Inflammatory and property effects of mitomycin C on the human medial rectus muscle

This study examined the effect of intraoperative mitomycin C (MMC) on adhesion reformation in human rectus muscles. Eight consecutive patients who underwent medial rectus recession had their post-operative rectus muscles divided into two groups: untreated (control) and treated with 0.02% MMC for 2 min, and were compared using three examination methods: histological analysis with hematoxylin-eosin staining to assess the inflammatory response and Masson's trichrome to semiquantify collagen fibrils, scanning electron microscopy analysis to quantify the diameter and D-periodicity of collagen fibrils, and atomic force microscopy analysis to quantify the diameter, D-periodicity and adhesion force of collagen fibrils. The rectus muscles treated with 0.02% MMC showed significantly increased inflammatory response (p < 0.0001), increased fibril diameter (p < 0.001 or p < 0.05) and decreased fibril adhesion force (p < 0.005) compared to controls. MMC may simultaneously cause an inflammatory response as well as nanostructural and mechanical property changes in the collagen fibril network.