Retinopathy of prematurity

Retinopathy of prematurity.  Photo from www.aravind.org

The possibilities of modern medicine allow foster infants, even with a mass of 500 g Unfortunately, almost one in five aborted child suffers from a disease of eyes — retinopathy of prematurity (ROP), and 8% of them — severe.

Retinopathy of prematurity — is an eye disease that occurs as a result of developmental disorders of the retina (the light sensitive area of the eye) in premature babies. The disease can lead to total blindness.

Causes

In 1951, a connection was established between the breach of vascular growth and a high concentration of oxygen in incubators. In the retina, metabolic processes are not carried out through respiration and glycolysis — which means that the energy source is glucose splitting flowing without oxygen consumption. Under the influence of oxygen inhibited glycolysis, andretina dies and is replaced by connective and scar tissue. So recently the only cause of retinopathy of prematurity was considered a high concentration of oxygen in incubators. However, the limitation of its use after this discovery, although reduced the frequency of the disease, but the impact on the increase in deaths from respiratory Distress Syndrome and the number of serious consequences of hypoxia in survivors.

It is currently believed that premature retinopathy — a multifactorial disease, i.e. it may occur under the influence of several factors. The group with the risk of retinopathy include premature infants with birth weight less than 2000 grams and gestational age up to 34 weeks. The risk increases significantly during mechanical ventilation more 3-x days oxygen and more than 1 month.

Among the additional risk factors include:

  • severe intrauterine infection;
  • hypoxia (ischemia) in the brain, bleeding in the brain caused by complications of pregnancy and childbirth.
  • One of the important factors that may influence the development of ROP is a light impact on the immature retina, as the in vivo formation of retinal vessels is completed in utero, in the absence of light. A premature baby gets in terms of excessive illumination.
  • There is a theory of a genetic predisposition to the disease.

What's going on?

At the heart disease retinopathy of prematurity is incomplete formation of the eyeball, the retina and its vascular system. Vascularization (formation of blood vessels) of the retina of the fetus begins at 16 weeks of pregnancy — from the center of the optic nerve to the periphery — and ends at the time of birth of a full-term baby. Accordingly, the earlier a child, the smaller the area of the retina covered by vessels and more extensive avascular, or avascular zone. In7-month-old fruit — concentric retinal vascular hypoplasia: its central department supplied with blood, and on the periphery of the blood vessels are not available. After the birth of a premature baby on the formation of abnormal blood vessels are various factors — environment, light, oxygen, which can lead to the development of retinopathy.

The main manifestation of retinopathy of prematurity is to stop the normal formation of blood vessels, sprouting them directly into the eye into the vitreous. Thereupon begins in the connective tissue neoplasm lens which causes tension and retinal detachment.

Onset of the disease accounts for4th week of life, and the peak — to8th (The birth of a full-term baby). The disease usually affects both eyes, but one may be more pronounced.

Classification

Retinopathy of prematurity is classified:

  1. localization of the pathological process (with respect to the optic nerve);
  2. on the prevalence of lesions. Circumference eyes may be separated as the dial — 24 hours. The prevalence of retinopathy is determined by the number of affected a "clock."
  3. by step. Retinopathy of prematurity — a progressive disease. It begins slowly, usually4 10th week of life, and may progress rapidly or slowly from1st to5th stage. Stage 3 is called the "threshold" and is an indication for the coagulation of the retina. Stage 5 is characterized by a total retinal detachment and complete loss of vision. ;
  4. on the activity of the current: active (acute) and the scar phase.

In 60-80% Of children develop spontaneous regression Diseases, in which55-60% With no residual changes in the fundus. In other cases, disease more severe and progresses to scar stages.

In 75% of cases of PH flows through the "classical" type passes sequentially through all 5 stages, but also distinguish this form of retinopathy as a "plus"-disease (or Rush-disease lightning PH), characterized by rapid, malignant course.

Retinopathy of prematurity is often accompanied by the development complications:

  • nearsightedness (myopia) and astigmatism;
  • strabismus and amblyopia ("lazy eye");
  • glaucoma;
  • cataracts;
  • retinal detachment. It can occur in adolescence as a result of stretching of scar tissue in the intensive growth of the eyeball.

Diagnostics

Examination of a premature baby for retinopathy are starting to do, starting with32-34 weeks of development (usually 3-4 weeks after birth). Next ophthalmologists examine the baby every 2 weeks until the completion of vascularization (formation of blood vessels of the retina). At the first signs of retinopathy examination conducted weekly until the regression of the disease or process activity subsided. When the "plus"-the disease — one every 3 days.

Fundus examination is carried out using binocular indirect ophthalmoscopy. Inspection is carried out with the obligatory mydriasis (with instillation of atropine) and the application of special children blepharostats. The first survey is usually conducted in the neonatal intensive care unit under the supervision of monitors.

In addition to diagnosing and monitoring the effectiveness of treatment used ultrasound of the eye. For the differential diagnosis between retinopathy and other diseases that cause dysfunction of the visual analyzer in premature infants — a partial atrophy of the optic nerve, optic nerve abnormalities, and others used the registration of visual evoked potentials (VEP), electroretinogram (ERG).

In the case of regression of retinopathy of prematurity child should be examined by an ophthalmologist once a6-12 months up to 18 years — graduation related retinopathy complications (particularly retinal adolescence).

Treatment

Treatment of stage 3 retinopathy ("threshold") is carried out by means of laser photocoagulation or cryocautery avascular (avascular) zone of the retina, the intervention must be held no later than 72 hours from the time of its findings. In the later stages of surgical treatment — a circular sealing trantsiliarnaya vitrectomy and scleral.

Cryocautery usually performed under general anesthesia, at least — under local anesthesia. Its technique is to freeze avascular (avascular) of the retina. In the case of success of the procedure (i.e.50-80% Of cases) is terminated development of scar tissue and a pathological process stops. At the same time, the procedure is associated with certain risks — may fall and cardiac and respiratory failure. Therefore, during the cryocautery patient needs constant monitoring. Upon completion of the eye child has swelling, bruising, redness, which take place during the week.

Most ophthalmologists are now favored photocoagulation avascular retina (
the so-called photocoagulation transpupillary) less traumatic because it is more effective gives fewer side reactions and enables precise kontrolivat intervention process. Other benefits of laser photocoagulation:

  • the procedure is painless, so there is no need for anesthesia child;
  • after the procedure there is practically no tissue edema;
  • effects on the heart and respiratory system is minimal.

With the ineffectiveness of cryotherapy and laser progression of retinal detachment or transition Retinopathy from3rd in4th and5th stage to the aid of surgery.

Surgical technique, called skleroplombirovkoy (Circular filling the sclera), quite effective in the treatment of retinal detachment, especially if detachment small. When skleroplombirovke externally inserted eyes "patch" in place of the detachment and pulling it up until touches the retina detachment location. Studies have shown that this technique is good, even in the latter stages. Vision, after a successful skleroplombirovki improved significantly. On failure skleroplombirovki or an inability to carry out applied vitrectomy.

Vitrectomy ("Vitreum" — vitreous, "ectomy" — delete) — a surgical procedure, the purpose of which — the removal of the vitreous and the modified scar tissue from the surface of the retina to eliminate its tension and delamination. In the case of a partial retinal detachment surgery offers the chance to save vision. In the case of complete detachment — unfavorable prognosis.

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