Ophthalmology and Optometry Coding Alert

Question: What is the code for mitomycin-C? The ophthalmologist used it to maintain the effect of glaucoma surgery. We filed it as an unlisted procedure with modifier -78 (Return to operating room for a related procedure during the postoperative period), and Medicare denied the claim. How should we have coded this scenario? California Subscriber Answer: There is no CPT code for using mitomycin-C. It is a medication supply used during surgery and is not typically reimbursed separately from the procedure when supplied by the physician. It is included in the code for trabeculectomy as part of the practice expense of the procedure. There are two trabeculectomy codes, 66170 (Fistulization of sclera for glaucoma; trabeculectomy ab externo in absence of previous surgery) and 66172 ( trabe-culectomy ab externo with scarring from previous ocular surgery or trauma [includes injection of antifibrotic agents]). The first is for a standard trabeculectomy. The second is for trabeculectomy with scarred conjunctiva, typically caused by previous surgery. Mitomycin-C might be used in either situation but, with either, you will not receive additional reimbursement for using it because it is included in the trabeculectomy codes.