Effects of orthokeratology on the progression of low to moderate myopia in Chinese children

Mengmei He, Yaru Du, Qingyu Liu, Chengda Ren, Junling Liu, Qianyi Wang, Li Li, Jing Yu, Mengmei He, Yaru Du, Qingyu Liu, Chengda Ren, Junling Liu, Qianyi Wang, Li Li, Jing Yu

Abstract

Background: To investigate the effectiveness of orthokeratology (ortho-k) in reducing the development of myopia in Chinese children with low to moderate myopia.

Methods: This was a retrospective study. In the ortho-k group, there were141 subjects, and the average age was (9.43 ± 1.10) years. The average spherical equivalent refractive error (SER) was (-2.74 ± 1.15)D, with examinations performed 1, 7, 30, and 90 days and 12 months after the patients started wearing ortho-k lenses. In the control group, there were 130 subjects, and the average age was (9.37 ± 1.00) years. The average SER was (-2.88 ± 1.39)D, with examinations performed every 6 months. Axial elongation, which is an important parameter reflecting the progression of myopia, was measured at baseline from the same IOLMaster each time by the same masked examiner and was compared between the groups after 1 year. The subjects were divided into two sub-groups according to age to further study the development of myopia at different ages. An unpaired t-test, paired t-test, Chi-square test and Spearman test were performed to analyze the data.

Results: After 1 year, the average axial elongation was (0.27 ± 0.17) mm in the ortho-k lens group and (0.38 ± 0.13) mm in the control group, with a significant difference between the groups (P < 0.001). Axial elongation was not correlated with SER but had a negative correlation with initial age (ortho-k group: r s = -0.309, p < 0.01; control group: r s = -0.472, p < 0.01). The percentages of individuals with fast myopic progression (axial elongation > 0.36 mm per year) were 38.0 % among younger children (7.00 to 9.40 years) and 24.3 % among older children (9.40 to 12.00 years), whereas the respective percentages were 76.5 and 12.9 % in the control group. When SER ranged from -5.0D to -6.0D, the axial elongation in the ortho-k group was 57.1 % slower than that in the control group.

Conclusions: Ortho-k lenses are effective in controlling myopic progression in Chinese children, particularly in younger children and in children with higher myopia.

Keywords: Axial length; Chinese; Effectiveness; Myopia control; Orthokeratology.

Figures

Fig. 1
Fig. 1
Scatter plots showing correlations of axial elongation with initial age (a) and SER at baseline (b) in the ortho-k and control groups
Fig. 2
Fig. 2
Percentage of subjects with different myopic progression speeds (slow, moderate, fast) in different age groups (younger, older) in the ortho-k and control groups
Fig. 3
Fig. 3
Percentage of subjects with different myopic progression speeds (slow, moderate, fast) among subjects withdifferent degrees of initial myopia in the ortho-k and control groups
Fig. 4
Fig. 4
Axial elongation of subjects with different degrees of baseline SER in the ortho-k and control groups, with a slower percentage for the ortho-k lens group compared with the control group

