THURSDAY, Aug. 20 (HealthDay News) -- After filtration surgery for glaucoma, mitomycin C-treated filtering blebs with persistent leaks often display aberrant wound healing, according to a study in the August issue of the Archives of Ophthalmology.
Victor M. Elner, M.D., from the University of Michigan in Ann Arbor, and colleagues histopathologically characterized 40 mitomycin C-treated filtering blebs excised for persistent leaks from 40 glaucoma patients.
The researchers found that 90 percent of leaking blebs contained areas of severe epithelial attenuation overlying poorly formed basement membrane and damaged conjunctival substantia propria in the domes of the blebs. Most blebs (75 percent) showed varying degrees of fibrovascular repair growing from the bleb margin. Alcian blue-positive myxoid stroma at the interface between the fibrovascular proliferation and the epithelial-stromal dome was present in 65 percent of samples. There was a significant association between the presence of fibrovascular proliferation and Alcian blue-staining myxoid stroma.
"In conclusion, intraoperative mitomycin C may deplete and damage fibroblasts, which then secrete a modified, myxoid extracellular matrix in leaking blebs," Elner and colleagues write. "Thus, alternative surgical protocols that primarily treat episcleral tissue with mitomycin C while minimizing substantia propria exposure and toxicity should be considered to decrease the risk of mitomycin C-related bleb leaks while achieving the desired outcomes of low intraocular pressure and leak-free bleb morphology."