MMC may not be needed post-PRK

Mitomycin C (MMC) 0.01% may not be needed to prevent post wavefront-guided photorefractive keratectomy (PRK) haze in highly myopic patients, reveals a recent paper.

A double-masked, randomized, prospective trial, managed by Dr Elizabeth M. Hofmeister, Naval Medical Centre, San Diego, California, USA, involved 60, 30 and 15 second exposure of MMC on eyes with high myopia. One eye received MMC via a surgical sponge and the fellow eye received a placebo.

A four-month tapering postoperative topical steroid regimen was applied to all eyes. Preoperative measures included endothelial cell densities, haze scores, high- and low-contrast acuities and manifest refraction. The same measurements were also taken 1, 3, 6 and 12 months postoperatively.

Mean preoperative manifest refraction spherical equivalent was -5.98 dioptres and no eye developed more than trace haze. A significant difference in haze scores was discovered between MMC-treated eyes and untreated eyes at 1 and 3 months postoperatively, compared to no difference at 6 and 12 months.

Endothelial cell densities decreased in treated eyes and untreated eyes at all 3 exposures. However, all eyes returned to baseline by six months and there were no differences in acuities or refractions with or without MMC.

Overall, the team concluded there were no clinically significant differences in haze formation between MMC eyes and control eyes. This means MMC may not be required to stop haze after PRK.

Please visit the Journal of Cataract and Refractive Surgery for the abstract.