Secondary Logo

Journal Logo

Review

Update on Myopia Control: The US Perspective

Rhee, Michelle K. M.D.

Author Information
Eye & Contact Lens: Science & Clinical Practice: March 2022 - Volume 48 - Issue 3 - p 105-109
doi: 10.1097/ICL.0000000000000872
  • Free

Abstract

Myopia is a global epidemic. Currently, 20% (or 1.5 billion people) of the global population is myopic. Of these 1.5 billion people, 163 million of them have high myopia, defined as greater than −5.00 diopters (D). By 2050, it is projected that half of the global population will be myopic.1 Although “garden variety” myopia can be corrected with spectacles or contact lenses, there is particular concern in those patients with high myopia, and the associated anatomic changes such as in axial length, and retinal pathology, some of which are so severe that the best-corrected visual acuity is limited. This subgroup of myopes is increasing in number. Genetics play an important role, but the increasing prevalence of myopia seems to be linked to environmental influences such as urbanization and reduced outdoor exposure.2

It is known that high myopes have exponentially higher risk: For every diopter of myopia saved, the risk of myopia maculopathy decreases by 40%.3 To address this epidemic, interest in myopia control has grown. In general terms, myopia control refers to the delay of onset and/or slowing of progression of myopia in children. The goal is not simply to reduce spectacle and contact lens use but to prevent ocular morbidity associated with myopia such as glaucoma, cataract, and retinal disease including choroidal neovascularization and retinal detachment. Convincing data have emerged in the efficacy of myopia control, specifically soft bifocal contact lenses, orthokeratology, and antimuscarinic agents; low-concentration atropine and outdoor time have been shown to delay the onset of myopia. This article reviews treatment options and current attitudes on myopia control, with particular attention to the US perspective.

OPTICAL CORRECTION

Contact Lenses

Contact lenses and spectacles have been a mainstay in the optical correction of myopia. Beyond refractive purposes, they have also been studied for their role in myopia control. Although single-vision contact lenses and spectacles are not effective in myopia control, multifocal contact lenses have emerged as a viable option for myopia control.

Walline4 studied soft bifocal contact lenses and found delay of myopia progression by an average of 46%. Anstice and Phillips5 noted that axial elongation was slower in the eye wearing a soft bifocal contact lens when compared with a soft spherical lens, even after switching treatment to the contralateral eye. Switching to the contralateral eye showed that accommodation was not the mechanism of action (because accommodation is yoked), but rather, another mechanism, such as peripheral myopic blur. It is believed that the soft bifocal contact lens acts by decreasing relative peripheral hyperopia defocus, and increasing peripheral myopia defocus, which slows axial length growth.6

Currently, the only treatment with specific labeling for myopia control by the US Food and Drug Administration (FDA) is the MiSight 1-day lens (CooperVision, Inc., Victor, NY). This daily disposable, hydrogel with a dual focus lens and concentric ring design was approved in 2019. It is indicated for children aged between 8 to 12 years with a refraction at the initiation of treatment ranging from −0.75 to −4.00 D of sphere, with no greater than 0.75 cylinder. The lens has a large central correction area of 3.36 mm with concentric zones of alternating distance and near powers which produce two focal planes. The treatment zones produce 2.00 D of simultaneous myopic retinal defocus during both distance and near viewing. Chamberlain et al.7 found that the MiSight reduced myopic progression by nearly 60% over a period of 3 years in a randomized controlled trial. They also found a 52% reduction in average axial lengthening and long-term efficacy extending out to 6 years of follow-up.8

Although all contact lens wear carries risk for microbial keratitis, the mode of wear with the most favorable safety profile is the daily disposable. Cope et al.9 reviewed 1,075 FDA-reported contact lens infections over the course of 10 years in the United States. Daily disposable wearers had the lowest rate of infection (3.3%) when compared with soft daily wear (57.2%), soft extended wear (35.4%), and rigid gas-permeable wear (4.0%). Woods et al.10 studied that 144 children aged 8 to 12 years who after 6 years of wearing MiSight 1 day or Proclear 1 day (both CooperVision, Inc.) had no serious adverse events. Furthermore, slitlamp examination of the anterior segment showed no significant changes from contact lens use.

