Myopia( myopia) - Causes, symptoms and treatment. MF.
Jun 20, 2018
Myopia is an abnormality of refraction, in which the rays are strongly refracted and collected in front of the retina( in the normal eye on the retina).Among patients, a different name for myopia is myopia. This condition is characterized by poor vision in the distance.
Vision in myopia
Causes of nearsightedness( myopia)
Myopia is congenital and acquired. The first is associated with impaired development of the eyeball during the intrauterine period. Risk factors for developing acquired myopia:
is a heredity( especially if both parents have myopia),
is a sedentary lifestyle,
has excessive eye strain( for example, prolonged work in the vicinity),
is a violation of the rules of reading and writing( distance,duration of continuous load),
- violations from the side of the organ of vision( strabismus, astigmatism).
Heredity, nevertheless, is a leading factor in the formation of myopia, the remaining factors only provoke myopia with the predisposition already present to it, especially in an adult. But the formation of vision in the child and adolescent affect all of the above factors.
Symptoms of myopia
By degree of refraction disorders, 3 degrees of myopia are distinguished: weak( up to -3 Dpt), medium( to -6 D), high( more than -6 D).
In the course of myopia, it is stationary and progressive( if the myopia increases by 1 dptr and more per year).
For a long time the course of myopia is asymptomatic. Usually, short-sightedness is detected during medical examinations, and the patient does not even suspect about his illness. Myopia is seen with poor vision in the distance. At school the child asks to be transplanted to the front desk, people do not see the number of fixed-route taxis, price tags in stores, it becomes uncomfortable to watch TV.
There is such a thing as false myopia. It is associated with a spasm of accommodation - the abnormal operation of the ciliary muscle, and is manifested by a violation of clear vision at a distance. The diagnosis is made after refractometry in the state of cycloplegia( dilate the pupil).Mydriatics are contraindicated in people with increased intraocular pressure,can provoke an acute attack of glaucoma.
Diagnosis of myopia
For the diagnosis, the following examinations will be required:
- visometry( determination of visual acuity with correction),
- perimetry( with complicated myopia can vary),
- skiascopy( with the help of an indirect ophthalmoscope, the doctor examines the movement of the shadow in the pupil area and determinesrefraction),
- refractometry( after dilating the pupil it is possible to determine the true refraction of the eye),
- tonometry-measurement of intraocular pressure for the elimination of glaucoma,
- ophthalmoscopy and examinationLazne bottom with Goldman lens( Fuchs spot myopic cone may be staphyloma-protrusion sclera possible hemorrhage, retinal dystrophy),
- Ultrasound determination of the eye and the anterior-posterior length( about 24 mm in the norm).
In an objective study, a decrease in visual acuity is determined, which is corrected by scattering lenses, an anterior-posterior segment of the eye, the formation of a Fuchs spot( at a high myopia pigment focus in the yellow spot area) due to increased fragility of the vessels, myopic cone or staphyloma due to high myopia,for overstretch of sclera, hemorrhage.
Treatment of myopia
There are several types of correction and treatment of myopia:
- spectacle and contact correction
Medical treatment of myopia
The course of drug treatment is recommended for all patients with shortsightedness 1-2 times a yearto prevent the progression of myopia. Assign a general gentle regimen, vitamins( C, group B), to relieve the spasm of accommodation of mydriatica( iritrin, mezaton of 1 k. Per night for a month, calcium preparations( for example, calcium chloride intravenously), tissue therapy( FIBS, vitreous, aloeintramuscularly), drugs that improve cerebral circulation( piracetam, pentoxifylline in.) Physiotherapeutic treatment helps to slow down the development of the disease( magnetotherapy, laser therapy, collar zone massage)
Scalar and contact correction of myopia
An ocular or contact correction for a patient is shown, depends on the patient's desire and the doctor's recommendations. The power of the lenses is selected in such a way that the tolerable diopter is weaker than the refraction. Many people prefer to wear glasses. But they are not always comfortable( they drop, mist over the windows, get dirty).In contrast, contact lenses have an advantage in terms of quality of life, but they have many contraindications, including inflammatory diseases of the eye, intolerance, allergies. If used improperly, complications occur, for example, keratitis.
Almost always use incomplete correction to save the accommodation reserve. With myopia, more than -3 Dptrs are assigned 2 pairs or bifocals. To work close to +1.5 - +2.5 D is less. With high myopia, glasses are prescribed depending on their tolerability.
orthokeratological lenses , which dress for the night, and 100% vision is provided for up to 24 hours, have appeared relatively recently. They are shown from the age of 6 years with low and medium degree myopia. They do not cause allergic reactions and oxygen starvation of the cornea. The effect is the same as with laser surgery, but temporary.
