Fig. 12. Scleral preparation and application of antimetabolite. A. Hemostasis is critical in order to obtain proper visualization of limbal structures. Use wet-field cautery sparingly to avoid scleral shrinkage and excessive astigmatism. B. and C. Application of an antimetabolite is a highly individual manner. Most surgeons use an antimetabolite in high-risk cases. MMC is typically applied before any incision is made on the sclera. Apply MMC 0.2 mg/mL soaked onto a Merocel 8 mm × 6 mm sponge (see also Fig. 2A) to the sclera for 3 to 4 minutes, with the conjunctiva and Tenon's capsule draped over the sponge. Obviously, the dose, duration, and location of the sponge will vary on a case-by-case basis. D. Remove the sponge, dry the area, and then irrigate vigorously with balanced salt solution.