Walline et al.11 performed a US multicenter, randomized controlled trial studying 294 children who wore either monthly replacement single-vision lenses or multifocal lenses with an add of +1.50 or +2.50. They found that over 3 years, the higher add of +2.50 was most effective in reducing the rate of myopia progression; it slowed progression by 43% (0.45 D) and axial length elongation by 36% (0.23 mm) when compared with the single-vision lens. The subjects are continuing to be followed in a 3-year extension of the study entitled BLINK2.

Although rigid gas-permeable contact lenses have not slowed myopia progression in children,12,13 orthokeratology (OK) has shown efficacy. Orthokeratology uses specially designed, reverse geometry, gas-permeable contact lenses to temporarily reshape the corneal surface.14 These lenses flatten the cornea and are worn overnight to treat the myopia. Walline4 reviewed multiple OK studies and found that these lenses slow the growth of an eye by an unweighted average of 43%. Cho and Cheung15 reported a statistically significant decrease in axial elongation in the OK group versus the single-vision spectacle group. They also examined a combination of OK and single-vision spectacles or by single-vision spectacles alone, which found a significant decrease in axial elongation in the former group. VanderVeen et al.16 led an ophthalmic technology assessment on the use of OK and found that current evidence showed a typical reduction in axial elongation by approximately 50% over a 2-year study period; this corresponds to approximately 0.3 mm for OK patients compared with 0.6 mm for control patients, which translates to a typical difference in refraction of approximately 0.5 D. The mechanism of action is the same as for the multifocal soft contact lens, specifically, increasing peripheral myopia defocus and decreasing peripheral hyperopic defocus.16 Overnight OK lenses were FDA approved in 2002 to treat myopic refractive error, but not for myopia control, and, therefore, are used off-label for this purpose. Although OK seems to be effective in myopia control at a similar level as atropine,16 there are safety concerns, particularly with overnight wear of contact lenses, which need to be reconciled. Patient selection is critical, and perhaps, younger children belong to a separate risk category from teenagers and young adults, who are less likely to have strict parental supervision with contact lenses.

Spectacles

Historically, undercorrection of myopia was prescribed to decrease the accommodative demand for near work which had been associated with myopia and its progression. This has fallen out of favor because studies have shown it ineffective.17,18 Similarly, bifocal or multifocal spectacles have not been clinically effective. The Correction of Myopia Evaluation Trial (COMET)19 recruited 469 children aged 6 to 11 years at enrollment with 98% retained for 5 years. All subjects had between −1.25 and −4.50 D of myopia at the time of enrollment. Half were randomized to progressive addition lenses (+2.00 D add) and the other half to single-vision lenses. The COMET group concluded that the use of progressive addition lenses versus single-vision lenses slowed the progression of myopia by a small, statistically significant, but clinically inconsequential amount.

Novel technology spectacles have shown mixed efficacy.20,21 Such designs include defocus incorporated multiple segments and diffusion optics technology (DOT) spectacles, which are not commercially available in the United States but are in other parts of the world, including Europe and Asia. These spectacles work by the modulation of peripheral contrast and reduction of peripheral hyperopic defocus. A multicenter US-based, Control of Myopia Using Novel Spectacle Lens Designs; NCT03623074, trial is being performed to study the efficacy of DOT spectacles. The outcome measures are axial length and refraction over 3 years, and follow-up is currently being extended.

