,2022,12(1):7104.
[16] Liu M,Huang J,Xie Z,et al.Dynamic changes of choroidal vasculature and its association with myopia control efficacy in children during 1-year orthokeratology treatment[J].Cont Lens Anterior Eye,2025,48(1):102314.
[17] Zhang R,Zhuang S,Zhou Y,et al.Associations between choroidal thickness and rate of axial elongation in orthokeratology lens users[J].Photodiagnosis Photodyn Ther,2025,51:104450.
[18] Tang W T,Luo X N,Zhao W J,et al.One-year results for myopia control of orthokeratology with different back optic zone diameters:a randomized trial using a novel multispectral-based topographer[J].Int J Ophthalmol,2024,17(2):324-330.
[19] Li N,Lin W,Zhang K,et al.The effect of back optic zone diameter on relative corneal refractive power distribution and corneal higher-order aberrations in orthokeratology[J].Cont Lens Anterior Eye,2023,46(1):101755.
[20] Chen W,Yang L,Zhang X,et al.Changes of axial elongation and corneal topography after switching from standard to reduced back optic zone diameter orthokeratology lenses[J].Cont Lens Anterior Eye,2025,48(5):102446.
[21] Zhou Y,Li H,Hao J,et al.The efficacy of orthokeratology lenses with smaller back optic zone diameter in myopia control.A meta-analysis[J].Ophthalmic Physiol Opt,2024,44(6):1215-1223.
[22] Guo B,Cho P,Cheung S W,et al.Optical changes and association with axial elongation in children wearing orthokeratology lenses of different back optic zone diameter[J].Eye Vis,2023,10(1):25.
[23] Liu T,Chen C,Ma W,et al.One-year results for myopia control with aspheric base curve orthokeratology lenses:A prospective randomised clinical trial[J].Ophthalmic Physiol Opt,2023,43(6):1469-1477.
[24] Guo Y,Zhang M,Tong Y,et al.Impact of pupil and defocus ring intersection area on retinal defocus[J].Ophthalmic Physiol Opt,2024,44(2):472-480.
[25] Pauné J,Fonts S,Rodríguez L,et al.The role of back optic zone diameter in myopia control with orthokeratology lenses[J].J Clin Med,2021,10(2):336.
[26] Chu M,Zhao Y,Hu P,et al.Is orthokeratology treatment zone decentration effective and safe in controlling myopic progression?[J].Eye Contact Lens,2023,49(4):147-151.
[27] Lin Z,Duarte-Toledo R,Manzanera S,et al.Two-dimensional peripheral refraction and retinal image quality in orthokeratology lens wearers[J].Biomed Opt Express,2020,11(7):3523-3533.
[28] Ding W,Lu W,Ji R,et al.Effects of orthokeratology lens decentration induced by paracentral corneal asymmetry on axial length elongation[J].Eye Contact Lens,2023,49(5):181-187.
[29] Lin W,Gu T,Bi H,et al.The treatment zone decentration and corneal refractive profile changes in children undergoing orthokeratology treatment[J].BMC Ophthalmol,2022,22(1):177.
[30] Wang J,Cheung S W,Bian S,et al.Anisomyopia and orthokeratology for myopia control-axial elongation and relative peripheral refraction[J].Ophthalmic Physiol Opt,2024,44(6):1261-1269.
[31] Chen X,Xiong Y,Qi X,et al.Nasal-temporal asymmetric ch-anges in retinal peripheral refractive error in myopic adolescents induced by overnight orthokeratology lenses[J].Front Neurol,2023,13:1006112.
[32] Xu X,Zang W,Wang A,et al.Repeatability and agreement of multispectral refraction topography in school children before and after cycloplegia[J].Biomed Eng Online,2024,23(1):110.
[33] Lu X L,Zheng X Y,Lian L H,et al.Comparative study of relative peripheral refraction in children with different degrees of myopia[J].Front Med,2022,9:800653.