Amblyopia - Causes, Symptoms and Treatment .MF .
Amblyopia - reduced visual acuity of one or both eyes, is not amenable to optical correction that occurs for no apparent reason (primary) or due to the lack of normal conditions for the functioning of the retina (the secondary).
Causes of amblyopia
The basis of pathology is cortical inhibition that is "off" of the visual process poorly seeing eye, preventing the development of diplopia (double vision).
Primary amblyopia occurs in violation of the eyeball in utero.
Causes of secondary amblyopia depending on the form:
- of obscure (due to the long-existing haze optical media eye, most of the lens).
- postobskuratsionnye (amblyopia, continuing after the removal of the cause of the of obscure).For example, after the replacement of the lens intraocular lens visual acuity does not improve
- strabizmaticheskie (arise squinting eyes).In these cases, the cortex suppresses the image from one eye to avoid double vision, and over time, the neurons do not conduct nerve impulses to the brain.
- refraction (at different degrees of refraction in the two eyes, when there is a big difference between them, and inadequate refractive error correction).
- ahromaziynye (associated with hypoplasia of the cone, so there tsvetoslepota).Only two-sided.
symptoms of amblyopia
Refractive amblyopia is asymptomatic.Revealed during the examination (medical examination) is more common in children 3-7 years.Occurs when hyperopic anisometropia, astigmatism, high myopia.In myopic anisometropia happens less often becauseworst eye is used for near vision.Amblyopia develops when the following refraction: hyperopic difference in both eyes more than 0.5 diopter, astigmatic, more than 1.5 diopters in any meridian myopic more than 2.0 diopters.
amenotropic amblyopia develops in the absence of a different refraction in both eyes, but at high degrees of myopia (more than 8 diopters bilaterally), hyperopia (more than 5 diopters on both sides) and astigmatism (more than 2.5 diopters in any meridian).Detected mainly in children under 7 years old are rarely accompanied by strabismus.
amblyopia of obscure origin occurs in the absence of the normal functioning of the retina of factors, such as ptosis, corneal opacities, cataracts, vitreous hemorrhage.
Strabizmaticheskaya develops in the presence of strabismus.Several options.Healthy Eye captures the image in the fovea and mowing or as or in decentralized, sometimes or always, or even with the absence of fixation.
degrees of amblyopia depending on visual acuity:
- low (0,4-0,8)
- average (0,2-0,3)
- high (0,1-0,05)
- veryhigh (more than 0,04)
different manifestations of amblyopia, possibly asymptomatic.Reduced visual acuity (there is no improvement in the correction), impaired color perception and dark adaptation, there strabismus (convergent, divergent, and others.).There may be organic causes, such as ptosis (complete or incomplete ptosis century), cataracts (clouding of the lens), corneal dystrophy, hemophthalmus (vitreous hemorrhage).
diagnosis of amblyopia
For diagnosis requires the following research methods:
- visual acuity with correction and without.Children who do not know the letters, use the table with pictures (for example, the table Orlova)
- perimetry, if possible
- definition of color perception using polychromatic tables Rabkin
Polihromoticheskie tables Rabkin
- dark adaptation is determined to adaptometry
- definition of squint angle method Hirschberg - normal reflex of the ophthalmoscope is located at the center of the pupil.When strabismus
asymmetric - determining the type and squint angle sinoptofore
- refractometry full cycloplegic (atropine desirable for 3-4 days)
- skiascopy - definition of refraction by the characteristic movement of the shadow in the pupil
- research in transmitted light to determine the transparency of media
eye - the ocular inspection of the day with a Goldman lens
- electroretinography to determine the functional state
retina - the critical flicker fusion frequency - examine the state of neurons.An indicator is the minimum number of flashes of light, which is perceived as a whole
- US eyes - examine the state of the eye media at their lack of transparency and the length of the anterior-posterior segment of the eye (matters when refractive errors)
- computed tomography, magnetic resonance therapy, consultation neurologistto eliminate the pathology of the nervous system treatment of amblyopia
treatment is not possible without an ophthalmologist, and delayed treatment of amblyopia leads to permanent loss of visual function.
Please select the optimum correction , older children may use contact lenses or night, laser correction, especially when anisometropia (different refractive errors in both eyes).Eliminate the cause of amblyopia of obscure origin (eyelid with ptosis, photorefractive surgery for corneal opacity, phacoemulsification and IOL implantation for cataract, resolution therapy or when vitreektomiya hemophthalmus).
When strabizmaticheskoy amblyopia used passive and active pleoptiku .
Passive performed by occlusion of the dominant eye (increased visual acuity at mowing), and then occlusion of the variable for the transition of strabismus in alternating (in this case on the fovea fixed image is from one, then the other eye).After that use the active pleoptiki methods.With adequate correction closed lead and stimulate the retina squinting eye (light, laser, electrical pulses and special computer programs).Pleoptic treatment is carried out 3-4 times a year to achieve the desired effect.
Hardware is the main treatment in amblyopia.For example, training on "Ambliokor", while depending on the activity of the cerebral cortex, recorded with electroencephalography, changing the characteristics of the image on the computer.
also used ASO-stimulation (via colored light pulses), KEM, PS-1, Mosaic PS-2, Panorama and others.
Children who can not tolerate occlusion method is used atropine penalization better seeing eye.Wide pupil dramatically reduces visual acuity, thereby causing "work" amblyopic eye.Atropine is instilled 1-2 times a week, and see to it that the mydriasis was constant.
widely used methods of physiotherapy - vibratory massage, reflexology.
treatment ends after reaching approximately the same visual acuity in both eyes.If there is a squint, his surgically remove.
forecast unfavorable amblyopia in adults, children must be adequately treated with full correction.
Ophthalmologist letyuk TZ