Effect of Repeated Low-level Red Light on Myopia Prevention Among Children in China With Premyopia: A Randomized Clinical Trial

Effectiveness of Low-level Red Light for Controlling Progression of Myopia in Children and Adolescents

OBJECTIVE

To evaluate the effectiveness of low-level red light (LRL) in controlling the progression of myopia in children and adolescents.

METHODS

A randomized controlled trial was conducted from March 2022 to June 2022 at the Xuzhou First People's Hospital. A total of 73 children and adolescents with myopia, between the ages of 6 and 14, and meeting the inclusion criteria, were randomly divided into two groups. The experimental group wore single vision spectacles with LRL intervention, while the control group wore single vision spectacles alone. Spherical equivalent refraction (SER), axial length (AL), subfoveal choroidal thickness (SFCT), and best-corrected visual acuity (BCVA) were measured for the participants. Data analysis was performed using chi-square test, independent samples t-test, and Mann-Whitney U test. To compare the changes in SER and AL between groups, we utilized the Generalized Estimating Equations (GEE) model.

RESULTS

The experimental group was composed of 36 individuals, while the control group had 37. The mean age of the participants was 8.9 ± 2.0 years. No statistically significant distinctions in SER, AL and SFCT were observed between the two groups at baseline (P > 0.05). After 6 months of intervention, the experimental group's increase in SER (-0.01D; 95% CI: -0.09, 0.06) was higher than that of the control group (-0.41D; 95% CI: -0.51, -0.32), with a significance level of P < 0.001. Furthermore, the changes over time revealed significant differences between the two groups (Wald χ2group×time: 31.576, P < 0.001). The experimental group's AL increase (-0.02mm; 95% CI: -0.07, 0.03) was less than the control group's (0.22mm; 95% CI: 0.19, 0.25) (P < 0.001), with a significant difference over time between them (wald χ2group×time: 62.305, P < 0.001). SFCT change after 6 months in the experimental group was significantly greater (29.19μm; 95% CI: 18.48, 39.91) compared to that of the control group (-6.59μm; 95% CI: -14.28, 1.09) (P < 0.001). No adverse events were observed, and there was no evidence of fundus structural damage on OCT imaging.

CONCLUSIONS

The findings suggest that low-level red light can effectively control myopia progression in children and adolescents within 6 months. No adverse reactions were observed.

Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status using swept-source optical coherence tomography

BACKGROUND

The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT).

METHODS

In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 μm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D).

RESULTS

Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL.

CONCLUSION

In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Repeated Low-Level Red Light Therapy for Myopia Control in High Myopia Children and Adolescents: A Randomized Clinical Trial

PURPOSE

To assess the effectiveness and safety of repeated low-level red light (RLRL), which is a newly available treatment for myopia control in children and adolescents with high myopia.

DESIGN

Multicenter, randomized, parallel-group, single-blind clinical trial (randomized controlled trial; NCT05184621).

PARTICIPANTS

Between February 2021 and April 2022, 192 children aged 6 to 16 years were enrolled. Each child had at least 1 eye with myopia of cycloplegic spherical equivalent refraction (SER) at least -4.0 diopters (D), astigmatism of ≤2.0 D, anisometropia of ≤3.0 D, and best-corrected visual acuity (BCVA) of 0.2 logarithm of the minimum angle of resolution or better. Follow-up was completed by April 2023.

METHODS

Participants were randomly assigned at a 1:1 ratio to intervention (RLRL treatment plus single-vision spectacles) or control (single-vision spectacles) groups. The RLRL treatment was administered for 3 minutes per session, twice daily with a minimum interval of 4 hours, 7 days per week.

MEAN OUTCOME MEASURES

The primary outcome and key secondary outcome were changes in axial length (AL) and cycloplegic SER measured at baseline and the 12-month follow-up visit. Participants who had at least 1 postrandomization follow-up visit were analyzed for treatment efficacy.

RESULTS

Among 192 randomized participants, 188 (97.91%) were included in the analyses (96 in the RLRL group and 92 in the control group). After 12 months, the adjusted mean change in AL was -0.06 mm (95% confidence interval [CI], -0.10 to -0.02 mm) and 0.34 mm (95% CI, 0.30 to 0.39 mm) in the intervention and control groups, respectively. A total of 48 participants (53.3%) in the intervention group were still experiencing axial shortening >0.05 mm at the 12-month follow-up. The mean SER change after 12 months was 0.11 D (95% CI, 0.02to 0.19 D) and -0.75 D (95% CI, -0.88 to -0.62 D) in the intervention and control groups, respectively.

