A comparative study of orthokeratology and low-dose atropine for the treatment of anisomyopia in children

Comparison of 0.02% atropine eye drops, peripheral myopia defocus design spectacle lenses, and orthokeratology for myopia control

CLINICAL RELEVANCE

There are many methods to control the progression of myopia. However, it is currently unknown which method could better control myopia progression: 0.02% atropine eye drops, peripheral myopic defocus design spectacle lenses (PMDSL), or orthokeratology (OK).

BACKGROUND

To compare the efficacy of 0.02% atropine, PMDSL, and OK to control axial length (AL) elongation in children with myopia.

METHODS

This study was analysed based on a previous cohort study (0.02% atropine group) and retrospective data (PMDSL and OK group). Overall, 387 children aged 6-14 years with myopia - 1.00D to - 6.00D in the three groups were divided into four subgroups according to age and spherical equivalent refraction (SER). The primary outcome was changed in AL over 1-year.

RESULTS

The mean axial elongation was 0.30 ± 0.21 mm, 0.23 ± 0.16 mm, and 0.17 ± 0.19 mm in the 0.02% atropine, PMDSL, and OK groups, respectively. Multivariate linear regression analyses showed significant differences in axial elongation among the three groups, especially in children aged 6-10, but not in children aged 10.1-14; the corresponding axial elongation was 0.35 ± 0.21 mm, 0.23 ± 0.17 mm, and 0.21 ± 0.20 mm (P < 0.05 between any two groups, except between PMDSL and OK groups at P > 0.05) and 0.22 ± 0.20 mm, 0.21 ± 0.13 mm, and 0.13 ± 0.18 mm (P < 0.05 between any two groups, except between 0.02% atropine and PMDSL groups at P > 0.05) in children with SER from - 1.00D to - 3.00D and from - 3.01D to - 6.00D, respectively.

CONCLUSIONS

Within the limits of this study design and using only the current brand of PMDSL, OK appeared to be the best method, followed by PMDSL and then 0.02% atropine, for controlling AL elongation over one year. However, different effects were found in the various age and SER subgroups.

Changes in axial length in anisometropic children wearing orthokeratology lenses

Purpose

There is a particular anisometropia occurring in one eye with myopia, while the other eye has very low myopia, emmetropia, or very low hyperopia. It is unclear how the binocular axial length changes when these children wear unilateral OK lenses only in the more myopic eyes. This study investigates the changes in the axial elongation of both eyes.

Methods

This is a 1-year retrospective study. In total, 148 children with myopic anisometropia were included. The more myopic eyes were wearing orthokeratology lenses (treated eyes), whereas the contralateral eyes were not indicated for visual correction (untreated eyes). The untreated eyes were classified into three subgroups based on the spherical equivalent refraction (SER): low myopia (≤ -0.50 D, n = 37), emmetropia (+0.49 to -0.49 D, n = 76), and low hyperopia (≥0.50 D, n = 35). Changes in the axial length (AL) were compared between the untreated and treated eyes and among the three subgroups.

Results

The axial elongation was 0.14 ± 0.18 mm and 0.39 ± 0.27 mm in all treated and untreated eyes, respectively (p < 0.001). The interocular AL difference decreased significantly from 1.09 ± 0.45 mm at the baseline to 0.84 ± 0.52 mm at 1 year (p < 0.001). The baseline median (Q1, Q3) SER of the untreated eyes were -0.75 D (-0.56, -0.88 D), 0.00 D (0.00, -0.25 D), and +0.75 D (+1.00, +0.62 D) in low myopia, emmetropia, and low hyperopia subgroups, respectively. The axial elongation was 0.14 ± 0.18 mm, 0.15 ± 0.17 mm, and 0.13 ± 0.21 mm (p = 0.92) in the treated eyes and 0.44 ± 0.25 mm, 0.35 ± 0.24 mm, and 0.41 ± 0.33 mm in the untreated eyes (p = 0.11) after 1 year. Multivariate linear regression analyses only showed significant differences in axial elongation between the emmetropia and low myopia subgroups of untreated eyes (p = 0.04; p > 0.05 between other subgroups).

