What is myopia?
Under normal conditions, parallel light from a distant object (5 meters away) passes through the refractive system of the unadjusted eye and converges on the retina, which is called orthophoria. If the light rays converge in front of the retina, the eye is nearsighted.
Level of myopia
Adolescent myopia
Low: -0.50 to -2.25.
Moderate: -2.50 to -4.75.
High: -5.00 or more.
Myopia in adults
Low: -0.50~-2.75.
Moderate: -3.00~-5.75.
High: -6.00 or more.
Factors that cause myopia
Genetic factors, developmental factors, environmental factors (excessive near vision, blur, noise), nutritional and physical factors.
How does myopia occur?
Myopia occurs when genetic factors manifest themselves through environmental factors.
The concept of “pseudomyopia”
Pseudomyopia is a transient myopia that occurs in ortho- or hyperopic eyes due to a spasm of accommodation. Myopia disappears after subjective optometry and atropine ciliary muscle paralysis, and appears as orthopia or even hyperopia, which can be recovered by resting the eyes.
Myopia development trend
Myopia has a tendency to increase with the development of culture and science. Low to moderate myopia accounts for the majority of myopia, and low myopia occurs most often during the school years, with a higher incidence among high school students. Children of myopic parents have a higher chance of becoming myopic.
The situation in China: China currently has about 300 million myopic patients, including more than 20 million with high myopia, second only to Japan as a “big country” with myopia.
Hazards of myopia
1.Far-sightedness decreases, while near-sightedness is mostly normal.
2, simple myopia can often obtain good corrected vision; myopia with amblyopia also has poor corrected vision.
3.The information received by the brain is damaged to varying degrees, affecting the perception of the environment and thinking.
4.Vision fatigue.
5.Eye axis becomes longer.
6.Eye position deviation: exotropia or even exotropia.
7.Limitation of employment options.
8. Reduced visual space and self-limitation of the scope of life, tend to be introverted, and affect the normal development of the psyche.
Hazards of high myopia: an important cause of blindness
Induced series of lesions: vitreous degeneration, liquefaction, turbidity, scleral retinal thinning, scleral chylomalacia, peripheral retinal degeneration, retinal fissure, retinal detachment, macular degeneration, macular hemorrhage.
Glaucoma.
Cataract.
Inheritance to the next generation: Generally, if one of the parents is highly myopic, it will be passed on to the child.
Prevention of myopia
Changing acquired environmental factors.
Reducing the burden of extracurricular work for students.
Pay attention to self-care measures.
”Treatment” of myopia
Myopia can only be corrected, not cured
Go to a regular hospital for a dilated eye exam to rule out pseudomyopia.
In case of true myopia, glasses are the most important correction method.
Non-traumatic: concave lens RGP OK lens
Traumatic: RK PRK LAISK
Myopia control methods
1.Drug therapy
Drug: Atropine, paralysis of ciliary muscle
Effects: Inhibit factors that promote scleral growth and inhibit the growth of scleral fibroblasts
Other commonly used similar drugs are cyclopentone, postmastropine and topiramate
Common disadvantages: is pupil dilatation photophobia and loss of near vision. Side effects and tolerability of long-term use, cannot be used as a routine drug to control myopia progression
Pirenzepine: M1 and M4 receptor antagonist, clinical trials have certain efficacy, there are side effects such as pupil dilation and affect regulation, its evaluation needs further study.
2. Acupoint stimulation, electromagnetic therapy, fog vision therapy
Lack of relevant clinical evidence
3, defocusing glasses and other similar glasses
Lack of rigorous scientific design studies to prove the effectiveness, which may lead to the destruction of binocular vision and produce strabismus as a side effect.
4.Progressive multifocal lenses
They are ineffective for most adolescents and may lead to the destruction of binocular vision and strabismus as a side effect.
5.Keratomileusis
Keratoplasty
A special contact lens that is used to change the curvature (curvature) of the cornea in myopic patients, reducing the myopic refraction and thus improving naked eye vision.
Research results show that the OK lens correction process for myopia is safe and reliable with significant results.
Features.
Rapid effect, reversible, non-invasive.
An alternative method for the correction of mild to moderate myopia in adolescents.
Use high quality lenses, strictly follow the procedure and insist on wearing the lenses.
Enhanced follow-up and regular lens replacement.
The medium and long-term results of correcting and controlling myopia are satisfactory.
OK lenses are made of breathable rigid material that contains almost no water.
As a result, there is less surface sediment and fewer pathogenic microorganisms, making it safer than the usual soft contact lenses.
However, it is not perfect, but also need to emphasize hygiene habits and regular review.
6.RGP
It is a breathable hard corneal contact lens, the main material is fluorosilicone acrylic resin (F-SAS), high oxygen permeability. It will not adsorb protein and grease precipitation in tears, with good safety and less complications. There is a certain degree of activity to promote tear exchange more in line with the normal physiological state of the cornea. High image clarity, control and delay of myopia.
Myopia control summary
Strengthen exercise and physical fitness.
Regular eye examinations for high myopia.
Wear OK lenses when available.
For low to moderate myopia without or with low astigmatism.
Wear OK lenses or RGP lenses when available.
Suitable for myopia that is used.