CONCLUSIONS

Repeated low-level red light demonstrates stronger treatment efficacy among those with high myopia, with 53.3% experiencing substantial axial shortening. Repeated low-level red light provides an excellent solution for the management of high myopia progression, a significant challenge in ophthalmology practice.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Safety of repeated low-level red-light therapy for children with myopia

BACKGROUD

To investigate the safety of repetitive low-level red-light therapy (RLRLT) in children with myopia.

METHODS

Children with myopia were assigned to the RLRL and control groups. Axial length (AL) and spherical equivalent refraction (SER) were followed up at 3-, 6-, and 12-month. To evaluate the safety of RLRLT, at 6 and 12 months in the RLRL group, multifocal electroretinography (mfERG) and contrast sensitivity were recorded. Furthermore, optical coherence tomography was used to measure the relative reflectance of the ellipsoid zone (rEZR), photoreceptor outer segment (rPOSR), and retinal pigment epithelium (rRPER).

RESULTS

A total of 108 children completed the trial (55 in the RLRL group and 53 in the control group). After 3, 6, and 12 months, AL was shorter and SER less myopic in the RLRL group than in the control group. Regarding the safety of the RLRLT, the response density and amplitude of the P1 wave of the first ring of the mfERG increased significantly at 6 months (P = 0.001 and P = 0.017, respectively). At 6 and 12 months, contrast sensitivity at the high spatial frequency increased. Moreover, the rEZR increased significantly at 6 months (P = 0.029), the rPOSR increased significantly at 6 and 12 months (both P < 0.001), and the increase in rPOSR was greater with greater AL regression.

CONCLUSIONS

Based on retinal function and structure follow-up, RLRLT was safe within 12 months. However, rEZR and rPOSR increased, the effects of this phenomenon requires further observation.

Daily Low-Level Red Light for Spherical Equivalent Error and Axial Length in Children With Myopia: A Randomized Clinical Trial

Importance

Treatments are needed to slow progression of or reduce incidence of myopia.

Objective

To evaluate the efficacy and safety of daily 650-nm low-level red light (LLRL) for myopia treatment.

Design, Setting, and Participants

Single-masked, randomized clinical trial at 1 site in China. Baseline measurements were completed from August to September 2021. Participants were children aged 6 to 12 years with spherical equivalent error (SER) of -6 diopters (D) to 3 D. Data were analyzed from March to July 2023.

Interventions

Irradiation daily with 650-nm LLRL for 3 minutes twice daily 4 or more hours apart or no intervention.

Main Outcomes and Measures

Primary outcomes were changes in cycloplegia SER and axial length (AL) at 6- and 12-month follow-up visits. Safety was assessed on masked fundus photograph evaluations.

Results

A total of 336 children were randomly allocated into the LLRL group or control group in a 1:1 ratio. The control group contained 86 female patients (51.2%), and the treatment group contained 90 female patients (53.6%). The mean (SD) age, SER, and AL were 9.0 (1.9) years, -1.3 (1.5) D, and 23.8 (1.0) mm for all patients. A total of 161 (95.8%) in the LLRL group and 159 (94.6%) in the control group returned for the 6-month follow-up. A total of 157 (93.5%) in the LLRL group and 152 (90.5%) in the control group returned for the 12-month follow-up. Mean (SD) changes in SER were 0.15 (0.16) D and -0.26 (0.21) D for the LLRL group and the control group, respectively (difference, -0.41 D; 95% CI, -0.48 to -0.34 D; P < .001), at 6 months and 0.24 (0.27) D and -0.65 (0.33) D for the LLRL group and the control group, respectively (difference, -0.89 D; 95% CI, -0.95 to -0.83 D; P < .001), at 12 months. Mean (SD) changes in AL were -0.06 (0.08) mm and 0.13 (0.12) mm for the LLRL group and control group, respectively (difference, 0.19 mm; 95% CI, 0.16 to 0.22 mm; P < .001), at 6 months and -0.11 (0.10) mm and 0.26 (0.16) mm for the LLRL group and control group, respectively (difference, 0.37 mm; 95% CI, 0.34 to 0.40 mm; P < .001). Masked fundus photograph review did not identify retinal changes in either group.

Conclusions and relevance

These findings suggest daily use of 650-nm LLRL for 1 year can slow progression of SER and AL without safety concerns identified. Confirmation of these findings at independent sites seems warranted, as well as determining whether these effects can be sustained with or without continued treatment and whether LLRL has any effect on pathological myopia.

Trial Registration

ChiCTR2200058963.

Impact of ophthalmic clinical service use in mitigating myopia onset and progression in preschool children: a retrospective cohort study

BACKGROUND

Although school screenings identify children with vision problems and issue referrals for medical treatment at an ophthalmic hospital, the effectiveness of this approach remains unverified.

