History
Patients with pterygia present with various complaints, ranging from no symptoms to significant redness, swelling, itching, irritation, and blurring of vision associated with elevated lesions of the conjunctiva and contiguous cornea in one or both eyes.
Physical
A pterygium can present as any of a range of fibrovascular changes on the surface of the conjunctiva and the cornea. It is more common for the pterygium to present on the nasal conjunctiva and to extend onto the nasal cornea, although it can present temporally, as well as in other locations.
The clinical presentation can be divided into 2 general categories.
One group of patients with pterygium can present with minimal proliferation and a relatively atrophic appearance. The pterygia in this group tend to be flatter and slow growing and have a relatively lower incidence of recurrence following excision.
The second group presents with a history of rapid growth and a significant elevated fibrovascular component. The pterygia in this group have a more aggressive clinical course and a higher rate of recurrence following excision.
Causes
Risk factors for pterygium include (1) increased exposure to ultraviolet light, including living in subtropical and tropical climates, [7] and (2) engaging in occupations that require outdoor activities.
A genetic predisposition to the development of pterygia appears to exist in certain families.
A predilection exists for males to develop this condition in significantly higher numbers than females, although this finding may represent an increased exposure to ultraviolet light in this portion of the population. [7]
Complications
Complications of pterygium include the following:
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Distortion and/or reduction of central vision
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Redness
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Irritation
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Chronic scarring of the conjunctiva and the cornea
Extensive involvement of the extraocular muscles may restrict ocular motility and contribute to diplopia. In patients who have not yet undergone surgical excision, scarring of the medial rectus muscle is the most common cause of diplopia. In patients with pterygia who have previously undergone surgical excision, scarring or disinsertion of the medial rectus muscle is the most common cause of diplopia.
In patients with significantly elevated pterygia, focal drying and subsequent thinning of the adjacent cornea may rarely occur.
Postoperative complications of pterygium repair can include the following:
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Infection
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Reaction to suture material
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Diplopia
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Conjunctival graft dehiscence [8]
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Corneal scarring
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Perforation of the globe, vitreous hemorrhage, or retinal detachment (all rare)
Late postoperative complications of beta radiation of pterygia can include scleral and/or corneal thinning or ectasia, which can present years or even decades after treatment. Some of these cases can be quite difficult to manage.
In some cases, adjunctive use of topical MMC at and after pterygium surgery has been reported to cause similar ectasia or melting of the sclera and/or the cornea. [9, 10, 11]
The most common complication of pterygium surgery is postoperative recurrence. Simple surgical excision has a high recurrence rate of approximately 50-80%. The rate of recurrence has been reduced to approximately 5-15% with use of conjunctival/limbal autografts or amniotic membrane transplants at the time of excision. [12, 13, 14, 15]
On rare occasion, malignant degeneration of epithelial tissue overlying an existing pterygium can occur.