PHARMACOLOGIC

Pharmacologic modalities include topical atropine and pirenzepine, which are both muscarinic receptor antagonists. Atropine has been studied at different concentrations, ranging from 0.01% to 1%. Chia et al.22,23 compared atropine at concentrations of 0.01%, 0.1%, and 0.5% in a group of 400 children (aged 6–12 years) with −2.00 D or more of myopia. The 0.01% group was most effective in slowing myopia progression as measured by both refraction and axial elongation with less visual side effects over 5 years. However, the study was limited by the absence of a placebo group. Recently, Yam et al.24 compared 0.01%, 0.025%, and 0.05% atropine eye drops in 438 children (aged 4–12 years) with at least −1.00 D of myopia and −2.50 D or less of astigmatism; when compared with the other concentrations and placebo, 0.05% atropine was most effective in controlling spherical equivalent progression (67% reduction) and axial elongation (51% reduction) over 1 year. The superior efficacy of 0.05% atropine was demonstrated by the phase two report of the Low-concentration Atropine for Myopia Progression (LAMP) study which showed sustained results over 2 years.25 Although atropine's mechanism of action in myopia is unclear, it is not due to reduced accommodation.26,27 Theories include a nonaccommodative mechanism through the nicotinic pathway and biochemical effects on the retina or sclera including scleral remodeling.28,29 The most effective concentration of atropine is 1%,30 but the photophobia and near blur side effects make it unacceptable for patients, even when progressive addition add powers and transitions lens spectacles are offered. Fortunately, there is strong evidence for the efficacy and safety of low-concentration atropine. However, it is off-label for myopia control in most countries and requires compounding at specialty pharmacies. Industry is actively working on commercial formulations and novel drug delivery systems such as ocular mists that would be more accurate in dosage and more child friendly in administration. Side effects include photophobia and near blur, but are generally well-tolerated, and are administered in the evening. Further study is needed to determine optimal concentration and frequency.

Pirenzepine, an M1-specific muscarinic receptor antagonist, is not commercially available in an ophthalmic preparation in the United States. M1 receptors are highly concentrated in the retina and are found rarely on the ciliary body or iris, thereby causing fewer cycloplegic side effects. Both atropine and pirenzepine have been shown to slow myopia progression by 51% to 77%.31,32

COMBINATION THERAPY WITH CONTACT LENSES AND ATROPINE

The Bifocal and Atropine in Myopia study is comparing the combination therapy of 0.01% atropine and +2.50 D center-distance soft bifocal contact lenses to bifocal contact lenses alone.33 Gao et al.34 performed a meta-analysis of five studies and concluded that axial elongation was lower in the combination OK and atropine group when compared with OK alone.

ENVIRONMENTAL AND BEHAVIORAL MODIFICATIONS

Environmental and behavioral modifications play an important role in myopia control. Time spent outdoors has been shown to delay the onset of myopia so much so that it has become national policy in Taiwan for children to play outside. It is believed that light induces dopamine release from the retina, which inhibits myopia elongation.35 Wu et al.36 showed that 2 hr a day outside decreased the trend of reduced visual acuity in children. Before implementation of the outdoor program, the prevalence of reduced vision was increasing 1.58% per year in 2010 and is now decreasing by 2.34% annually. An earlier study of 6-year-old children showed that 40 min of outdoor activity during school reduced the incidence rate of myopia over the next 3 years.37 Studies have shown that the protective effect of increased outdoor time is not simply because of the resultant reduction in time spent on near work.38 However, outdoor time does not reduce progression in myopic subjects. Because the strongest predictor of high myopia is the age of onset,39 having a well-established38 and modifiable protective factor is meaningful. The optimal type, amount, and duration of outdoor exposure remain to be seen. Near work is also associated with myopia.40 Recently, China tightened a law on limiting video game screen time for children younger than 18 years to 3 hr a week.41

US CURRENT STATE AND PERSPECTIVE

The American Academy of Ophthalmology created a task force on myopia in 2019, in recognition of the growing global public health concern, and need for a cohesive and comprehensive action plan.42 The task force was composed of global experts with the goal of reducing the global burden of myopia, delaying onset and reducing progression in children, and preventing the more severe consequences of higher levels of myopia. The current literature was reviewed by the multidisciplinary team consisting of ophthalmology, optometry, pediatrics, family medicine, and public health experts. The necessity of this task force in 2019 was prescient, given the 2020 COVID-19 pandemic's impact on children and schooling, which will have an impact on the myopia epidemic in ways that are yet to be fully known.43