OBJECTIVE

To investigate the impact of ophthalmic clinical services on the onset and progression of myopia in preschool children identified with vision impairment.

METHODS

Using data from the Shanghai Child and Adolescent Large-scale Eye Study (SCALE), this retrospective cohort study evaluated the visual development of children from three districts-Jing'an, Minhang, and Pudong-which are representative of geographic diversity and economic disparity in Shanghai's 17 districts. Initially, in 2015, the study encompassed 14,572 children aged 4-6 years, of whom 5,917 needed a referral. Our cohort consisted of 5,511 children who had two or more vision screenings and complete personal information over the follow-up period from January 2015 to December 2020. We divided these children into two groups based on their initial spherical equivalent (SE): a High-risk group (SE > -0.5 D) and a Myopia group (SE ≤ -0.5 D). Within each of these groups, we further categorized children into Never, Tardily, and Timely groups based on their referral compliance to compare the differences in the occurrence and progression of myopia. Cox proportional models were applied to estimate hazard ratios (HRs) for myopia incidence per person-years of follow-up in High-risk group. Generalized additive models(GAM) was used to calculating the progression for annual spherical equivalent changes in all children.

RESULTS

Of the 5,511 preschool children (mean age, 5.25 years; 52.24% male) who received a referral recommendation, 1,327 (24.08%) sought clinical services at an ophthalmic hospital. After six years of follow-up, 65.53% of children developed myopia. The six-year cumulative incidence of myopia in the Never, Tardily, and Timely groups was 64.76%, 69.31%, and 57.14%, respectively. These percentages corresponded to hazard ratios (HRs) of 1.31 (95% CI, 1.10-1.55) for the Tardily group and 0.55 (95% CI, 0.33-0.93) for the Timely group, compared with the Never group. The HRs were adjusted for age, sex, and SE at study entry. Interestingly, the Timely group showed significantly less SE progression than the other groups (P < 0.001), and SE progression was higher in the High-risk group (-0.33 ± 0.37D/year) than in children with myopia (-0.08 ± 0.55D/year).

CONCLUSION

Timely utilization of ophthalmic clinical services among children aged 4 to 6 years who fail school vision screenings can significantly reduce the incidence of myopia and slow SE progression.

Advances in myopia control strategies for children

Myopia has long been a global threat to public health. Timely interventions are likely to reduce the risk of vision-threatening complications. There are both established and rapidly evolving therapeutic approaches to slow myopia progression and/or delay its onset. The effective methods for slowing myopia progression include atropine eye-drops, defocus incorporated multiple segments (DIMS) spectacle lenses, spectacle lenses with highly aspherical lenslets target (HALT), diffusion optics technology (DOT) spectacle lenses, red light therapy (RLT), multifocal soft contact lenses and orthokeratology. Among these, 0.05% atropine, HALT lenses, RLT and +3.00 peripheral addition soft contact lenses yield over 60% reduction in myopia progression, whereas DIMS, DOT and MiSight contact lenses demonstrate at least 50% myopia control efficacy. 0.05% atropine demonstrates a more optimal balance of efficacy and safety than 0.01%. The efficacy of 0.01% atropine has not been consistent and requires further validation across diverse ethnicities. Combining atropine 0.01% with orthokeratology or DIMS spectacles yields better outcomes than using these interventions as monotherapies. Increased outdoor time is an effective public health strategy for myopia prevention while recent studies suggest that 0.05% low-concentration atropine and RLT therapy have promising potential as clinical myopia prevention interventions for high-risk groups. Myopia control spectacle lenses, being the least invasive, are safe for long-term use. However, when considering other approaches, it is essential to ensure proper instruction and regular follow-ups to maintain safety and monitor any potential complications. Ultimately, significant advances have been made in myopia control strategies, many of which have shown meaningful clinical outcomes. However, regular use and adequate safety monitoring over extended durations are imperative to foster confidence that can only come from extensive clinical experience.

