Pterigium - growing of triangular shape which is formed from the medial (internal) party of a conjunctival cover of an eyeball and has extent to cornea blankets. Proceeds more often asymptomatically, at aggravation of a disease there can be complaints to cosmetic defect, dryness of eyes, decrease in visual acuity. Pathology is diagnosed by means of a method of a biomikroskopiiya, an oftalmoskopiya, the analysis of plaintive liquid, a histologic research, a fluorescent angiography. Treatment is surgical, however if does not cause subjective complaints and discomfort, then treatment is not carried out.
Pterigium (wing-shaped pleva) is a disease, the bilateral, representing subepitelialny growing of degenerately changed bulbarny conjunctiva in the form of a triangle from a limb on a cornea is more often. In a pterigiuma allocate a head, a neck and a body. The head is a top of triangular education, its progressing part. Further there is a neck – small narrowing. The widest part is called a body of a pterigium. Most often comes to light at residents of the countries with hot climate. The geographical zone called "a periekvatorialny belt of a pterigium" settles down to 37 ° to the North and to the South from the equator. The disease meets at men more often, than at women. The age of emergence of a pterigium - of 40 years is also more senior.
Reasons of a pterigium
Development of a pterigium requires long impact of any irritating factors on an eye conjunctiva. For example, the increased level of ultra-violet and/or infrared radiation causes a syndrome of a dry eye. Stay in the open air more than 5 hours a day (workers of agriculture, fans of hunting and fishing) or long stay indoors with the high level of dust (the persons occupied in the construction sphere – carpenters, painters, plasterers) is risk factor for development of the inflammation of a conjunctiva turning into chronic process. Dryness of eyes and chronic conjunctivitis – the main mechanisms leading to development of a pterigium. In recent years in risk group began to allocate people who spend much time at the computer therefore, owing to insufficient moistening of a conjunctiva, there is a syndrome of a dry eye that too leads to formation of a pterigium.
Long influence of adverse external factors involves damage of cages of an integumentary epithelium, there is an inflammatory reaction, natural protection of a conjunctiva decreases. There is a violation of a structure of scyphoid cages, development of a syndrome of "a dry eye" begins. Microcirculation is broken that leads to intensive formation of new vessels. The continuing influence of adverse factors promotes further development of pathological processes and formation of a pterigium.
At a histologic research of a pterigium the subconjunctival connecting fabric hypertrophied and changed on structure containing a large number of fibroblast and neogenic blood vessels which grow into a cornea comes to light. In all cases inflammatory infiltration and abnormal adjournment in intercellular space of elastin and collagen is defined.
Classification of a pterigium
On extent of progressing in ophthalmology distinguish stationary and progressing . The progressing form of a pterigium is distinguished by the following signs: the reinforced head acts over a cornea surface; full-blooded wavy vessels form the developed network in a pterigiuma. Depending on a condition of vessels episkler it is possible to define ability of a pterigium to progressing:
1 degree – transparent, atrofichny, through it vessels episkler are well looked through; the probability of progressing is minimum.
2 degree – the speaker, translucent, vessels episkler are looked through partially.
3 degree – highly active, opaque; vessels are not visible.
On the basis of prevalence of growing, size of an astigmatism and decrease in visual acuity allocate five clinical stages of a pterigium: from initial – to expressed, leading to considerable decrease in sight:
The I Art. – education is observed only at a limb, patients do not show any complaints.
The II Art. – a head of a pterigium is on the middle of distance between a limb and edge of a pupil. Emergence of a neprayovilny astigmatism of a cornea in a zone neposredstvenyono before a head of a pterigium is characteristic, and in an optical zone the correct astigmatism of small degree comes to light. Visual acuity can be reduced to 0,9–0,7.
The III Art. – a head of a pterigium is on a cornea at edge of a pupil, the astigmatism owing to a thickening of a horizontal meridian of a royogovitsa amplifies, visual acuity can decrease to 0,5.
The IV Art. – the head reaches the center of a cornea (a projection of the center of a pupil). The expressed wrong or correct astigmatism (2,5–7,5 dioptries) prevails much. Visual acuity decreases to 0,3–0,2.
The V Art. – a head of a pterigium comes for the center of a cornea and can extend further on a cornea. Refyoraktion cannot be defined, visual acuity lower than 0,1; the cornea cataract, an union of the changed conjunctiva with centuries or plaintive bodies can develop.
Symptoms of a pterigium
Pterigium can be defined on one eye from the nasal party, however its increase on a cornea from two parties is possible at once. At initial stages the patient does not feel any discomfort, the only thing that can disturb him - small consolidation in a zone of a limb or visible cosmetic defect in the form of a film of grayish color of triangular shape with the top turned towards a pupil. In process of the progressing growth of a pterigium feelings of a foreign matter, dryness and irritation of eyes appear. The inflammation of the changed conjunctiva is followed by hypostasis, reddening, an itch, dacryagogue.
At further growth of a pterigium the astigmatism and decrease in sight of various degree of expressiveness develops. From complications cicatricial changes of a conjunctiva and cornea, restriction of mobility of an eyeball, developing of squint, malignant regeneration of a pterigium are noted.
Diagnostics of a pterigium
Pterigium is rather easily diagnosed by the ophthalmologist. The leading method of diagnostics – biomicroscopy with use of a slot-hole lamp. This technique allows the ophthalmologist to estimate visually the size of a pterigium and extent of its growth. For specification of a stage of a pterigium carry out an oftalmoskopiya, a vizometriya and refractometry.
From additional methods of inspection use high-precision procedures for detailed studying of a pterigium, such as research of plaintive function with a crystallography of plaintive liquid (it is necessary for the forecast of extent of further growth and a possible retsidivirovaniye of a pterigium after expeditious treatment), a keratotopografiya (for definition of degree and a form of a pterigium), a morphological research of fabric of a pterigium (for detection and assessment of activity of proliferation of a vascular component), a method of a fluorescent angiography (for identification of changes mikroangioarkhitektonik, characteristic of a pterigium).
Treatment of a pterigium
Treatment is carried out or with the cosmetic purpose at the request of the patient, or at achievement pterigiumy an optical part of a cornea. The method on separation of the changed conjunctiva from a surface of a cornea, a limb, skler, its resections and plasticity of defect the moved rags is the cornerstone of operation on removal of a pterigium. There are ways of treatment with application of an amniotic membrane and alloplastichesky materials, use of tsitostatik (the mitomitsina With, 5-ftoruratsit) and the dosed radiation by β-radiation, and also photodynamic therapy, laser coagulation of vessels of fabrics of a pterigium. Pterigium is characterized by a frequent recurrence after excision.
Because of numerous surgical interventions there can be complications in the form of an eyeball conjunctiva union with a conjunctiva a century () and plaintive bodies, unions of edges a century or cataracts of a cornea. The meeting squint can result from violation of the movement of eyes.
Prevention of a pterigium
Prevention of a pterigium requires reduction of the time spent in rooms with various irritating factors. Use of eye protections from dust, dry air, chemicals is obligatory. When developing inflammatory diseases timely and adequate treatment and observation at the ophthalmologist is necessary. After 40 years it is recommended to people at stay in the sun to put on glasses with high protection against ultraviolet. In operating time at the computer it is obligatory to do breaks each 30-40 minutes and to dig in the moistening drops at the first signs of discomfort in eyes.