October 3, 2022
By Krupa Philip, B.Optom, PhD, Senior Research Scientist at BHVI
Depending on the strategy, there are some additional considerations when fitting a high myope in a myopia management strategy. Closer monitoring is essential since these children are at increased risk of progression and may have other abnormalities (systemic and/or ocular).
High myopia is defined as spherical equivalent refractive error of the eye of either ≤ -5.00D or ≤ -6.00D when ocular accommodation is relaxed.1,2 The lower cut-off value of -5.00D is thought to facilitate study of the prevalence of myopia as well as its impact in populations; furthermore, uncorrected myopia of -5.00D impacts vision to a level that meets the threshold of blindness. On the other hand, -6.00D is the threshold commonly used in published studies and for assessing clinical relevance in an individual.3 Whatever may be the threshold to define high myopia, higher levels of myopia are associated with an increased risk of progression,4,5 as well as the risk of developing sight-threatening ocular complications, such as cataract, posterior vitreous detachment, vitreous lacunae, and liquefaction, glaucoma, and a range of retinal and macular anomalies known as myopic maculopathy.6 Children with high myopia (-6.00D to -9.00D) were also found to have faster progression than low and moderate myopes.4
Thus, it is vital to identify and appropriately manage children with higher levels of myopia. Many of these eyes have systemic and ocular abnormalities; therefore, a more frequent and detailed examination is needed, and patients may potentially need to be co-managed with an ophthalmologist. High myopia may be part of a constellation of signs associated with syndromes such as Stickler, Marfan, Noonan, Down syndrome, and retinal dystrophies.7 In a retrospective analysis of 112 highly myopic children (3-10 years of age), 54% had an underlying systemic association, and 38% had ocular problems associated with high myopia, such as lens subluxation, coloboma, retinal dystrophy, anisometric amblyopia. Only 8% had simple high myopia.7 Where possible, axial length measurement is helpful in assessing the risk as well as progression of high myopia.
Treatments for High Myopia
Concerning managing progression of myopia, optical (novel spectacles, multifocal/EDOF soft contact lenses, orthokeratology), pharmaceutical (atropine), as well as combination strategies are available to slow myopia progression.8-10 Be aware that while many of these strategies are effective, most with few exceptions were trialed on children with low to moderate amounts of myopia, i.e., from -0.75D to -5.00D. There is little data on their efficacy in high myopes. Additionally, higher powers of prescriptions may not be available with certain types of lenses, or the strategy, as in the case of OrthoK, may not fully correct the myopic error.
Spectacles, including myopia control spectacles, are available for higher-powered prescriptions. When fitting highly myopic eyes with spectacles, some additional considerations/requirements exist to achieve a satisfactory wearing experience. Consider high refractive index and/or smaller optical apertures to manage the thickness of the lens and accurately determine the vertex distance to prevent over-minusing. For subjective refraction, place lenses in the trial frame as close to the measured vertex distance as possible to simulate the real-life experience.
As with spectacles, contact lenses are also available in higher powers (for example, Mylo [Mark’ennovy] and NaturalVue [Visioneering Technologies Inc.] contact lenses are available up to -15.00D and -12.00D, respectively). For a high myope, a contact lens provides benefits in terms of better vision due to reduced image magnification, reduced aberrations, and improved cosmesis. These benefits may translate to an improved quality of life. Evidence indicates that with high-powered spectacles there is reduced contrast sensitivity at high spatial frequencies; no such loss was observed with contact lenses.11 Since unaided vision in high myopes is severely limited, it is critical that any contact lens wearer also has an up-to-date pair of spectacles for use when contact lenses are not worn and aid in lens insertion, removal, and care.
