MMC requires different exposure times for different indications

ATLANTA — Topical mitomycin C has been used for 10 years in corneal refractive surgery with no major complications, a speaker said here, but there is no consensus on its use, which he said should be customized.

Marcelo V. Netto, MD, speaking at the Refractive Surgery Subspecialty Day preceding the American Academy of Ophthalmology meeting, made recommendations for using MMC in patients with high risk of developing postoperative corneal haze.

For prophylactic use in virgin corneas, a concentration of 0.02% should be used with exposure time of 12 seconds. For prophylactic use after previous corneal procedures, a concentration of 0.02% should be used with an exposure time of 1 minute. For therapeutic purposes in patients with previous corneal haze, a concentration of 0.02% should be used with an exposure time of 2 minutes.

Dr. Netto said that he does not use alcohol to remove the epithelium when using MMC in these procedures so as to avoid increasing the toxicity of the agents.

The use of MMC in surface ablation with excimer laser has been proven to be safe and successful for several years. This paper addresses one of the problems with the use of this important drug in the surgical theater: the lack of a protocol and/or consensus about what is the safest and most effective time of exposure. Dr. Netto clarifies that the concentration in all instances should be 0.02% as has been shown also in other lectures and papers. Times of exposure as suggested by Dr. Netto’s lecture are the most accepted ones and certainly this paper creates a protocol that should be followed to get the best results.

Gustavo Tamayo, MD
OSN Latin America Edition Board Member