A 47-year-old farmer presents with the lesion pictured in the figure below. He states it has been present for at least 2 years, and it has been gradually increasing in size. This lesion may lead to all of the following except:
an adjacent dellen
flattening in the involved meridian with change in central astigmatism
destruction of Bowman layer
Answer: D. Distant metastasis
- The figure shows a pterygium of the right eye. Pterygia are wing-shaped folds of conjunctiva and fibrovascular tissue that invade the superficial cornea.
- The exact etiology is not known, but a strong causal relationship has been documented with ultraviolet light exposure.
- Destruction of Bowman layer and changes in corneal astigmatism often occur.
- If inflamed, they may become hypertrophic with localized changes of the adjacent cornea, which may include punctate keratopathy and even dellen formation.
- Iron deposition at the leading edge of the pterygium is known as a Stocker line.
- They may be observed, but excision is often indicated if the visual axis is threatened or if extreme irritation exists.
- The recurrence rate is significant, with approximately 40% recurring by simple excision.
- Conjunctival autograft and amniotic membrane graft may lower recurrence rate according to some studies. Application of mitomycin C may also prevent recurrence.
- These lesions are rarely malignant, and metastasis would be extremely uncommon.