Content area
Full Text
ABSTRACT
Over a 5-year period, 800 patients with primary pterygium underwent "merest sclera" surgery, a procedure in which the injured limbo-conjunctival area is covered completely with superior and inferior conjunctiva) flaps so that the tear film can be reestablished. After a 1-year follow-up, 17 recurrences were found (2.1%). All these resulted from premature wound dehiscence and/or postoperative infection.
Pterygium is primarily a lesion of the tropical and subtropical regions. Treatment of the condition has challenged ocular surgeons for several thousand years.
It is generally agreed that the lesion begins in the conjunctiva in response to damage from ultraviolet light (UV-B 320 nm to 286 nm).1'4 In my experience early changes in the normal tear film, visible with the slit lamp, precede actual pterygium formation. These changes include an increase in the oily layer and a decrease in the water layer. Patients often complain of a "sandy" feeling in their eyes. The area involved, usually nasal, appears to be thickened, with increased vascularity and congestion.
At this stage, treatment may consist of tear film replacements to enhance the water layer, mild decongestants, and protection from ultraviolet light. Further prolonged exposure to ultraviolet light elicits a movement of the conjunctiva onto and into the cornea with subsequent destruction of Bowman's membrane.3 Very vascular, wide-bodied, and narrow-headed lesions appear to grow faster and are more symptomatic than narrow-bodied and wide-headed ones. The astigmatism induced will affect visual acuity and may remain even after the pterygium has been successfully removed.5
Surgical treatment of the primary pterygium is indicated as soon as there are signs of corneal involvement at the Iimbus. The objective is to return as far as possible the conjunctiva and the cornea to their original smoothness so as to reestablish the protective tear film. The "bare sclera" technique, which still appears in surgical textbooks,6 leaves the limbo-conjunctival area rough and inadequately covered. The tear film distribution remains uneven, and the eye stays irritated. These conditions prompt the pterygium to grow again, since the original irritative conditions persist. Attempts to stem the regrowth with Beta-irradiation,7-9 though somewhat successful, are by no means always so and not infrequently have adverse effects.
Prior to the present series of primary pterygium cases, the "bare sclera" technique, with administration of...