IMPACT OF INCREASING PREVALENCEOF MYOPIA AND HIGH MYOPIA.
The occurrence of myopia and high myopia are increasing globally at an alarming rate, with substantial increases in the risks for vision impairment from pathologic conditions associated with high myopia, including retinal damage, cataract and glaucoma. The impact of myopia is challenging to identify, due to the fact that there are no standard definitions of myopia and high myopia, and recognition that myopia can lead to vision impairment which is limited by the absence of a specified category of myopic retinal disease that triggers long-term vision impairment. An additional impediment to progress in this area is insufficient evidence of the efficacy of various methods for managing myopia.
The epidemiological surveys presently used to determine the status of vision (e.g. the World Health Organisation’s protocol and Fast Assessment of Avoidable Blindness) do not permit the interpretation of high myopia as a possible cause of vision impairment, partially because these studies do not include a description of this condition or any type of measurement of refractive error. The group concurred that action ought to be taken to include myopia and high myopia among the attributable reasons for vision impairment disability in the surveys presently used.
Measures for the detection and management of myopia ought to be an integral part of plans for the provision of eye-care services. They ought to be part of general health care for vision impairment due to
(i) the uncorrected refractive error associated with related to the increased prevalence of myopia;
(ii) the pathologic repercussions of myopia.
The term “myopic macular degeneration” (MMD) should be used scientifically and in research to classify the blinding retinal diseases associated with high myopia. Presently, a number of terms are used, including MMD, myopic maculopathy, myopic retinopathy and myopic choroidal neovascularization.
Epidemiological data are lacking on the occurrence of myopia, high near-sightedness and vision impairment connected with high myopia in Africa, Central America, South America and Oceania. These locations ought to be priorities for future research study.
Interpretations of myopia and high myopia
The medicinal definition of myopia is “a condition in which the spherical equivalent objective refractive error is ≤– 0.50 diopter (– 0.50 D) in either eye”.
Medical definition of myopic macular degeneration.
The scientific definition of myopic macular degeneration (MMD) is “a vision-threatening condition in individuals with near-sightedness, usually high myopia, which comprises diffuse, patchy macular atrophy with or without lacquer cracks, choroidal neovascularization and Fuchs spot”.
It was concurred that the straight ophthalmoscope lens power wheel should be used in fast assessments of avoidable blindness and other surveys to record the power at which the fundus is clearest, to ensure that possible cases of high myopia are recorded.
In fact, the access to correction for myopia is essential to avoid vision impairment. All people with myopia ought to have accessibility to appropriate, precise refractive correction.
Although there is an extensively held clinical view that under correction of myopia is beneficial in preventing its development, the available proof does not support this concept. Recent reports show that under correction is associated with a higher rate of progression of myopia.
Some preliminary released evidence indicates that time invested outdoors can delay the onset and possibly reduce the development of myopia, although even more research study is required, as it is likewise potentially a risk factor. If the proof is confirmed appropriate, it will certainly include advantageous eye care to the listing of other health-promoting outdoor activities e.g. reduction of childhood obesity through workout, direct exposure to sunlight for vitamin D manufacturing, ready socialization.
There is a published evidence that, excessive near work increases the risk of myopia.
There is published evidence that multifocal spectacles can slightly reduce the rate of development of myopia; executive bifocal lenses are associated with substantially bigger reductions.
Specially designed contact lenses that minimize peripheral hyperopia and/or create significant myopic defocus can slow down the progress of myopia. It is essential that contact lenses can slow down the progress of myopia, but overnight wear of contact lenses is related to risks.