Lenses and Spectacles to Prevent Myopia Worsening in Children

Autor:	Banerjee S, Horton J
Jazyk:	angličtina
Zdroj:	2021 Apr.
Abstrakt:	Myopia is also known as near-sightedness or short-sightedness. In myopia, the light rays entering the eye from distant objects are focused in front of the retina instead of on the surface of the retina as in the emmetropic (normal) eye, resulting in distant objects appearing blurred. ¹ Myopia occurs due to the cornea and/or lens being too curved, the length of the eyeball being too long, or a combination of these factors. ¹ It is a type of refractive error that is measured in terms of spherical equivalent. Myopia is defined as a spherical equivalent of less than 0 dioptres (D), clinically significant myopia as −1 D or less, and moderate or high myopia as less than −3 D. ² Myopic individuals may have anisomyopia (a difference of more than 1 D in refractive status between the eyes) ³ or anisometropia (the eyes have different refractive powers). ⁴ The prevalence of myopia increases throughout childhood. In the US, it is estimated that prevalence of myopia is 1% to 5% in preschool children, approximately 9% in school-aged children, and approximately 30% in adolescents. ⁵ If left untreated, myopia will progress to high myopia. ⁶ High levels of myopia are associated with ocular diseases such as glaucoma, macular degeneration, cataracts, and retinal detachment, and can lead to significant visual impairment. ⁷ ^– ⁹ The prevalence of myopia has increased worldwide, and it is a global public health problem. ¹⁰ ^, ¹¹ It is estimated that by 2050 half of the world’s population will have myopia. ¹ ^, ¹² It is important that progression of myopia is controlled to reduce the incidence of other detrimental eye conditions later on. Treatment options for controlling myopia include optical interventions (a variety of lenses) as well as pharmaceutical interventions (such as atropine and timolol drops). ¹ For children, spectacles are used typically as the initial treatment of myopia because they provide clear vision with few potential side effects. ¹ Contact lenses may be used but their use requires greater dexterity and responsibility. ¹ Lenses of various designs have been developed to control the progression of myopia. There appears to be lack of consensus regarding the use of the various lens types. ¹³ To control the progression of myopia in children, there has been interest regarding the clinical effectiveness and cost-effectiveness of certain optical interventions, such as soft contact lenses (i.e., MiSight), defocus integrated multiple segments (DIMS) spectacle lenses, orthokeratology (OK), and multifocal contact lenses. The MiSight contact lens comprises a large central correction area surrounded by concentric zones of alternating distance and near power. ⁸ The DIMS spectacle lens comprises a hexagonal central zone of distance refractive correction surrounded by an annular defocus zone with dense microlens segments of 3.5 D added. ¹² The OK lenses are specially designed and fitted contact lenses to temporarily reshape the cornea to improve vision. Most OK lenses are worn at night to reshape the front surface of the eye while the wearer is sleeping. ¹⁴ The purpose of this report is to summarize the evidence regarding the clinical effectiveness and cost-effectiveness of specific optical interventions (e.g., soft contact lenses, such as MiSight; DIMS; OK; and multifocal contact lenses) for control of progression of myopia in children. (Copyright © 2021 Canadian Agency for Drugs and Technologies in Health.)
Databáze:	MEDLINE
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