FUTURE DIRECTIONS AND QUESTIONS

Myopia control is a burgeoning area of study. Table 1 highlights key studies on treatment options. Future areas for exploration include contact lens and atropine combination therapies; new technology spectacles; preferred sequence of treatment modalities such as ideal dose, frequency, and delivery of atropine; optimal implementation of outdoor exposure; and determining permanence of therapies. There are a plethora of ongoing randomized multicenter studies in the United States and Europe on low-concentration atropine including the Myopia Treatment Study 1 (NCT03334253) which examines atropine 0.01% treatment and 6 months after cessation; the STAAR study (NCT03918915) which explores SYD-101, a proprietary formulation of atropine at different concentrations and the withdrawal period; the Childhood Atropine for Myopia Progression (NCT03350620) study (NCT03350620) which compares different concentrations of a preservative free formulation of atropine; the CHAPERONE (Microdosed Atropine 0.1% and 0.01% Ophthalmic Solutions for Reduction of Pediatric Myopia Progression; NCT03942419) study (NCT03942419) which investigates 0.1% and 0.01% atropine using a microdosing mister; MOSAIC(Myopia Outcome Study of Atropine in Children; ISRCTN36732601) which assesses 0.01% atropine in a White population; and ATOM3 (The Use of Atropine 0.01% in the Prevention and Control of Myopia; NCT03140358), which studies whether atropine can affect the onset of myopia. Other areas of research include the impact of oral riboflavin and outdoor sunlight exposure (NCT03552016) and novel extended depth of focus contact lenses (NCT03358862).

