Afakia - Lens deficiency. Afakichny called the optical apparatus of vision in the absence of the lens. Occasionally there is a congenital deficit of this biological lens.
If the transparency is violated or the dislocation, the lens is removed promptly. In case of accident, when there is a penetrating damage, there is a possibility of its falling out.
Diagnosis of the absence of the lens
During the diagnosis of an eye with a deficiency of the lens, the doctor observes the jerking of the iris (iridonodes) and the deep anterior chamber. With the preservation of the posterior chamber, the movement of the iris is much less pronounced. Concussion of the vitreous humor is fixed in the period of motor action.
As a result of a biomicroscopic study of the optical apparatus, the light beam determines where the capsule and the light capacity are located. With a deficiency of the lens bag, the substance located between the lens and the retina adheres and slightly protrudes into the pupillary site of the pupil. It is recorded only by the front edge. This pathology is called the hernia of the vitreous. The situation is complicated when there is damage to the membrane in the anterior chamber and the release of fiber bundles from the vitreous.
What is to be diagnosed?
Lens of the eye.
What kind of specialist should I use?
Methods of treatment of aphakia
The level of refraction sharply changes when the operative removal of the biological lens is made. A high degree of hyperopia is formed.
Refraction of the optical apparatus of vision, it is possible to compensate by various means of optical choice. Means include contact lenses and glasses. Or to make compensation as a result of the operation of installing an artificial lens.
Correction of the state of the eye without the lens with the help of lenses or spectacle correction is infrequent. To correct the aphakia of a normal optical vision apparatus, glasses of +10.0 diopters are needed. The refraction of the aphakic eye is 19.0 diopters. In a complexly arranged system of vision, the glasses glass is located in a special area. The lens of the glass covers the air space, and the lens is surrounded by a liquid medium. It has a similar refractive index with matter. For hypermetropic force, the glass is more powerful by several dpt.
In myopic eyes, the lens is thinner, and the optical force is less. If before surgery, hypermetropia was at 19.0 D, then after surgery the power of the optics system is neutralized by the direction into the distance. The person and the lens will not feel the need to correct vision with the help of glasses for long-range vision.
The apparatus of vision with lens deficiency is deprived of accommodation. For activities in the vicinity there is a need for glasses 3.0 dpts stronger than for long distances. There is no way to improve vision with glasses if there is one-way aphakia. A qualitative magnifying glass is characterized by a lens of +10.0 diopters. During its installation in front of one eye, a person's vision perceives images that are not similar in size, which do not merge into a single image. With a one-sided deficit of the lens, it is possible to restore eyesight contact or intraocularly.
Correction of aphakia intraocular is an operative manipulation, while a dislocated or clouded natural lens is replaced by an artificial lens. It has a similar power. The doctor makes the calculations. He refers to tables, computer and nomograms. To calculate the doctor uses the results of the depth of the anterior chamber, the thickness of the biological lens, refraction and the length of the eyeball. The entire refractive power is calculated based on the customer's desires. For people who are engaged in active work and driving, determine emmetropia. For those patients whose work is related to reading, writing and doing small activities without glasses, they have a way of planning a low myopic refractive power. Also provided that the other eye is nearsighted.
Correction of aphakia in childhood
To achieve high visual acuity of the eye with lens deficiency, there is a need for a clear correction of refractive power violations. Gradually, with decreasing refraction and growth of the visual apparatus, the child needs regular replacement of contact lenses. Some methods are used to improve this pathological condition.
This is the leading way to correct the bilateral absence of the lens. With aphakia, on the one hand, glasses are rarely restored. Only if the contact lens is intolerant. Pros of spectacle correction are in a small price category.
Complexity determines the selection of heavy glasses for children of the younger age group. In this case, the small nose of the child is not able to keep a significant weight in the rim of the glasses.
Contact lenses are the leading method of normalizing eyesight with aphakia of one or two eyes. For young children, breathing contact lenses are used, which have a rigid and soft structure. At the beginning of a child's life, contact lenses made of silicone are the most effective. This method of correction has a higher cost than spectacle correction.
This is observed due to the fact that there is frequent consumption of the lens, and with the growth of the eye, a constant replacement of lenses is necessary. There is information that keratitis and scarring occur in children with aphakic eyes. But when wearing contact lenses, these problems are very rare.
This manipulation uses a transplant from the superficial corneal lamellar layer. The procedure was not very successful, so at this time it is not produced.
After surgical manipulation in children, there is a need for intraocular lenses to correct the absence of the lens. This is due to the removal of post-traumatic, developing and congenital cataracts.
Doctors note the ability to fix artificial lenses in children at the age of two. During this period of life, the growth of children's eyes stops, and it becomes possible to calculate the strength of the lens for people of different ages. But there are discussions in the installation of intraocular lenses with cataracts since birth.
Operative manipulation, which is associated with implantation at the beginning of the life of the child, is inappropriate. There is a difficulty in characterizing the strength of the intraocular lens by calculation, because of the further growth of the infant's eye. In addition, the concomitant pathology of this disease is microphthalmos. The question arises whether the intraocular lens does not adversely affect the growth of the eyeball.