Effect of exogenous calcitriol on myopia development and axial length in guinea pigs with form deprivation myopia

The annual increase in myopia prevalence poses a significant economic and health challenge. Our study investigated the effect of calcitriol role in myopia by inducing the condition in guinea pigs through form deprivation for four weeks. Untargeted metabolomics methods were used to analyze the differences in metabolites in the vitreous body, and the expression of vitamin D receptor (VDR) in the retina was detected. Following form deprivation, the guinea pigs received intraperitoneal injections of calcitriol at different concentrations. We assessed myopia progression using diopter measurements and biometric analysis after four weeks. Results indicated that form deprivation led to a pronounced shift towards myopia, characterized by reduced choroidal and scleral thickness, disorganized collagen fibers, and decreased scleral collagen fiber diameter. Notably, a reduction in calcitriol expression in vitreous body, diminished vitamin D and calcitriol levels in the blood, and decreased VDR protein expression in retinal tissues were observed in myopic guinea pigs. Calcitriol administration effectively slowed myopia progression, preserved choroidal and scleral thickness, and prevented the reduction of scleral collagen fiber diameter. Our findings highlight a significant decrease in calcitriol and VDR expressions in myopic guinea pigs and demonstrate that exogenous calcitriol supplementation can halt myopia development, enhancing choroidal and scleral thickness and scleral collagen fiber diameter.

Effectiveness of repeated low-level red light in myopia prevention and myopia control

BACKGROUND/AIMS

To compare the effects of repeated low-level red light (RLRL) treatment on axial length growth and refractive error changes in myopic and premyopic children.

METHODS

Subjects were assigned randomly to four subgroups: myopia-RLRL group (M-RL), myopia-control group (M-C), premyopia-RLRL group (PM-RL) and premyopia-control group (PM-C). Subjects in the RLRL group completed a 12-month treatment composed of a 3 min RLRL treatment session twice daily, with an interval of at least 4 hours, for 7 days per week. Visits were scheduled before and at 1-month, 3-month, 6-month, 9-month and 12-month follow-up after the treatment. Repeated-measures analysis of variance was used to compare the spherical equivalent refractive errors (SE) and axial length (AL) changes between the groups across the treatment period.

RESULTS

After 12 months of treatment, in the myopia group, SE and AL changes were -0.078±0.375 D and 0.033±0.123 mm for M-RL and -0.861±0.556 D and 0.415±0.171 mm for M-C; in the premyopia group, the progression of SE and AL was -0.181±0.417 D and 0.145±0.175 mm for PM-RL and -0.521±0.436 D and 0.292±0.128 mm for PM-C. PM-RL indicated a lower myopia incidence than PM-C (2.5% vs 19.4%). Additionally, the percentage of AL shortening in the M-RL was higher than that in the PM-RL before the 9-month follow-up.

CONCLUSION

RLRL effectively delayed myopia progression in children with myopia and reduced the incidence of myopia in premyopic children. Moreover, RLRL exhibited a stronger impact on myopic children compared with premyopic individuals.

Efficacy and Safety of Low-Dose Atropine on Myopia Prevention in Premyopic Children: Systematic Review and Meta-Analysis

Background: Early-onset myopia increases the risk of irreversible high myopia. Methods: This study systematically evaluated the efficacy and safety of low-dose atropine for myopia control in children with premyopia through meta-analysis using random-effects models. Effect sizes were calculated using risk ratios (RRs) with 95% confidence intervals (CIs). Comprehensive searches of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov were conducted until 20 December 2023, without language restrictions. Results: Four studies involving 644 children with premyopia aged 4-12 years were identified, with atropine concentrations ranging from 0.01% to 0.05%. The analysis focused on myopia incidence and atropine-related adverse events. Lower myopia incidence (RR, 0.62; 95% CI, 0.40-0.97 D/y; p = 0.03) and reduction in rapid myopia shift (≥0.5 D/1y) (RR, 0.50; 95% CI, 0.26-0.96 D/y; p < 0.01) were observed in the 12-24-month period. Spherical equivalent and axial length exhibited attenuated progression in the atropine group. No major adverse events were detected in either group, whereas the incidence of photophobia and allergic conjunctivitis did not vary in the 12-24-month period. Conclusions: Our meta-analysis supports atropine's efficacy and safety for delaying myopia incidence and controlling progression in children with premyopia. However, further investigation is warranted due to limited studies.

Assessing the rebound phenomenon in different myopia control treatments: A systematic review

PURPOSE

To review the rebound effect after cessation of different myopia control treatments.

METHODS

A systematic review that included full-length randomised controlled studies (RCTs), as well as post-hoc analyses of RCTs reporting new findings on myopia control treatments rebound effect in two databases, PubMed and Web of Science, was performed according to the PRISMA statement. The search period was between 15 June 2023 and 30 June 2023. The Cochrane risk of bias tool was used to analyse the quality of the selected studies.

