Lens luxation is a pathology in which the biological lens is displaced into the anterior or posterior chamber of the eye. Dislocation or ectopia of the lens can be the result of cataract surgery, complex operations on the retina or vitreous body of the eye, trauma or congenital pathology.
The human eye is the most complex organ. We see only the pupil, iris and cornea. Behind them is the lens, the vitreous body, which conducts light rays, and the retina. The natural lens is held in place by ligaments of cinnamon , which, like thin threads, connect it to the ciliary (ciliary) body. This structure is responsible for accommodation and generation of intraocular fluid.
shape and refractive power of the lens directly depend on the tension of the zinn ligaments. Due to underdevelopment or damage to the ligaments, the lens changes its position, the eye loses the ability to focus. Why is this happening?
Causes of dislocation of the lens
- Due to genetic predisposition;
- With congenital anomalies, for example, underdevelopment of the ciliary body;
- After surgical treatment of cataracts (clouding of the lens) and its replacement with an artificial one;
- In view of the increase in the eyeball (hypermetropia) with farsightedness;
- Due to trauma to the muscles and ligaments of the visual organ.
Signs and symptoms of dislocation of the lens. How to recognize it?
- In case of congenital dislocation, the baby’s parents or neonatologist during the examination notes the incorrect position and excessive mobility of the lens in the child’s eye;
- Acquired dislocation usually occurs after blunt trauma to the head or eye causes dull pain, and is accompanied by a sharp decrease in vision;
- Trying to focus on an object causes a headache;
- Also, a dislocation can be signaled by double vision even when one of them is closed, a general deterioration in vision;
- The patient experiences discomfort in the area of the affected eye, the conjunctiva turns red;
- Trembling of the iris ( iridodonez ) is a characteristic symptom of dislocation of the lens.
Classification of dislocations of the lens
According to the origin of the pathology, the following types of dislocation of the lens are distinguished:
- Primary, or congenital, in which a person has a hereditary factor ( Marfan syndrome , homocystinuria , Weill-Marquezani syndrome and developing as an independent disease;
- Secondary, or acquired, when the disorder is provoked by the influence of one or another concomitant disease, for example, chronic inflammatory processes, syphilis, advanced cataracts.
According to the severity of dislocations are:
- I degree. At this stage, the lens is of normal size, its equator can only be seen with mydriasis (pupil dilation) up to 6-8 mm;
- At the II degree, a decrease in the size of the lens is observed and its equator is detected with mydriasis of 3.5 mm, the fibers of the zinn ligament are stretched;
- III degree (partial) with rupture of zinn ligaments on ½ or ¾ of the circumference. The displacement of the lens is also visible with a narrow pupil;
- IV degree (full). Zinn’s ligaments are torn off along the entire circumference and the lens is not visible in the lumen of the pupil. With this degree of dislocation, the lens can move freely in the eye cavity.
In the clinical classification, there are three types of dislocation (dislocation) of the lens:
- In the anterior chamber of the eye. The lens moves forward and is visible in the eye with the naked eye. Causes damage to the cornea, accompanied by an increase in intraocular pressure (IOP) and decreased vision. This condition requires urgent medical attention;
- into the vitreous body. The lens can be both fixed (in the presence of adhesions to the retina or optic nerve head) and mobile;
- Migrating, when the lens moves freely through the eye cavity, from the cornea to the iris and back, depending on the position of the head .. The presence of pain indicates dislocation.
Treatment of dislocation of the lens
An unambiguous conclusion about the presence of signs of ectopia of the lens can only be made by a doctor after an ophthalmological examination using additional diagnostic methods:
- Visiometry – checking visual acuity with and without correction;
- Computer refractometry to assess the level of refraction;
- Tonometry – non-contact measurement of intraocular tone;
- Ultrasound examination (ultrasound) of the eye to identify the dislocation zone and in order to understand what type of ligament rupture the patient has – unilateral or bilateral. When fixing the lens with adhesions, detachment can be observed;
– examination with a slit lamp to visualize hemorrhage, determine the
transparency of eye structures and defects.
If the specialist detects ophthalmohypertension , then he will additionally conduct a study of the visual fields (perimetry), gonioscopy and pachymetry , in order to study the structure of the angle of the anterior chamber of the eye, measure the thickness of the cornea. These data may be the basis for the diagnosis of “Suspicion of glaucoma” and re-examination after 2-4 weeks. If after tonography , daily pressure measurements and optical coherence tomography, the diagnosis is confirmed, treatment will be aimed at eliminating this disease as the root cause of lens displacement. First of all, therapy is aimed at lowering IOP with drugs or drops. When high IOP is resistant to medication, the doctor raises the question of surgical intervention.
The selection of treatment tactics is based on many factors: the nature and degree of displacement, visual acuity, ophthalmotonus and the general condition of the organ of vision. Subluxation does not cause a significant deterioration in vision and an increase in intraocular pressure, and therefore does not require removal. With a complete displacement of the lens, lensvitrectomy , or phacoemulsification , is performed – removal of the lens, followed by replacement with an artificial intraocular lens.
If you do not delay the treatment of lens dislocation, the prognosis will be positive. Modern methods of treatment provide recovery, restoration of vision and normalization of intraocular fluid circulation in ⅔ of cases. As a preventive measure for complications and elimination of edema after surgery, anti-inflammatory drugs based on glucocorticosteroids are prescribed . Of course, as with any manipulation, there is a risk of complications after IOL implantation: secondary displacement, retinal detachment, macular edema, and increased IOP. They will help to avoid following the recommendations of the attending physician, regular scheduled examinations to control the dynamics.
Any disease is better to prevent than to cure. To avoid displacement of the lens, ophthalmologists recommend avoiding injuries, blows to the head and eyes. Use protective goggles or screens if your work involves construction, repairs, dangerous devices and be sure to seek medical help at the first sign of pathology.