Pterygium | Etiology|clinical feature| symptoms,signs| types| complication| treatment)

Pterygium is a wing-shaped fold of the conjunctiva encroaching upon the cornea from either side within the interpalpebral fissure. 

The growth of tissue in the corner of the eye is known as pterygium. It is in triangular shape. If it is left untreated it will grow and can extend across the pupil obscuring vision or distorting the surface of the eye which cause blur vision.

Causes

1.  Exposure to the sun ultraviolet rays, dry, high wind, and abundance of dust.
2.  Degenerative and hyperplastic condition of the conjunctiva.
3. Subconjunctival tissue undergoes elastotic degeneration.
4.  Proliferates as vascularized granulation tissue under the epithelium.
5.  Corneal epithelium, Bowman's layer, and superficial stroma and destroyed.

It is more common on the people living in sunny area and who work in the field such as Farmers, fisherman, etc 

Risk factors

The factory that cause the development of pterygium include environmental irrigation like:

1. Air pollution
2. Chemical
3. Ultraviolet light
4. Family history of disorder

These is most common in people after 40 years of age. They can affect one or both eyes in same time.

Clinical feature

1. Old age
2. Person doing outdoor works more common.
3. Unilateral or bilateral
4. Usually nasal side. but in some cases, it occurs on the temporal side.

Symptoms

1. Redness and inflammation
2. Foreign body sensation, irritation
3. Gritty or burning sensation
4. Dryness of the eye due to reduced tear production
5. Defective vision- Pupil, fibrosis
6. Blurring of vision
7. Growth encroaches across the pupil
8. Diplopia- due to the limitation of ocular movement.

Signs

1.  Very rarely- Primary double pterygium(both nasal and temporal side)
2.  Parts of fully developed pterygium.

Types

• Progressive pterygium

1. Thick fleshy
2. Vascular
3. Whitish infiltrates in the cornea
4. Fuchs of Vogt
5. cap of pterygium

• Regressive pterygium

1. Thin
2. Atrophic
3. Attenuated
4. Very little vascularity
5. No cap
6. Becomes membranous
7. Never disappears

Diagnosis

Pterygium is diagnosed by your doctor with slit lamp, as looking at your symptoms. In early stages it may be confused with similar condition of pinguecula, which is also a another form of tissue growth that affect conjunctiva.

Complication

1. Cystic degeneration and infection are infrequent.
2. Neoplastic change to epithelioma, fibrosarcoma, malignant melanoma rarely.

Treatment

Pterygium often doesn't cause problems. But if you start getting problem with it then. There are two main treatment to be considered.

Medication

Using short term of topical corticosteroids eye drops help to reduce redness and inflammation. If you feel dryness in your eye, artificial tears are used to keep your eye lubricated.

But this treatment is only for temporary.

Surgery

Surgery is recommended if your vision is affected or symptoms are problematic.

During surgery, your pterygium is removed and the section of your conjunctiva is taken from under eyelid and is grafted into the area where the pterygium was. Surgery is performed by using local anesthesia and it might take 30 minutes to complete.

It can be possible to recur pterygium after surgery, though this may happen only in some cases.

Prevention

1. Use spectacles which block UV light
2. Wear sunglasses and hat when you are out door.
3. Avoid exposure to environmental irrigation like: air pollution, chemical pollution,etc.

Written by Barsha Panth