Commentary: Newer modalities to prevent myopia progression : Indian Journal of Ophthalmology

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Commentary

Commentary: Newer modalities to prevent myopia progression

Tripathy, Koushik; Sridhar, Uma1,

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doi: 10.4103/ijo.IJO_1333_22

An interesting review article in the current issue of the Indian Journal of Ophthalmology (IJO)[1] focuses on intermittent red light therapy to prevent myopia progression and also focuses on the positive effects of red light irradiation on the cornea and the retina.

Myopia is increasing over the last three decades. The possible causative factors include lifestyle changes and increasing screen time resulting in more near work and indoor activity (less time spent outdoors). Genetic factors including myopia in parents are important.[2] It is known that form deprivation and hyperopic defocus of the retina cause biochemical changes in the retina and the retinal pigment epithelium (RPE) that play a crucial role in the pathogenesis of myopia and its progression. These signals cause changes in the scleral extracellular matrix (ECM) deposition and biomechanical attributes of the sclera. The progression of myopia follows the same mechanism of emmetropization. The choroid can modulate its thickness to place the retina at the focal plane (choroidal accommodation), and a thick choroid may reduce myopia progression and a thin choroid may be associated with the development of myopia. Growth factors from the choroid can potentially control the biomechanical strength of the sclera and scleral remodeling, and thereby the progression of myopia. The progression of myopia is faster in females compared to males. Other factors associated with myopia include high education, urban location, very low birth weight, retinopathy of prematurity, increased AC/A (accommodative convergence: accommodation) ratio, accommodation lag (causing hyperopic defocus), and reduced accommodation facility. Reading a black text on a white background stimulates “off” pathways causing choroidal thinning and possible myopia development. White text on black background stimulates “on” pathways of the retina and may prevent myopia development.[3]

Many methods are used to prevent or control myopia. Environmental factors can be modified by increasing the duration of outdoor activity and reducing the near work. Time outdoors rather than physical activity can protect against myopia development. Contrary to the current review,[1] it has been suggested that the absence of ultraviolet ray exposure indoors or otherwise may promote myopia.[45] Outdoor-light stimulated release of dopamine may protect against increasing axial elongation. Spatial features of indoors may simulate diffusing filters that cause deprivation amblyopia in animals. Other described interventions include vitamin D supplementation in deficient individuals, increasing indoor light intensity, and avoiding LED (light-emitting diode) lights indoors.

Undercorrection in myopic glasses is currently not advised as it does not prevent progression and may even increase the progression of myopia.[2] Progressive additional lens and bifocal glasses (with or without base-in prisms) may slow the myopia progression. Though the results on spectacles to reduce peripheral hyperopic defocus are inconsistent, the “Defocus Incorporated Multiple Segments (DIMS)” glasses as described by Lam and colleagues appear to be a promising modality.[6]

The soft contact lenses and rigid gas permeable lens (RGP) appear to be ineffective in preventing myopia progression or axial elongation.[2] Orthokeratology using RGP contact lenses overnight may reduce myopia progression and axial elongation but corneal infection is a concern. Bifocal and multifocal soft contact lenses with a central area for distance vision and peripheral rings/progressive power change for creating myopic defocus have shown promising results. Concentric rings may provide better protection than progressive design. Other interesting designs of contact lenses include soft radial refractive gradient (SRRG) contact lenses (to change peripheral hyperopic defocus to myopic defocus and to increase higher-order aberration), aberration-controlled contact lenses, MiSight soft contact lenses (CooperVision, Inc., Pleasanton, CA) with multizone design, and defocus incorporated soft contact lens (DISC).[26] Auditory biofeedback to improve accommodation is another innovative approach to reducing myopia progression.

Surgical interventions described for prevention of myopia progression include posterior scleral reinforcement, posterior scleral contraction, crosslinking of sclera with genipin or riboflavin (avoided due to loss of photoreceptors, outer nuclear layer, and RPE) or nonenzymatic glycation, intravitreal aquaporin-1 injection, scleral strengthening using subtenon chemicals (including acrilamidehydrazide, polyvinylpyrrolidone, and ethyl acrylate), and subscleral injection of dopamine and mesenchymal stem cells.

Low dose eye drop atropine 0.01% once daily is available in India to prevent myopia progression. Atropine may increase ECM synthesis by scleral fibroblast improving the mechanical strength of sclera, improve scleral blood supply by reducing ECM synthesis in choroidal fibroblast, and increase dopamine that can prevent axial elongation. Though high doses of atropine (0.5%, 1%) may be more effective, the rebound myopia progression and side effects are more. Topical pirenzepine and oral tablets of 7-methylxanthine are promising therapies to slow axial elongation. The role of antiglaucoma drops including timolol, latanoprost, and brimonidine needs further research. A combination of various therapy has also been tried.

The role of light signaling in the development of myopia has been discussed in detail by the authors[7] in another review which explains the role of different wavelengths of light in the process of emmetropization and the potential of red light in the therapy of myopia. The current review explores red light as a potential tool for prevention and control of myopia and it may become an important therapy in the future.[1]

References

1. Huang Z, He T, Zhang J, Du C Red light irradiation as an intervention for myopia Indian J Ophthalmol 2022 70 3198 201
2. Németh J, TapasztóB, Aclimandos WA, Kestelyn P, Jonas JB, De Faber JTHN, et al. Update and guidance on management of myopia. European society of ophthalmology in cooperation with International Myopia Institute Eur J Ophthalmol 2021 31 853 83
3. Aleman AC, Wang M, Schaeffel F Reading and myopia:Contrast polarity matters Sci Rep 2018 8 10840
4. Prepas SB Light, literacy and the absence of ultraviolet radiation in the development of myopia Med Hypotheses 2008 70 635 7
5. Torii H, Ohnuma K, Kurihara T, Tsubota K, Negishi K Violet light transmission is related to myopia progression in adult high myopia Sci Rep 2017 7 14523
6. Lam CSY, Tang WC, Tse DYY, Lee RPK, Chun RKM, Hasegawa K, et al. Defocus incorporated multiple segments (DIMS) spectacle lenses slow myopia progression:A 2-year randomised clinical trial Br J Ophthalmol 2020 104 363 8
7. Zhang P, Zhu H Light Signaling and myopia development:A review Ophthalmol Ther 2022 11 939 57
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