Mitomycin C reduces corneal light scattering after excimer keratectomy

Area of Science:

• Ophthalmology
• Corneal Surgery
• Pharmacology

Background:

• Excimer laser keratectomy is used for corneal reshaping.
• Corneal light scattering can be a side effect of keratectomy.
• Mitomycin C (MMC) is an antifibrotic agent with potential applications in ophthalmic surgery.

Purpose of the Study:

• To investigate the impact of intraoperative mitomycin C (MMC) application on corneal light scattering following excimer laser keratectomy.
• To compare the effects of different MMC application methods (disc vs. annular) and concentrations on corneal light scattering.

Main Methods:

• Phototherapeutic keratectomy (PTK) was performed on 24 rabbit eyes with 40-microm epithelial ablation.
• Animals were divided into groups receiving MMC (0.5 mg/mL or 0.25 mg/mL) via disc or annular filter paper application for 1 minute, or vehicle control.
• Corneal light scattering was measured using a scatterometer weekly for 6 weeks, at 10 weeks, and at 8 and 13 months, with a calculated light scattering index (SI).

Main Results:

• A statistically significant decrease in mean SI was observed in the group receiving 0.5 mg/mL MMC via annular application (group 2A) compared to controls at 2 weeks (p<0.05).
• At 10 weeks, SI returned to baseline levels in the annular MMC and control groups, but significantly increased in the disc MMC group (p<0.05).
• No significant differences in SI were found between any groups at 8 and 13 months post-procedure.

Conclusions:

• Controlled application of 0.5 mg/mL MMC in the corneal midperiphery using an annular method can transiently reduce corneal light scattering after excimer keratectomy.
• The method of MMC application is crucial, as disc application did not yield the same transient reduction in light scattering.
• These findings suggest a potential, albeit temporary, benefit of localized MMC in managing light scattering post-keratectomy in a rabbit model.