Corneal and conjunctival findings after mitomycin C application in pterygium surgery: an in-vivo confocal microscopy study

To perform a qualitative assessment of the topical side-effects of mitomycin C on cornea after pterygium surgery. In-vivo confocal microscopy (Heidelberg Retina Tomograph II in combination with the Rostock Cornea Module) was performed in 10 patients with unilateral primary pterygium. Mitomycin C 0.02% was applied topically to seven eyes for 5 min intraoperatively and twice daily for 5 days postoperatively. Three eyes underwent surgery without application of cytostatic agent. Patient follow-up was 1 month. After application of mitomycin C, complete epithelialization of the operated zone was found 2 weeks after surgery. In-vivo confocal microscopy revealed signs of superficial punctate keratitis for 2 weeks in the central cornea only after application of mitomycin C. The presence of epithelial and stromal oedema in this group was noted for up to 2 weeks in the central cornea and for up to 4 weeks in the operated zone. In the control group, complete epithelialization was found after 1 week; there were no signs of oedema after 1 week in the central cornea or after 2 weeks in the operated zone. Leucocyte infiltration and increased Langerhans cell density were noted in both groups in the operated and central zones. Analysis of the conjunctiva revealed a decrease in goblet cell density following cytostatic application. Local application of mitomycin C delays corneal epithelialization, and prolongs postoperative epithelial and stromal oedema in both the centre and periphery. Moreover, signs of punctate keratitis were noted 2 weeks after surgery in central intact cornea. Nevertheless, in-vivo confocal microscopy shows that these changes are reversible 4 weeks after application of mitomycin C 0.02%.