A pterygium is an elevated, superficial, abnormal growth of conjunctiva and fibrovascular tissue that invades the cornea. Pterygia can vary from small, quiet and slowly growing, to large, aggressive lesions that will grow to cover and distort the cornea.

What causes Pterygia?

The main factor in their development seems to be increased ultraviolet exposure: including living in subtropical or tropical climates or engaging in occupations that require prolonged outdoor exposure. A genetic predisposition to the development of pterygia appears to exist in some families. Males have a prevalence of pterygia twice that of females. Dryness, ocular inflammation and exposure to wind and dust may also play a role in the development.


Some patients with pterygia may not have any symptoms, while other may complain of significant redness, itching and irritation. A large pterygium can cause decreased vision by distorting the cornea  (causing astigmatism) or scarring of the deeper layers of the cornea. Sometimes large pterygia can cause double vision when they involve the muscles of the eye.


It is advisable to wear ultraviolet blocking sunglasses to reduce the exposure to additional ultraviolet radiation.

Patients with pterygia can be observed unless the lesion exhibits: growth toward the centre of the cornea, significant redness and irritation, or alterations in visual function.

Medical therapy of pterygia is used for redness and irritation. It consists of topical lubricating drops and/or gels.  A short course of topical corticosteroid anti-inflammatory drops may be prescribed by your doctor when symptoms are more severe.

Surgical Therapy

Pterygia can be removed because of severe irritation or visual disturbances. They may also be removed for cosmetic reasons. Surgery is usually performed as a day surgery under local anaesthetic with sedation if necessary. The pterygium is removed. The bare area is then covered with a small piece of conjunctiva removed from the same eye (conjunctival graft). Typically the graft is taken from an area under the upper eyelid and either glued or sewn in place. The eye is patched overnight. Topical antibiotic drops and topical anti-inflammatory drops will be used for up to two months following the surgery.


The visual and cosmetic prognosis following excision of pterygia is good. The procedure is well tolerated. Some discomfort is expected for the first few postoperative days but patients can usually return to normal activities within a few days of surgery. Complications although uncommon include: recurrence of the pterygium, infection, reaction to suture material, corneal scarring, graft dehiscence and double vision. Recurrent pterygia can be treated with repeat excision and grafting.