Ophthalmologists Miss Seema Verma, Miss Lola Ogunbowale and Miss Claire Daniel advise on common features, examination and referral
A 46-year-old woman presents with a one-year history of a lesion developing in the corner of her right eye. She has noticed that the lesion is getting larger and growing towards her pupil.
It is slightly red and occasionally irritates her, and she has been troubled by her vision on that side becoming slightly blurred. She has no past ocular history and is otherwise fit and well, and not on any medication. She has recently moved to the UK from Turkey.
Examination reveals visual acuities of 6/9 in each eye. There is a fleshy growth from the nasal conjunctiva covering the nasal half of the cornea, just stopping short of the pupil edge.
The lesion looks mildly inflamed. Fluorescein staining reveals an irregular tear film, but the rest of the eye examination is normal.
The diagnosis is pterygium.
The problem
Pterygia are common, but normally require no intervention. However, occasionally they can become inflamed and, as a result, cause a foreign-body sensation in the eye.
They are more common in men than in women, and the prevalence rises with proximity to the equator and increased exposure to ultraviolet light.
They are nearly always preceded by pingueculae – smaller degenerative nodules of the conjunctivae. It is unknown why some people only have pingueculae while others go on to develop pterygia.
Features
A pterygium is a benign growth.
The appearance is quite typical, with a triangular fold of raised fibrovascular tissue and conjunctiva that invades the cornea.
Persistent redness and irritation may cause watering. A pigmented line may be visible at the leading edge encroaching on the cornea.
Differential diagnosis
• Trauma – chemical or mechanical
• Carcinoma in situ of the conjunctiva – rare in temperate climates, more common over the age of 50, typically unilateral and, unlike pterygia which typically arise from the medial or lateral limbal cornea, can occur at any position on the cornea
• Pinguecula – yellowish, round lesion present on the medial or occasionally on the temporal bulbar conjunctiva.
Treatment
• Topical lubricants can ease irritation and foreign-body sensation.
• Topical steroids for recurrent inflammation..
• Surgical excision with a conjunctival autograft is indicated if the vision is becoming affected.
• Recurrence after surgery is common and can be very aggressive. In cases of asymptomatic pterygia, patients need to be made aware of this. Mitomycin C or
5-fluorouracil (as an antifibrotic agent) may be used for large or recurrent pterygia. Radiotherapy has also been used for recurrences.
Referral
The following are indications for referral:
• if the visual axis is threatened or encroached upon
• blurring of vision due to astigmatism
• failure to respond to first-line treatment, such as simple lubricants (in which case, steroid eye drops may occasionally be necessary)
• cosmetic issues.
Miss Seema Verma is a consultant ophthalmologist, Miss Lola Ogunbowale is a clinical fellow and Miss Claire Daniel is a consultant ophthalmic surgeon at Moorfields Eye Hospital, London.
Reference
Farjo QA and Sugar A. Pterygium and conjunctival degenerations. In: Yanoff M, Duker JS (eds). Ophthalmology (3rd edition). Mosby Elsevier; 2008
