Above are photos of a lady with reduced vision and irritation on her right eye.
Questions:
1) What is the diagnosis?
2) With simple excision what is the risk of recurrence?
1. Pterygium
2. Very high especially in young patients, maybe 70 to 80 %
Discussion:
Pterygium, literally wing, rarely causes visual disturbance in patients seen in the UK but in hot dusty environments pterygia may be very advanced and cross the pupil margin.
In this case the lesion looks typical but occasionally a squamous cell neoplasm may be mistaken for a pterygium.
Indications for Surgery
1) Visually significant induced astigmatism
2) Threat of involvement of the visual axis
3) Severe symptoms of irritation
Examples of surgical techniques include:
Bare sclera, simple closure, flap, rotational conj flap
Adjuncts to reduce the risk of recurrence include:
MMC, 5 FU, cyclosporin A, Bevacizumab, beta radiation, Amniotic membrane
Surgical excision and graft
Aim to achieve a smooth corneal surface and low recurrence.
Excision of the pterygium - dissect a smooth plane from the cornea towards limbus, down to sclera but leaving episcleral vessels intact.
Conjunctival autograft technique - Recurrence rates ~2- 40%. Autograft obtained from the supero(temporal) bulbar conjunctiva, and removal of Tenon's tissue. It is then sutured to cover the exposed sclera. MMC (inhibit fibroblasts) can be used directly to the scleral bed after pterygium excision as an adjunct to reduce recurrence. Healing may take 6 weeks +
Complications include: graft failure, granuloma, scarring, infection, delayed healing, diplopia, perforation, and recurrence (to name a few).