Conclusion

Unilateral orthokeratology lenses effectively reduced axial elongation in the more myopic eyes and reduced interocular AL differences in children with myopic anisometropia. The refractive state of the untreated eyes did not affect the axial elongation of the more myopic eye wearing the orthokeratology lens. In the untreated eyes, AL increased faster in the low myopia subgroup than in the emmetropia subgroup.

Effectiveness of 0.01% atropine in anisomyopic children

Purpose

To investigate the change in ocular parameters of anisomyopic children treated with 0.01% atropine.

Methods

This retrospective study analyzed the data of anisomyopic children who underwent comprehensive examination at a tertiary eye center in India. Anisomyopic subjects (difference of ≥1.00 D) of age 6-12 years who were treated with 0.01% atropine or prescribed regular single vision spectacle and had follow-ups of more than 1 year were included.

Results

Data from 52 subjects were included. No difference was observed in the mean rate of change of spherical equivalent (SE) of more myopic eyes between 0.01% atropine (-0.56 D; 95% confidence interval [CI]: -0.82, -0.30) and single vision lens wearers (-0.59 D; 95% CI: -0.80, -0.37; P = 0.88). Similarly, insignificant change in the mean SE of less myopic eyes was noted between the groups (0.01% atropine group, -0.62 D; 95% CI: -0.88, -0.36 vs. single vision spectacle wearer group, -0.76 D; 95% CI: -1.00, -0.52; P = 0.43). None of the ocular biometric parameters showed any difference between the two groups. Though anisomyopic cohort treated with 0.01% atropine revealed a significant correlation between the rate of change of mean SE and axial length in both eyes (more myopic eyes, r = -0.58; P = 0.001 and less myopic eyes, r = -0.82; P < 0.001) compared to single vision spectacle wearer group, the change was not significant.

Conclusion

Administration of 0.01% atropine had minimal effect on reducing the rate of myopia progression in anisomyopic eyes.

IMI-Management and Investigation of High Myopia in Infants and Young Children

Purpose

The purpose of this study was to evaluate the epidemiology, etiology, clinical assessment, investigation, management, and visual consequences of high myopia (≤-6 diopters [D]) in infants and young children.

Findings

High myopia is rare in pre-school children with a prevalence less than 1%. The etiology of myopia in such children is different than in older children, with a high rate of secondary myopia associated with prematurity or genetic causes. The priority following the diagnosis of high myopia in childhood is to determine whether there is an associated medical diagnosis that may be of greater overall importance to the health of the child through a clinical evaluation that targets the commonest features associated with syndromic forms of myopia. Biometric evaluation (including axial length and corneal curvature) is important to distinguishing axial myopia from refractive myopia associated with abnormal development of the anterior segment. Additional investigation includes ocular imaging, electrophysiological tests, genetic testing, and involvement of pediatricians and clinical geneticists is often warranted. Following investigation, optical correction is essential, but this may be more challenging and complex than in older children. Application of myopia control interventions in this group of children requires a case-by-case approach due to the lack of evidence of efficacy and clinical heterogeneity of high myopia in young children.

Conclusions

High myopia in infants and young children is a rare condition with a different pattern of etiology to that seen in older children. The clinical management of such children, in terms of investigation, optical correction, and use of myopia control treatments, is a complex and often multidisciplinary process.

Controlling anisomyopia in children by orthokeratology: A one-year randomised clinical trial

PURPOSE

To investigate the effects of overnight orthokeratology (OK) lenses wear on the interocular axial length (AL) difference in anisomyopic children.

METHODS

Sixty anisomyopic children (8-14 years old) were enrolled in this one-year prospective, randomised controlled study. Subjects were randomly assigned to wear OK lenses (OK group) or single-vision spectacles (control group). AL was monitored at baseline and every six months using an IOL Master biometer, and axial elongation and interocular AL differences were compared between the groups.