References

    1. Wu LJ, You QS, Duan JL, Luo YX, Liu LJ, Li X, et al. Prevalence and associated factors of myopia in high-school students in Beijing. PLoS One. 2015;10:e120764.
    1. Saxena R, Vashist P, Tandon R, Pandey RM, Bhardawaj A, Menon V, et al. Prevalence of myopia and its risk factors in urban school children in Delhi: the North India myopia study (nim study) PLoS One. 2015;10:e117349.
    1. Cho P, Cheung SW, Edwards MH. Practice of orthokeratology by a group of contact lens practitioners in Hong Kong--part 1. general overview. Clin Exp Optom. 2002;85:365–371. doi: 10.1111/j.1444-0938.2002.tb02387.x.
    1. Williams KM, Verhoeven VJ, Cumberland P, Bertelsen G, Wolfram C, Buitendijk GH, et al. Prevalence of refractive error in Europe: the european eye epidemiology (e(3)) consortium. Eur J Epidemiol. 2015;30:305–315. doi: 10.1007/s10654-015-0010-0.
    1. Zhao J, Mao J, Luo R, Li F, Munoz SR, Ellwein LB. The progression of refractive error in school-age children: Shunyi district, china. Am J Ophthalmol. 2002;134:735–743. doi: 10.1016/S0002-9394(02)01689-6.
    1. Lee JY, Sung KR, Han S, Na JH. Effect of myopia on the progression of primary open-angle glaucoma. Invest Ophthalmol Vis Sci. 2015;56:1775–1781. doi: 10.1167/iovs.14-16002.
    1. Kamal SR, Morillo-Sanchez MJ, Garcia-Ben A, Rius-Diaz F, Cilveti-Puche A, Figueroa-Ortiz L, et al. The effect of peripapillary detachment on retinal nerve fiber layer measurement by spectral domain optical coherence tomography in high myopia. Ophthalmologica. 2015;233(3-4):209–15. doi: 10.1159/000371903.
    1. Coppe AM, Ripandelli G, Parisi V, Varano M, Stirpe M. Prevalence of asymptomatic macular holes in highly myopic eyes. Ophthalmology. 2005;112:2103–2109. doi: 10.1016/j.ophtha.2005.06.028.
    1. Zhu MJ, Feng HY, He XG, Zou HD, Zhu JF. The control effect of orthokeratology on axial length elongation in Chinese children with myopia. BMC Ophthalmol. 2014;14:141. doi: 10.1186/1471-2415-14-141.
    1. Lum E, Swarbrick HA. Lens dk/t influences the clinical response in overnight orthokeratology. Optom Vis Sci. 2011;88:469–475. doi: 10.1097/OPX.0b013e31820bb0db.
    1. Si JK, Tang K, Bi HS, Guo DD, Guo JG, Wang XR. Orthokeratology for myopia control: a meta-analysis. Optom Vis Sci. 2015;92(3):252–7. doi: 10.1097/OPX.0000000000000505.
    1. Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest Ophthalmol Vis Sci. 2011;52:2170–2174. doi: 10.1167/iovs.10-5485.
    1. Sun Y, Xu F, Zhang T, Liu M, Wang D, Chen Y, et al. Orthokeratology to control myopia progression: a meta-analysis. PLoS One. 2015;10(4):e0 124535. doi: 10.1371/journal.pone.0124535.
    1. Rabbetts RB, Mallen EAH. Bennett and Rabbetts’ clinical visual optics. 4. Edinburg: Elsevier/Butterworth–Heinemann; 2007. Distribution and ocular dioptrics ofametropia; p. 425.
    1. Reinstein DZ, Gobbe M, Archer TJ, Couch D, Bloom B, et al. Epithelial, stromal, and corneal pachymetry changes during orthokeratology. Optom Vis Sci. 2009;86:e1006–e1014. doi: 10.1097/OPX.0b013e3181b18219.
    1. Zhong X, Chen X, Xie RZ, Yang J, Li S, Yang X, et al. Differences between overnight and long-term wear of orthokeratology contact lenses in corneal contour, thickness, and cell density. Cornea. 2009;28:271–279. doi: 10.1097/ICO.0b013e318186e620.
    1. Kang P, Swarbrick H. Peripheral refraction in myopic children wearing orthokeratology and gas-permeable lenses. Optom Vis Sci. 2011;88:476–482. doi: 10.1097/OPX.0b013e31820f16fb.
    1. Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (to-see study) Invest Ophthalmol Vis Sci. 2013;54:6510–6517. doi: 10.1167/iovs.13-12527.
    1. Swarbrick HA, Alharbi A, Watt K, Lum E, Kang P. Myopia control during orthokeratology lens wear in children using a novel study design. Ophthalmology. 2015;122:620–630. doi: 10.1016/j.ophtha.2014.09.028.
    1. Pauné J, Morales H, Armengol J, Quevedo L, Faria-Ribeiro M, González-Méijome JM. Myopia control with a novel peripheral gradient soft lens and orthokeratology: a 2-year clinical trial. Biomed Res Int. 2015;2015:507572. doi: 10.1155/2015/507572.
    1. Hiraoka T, Kakita T, Okamoto F, Takahashi H, Oshika T. Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study. Invest Ophthalmol Vis Sci. 2012;53:3913–3919. doi: 10.1167/iovs.11-8453.
    1. Lin HJ, Wan L, Tsai FJ, Tsai YY, Chen LA, Tsai AL, et al. Overnight orthokeratology is comparable with atropine in controlling myopia. BMC Ophthalmol. 2014;14:40. doi: 10.1186/1471-2415-14-40.
    1. Smith ER, Hung LF, Huang J. Relative peripheral hyperopic defocus alters central refractive development in infant monkeys. Vision Res. 2009;49:2386–2392. doi: 10.1016/j.visres.2009.07.011.
    1. Mutti DO, Sholtz RI, Friedman NE, Zadnik K. Peripheral refraction and ocular shape in children. Invest Ophthalmol Vis Sci. 2000;41:1022–1030.
    1. Norton TT, Jr Siegwart JT. Animal models of emmetropization: matching axial length to the focal plane. J Am Optom Assoc. 1995;66:405–414.
    1. Fan DS, Lam DS, Lam RF, Lau JT, Chong KS, Cheung EY, et al. Prevalence, incidence, and progression of myopia of school children in hong kong. Invest Ophthalmol Vis Sci. 2004;45:1071–1075. doi: 10.1167/iovs.03-1151.
    1. Edwards MH. The development of myopia in Hong Kong children between the ages of 7 and 12 years: a five-year longitudinal study. Ophthalmic Physiol Opt. 1999;19:286–294. doi: 10.1046/j.1475-1313.1999.00445.x.
    1. Donovan L, Sankaridurg P, Ho A, Naduvilath T, Smith ER, Holden BA. Myopia progression rates in urban children wearing single-vision spectacles. Optom Vis Sci. 2012;89:27–32. doi: 10.1097/OPX.0b013e3182357f79.
    1. Walline JJ, Rah MJ, Jones LA. The children’s overnight orthokeratology investigation (cooki) pilot study. Optom Vis Sci. 2004;81:407–413. doi: 10.1097/01.opx.0000135093.77007.18.
    1. Chan TC, Li EY, Wong VW, Jhanji V. Orthokeratology-associated infectious keratitis in a tertiary care eye hospital in Hong Kong. Am J Ophthalmol. 2014;158(6):1130–1135. doi: 10.1016/j.ajo.2014.08.026.
    1. Lo J, Kuo MT, Chien CC, Tseng SL, Lai YH, Fang PC. Microbial bioburden of orthokeratology contact lens care system. Eye Contact Lens. 2016;42:61–7.
    1. Watt KG, Swarbrick HA. Trends in microbial keratitis associated with orthokeratology. Eye Contact Lens. 2007;33:373–377. doi: 10.1097/ICL.0b013e318157cd8d.

Source: PubMed

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