Excimer laser technology provides a safe and effective approach for the correction of refractive errors.
1 2 3 4 5 6 7 Photorefractive keratectomy (PRK)
1 2 3 4 and laser in situ keratomileusis (LASIK)
4 5 are the most frequently performed surgical procedures for refractive error treatment. Recently, laser subepithelial keratomileusis (LASEK) has been introduced, in which concentrations of 18% to 30% alcohol are used to create an epithelial flap, followed by excimer laser ablation and repositioning of the flap.
6 7 LASEK is an alternative to these former two refractive surgical procedures because of the decrease in the pain and corneal haze of conventional PRK
8 9 10 11 and the absence of the flap complications of LASIK.
12 13 14 15 16 17 However, in LASEK for high myopia, some degree of corneal haziness and regression is inevitable. Currently, mitomycin C (MMC) is used clinically to prevent corneal haze in treatments requiring high-risk LASEK, such as high myopia, second LASEK, and removal of subepithelial fibrosis.
18 MMC, an alkylating antibiotic agent derived from
Streptomyces caespitosus, blocks DNA and RNA replication and protein synthesis.
19 MMC inhibits mitosis and proliferation of capillary and corneal endothelial cells, corneal epithelial cells, and conjunctival, Tenon’s capsule, and other fibroblasts.
20 21 However, the long-term safety of this compound in LASEK is not guaranteed.