RESULTS

In the control group, the more myopic eyes had similar axial elongation (0.36 ± 0.17 mm) to the less myopic eyes (0.37 ± 0.17 mm) at the one-year follow-up (P > 0.05). In the OK group, the less myopic eyes exhibited significantly greater axial elongation (0.24 ± 0.17 mm) than the more myopic eyes (0.13 ± 0.13 mm) at the one-year follow-up (P < 0.05). The mean interocular AL difference significantly decreased in the OK group over one year, from 0.47 ± 0.24 mm to 0.35 ± 0.22 mm (P < 0.05). However, the mean interocular AL difference decreased only slightly in the control group, from 0.56 ± 0.28 mm to 0.55 ± 0.28 mm (P > 0.05).

CONCLUSION

This randomised, controlled study demonstrated that OK reduces the interocular AL difference in anisomyopic children due to stronger myopic control of the more myopic eye.

Effect of Atropine 0.01% Eye Drops on the Difference in Refraction and Axial Length between Right and Left Eyes

INTRODUCTION

This study sought to determine whether the application of 0.01% atropine eye drops could impact the disparity in refraction and axial length (AL) between the right and left eyes in Chinese children.

METHODS

The study was designed as a double-blind, placebo-controlled randomized trial. A total of 220 children aged 6-12 years were recruited from the Beijing Tongren Hospital in Beijing, China. Participants were randomized in a 1:1 ratio and were prescribed 0.01% atropine or placebo eye drops to be administered once a night to both eyes for the duration of 1 year. The cycloplegic refraction and AL were recorded including baseline, 6 months, and again at the 12 months.

RESULTS

After 1-year follow-up period, 76 (69%) and 83 (75%) subjects of the initial 220 participants were identified as the 0.01% atropine and placebo groups, respectively. The inter-ocular difference in spherical equivalent refraction (SER) and AL demonstrated stable values in the 0.01% atropine treatment group (SER: p = 0.590; AL: p = 0.322) analyzed after 1 year, but found a significant increase (SER: p < 0.001; AL: p = 0.001) in the placebo group. Furthermore, over 1 year, eyes with greater myopia in the atropine group exhibited slower myopia progression (0.45 ± 0.44 D) than the lesser myopic eye (0.56 ± 0.44 D) (p = 0.003).

CONCLUSION

This study demonstrated that 0.01% atropine could maintain the inter-ocular SER and AL difference. And 0.01% atropine appeared to be more effective in delaying the progression of myopia in eyes with more myopia than in the less myopic eyes.

Comparison of the Effects of Orthokeratology Lens and Cyclopentolate on Myopia Progression in Children

Purpose: To compare the effects of orthokeratology lens (Ortho‐K lens) and topical cyclopentolate on myopia progression in children. Methods: This retrospective study analyzed the medical records of 36 children who received Ortho‐K lens and 28 who received cyclopentolate (i.e., total of 64 eyes). The following data were recorded: sex, age, age at first intervention, follow‐up duration, and visual acuity and axial length (AL) at the time of first treatment and after 6, 12, and 24 months of treatment. Results: In the Ortho‐K group, the changes of AL significantly decreased by 0.3 ± 0.25 mm at 12 months and 0.52 ± 0.34 mm at 24 months (p for trend < 0.001). In the cyclopentolate group, the changes of AL significantly decreased by 0.36 ± 0.17 mm at 12 months and 0.62 ± 0.29 mm at 24 months (p for trend = 0.022). Compared to the use of cyclopentolate, the use of Ortho‐K lens resulted in smaller changes in AL during follow‐up (p = 0.038). Conclusions: In myopic children, Ortho‐K reduced myopia progression, whereas cyclopentolate significantly less affect myopia progression than Ortho‐K lens.

Efficacy of long-term orthokeratology treatment in children with anisometropic myopia

AIM

To explore the efficacy of the orthokeratology lens for anisometropic myopia progression.

METHODS

A retrospective study was performed. Cycloplegic refraction and axial length (AL) were collected from 50 children (10.52±1.72y) who visited Peking University Third Hospital from July 2015 to August 2020. These children's one eyes (Group A) received monocular orthokeratology lenses at first, after different durations (12.20±6.94mo), their contralateral eyes (Group B) developed myopia and receive orthokeratology as well. The data in 1-year of binocular period were recorded. AL growth rate (difference of follow-up and baseline per month) were compared between two groups by paired t test. Interocular differences of AL were compared by Wilcoxon test.

