A pterygium is a wedge-shaped tissue of conjunctiva that is vascular and grows slowly towards and over the cornea. Because it is a vascular tissue, it looks pink and causes irritation. It is believed that ultra-violet light is a factor in causing the fibrous and vascular changes in the exposed conjunctiva, which gradually grows onto the cornea. If pterygium advances enough to the center of cornea it will obviously threaten vision. This growth is seen mostly in people that have been outdoors for a long time, especially in equator regions (e.g. farmers).
Patients usually complain of a pink spot on their eye, irritation, watering and foreign body sesation. The pinkish appearance of the eye is also a concern for the patients. By progression of the vascular tissue onto the cornea, it will deform the surface of the cornea and cause irregular astigmatism.
Mild decongestant/steroid eye drops, artificial tears and sunglasses are recommended by eye doctors for the early stages of pterygium. Because of high recurrence rate after surgical excision (up to 40% of cases), the aim is to manage the disease with medication, if possible, as long as vision is not threatened. But if the eye doctor and the patient are concerned about vision and the progression of pterygium, a plan for the method of surgery will be contemplated. The methods of surgical excision are simple excision, excision with conjunctival graft, excision and use of amniotic membrane to cover the wound, application of antimetabolites to prevent recurrence, and applying different radiation.
Above is a schematic presentation of the 3 stages of pterygium progression. It is advisable that before ptregium advances to stage three, an excision be performed, otherwise an excision and corneal graft may be required.