With OrthoK, full correction of up to -6.00D has been reported. For higher levels, there is an option to partially correct myopia with OrthoK and treat the residual error with spectacle lenses. In a randomized clinical trial, highly myopic children (worse than -5.00D) fitted with a combination of OrthoK and spectacles (residual refractive error correction in daytime) had a 63% reduction in axial length elongation compared to controls fitted with single vision spectacles.12
Atropine, combined with OrthoK, spectacles, or contact lenses, is another effective management option for high myopia. In children with or at risk of developing high myopia, a higher concentration (0.5%) was effective.13 Low-dose atropine combined with OrthoK or multifocal spectacles effectively controlled myopia progression (50% reduction in myopia progression) compared to OrthoK alone in low to moderate myopes.14,15 However, it is well known that use of atropine, especially at higher concentrations, is associated with glare, photophobia, and loss of accommodation and requires appropriate supplemental strategy to manage these side effects.
In summary, identify if the high myopia is simply myopia or associated with a syndrome, as the management may vary. Also, identify if there are any other ocular abnormalities and if the child is at risk of progression. Depending on the strategy, there are some additional considerations when fitting a high myope in a myopia management strategy. Finally, closer monitoring is essential since these children are at increased risk of progression and may have other abnormalities (systemic and/or ocular).
|Dr. Krupa Phillip has over 10 years of experience in myopia management and holds post-doctoral qualifications as a senior research scientist working in refractive errors and myopia with Prof. Sankaridurg at BHVI. She has a particular interest in ocular aberrations and visual experience with various myopia management strategies. Dr. Phillip has published several articles and co-authored a book chapter on refractive error and eye health in Southeast Asia. Currently, she is managing clinical trials in general health.|
- Flitcroft, D.I., et al., IMI – Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiologic Studies. Invest Ophthalmol Vis Sci, 2019. 60(3): p. M20-M30.
- Holden, B.A., et al., Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology, 2016. 123(5): p. 1036-42.
- Sankaridurg, P., et al., IMI Impact of Myopia. Investigative Ophthalmology & Visual Science, 2021. 62(5): p. 2-2.
- Verkicharla, P.K., P. Kammari, and A.V. Das, Myopia progression varies with age and severity of myopia. PLoS One, 2020. 15(11): p. e0241759.
- Haarman, A.E.G., et al., The Complications of Myopia: A Review and Meta-Analysis. Invest Ophthalmol Vis Sci, 2020. 61(4): p. 49.
- Tideman, J.W., et al., Association of Axial Length With Risk of Uncorrectable Visual Impairment for Europeans With Myopia. JAMA Ophthalmol, 2016. 134(12): p. 1355-1363.
- Marr, J.E., et al., Associations of high myopia in childhood. Eye (Lond), 2001. 15(Pt 1): p. 70-4.
- Wildsoet, C.F., et al., IMI – Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report. Invest Ophthalmol Vis Sci, 2019. 60(3): p. M106-m131.
- Jong, M., et al., IMI 2021 Yearly Digest. Investigative Ophthalmology & Visual Science, 2021. 62(5): p. 7-7.
- Bao, J., et al., Spectacle Lenses With Aspherical Lenslets for Myopia Control vs. Single-Vision Spectacle Lenses: A Randomized Clinical Trial. JAMA Ophthalmol, 2022.
- Collins, J.W. and L.G. Carney, Visual performance in high myopia. Curr Eye Res, 1990. 9(3): p. 217-23.
- Charm, J. and P. Cho, High myopia-partial reduction ortho-k: a 2-year randomized study. Optom Vis Sci, 2013. 90(6): p. 530-9.
- Polling, J.R., et al., A 3-year follow-up study of atropine treatment for progressive myopia in Europeans. Eye (Lond), 2020. 34(11): p. 2020-2028.
- Kinoshita, N., et al., Additive effects of orthokeratology and atropine 0.01% ophthalmic solution in slowing axial elongation in children with myopia: first year results. Jpn J Ophthalmol, 2018. 62(5): p. 544-553.
- Tan, Q., et al., Combined Atropine with Orthokeratology for Myopia Control: Study Design and Preliminary Results. Curr Eye Res, 2019. 44(6): p. 671-678.