Document Type
Article
Publication Date
2006
Abstract
PURPOSE—To determine the mechanism through which topical mitomycin C prevents and treats corneal haze after photorefractive keratectomy (PRK) and to examine the effects of dosage and duration of exposure.
METHODS—In 224 New Zealand rabbits, −9.0 diopter PRK with mitomycin C or balanced salt solution was performed. Haze level was graded at the slit-lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks, or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67 and α-SMA.
RESULTS—TUNEL-positive apoptotic cells marginally increased in all mitomycin C groups whereas Ki67-positive mitotic cells decreased significantly following mitomycin C application. A greater decrease in myofibroblasts was noted with prophylactic mitomycin C treatment than therapeutic mitomycin C treatment. There was, however, an anterior stromal acellular zone (approximately 20% of the total stroma) in eyes treated with mitomycin C, which persisted to the maximum follow-up of 6 months.
CONCLUSIONS—Mitomycin C treatment induces apoptosis of keratocytes and myofibroblasts, but the predominate effect in inhibiting or treating haze appears to be at the level of blocked replication of keratocytes or other progenitor cells of myofibroblasts. Treatment with 0.002% mitomycin C for 12 seconds to 1 minute appears to be just as effective as higher concentrations for longer duration in the rabbit model. However, a persistent decrease in keratocyte density in the anterior stroma could be a warning sign for future complications and treatment should be reserved for patients with significant risk of developing haze after PRK.
Recommended Citation
Netto MV, Mohan RR, Sinha S, Sharma A, Gupta PC, Wilson SE. Effect of Prophylactic and Therapeutic Mitomycin C on Corneal Apoptosis, Cellular Proliferation, Haze, and Long-term Keratocyte Density in Rabbits. J Refract Surg. 2006;22(6):562-574.
Copyright
Slack
Included in
Animal Experimentation and Research Commons, Animals Commons, Musculoskeletal, Neural, and Ocular Physiology Commons, Ophthalmology Commons, Other Pharmacy and Pharmaceutical Sciences Commons
Comments
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Journal of Refractive Surgery, volume 22, issue 6, in 2006 following peer review. The definitive publisher-authenticated version is available online at DOI: 10.3928/1081-597X-20060601-08.