With the elevated incidence and severity of myopia worldwide and its associated increased irreversible vision loss risk (see “Adverse Effects of Myopia,” below), more and more eye care providers are making the identification and management of myopia a priority in their practices. What’s more, both optometric and ophthalmic organizations have weighed in on the importance of myopia detection and control. As an example, the World Council of Optometry released “Standard of Care Guidelines for Myopia Management.” (See https://myopia.worldcouncilofoptometry.info/standard-of-care/ .)

Given this focus by eye care providers, this article provides a summary of the evidence-based approaches regarding identifying risk, making a timely diagnosis, and myopia control. (See “The Myopia Opportunity,” p.19.)

Identifying risk

Numerous studies in pre-myopic children of diverse ethnicity reveal predictive factors for myopia onset.^1,2 The most consistent predictive factors reported in most studies include uncorrected distance visual acuity (UDVA), spherical equivalent (SE), axial length (AL), flat K, gender, and myopic parents, all of which combined have predicted over 70% of myopia onset. (Providing a range for each predictive factor is not possible, as they are continuous variables correlated.)

It is worth noting that despite the shifting emphasis on AL-driven growth models in recent years, most studies report better performance of baseline SE (lower hyperopic buffer in both cycloplegic and non-cycloplegic refraction) as a single predictor of myopia onset than that of AL and environmental predictors, such as time spent outdoors and near work.^1-3 The more predictive value of SE makes an argument that the combined optical changes within the eye (e.g., corneal curvature, lens power, and anterior and posterior chamber depths) have a greater influence on myopia onset. On the other hand, cross-sectional AL data should be used in combination with SE for the best predictability of myopia onset on an individual child. This is because cross-sectional AL data are significantly influenced by age, gender, and physiological growth.

Another critical finding from longitudinal studies of premyopic children is the mismatch between the onset of myopia and that of the accelerated AL growth for which the abnormal AL elongation preceded the refractive onset of myopia by a couple years. Consequently, the change of AL provides much more predictive value in myopia onset than a random measure of AL, arguing for the critical effort in the early establishment of an ocular biometric profile, and continuous follow up prior to myopia onset.

Making a timely diagnosis

Due to the irreversible nature of scleral stretching and axial elongation during myopia development, it is crucial for optometrists to implement a set of clearly defined and easy-to-perform tests to identify children at high risk for myopia and to detect the progressive condition in a timely manner to allow for early intervention.

In summary, UDVA, autorefraction combined with auto-keratometry, and AL, performed six months apart, can be considered an efficient battery of tests for the early detection of the premyopic, accelerated AL growth, as well as myopia onset. (See “Referring for Retinal Findings,” below.)

Control

Thus far, five evidenced-based approaches are available for myopia control:

1. Visual hygiene. Converging evidence from both animal work and clinical studies suggest that short but more frequent doses of “myopia-stop” signals (e.g., bright light or plus defocus) cancel out the “myopia-go” signals (e.g., hyperopic defocus or form deprivation) more effectively than less frequent doses in longer duration.^4,5 Thus, visual hygiene practice should consist of more frequent outdoor breaks delivered immediately after prolonged near work (e.g., 40 minutes for arm length and 20 minutes for closer distance, such as from smart phones and digital tablets, in my opinion. There is not much peer reviewed evidence to define “prolonged near work.”) In children for whom the total duration of academic workload is higher, the near work should be divided into shorter and more frequent sessions instead of fewer but longer sessions.
2. Atropine 0.05% in the myopic eye. In studies thus far, this concentration has shown a clinically meaningful myopia-controlling efficacy.^6,7 Something to keep in mind: In this author’s clinical experience, over 30% of children using 0.05% atropine treatment reported light sensitivity that required either sunglasses in bright outdoor exposure or a reduction in outdoor time. As a result, the preparation of both patients and parents, in terms of what to expect with this approach, is needed at the baseline of treatment to ensure long-term compliance of the modality.
3. Multi (dual) focus soft contact lens (MFSCL). Studies show these lenses provide statistically and clinically significant myopia-inhibiting effects.⁸ Optometrists should consider the breathability and surface wettability of the lens material, replacement schedule, the balance between efficacy and visual quality of the optical design, patients’ lifestyle and maturity (typically ages eight to 12, although maturity is not always reflected by patient age, in my experience), and living environment to determine MFSCL candidates.For example, I have found this option to be ideal for children who have strong motivation to be spectacle-free and the ability to handle the application and removal of the lenses independently.
4. Overnight orthokeratology lenses. These lenses have consistently demonstrated an axial-inhibiting effect in numerous studies in a wide distribution of age, ethnicity, and level of baseline myopia.^9,10 They have become a popular choice in younger myopes, who have an active lifestyle, and strong motivation to be spectacle free.
5. Spectacle designs. Despite the unavailability in the U.S. market for myopia control, multiple industry-sponsored clinical trials have shown highly promising results.^11,12 Spectacles for myopia control offer convenience, feasibility for children of all ages and levels of myopia, and ease of prescribing by practitioners. (See “Myopia Control Spectacles: Review of the Latest Research,” at bit.ly/OM0823MyopiaGlasses .)

