<prompt> What is the most common problem following surgical treatment of pterygium?RecurrenceCorneal ulcerationAstigmatismScleral scarring  <response>: Recurrence of the pterygium after surgical excision is the main problem 30-50. However, it can be reduced by any of the following measures: Transplantation of pterygium in the lower fornix McReynolds operation is not performed now. Postoperative beta irradiations not used now. Postoperative use of antimitotic drugs such as mitomycin-C or thiotepa. Surgical excision with bare sclera. Surgical excision with free conjunctival graft taken from the same eye or other eye is presently the preferred technique. In recurrent recalcitrant pterygium, surgical excision should be coupled with lamellar keratectomy and lamellar keratoplasty. ref: A K KHURANA OPHTALMOLOGY,E4, Page-81 