It is a degenerative condition of the sub-conjunctival tissue, which proliferates as a triangular fold of tissue-mass to invade the cornea, involving the Bowman,s membrane and the superficial stroma, the whole thing is covered by conjunctival epithelium. Literally, it means “a wing”.
It's not clear what causes a pterygium to develop. But most experts believe that significant risk factors include:
- Prolonged exposure to ultraviolet light
- Dry eye
- Irritants such as dust and wind
The signs of pterygium are based on the clinical appearance of the lesion. Typical findings include:
- Fibrovascular conjunctival growth within the palpebral fissure extending onto the corneal surface
- Triangular shape with the apex, or head, extending onto the cornea
- Vascular straightening in the direction of the advancing head of the pterygium on the corneal surface.
- May be a thin translucent membrane or significantly thickened with an elevated mound of gelatinous material.
- It may affect the nasal and temporal limbus of both eyes or only a single location.
- Raised lesion, white to pink in color depending on vascularity.
Today a variety of options are available for the management of pterygium, from irradiation to conjunctival auto-grafting or amniotic membrane transplantation, along with glue and suture application. As it is a benign growth, pterygium typically does not require surgery unless it grows to such an extent that it covers the pupil, obstructing vision or presents with acute symptoms. Some of the irritating symptoms can be addressed with artificial tears.