Research continues

At the time of this writing, the evidence for the synergistic effect of combining atropine with one of the optical interventions from clinical studies has been scarce and inconsistent. Plausible explanations include different concentration used, and different baseline rate of myopia progression among cohorts of the studies. While awaiting more conclusive evidence on this, among other possible myopia control approaches, the above approaches have shown significant myopia-control efficacy with great long-term safety. Identifying the risk factors for myopia, early diagnosis, and intervention are the keys to the long-term success. OM

References

1. Wong YL, Yuan Y, Su B, et al., Prediction of myopia onset with refractive error measured using non-cycloplegic subjective refraction: the WEPrOM Study. BMJ Open Ophthalmol. 2021;6(1):e000628. doi: 10.1136/bmjophth-2020-000628.
2. Wang SK, Guo Y, Liao C, et al. Incidence of and Factors Associated With Myopia and High Myopia in Chinese Children, Based on Refraction Without Cycloplegia. Multicenter Study. JAMA Ophthalmol. 2018;136(9):1017-1024. doi: 10.1001/jamaophthalmol.2018.2658.
3. Ma Y, Zou H, Lin S, et al. Cohort study with 4-year follow-up of myopia and refractive parameters in primary schoolchildren in Baoshan District, Shanghai. Clin Exp Ophthalmol. 2018;46(8):861-872. doi: 10.1111/ceo.13195.Epub 2018 Apr 16.
4. Huang PC, Hsiao YC, Tsai CY, et al. Protective behaviours of near work and time outdoors in myopia prevalence and progression in myopic children: a 2-year prospective population study. Br J Ophthalmol. 2020 Jul;104(7):956-961. doi: 10.1136/bjophthalmol-2019-314101.Epub 2019 Oct 15.
5. Cao K, Wan Y, Yusufu M, Wang N. Significance of Outdoor Time for Myopia Prevention: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials. Ophthalmic Res. 2020;63(2):97-105. doi: 10.1159/000501937.Epub 2019 Aug 20.
6. Wei, S., et al., Safety and Efficacy of Low-Dose Atropine Eyedrops for the Treatment of Myopia Progression in Chinese Children. JAMA Ophthalmology. 2020;138(11): p. 1178.
7. Wu PC, Chuang MN, Choi J, et al. Update in myopia and treatment strategy of atropine use in myopia control. Eye (Lond). 2019;33(1):3-13. doi: 10.1038/s41433-018-0139-7.
8. Lawrenson JG, Shah R, Huntjens B, et al. Interventions for myopia control in children: a living systematic review and network meta-analysis. Cochrane Database Syst Rev. 2023;2(2):CD014758. doi: 10.1002/14651858.CD014758.pub2.
9. Hiraoka T. Myopia Control With Orthokeratology: A Review. Eye Contact Lens. 2022;48(3):100-104. doi: 10.1097/ICL.0000000000000867.
10. Tsai HR, Wang JH, Huang HK, Chen TL, Chen PW, Chiu CJ. Efficacy of atropine, orthokeratology, and combined atropine with orthokeratology for childhood myopia: A systematic review and network meta-analysis. J Formos Med Assoc. 2022;121(12):2490-2500. doi: 10.1016/j.jfma.2022.05.005.
11. Bao J, Yang A, Huang Y, et al., One-year myopia control efficacy of spectacle lenses with aspherical lenslets. Br J Ophthalmol. 2022;106(8):1171-1176. doi: 10.1136/bjophthalmol-2020-318367.
12. Lam CSY, Tang WC, Tse DYY, et al. Defocus Incorporated Multiple Segments (DIMS) spectacle lenses slow myopia progression: a 2-year randomised clinical trial. Br J Ophthalmol. 2020;104(3):363-368. doi: 10.1136/bjophthalmol-2018-313739.

DR. LIU is an associate professor at Herbert Wertheim School of Optometry & Vision Science, University of California Berkeley. She is also the founder of the Myopia Control Clinic, UC Berkeley Eye Center. She received her bachelor’s degree of Clinical Medicine from Peking University, her OD from Pacific University, and her PhD and MPH from UC Berkeley. She is a world-recognized clinical researcher in myopia. Dr. Liu is a consultant for Coopervision and Essilor China.