Avoiding use of mitomycin C on the scleral bed during pterygium extraction is a modification of the Anduze bare scleral approach.
Take-home message: Avoiding use of mitomycin C on the scleral bed during pterygium extraction is a modification of the Anduze bare scleral approach.
By Lynda Charters; Reviewed by William B. Trattler, MD
Miami-A scleral melt is among the risks when using mitomycin C (MMC) during pterygium surgery.
Most surgeons recognize the risk associated with placement of a sponge soaked in MMC directly on the scleral bed, and avoid it by placing sponges soaked with MMC under the subconjunctival tissue for 1 to 4 minutes to keep the scleral bed free of MMC.
Alfred Anduze, MD, developed a modification to this method of MMC application in which he places a small injection of MMC directly into the subconjunctival tissue. The use of this technique appears to provide excellent safety, with a low recurrence rate.
Though numerous surgical techniques for pterygium removal exist, some are associated with high rates of recurrence or an increased rate of complications, said William B. Trattler, MD, in private practice, Miami, and volunteer assistant professor of ophthalmology, Florida International University Wertheim College of Medicine.
Current management strategies include various types of grafts using sutures or tissue glue and adjunctive therapies that include application of MMC, Dr. Trattler noted.
Previous recommendations for application of MMC were found to be incorrect, and they specifically instructed that a sponge saturated with MMC be placed on the bare sclera for 1 to 3 minutes after the pterygia are removed, he offered.
Though MMC is used by surgeons to maintain a low recurrence rate, it is critical that MMC be used properly to avoid complications, such as scleral melts. Based on work published by Dr. Anduze, Dr. Trattler injects the drug into the subconjunctival tissue to avoid the bare sclera completely.
Inflammation plays a key role in the pathogenesis and recurrence of pterygia, Dr. Trattler noted.
“Therefore, limiting the use of pro-inflammatory sutures or glues also can be advantageous in preventing pterygium recurrence,” he said.
Underscoring the importance of MMC to the procedure, Dr. Anduze-who developed the Anduze bare scleral approach in the 1990s-reported that of 870 cases who underwent scleral conjunctival flap excision with one application of 0.1 cc of 0.4 mg/mL of MMC to the subconjunctival space, only 3 pterygia recurred (Anduze AL. Pterygium surgery with mitomycin-C: ten-year results. Ophthalmic Surg Lasers. 2001;32:341-345).
Dr. Trattler begins the procedure with a subconjunctival injection of 2% lidocaine with epinephrine into the lesion. He creates a linear incision to isolate the head of the pterygium and elevate it. The head is removed and the cornea is polished with a diamond burr. The subconjunctival fibrovascular tissue is removed, which is important to preventing recurrences, before MMC is injected.
MMC 0.02% (0.1 cc) is injected into the subconjunctival tissue using a 30-gauge needle with care taken to protect the bare sclera. MMC remains in the tissue at the end of surgery. The area is rinsed with balanced saline solution.
At the conclusion of the surgery, no cautery is performed or glue applied, Dr. Trattler emphasized.
Dr. Trattler and colleagues conducted a retrospective case study to evaluate the effectiveness of the subconjunctival injection of MMC after pterygium removal. Patients were included in this study who had either primary or recurrent pterygia and underwent bare sclera excision with injection of 0.1 ccs of 0.02% MMC into the subconjunctival tissue.
Importantly, no cautery was applied, MMC was not applied to the bare sclera, and no sutures or tissue glue was used.
On postoperative day 1, all patients received a silicone punctal plug in the lower punctum to avoid dry eye, and all were on an 8-week tapering dose of a strong topical steroid, during which time IOP was measured at 3 and 6 weeks postoperatively. Follow-up visits included evaluation of the cosmetic appearance of the eye, development of any complications, and signs of pterygium recurrence.
A total of 112 eyes were studied. The average patient age was 53 years (range, 19 to 78 years). Most (62.5%) patients were men. The patients were followed for an average of 171.4 days (range, 1 to 1,026 days).
Dr. Trattler reported pterygium recurrences in 2 (1.8%) eyes. Complications occurred in 4 (3.6%) eyes, with pyogenic granuloma the only problem. The granulomas were excised under slit lamp observation. No vision-threatening complications developed. There were no cases of scleral melt. The 2 eyes with early recurrences were treated with topical anti-inflammatory medications-one recurrence developed between 4 and 6 months postoperatively and the second after 1 year postoperatively.
“The results of this clinical review demonstrated that the Anduze bare scleral approach is an effective surgical technique for pterygium excision,” Dr. Trattler said. “Injection of 0.1mL of MMC directly into the subconjunctival space provides excellent results with minimal risk to the patient.”
William B. Trattler, MD
Dr. Trattler and colleagues have no financial interest in any aspect of this report.