Efficacy of orthokeratology lenses depending on topograpy pupil diameter and lens optical zone size
R. A. Parkhomets
Kharkiv National Medical University; Raduzhka Pediatric Ophthalmology Center; Kharkiv (Ukraine)
Background: Management of progressive myopia is a major issue in current optometry and oph-thalmology in general. Refractive therapy with orthokeratology lenses (OKL) has become an in-creasingly popular technique for controlling the progression of myopia.
Purpose: To assess the efficacy of orthokeratology lenses depending on the topography pupil size and lens optical zone (OZ) size.
Material and Methods: Sixty children (117 eyes) with mild or moderate uncomplicated myopia were involved in this study. They underwent a comprehensive eye examination, corneal topography and pupillometry. Statistical analysis of correlations between the pupil diameter and axial elongation was performed. In order to conduct longitudinal surveillance of myopia, we compared two OKL designs, one with a conventional OZ diameter, and another with a smaller OZ diameter, for the efficacy of myopia control.
Results: The pupil diameter was inversely correlated with the axial elongation both in mild myopes (r = -0.48, p < 0.001) and in moderate myopes (r = -0.7, p < 0.001). Patients showed slower axial length progression when treated with a 5.5-mm OZ lens design than with a conventional 6.0-mm OZ lens design.
Conclusion: When examining a child with progressive myopia, it is important to pay attention to the photopic pupil size because the size may be a predictor of myopia progression and exert an influ-ence on the choice of correction. Orthokeratology lenses with a smaller (5.5-mm) optical zone diam-eter are more effective for myopia control, which should be taken into consideration when selecting a lens design for children.
Keywords: myopia, refractive therapy, orthokeratology lenses, corneal topography, pupil diameter
1.Pan CW, Ramamurthy D, Saw SM. Worldwide prevalence and risk factors for myopia. Ophthalmic Physiol Opt. 2012; 32(1): 3–16.
2.Smirnova IIu, Larshyn AS. [Current visual status among schoolchildren: prospects and challenges]. Glaz. 2011;3:2-8. Russian.
3.Moiseienko EO, Golubchikov MV, Mykhalchuk VM, Rykov SO. [Ophthalmological care in Ukraine in 2014-2017]. Kropyvny-tskyi: Polium; 2018. Ukrainian.
4.Poveshchenko IuL. [Clinical characteristics of disabling myopia]. Medychni perspektyvy. 1999;3:66-9. Ukrainian.
5.Mingazova EM, Samoilov Shiller SI. [Role of social and medical factors in the development of myopia]. Kazanskii meditsinskii zhurnal. 2012;6:958-61. Russiаn.
6.Lytvynchuk LM, Sergiienko AM, Rikhard G, et al. [Frequency of retinal complications in high myopia]. Ukrainskyi medychnyi almanakh. 2012; 5:109–10. Ukrainian.
7.Vitovska OP, Savina OM. [[The structure and sickness rate of eye and adnexa diseases in children in Ukraine]. Medicni perspek-tivi. 2015;3:133-8. Ukrainian.
8.Rykov SO, Varyvonchyk DV. [Pediatric blindness and visual impairment in Ukraine: a situation analysis]. Kyiv: Logos; 2005. Ukrainian.
9.Lee EJ, Lim DH, Chung TY, Hyun J, Han J. Association of axial length growth and topographic change in orthokeratology. Eye Contact Lens. 2018; 44:292–8.
10.Chakraborty R, Read SA, Collins MJ. Hyperopic defocus and diurnal changes in human choroid and axial length. Optom Vis Sci. 2013; 90(11):1187–98.
11.Charman WN, Jennings JA. Longitudinal changes in peripheral refraction with age. Ophthalmic Physiol Opt. 2006;26:447–55.
12.Charman WN, Radhakrishnan H. Peripheral refraction and the development of refractive error: a review. Ophthalmic Physiol Opt. 2010;30:321–38.
13.Chen X, Sankaridurg P, Donovan L, et al. Characteristics of peripheral refractive errors of myopic and nonmyopic Chinese eyes. Vision Res. 2010;50:31–5.
14.Chen Z, Niu L, Xue F et al. Impact of pupil diameter on axial growth in orthokeratology. Optom Vis Sci. 2012;89(11):1636-40.
15.Downie LE, Lowe R. Corneal Reshaping Influences Myopic Prescription Stability (CRIMPS): an analysis of the effect of or-thokeratology on childhood myopic refractive stability. Eye Contact Lens. 2013;39:303–10.
16.Faria-Ribeiro M, Navarro R, González-Méijome J, et al. Effect of Pupil Size on Wavefront Refraction during Orthokeratology. Optom Vis Sci. 2016; 93(11):1399-1408.
17.Faria-Ribeiro M, Queirós A, Lopes-Ferreira D, et al. Peripheral refraction and retinal contour in stable and progressive myopia. Optom and Vis Sci. 2013;90(1):9-15.
18.Marcotte-Collard R, Simard P, Michaud L. Analysis of two orthokeratology lens designs and comparison of their optical effects on the cornea. Eye Contact Lens.2018;44(5):322–9.
19.Carracedo G, Espinosa-Vidal TM, Martínez-Alberquilla I, Batres L. The Topographical Effect of Optical Zone Diameter in Or-thokeratology Contact Lenses in High Myopes. J Ophthalmol. 2019 Jan 2;2019:1082472. doi: 10.1155/2019/1082472.