Properly selected contact lenses do not promote the development of myopia, but can affect the change in the tissues of the eye surface, which is often accompanied by discomfort and dry eye syndrome. To provide a healthy state of the eye surface will help a complex solution - the use of ophthalmic gel and drops for the eyes. Eliminates the causes of discomfort gel "Korneregel".It includes carbomer on a soft gel base, which retains full hydration, and dexpanthenol, which has a healing effect. For those who feel discomfort and dryness 3 or more times a day, it is worth choosing the drops of "Artelak Balance", which combine a unique combination of hyaluronic acid and vitamin B12.Hyaluronic acid on the surface of the eye forms a film that provides long-lasting hydration. The action of hyaluronic acid prolongs the special protector. Vitamin B12 - the strongest antioxidant, protecting cells from damage by free radicals. For those who experience discomfort not more than 2-3 times a day, the "Artelak Splash" drops, which have hyaluronic acid as part of the composition, provide instant moisturizing. Regardless of the symptoms for the prevention of discomfort and dryness, it is good to use in combination the eye drops with a gel based on dexpanthenol.
In the treatment of myopia, orthoptic treatment is used, for example, ciliary muscle training with the help of negative lenses, and hardware treatment aimed at increasing the accommodation reserves and stimulating the optic nerve. Especially shown with amblyopia. Types of hardware treatment: ccomodotrener, color pulse treatment, laser stimulation, etc.
Surgical treatment of myopia
Surgical treatment is indicated with progressive myopia in order to stop its development. Scleroplasty is performed if the sclera size increases by more than 1 mm per year. With high myopia, the lens is removed and replaced by the intraocular lens of the desired refractive force. Thermocoagulation of the cornea is possible-incisions( micro-burns) are made in certain meridians.
Laser vision correction
In recent years, refractive surgery, or laser vision correction, has become common.
- myopia up to -12 dptr
- myopic astigmatism up to 10 dpt.
- farsightedness up to +8 ds.
- hypermetropic astigmatism up to 8 ds.
- professional( occupations in which glasses or contact lenses can not be used by pilots, athletes)
- medical( anisometropia, binocular vision disorders)
- curative( corneal opacity, dystrophy)
- age under 18
- myopia progression
- single eye
- thin cornea( less than 450 microns)
- inflammatory eye diseases( acute and chronic)
- common diseases( diabetes, autoimmune and systemic diseases)
Photorefractive keratectomy( PRK) is the first laser treatment for myopia. At the same time, the epithelium is removed from the cornea with a knife, then a certain volume of tissue is evaporated by means of a laser and contact lenses are put on. After surgery, it is possible to develop an abnormal corneal astigmatism.epithelium uneven.
LASEK-laser epithelial keratomileusis - the epithelium is treated with alcohol and separated. After evaporation, it is returned to its place( it helps healing and reduces painful sensations).They put on the lenses.
LASIK( laser keratomileus insitu) - with the help of a microkeratome form the epithelial-stromal flap of the cornea on the leg, which reclines, the epithelium is ablated and returned to its place. Do not use contact lenses. Contraindication is a thin cornea. Variety-epiLASIK, when the epithelial flap is formed.
The most modern and fastest method is Femto - or IntraLASIK.In this case, the flap is formed by means of a femtosecond laser, and ablation with the help of excimer radiation. The least traumatic, more physiological method, few side effects.
Laser correction of vision
The percentage of complications is small and all states are quickly compensated.
Side effects of laser surgery:
- unrealistic expectations, i.e.the patient at first can not get used to normal vision,
- hyper, hypocorrection,
- corneal astigmatism,
- dry eye syndrome in 1 of 5 people,
- keratitis, conjunctivitis.
Complications of myopia
In case of untimely treatment or improper correction of myopia, progression of the disease and occurrence of complications such as amblyopia( uncorrectable reduction in visual acuity), staphylocclusion of the sclera( protrusion), dystrophy and hemorrhage on the retina and in the vitreous humor, in severe cases of their detachment.
Much attention is paid to the prevention of myopia, especially among school children:
- the book should be read at arm's length from the eyes( this also applies to the computer), TV-at least 3 meters,
- adequate lighting( general and local),
- correct vision correction, if necessary.
In adults, such prophylaxis, except for correction, is less effective.
Doctor ophthalmologist Letyuk T.Z.