Pterygium: It’s a growth of the conjunctiva, the thin membrane that covers the front of the eye, which extends over the cornea, the clear dome-like surface that covers the colored part of the eye (iris).
- Common ocular surface disorder.
- Triangular-shaped fibrous tissue growing under the conjunctiva.
- Can encroach onto the cornea.
- Most common site: nasal conjunctiva, but also seen on temporal conjunctiva.
- Exposure to dry, dusty conditions, especially in rural populations working in hot, dry, windy weather.
- Prolonged sun exposure, as UV radiation causes pterygium.
- Genetic predisposition can play a role.
- In India, prevalence ranges from 9.5% to 13%, more common in rural areas.
- More common in males due to outdoor work.
- Light passing through the cornea concentrates on the nasal conjunctiva.
- Nose shadow reduces the strength of light on the temporal conjunctiva.
- Longer eyelashes on the outside of the lid filter light falling on the temporal side.
- Natural tears flow from the temporal to the nasal side, carrying dust that irritates the nasal conjunctiva.
- UV rays damage limbal stem cells.
- Damaged limbal stem cells activate tissue and blood vessel growth factors.
- This leads to pterygium formation with blood vessels.
- Excessive tearing.
- Foreign body sensation.
- Cosmetic concerns.
- Reduced vision if the cornea is encroached upon.
- Difficulty fitting contact lenses.
Types of Pterygium:
- Thick, fleshy, vascular.
- Progressively encroaches onto the cornea.
- Thin, attenuated, poor vascularity.
- Stationary, doesn’t progress as aggressively.
- Surgical removal of the pterygium.
- Conjunctival auto graft placement (conjunctiva taken from the upper part of the eye).
- Medical treatment includes drops to alleviate symptoms.
- Untreated pterygium can lead to complications.