How does pterygium develop?
Ultraviolet radiation damages cells in the limbus area - the border of the cornea and the protein membrane. The conjunctival tissue thickens, vessels and connective fibers grow in it, and it gradually creeps onto the transparent cornea in the form of a triangle with its apex towards the center. The process goes slowly, over the years, with periods of rest and active growth, when the eye becomes red and irritated. The initial stage, when the thickening is only at the limbus and does not extend into the cornea, is called pinguecula: this is not yet a pterygium, but the same mechanism.
- Pinguecula - yellowish thickening at the edge of the cornea
- Pterygium - tissue has moved to the cornea
- Growth is more common on the side of the nose
- Vessels in the tissue become stronger when irritated
- Noticeable astigmatism with significant size
Causes and risk factors
The main factor is the total dose of ultraviolet radiation over a lifetime, so pterygium is more common in hot sunny regions and in those who spend a lot of time outdoors without sunglasses. Additionally, dust, wind, sand and dry air irritate the eyes. Chronic dry eye, hereditary predisposition and, probably, long-term inflammation of the ocular surface play a role. Men of working age get sick more often, which is due to the nature of their work.
- Prolonged sun exposure
- Outdoor work
- Dust, wind, dry climate
- Dry eye syndrome
- Heredity
- No sunglasses
Symptoms
For a long time, the only complaint was a visible growth on the white of the eye and cosmetic discomfort. As it grows, a foreign body sensation, dryness, periodic redness and lacrimation occur, especially in the wind and when working behind a screen. When the tissue reaches the cornea, it tightens it and causes astigmatism: the image becomes blurry, and glasses no longer fully correct vision. If the pterygium reaches the pupil, vision decreases noticeably and is more difficult to restore.
- Visible triangular growth on the eye
- Sensation of sand and foreign body
- Periodic redness
- Tear in the wind
- Increasing astigmatism
- Decreased vision as you grow toward the center
Diagnosis and observation
The diagnosis is made by an ophthalmologist during examination at a slit lamp, where the size, activity of the vessels and the border of the transition to the cornea are clearly visible. Be sure to check visual acuity and perform autorefractometry and keratometry - they show how much the growth has distorted the shape of the cornea. The doctor measures the length of the pterygium in millimeters and often takes a photograph so that at the next visit they can compare and understand whether it is growing. If the formation is atypical, a biopsy is needed to rule out a tumor.
- Slit lamp examination
- Visual acuity test
- Autorefractometry and keratometry
- Measuring the length of the build-up
- Photocontrol in dynamics
- Biopsy for an atypical picture
Treatment and prevention of relapse
For small pterygium without affecting vision, observation is sufficient: sunglasses with an ultraviolet filter, a hat with a visor, moisturizing drops, and in case of exacerbations, short courses of anti-inflammatory drugs as prescribed by a doctor. Surgery is indicated for corneal growth toward the center, severe astigmatism, persistent discomfort, and for cosmetic reasons. Simple cutting of tissue often results in relapse, so today the defect is covered with one’s own conjunctival flap. After the operation, drops are used for several weeks and be sure to protect the eyes from the sun.
- Sunglasses with UV filter
- Headdress with brim or visor
- Moisturizing drops
- Surgery for vision threatening and persistent discomfort
- Plastic surgery using your own conjunctival flap
- Strict sun protection after surgery
