Mitomycin C application after photorefractive keratectomy in high,moderate, or low myopia: Systematic review and meta-analysis

Photorefractive keratectomy (PRK) is considered a safe approach laser procedure with a clinical significance in correcting myopia results. PRK requires removing the whole superficial epithelium. The integrity of the epithelial basement membrane and the deposition of abnormal extracellular matrix can put the cornea in a probable situation for corneal haze formation. Mitomycin C (MMC) is applied after excimer laser ablation as a primary modulator for wound healing, limiting corneal haze formation. We aim to summarize the outcomes of MMC application after laser ablation. We searched Scopus, PubMed, Cochrane CENTRAL, and Web of Science till December 2020 using relevant keywords. The data were extracted and pooled as mean difference (MD) or risk ratio (RR) with a 95% confidence interval (CI), using Review Manager software (version 5.4). Our analysis demonstrated a statistically significant result for MMC application over the control group in terms of corneal haze formation postoperatively (RR = 0.29, 95% CI: [0.19, 0.45], P < 0.00001). Regarding corrected distance visual acuity (CDVA), no significant difference was observed between the MMC group and the control group (MD = 0.02; 95% CI: [-0.04, 0.07]; P = 0.56). Regarding the uncorrected distance visual acuity (UDVA), the analysis favored the MMC application with (MD -0.03, 95% CI: [-0.06, -0.00]; P = 0.05). There was no statistically significant increase in complications with MMC. In conclusion, MMC application after PRK is associated with a lower incidence of corneal haze formation with no statistically significant side effects. The long term effect can show improvement regarding UDVA favoring MMC. However, there is no significant effect of MMCs application regarding CDVA, and SE.