A case of a uniocular pterygium related to an unusual occupation.

A Pterygium is a characteristic triangular shaped fibrovascular growth of conjunctival and subconjunctival tissue, which invades the cornea between the epithelium and Bowman’s layer at its apex. Pterygia occur within the intrapalpebral space and are more common on the nasal rather than temporal side.They have three components: the cap, a grey avascular zone that precedes the head of the lesion surrounding it like a halo; the head, which is white and slightly elevated; and the body, which is a flat sheet of pink, highly vascularised connective tissue. When the pterygium is actively growing the tissue is red and inflamed but as the lesion becomes inactive the vascularity diminishes and the redness disappears. They tend to occur on the medial aspect of the cornea and are more common in people who live or have lived in hot, dry climates. Firstly, as they are mildly raised, they can interfere with the normal wetting of the eye causing local irritation and discomfort. As they enlarge they may also begin to encroach on the visual axis of the eye (though they never involve more than half of the cornea). Finally, patients sometimes find them unsightly and want them removed for cosmetic reasons. There is, however, a significant recurrence rate after surgery with an estimated 40% reappearing (1). Reduced recurrence rates are seen where the excision is augmented with other strategies: Beta irradiation to the area of excision (20-23%) (1,2); the use of intraoperative or post-operative mitomycin C (4-12.5%) (2-4); and limbal conjunctival stem cell autograft (14.6%) (3). This man’s pterygium was excised and the exposed area replaced with a transplanted free conjunctival autograft, which produced a good cosmetic result at 6 months.