TABLE 1. - Key Studies on Treatment Options for Myopia Control
Topic Study Conclusion Ref
Contact lenses (CLs) Anstice NS, Phillips JR. Effect of dual-focus soft contact lens wear on axial myopia progression in children. Ophthalmology 2011;118:1152–1161. Axial elongation was slower in the eye wearing a soft bifocal CL when compared with a soft spherical lens. 5
Ticak A, Walline JJ. Peripheral optics with bifocal soft and corneal reshaping contact lenses. Optom Vis Sci 2013;90:3–8. Soft bifocal CLs decrease relative peripheral hyperopia defocus, which slows axial length growth. 6
Chamberlain P, Peixoto-de-Matos SC, Logan NS, et al. A 3-year randomized clinical trial of MiSight lenses for myopia control. Optom Vis Sci 2019;96:556–567. MiSight reduced myopic progression by nearly 60% and axial lengthening by 52% over a 3-year period. 7
Woods J, Jones D, Jones L, et al. Ocular health of children wearing daily disposable contact lenses over a 6-year period. Cont Lens Anterior Eye 2021;44:101391. There were no cases of microbial keratitis in a study of 144 children (aged 8–12 years) after 6 years of wearing the MiSight 1 day or Proclear 1 day. 10
Walline JJ, Walker MK, Mutti DO, et al. Effect of high add power, medium add power, or single-vision contact lenses on myopia progression in children. The BLINK randomized clinical trial. JAMA 2020;324:571–580. In a study of 294 children over 3 years, the multifocal CL with an add of +2.50 was most effective in reducing the rate of myopia progression when compared with a single-vision CL or multifocal CL with add of +1.50. 11
Cho P, Cheung SW. Retardation of myopia in orthokeratology (ROMIO) study: a 2-year randomized clinical trial. Invest Ophthalmol Vis Sci 2012;53:7077–7085. Orthokeratology showed a significant decrease in axial elongation when compared with single-vision spectacles. 15
VanderVeen DK, Kraker RT, Pineles SL, et al. Use of orthokeratology for the prevention of myopia progression in children: a report by the American Academy of Ophthalmology. Ophthalmology 2019;126:623–636. Orthokeratology showed a typical reduction in axial elongation by approximately 50% over a 2-year study period. 16
Spectacles Gwiazda J, Hyman L, Hussein M, et al. A randomized clinical trial of progressive addition lenses versus single vision lenses on the progression of myopia in children. Invest Ophthalmol Vis Sci 2003;44:1492–1500. The Correction of Myopia Evaluation Trial (COMET) recruited 469 children (aged 6–11 years) and studied them for 5 years. When compared with single-vision lenses, progressive addition lenses slowed myopia progression by a small, statistically significant, but clinically inconsequential amount. 19
Atropine Chia A, Chua WH, Cheung YB, et al. Atropine for the treatment of childhood myopia: safety and efficacy of 0.5%, 0.1%, and 0.01% doses (Atropine for the Treatment of Myopia 2). Ophthalmology 2012;119:347–354. The 0.01% group was most effective in slowing myopia progression as measured by refraction and axial elongation with less visual side effects. However, the study was limited by the absence of a placebo group. 22
Chia A, Lu QS, Tan D. Five-year clinical trial on Atropine for the Treatment of Myopia 2: myopia control with atropine 0.01% eye drops. Ophthalmology 2016;123:391–399. This study showed sustained results from ATOM2 over 5 years. 23
Yam JC, Jiang Y, Tang SM, et al. Low-Concentration Atropine for Myopia Progression (LAMP) Study: a randomized, double-blinded, placebo-controlled trial of 0.05%, 0.025%, and 0.01% atropine eye drops in myopia control. Ophthalmology 2019;126:113–124. When compared with the other concentrations and placebo, 0.05% atropine was most effective in controlling spherical equivalent progression (67% reduction) and axial elongation (51% reduction) over one year. 24
Yam JC, Li FF, Zhang X, et al. Two-year clinical trial of the low-concentration atropine for myopia progression (LAMP) study Phase 2 report. Ophthalmology 2020;127:910–919. The superior efficacy of 0.05% atropine was demonstrated by the phase 2 report of the LAMP study which showed sustained results over 2 years. 25
Chua WH, Balakrishnan V, Chan YH, et al. Atropine for the treatment of childhood myopia. Ophthalmology 2006;113:2285–2291. The most effective concentration of atropine is 1%, but the photophobia and near blur side effects make it unacceptable for patients, even when progressive addition add powers and transitions lens spectacles are offered. 30
Combination therapy Gao C, Wan S, Zhang Y, et al. The efficacy of atropine combined with orthokeratology in slowing axial elongation of myopia children: a meta-analysis. Eye Contact Lens 2021;47:98–103. This meta-analysis of 5 studies concluded that axial elongation was lower in the combination orthokeratology and atropine group when compared with orthokeratology alone. 34
Outdoor time Wu PC, Chen CT, Chang LC, et al. Increased time outdoors is followed by reversal of the long-term trend to reduced visual acuity in Taiwan primary school students. Ophthalmology 2020;127:1462–1469. Two hours a day outside decreased the trend of reduced visual acuity in children. Before implementation of the outdoor program, the prevalence of reduced vision was increasing 1.58% per year in 2010 and is now decreasing by 2.34% annually. 36
He M, Xiang F, Zeng Y, et al. Effect of Time Spent Outdoors at School on the Development of Myopia Among Children in China: A Randomized Clinical Trial. JAMA 2015;314:1142–8. 40 min of outdoor activity at school reduced the incidence rate of myopia over the next 3 years in 6-year-old children. 37