RESULTS

A total of 11 studies were included in this systematic review. Unifying the rebound effects of all myopia control treatments, the mean rebound effect for axial length (AL) and spherical equivalent refraction (SER) were 0.10 ± 0.07 mm [-0.02 to 0.22] and -0.27 ± 0.2 D [-0.71 to -0.03] after 10.2 ± 7.4 months of washout, respectively. In addition, spectacles with highly aspherical lenslets or defocus incorporated multiple segments technology, soft multifocal contact lenses and orthokeratology showed lower rebound effects compared with atropine and low-level light therapy, with a mean rebound effect for AL and SER of 0.04 ± 0.04 mm [0 to 0.08] and -0.13 ± 0.07 D [-0.05 to -0.2], respectively.

CONCLUSIONS

It appears that the different treatments for myopia control produce a rebound effect after their cessation. Specifically, optical treatments seem to produce less rebound effect than pharmacological or light therapies. However, more studies are required to confirm these results.

Red light instruments for myopia exceed safety limits

PURPOSE

Low-level red light (LLRL) therapy has recently emerged as a myopia treatment in children, with several studies reporting significant reduction in axial elongation and myopia progression. The goal of this study was to characterise the output and determine the thermal and photochemical maximum permissible exposure (MPE) of LLRL devices for myopia control.

METHODS

Two LLRL devices, a Sky-n1201a and a Future Vision, were examined. Optical power measurements were made using an integrating sphere radiometer through a 7-mm diameter aperture, in accordance with ANSI Z136.1-2014, sections 3.2.3-3.2.4. Retinal spot sizes of the devices were obtained using a model eye and high-resolution beam profiler. Corneal irradiance, retinal irradiance and MPE were calculated for an eye positioned at the oculars of each device.

RESULTS

Both devices were confirmed to be Class 1 laser products. Findings showed that the Sky-n1201a delivers laser light as a point source with a 654-nm wavelength, 0.2 mW power (Ø 7 mm aperture, 10-cm distance), 1.17 mW/cm2 corneal irradiance and 7.2 W/cm2 retinal irradiance (Ø 2 mm pupil). The MPE for photochemical damage is 0.55-7.0 s for 2-7 mm pupils and for thermal damage is 0.41-10 s for 4.25-7 mm pupils. Future Vision delivers the laser as an extended source subtending 0.75 × 0.325°. It has a 652-nm wavelength, 0.06 mW power (Ø 7 mm aperture, 10 cm distance), 0.624 mW/cm2 corneal irradiance and 0.08 W/cm2 retinal irradiance (Ø 2 mm pupil). MPE for photochemical damage is 50-625 s for 2-7 mm pupils.

DISCUSSION

For both of the LLRL devices evaluated here, 3 min of continuous viewing approached or surpassed the MPE, putting the retina at risk of photochemical and thermal damage. Clinicians should be cautious with the use of LLRL therapy for myopia in children until safety standards can be confirmed.

Effect of wearing peripheral focus-out glasses on emmetropization in Chinese children aged 6-8 years: study protocol for a 2-year randomized controlled intervention trial

BACKGROUND

Myopia is one of the most common eye diseases causing visual impairment and blindness, and the high prevalence in adolescents remains a major public health concern. Based on clinical studies using optical defocus to regulate ocular growth and refractive changes through visual feedback, we hypothesize that early wearing of peripheral myopic defocusing spectacles in children with high risk of myopia may slow the process of emmetropization and even prevent the onset of myopia by inducing more peripheral myopic defocus. The aim of this study is to investigate whether the wearing of peripheral focus-out glasses can be effective in delaying emmetropization in non-myopic children aged 6-8 years.

METHODS

The study is a 2-year randomized controlled trial. A total of 160 subjects will be randomized into the experimental group or the control group. The experimental group will be fitted with direct emmetropia with focus-out glasses (DEFOG) to guide the emmetropization process. The control group will not receive any treatment and will serve as a blank control group. The primary aim is to determine whether non-myopic children wearing DEFOG lenses are superior to those who do not receive any intervention on the progression of cycloplegic objective refraction over 2 years.

DISCUSSION

This is the first randomized controlled trial aiming at myopic prevention by non-invasive intervention in non-myopic children. This study aims to initially investigate whether wearing peripheral focus-out glasses can effectively delay the process of emmetropization in children aged 6-8 years with high risk of myopia, which might give potential clues for further exploration on early prevention of myopia.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05689567. Registered on 10 January 2023.

Preventing the Progression of Myopia in Children-A Review of the Past Decade

The growing incidence of myopia worldwide justifies the search for efficient methods of myopia prevention. Numerous pharmacological, optical, and lifestyle measures have already been utilized, but there remains a need to explore more practical and predictable methods for myopia control. This paper presents a review of the most recent studies on the prevention of myopia progression using defocus-incorporated multiple-segment spectacle lenses (DIMSsl), repeated low-level red-light (RLRL) therapy, and a combination of low-dose atropine (0.01%) with orthokeratology lenses.