RESULTS

During monocular period, the AL growth rate of the Group A (0.008±0.022 mm/mo) was significantly slower than that of the Group B (0.038±0.018 mm/mo; P<0.0001). However, during binocular period, the AL growth rate of the Group A (0.026±0.014 mm/mo) was significantly faster than that of the Group B (0.016±0.015 mm/mo; P<0.0001). The AL difference between both eyes was 0.6 (0.46) mm, then significantly decreased to 0.22 (0.39) mm when started binocular treatment (P<0.0001). However, it was significantly increased to 0.30 (0.32) mm after a year (P<0.0001), but still significantly lower than baseline (P<0.0001).

CONCLUSION

The orthokeratology lens is efficient for control the AL elongation of monocular myopia eyes and reduce anisometropia. For the condition that the contralateral eyes develop myopia and receive orthokeratology lens later, there is no efficiency observed on control interocular difference of AL during binocular treatment.

Differences in Retinal and Choroidal Vasculature and Perfusion Related to Axial Length in Pediatric Anisomyopes

Purpose

The purpose of this study was to evaluate the interocular differences in choroidal vasculature, choriocapillaris perfusion, and retinal microvascular network, and to explore their associations with interocular asymmetry in axial lengths (ALs) in children with anisomyopia.

Methods

Refractive error, AL, and other biometric parameters were measured in 70 children with anisomyopia. Using optical coherence tomography (OCT) and OCT-angiography, we measured the submacular choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), stromal area (SA), choroidal vascularity index (CVI), choriocapillaris flow deficit (CcFD), retinal vessel density (VD), and foveal avascular zone (FAZ) area.

Results

The mean interocular differences in spherical equivalent refraction and AL were −2.26 ± 0.94 diopters and 0.95 ± 0.46 mm, respectively. Submacular ChT, TCA, LA, SA, and CVI were all significantly lower in the more myopic (longer AL) eyes than in the less myopic (shorter AL) fellow eyes. In eyes with longer ALs, both the CcFD and FAZ areas were significantly greater, whereas the superficial and deep retinal VDs were significantly less. After adjusting for corneal power and intraocular pressure, interocular differences in LA (β = −0.774), SA (β = −0.991), and CcFD (β = 0.040) were significantly associated with interocular asymmetry in AL (all P < 0.05).

Conclusions

In pediatric anisomyopes, eyes with longer ALs tended to have lower choroidal vascularity and choriocapillaris perfusion than the contralateral eyes with shorter ALs. Longitudinal investigations would be useful follow-ups to test for a causal role of choroidal circulation in human myopia.

Effect of orthokeratology on anisometropia control: A meta-analysis

BACKGROUND

The effectiveness of orthokeratology in retarding anisometropic progression has been investigated in several small-sample studies. This quantitative analysis aimed to elucidate the efficacy of orthokeratology for anisometropia control.

METHODS

We searched PubMed, Embase, and Cochrane databases for relevant studies through September 2020. Axial length (AL) data at baseline and final follow-up were extracted, and AL elongation and difference were calculated. Methodological quality was evaluated using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool. Meta-analyses were performed using a fixed-effect model based on the heterogeneity.

RESULTS

A total of 10 cohort studies (nine retrospective studies; one prospective study) were included. The pooled results for the unilateral myopia group showed that the mean AL elongation difference between myopic and emmetropic eyes was -0.27 mm (95% CI, -0.31 to -0.22; p < 0.01) at the one-year follow-up (four studies) and -0.17 mm (95% CI, -0.33 to -0.02; p = 0.03) at the two-year follow-up (two studies). In the bilateral anisomyopic group, mean AL elongation difference between high and low myopic eyes was -0.06 mm (95% CI, -0.09 to -0.04; p < 0.01) at the one-year follow-up (seven studies) and -0.13 mm (95% CI, -0.21 to -0.06; p < 0.01) at the two-year followup (three studies).

CONCLUSION

This study demonstrated that orthokeratology can effectively retard myopic progression and reduce anisomyopic values. However, additional wellstructured randomized controlled trials or prospective studies with longer follow-up periods are warranted to address this topic in more detail.