REFERENCES

1. Holden BA, Fricke TR, Wilson DA, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology 2016;123:1036–1042.
2. Wong TY, Ferreira A, Hughes R, et al. Epidemiology and disease burden of pathologic myopia and myopic choroidal neovascularization: An evidence-based systematic review. Am J Ophthalmol 2014;157:9–25.e12.
3. Bullimore MA, Brennan NA. Myopia control: Why each diopter matters. Optom Vis Sci 2019;96:463–465.
4. Walline JJ. Myopia control: A review. Eye Contact Lens 2016;42:3–8.
5. Anstice NS, Phillips JR. Effect of dual-focus soft contact lens wear on axial myopia progression in children. Ophthalmology 2011;118:1152–1161.
6. Ticak A, Walline JJ. Peripheral optics with bifocal soft and corneal reshaping contact lenses. Optom Vis Sci 2013;90:3–8.
7. Chamberlain P, Peixoto-de-Matos SC, Logan NS, et al. A 3-year randomized clinical trial of MiSight lenses for myopia control. Optom Vis Sci 2019;96:556–567.
8. Chamberlain P, Logan N, Jones D, et al. Clinical Evaluation of a Dual-Focus Myopia Control 1 Day Soft Contact Lens: 6-year Results. American Academy of Optometry Annual Meeting, Virtual; October 9, 2020; 2020. Abstract.
9. Cope JR, Collier SA, Srinivasan K, et al. Contact lens-related corneal infections–United States, 2005-2015. MMWR Morb Mortal Wkly Rep 2016;65:817–820.
10. Woods J, Jones D, Jones L, et al. Ocular health of children wearing daily disposable contact lenses over a 6-year period. Cont Lens Anterior Eye 2021;44:101391.
11. Walline JJ, Walker MK, Mutti DO, et al. Effect of high add power, medium add power, or single-vision contact lenses on myopia progression in children: The BLINK randomized clinical trial. JAMA 2020;324:571–580.
12. Walline JJ, Jones LA, Mutti DO, et al. A randomized trial of the effect of rigid contact lenses on myopia progression. Arch Ophthalmol 2004;122:1760–1766.
13. Katz J, Schein OD, Levy B, et al. A randomized trial of rigid gas permeable contact lenses to reduce progression of children's myopia. Am J Ophthalmol 2003;136:82–90.
14. Swarbrick HA, Alharbi A, Watt K, et al. Myopia control during orthokeratology lens wear in children using a novel study design. Ophthalmology 2015;122:620–630.
15. Cho P, Cheung SW. Retardation of myopia in orthokeratology (ROMIO) study: A 2-year randomized clinical trial. Invest Ophthalmol Vis Sci 2012;53:7077–7085.
16. VanderVeen DK, Kraker RT, Pineles SL, et al. Use of orthokeratology for the prevention of myopia progression in children: A report by the American Academy of Ophthalmology. Ophthalmology 2019;126:623–636.
17. Adler D, Millodot M. The possible effect of undercorrection on myopia progression in children. Clin Exp Optom 2006;89:315–321.
18. Chung K, Mohidin N, O'Leary DJ. Undercorrection of myopia enhances rather than inhibits myopia progression. Vis Res 2002;42:2555–2559.
19. Gwiazda J, Hyman L, Hussein M, et al. A randomized clinical trial of progressive addition lenses versus single vision lenses on the progression of myopia in children. Invest Ophthalmol Vis Sci 2003;44:1492–1500.
20. Zhang HY, Lam CSY, Tang WC, et al. Defocus incorporated multiple segments spectacle lenses changed the relative peripheral refraction: A 2-year randomized clinical trial. Invest Ophthalmol Vis Sci 2020;61:53.
21. Kanda H, Oshika T, Hiraoka T, et al. Effect of spectacle lenses designed to reduce relative peripheral hyperopia on myopia progression in Japanese children: A 2-year multicenter randomized controlled trial. Jpn J Ophthalmol 2018;62:537–543.
22. Chia A, Chua WH, Cheung YB, et al. Atropine for the treatment of childhood myopia: Safety and efficacy of 0.5%, 0.1%, and 0.01% doses (atropine for the treatment of myopia 2). Ophthalmology 2012;119:347–354.
23. Chia A, Lu QS, Tan D. Five-year clinical trial on atropine for the treatment of myopia 2: Myopia control with atropine 0.01% eyedrops. Ophthalmology 2016;123:391–399.
24. Yam JC, Jiang Y, Tang SM, et al. Low-concentration atropine for myopia progression (LAMP) study: A randomized, double-blinded, placebo-controlled trial of 0.05%, 0.025%, and 0.01% atropine eye drops in myopia control. Ophthalmology 2019;126:113–124.
25. Yam JC, Li FF, Zhang X, et al. Two-year clinical trial of the low-concentration atropine for myopia progression (LAMP) study: Phase 2 report. Ophthalmology 2020;127:910–919.
26. Stone RA, Lin T, Laties AM. Muscarinic antagonist effects on experimental chick myopia. Exp Eye Res 1991;52:755–758.
27. McBrien NA, Moghaddam HO, Reeder AP. Atropine reduces experimental myopia and eye enlargement via a non-accomodative mechanism. Invest Ophthalmol Vis Sci 1993;34:205–215.
28. Qu J, Zhou X, Xie R, et al. The presence of m1 to m5 receptors in human sclera: Evidence of the sclera as a potential site of action for muscarinic receptor antagonists. Curr Eye Res 2006;31:587–597.
29. Tan D, Tay SA, Loh KL, et al. Topical atropine in the control of myopia. Asia Pac J Ophthalmol (Phila) 2016;5:424–428.
30. Chua WH, Balakrishnan V, Chan YH, et al. Atropine for the treatment of childhood myopia. Ophthalmology 2006;113:2285–2291.
31. Tan DT, Lam DS, Chua WH, et al. One-year multicenter, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia. Ophthalmology 2005;112:84–91.
32. Siatkowski RM, Cotter SA, Crockett RS, et al. Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia. J AAPOS 2008;12:332–339.
33. Huang J, Mutti DO, Jones-Jordan LA, et al. Bifocal and atropine in myopia study: Baseline data and methods. Optom Vis Sci 2019;96:335–344.
34. Gao C, Wan S, Zhang Y, et al. The efficacy of atropine combined with orthokeratology in slowing axial elongation of myopia children: A meta-analysis. Eye Contact Lens 2021;47:98–103.
35. Feldkaemper M, Schaeffel F. An updated view on the role of dopamine in myopia. Exp Eye Res 2013;114:106–119.
36. Wu PC, Chen CT, Chang LC, et al. Increased time outdoors is followed by reversal of the long-term trend to reduced visual acuity in Taiwan primary school students. Ophthalmology 2020;127:1462–1469.
37. He M, Xiang F, Zeng Y, et al. Effect of time spent outdoors at school on the development of myopia among children in China: A randomized clinical trial. JAMA 2015;314:1142–1148.
38. French AN, Ashby RS, Morgan IG, et al. Time outdoors and the prevention of myopia. Exp Eye Res 2013;114:58–68.
39. Hu Y, Ding X, Guo X, et al. Association of age at myopia onset with risk of high myopia in adulthood in a 12-year follow-up of a Chinese cohort. JAMA Ophthalmol 2020;138:1129–1134.
40. Gwiazda JE, Hyman L, Norton TT, et al. Accomodation and related risk factors associated with myopia progression and their interaction with treatment in COMET children. Invest Ophthalmol Vis Sci 2004;45:2143–2151.
41. Coster H. ‟Oh, that's an idea…”: US parents respond to China screen time ban. Available at: Reuters online. Accessed September 14, 2021.
42. Modjtahedi BS, Abbott RL, Fong DS, et al. Reducing the global burden of myopia by delaying the onset of myopia and reducing myopic progression in children: The Academy's Task Force on Myopia. Ophthalmology 2021;128:816–826.
43. Wong CW, Tsai A, Jonas JB, et al. Digital screen time during the COVID-19 pandemic: Risk for a further myopia boom? Am J Ophthalmol 2021;223:333–337.
Keywords:

Myopia control; Contact lenses; Atropine

© 2021 Contact Lens Association of Ophthalmologists