To assess the efficacy and safety of local application of intraoperative mitomycin C (MMC) at osteotomy site in endoscopic dacryocystorhinostomy(EN-DCR).

Mitomycin C (MMC) is an antineoplastic agent that inhibits the synthesis of DNA, cellular RNA, and protein by inhibiting the synthesis of collagen by fibroblasts. MMC was originally used as a systemic chemotherapeutic agent, it has been widely used in ophthalmic practice both intraoperatively and postoperatively for prevention of pterygium recurrence, enhancing the success rate of glaucoma filtration surgery. Recently, use of MMC has been described in lacrimal drainage surgery. It is postulated that adjunctive use of MMC over the osteotomy site in endoscopic dacryocystorhinostomy(EN-DCR)surgery could inhibit scarring and granulation tissue formation around the osteotomy site or common canaliculus and enhance the success of EN-DCR surgery.

Many controlled trials have investigated adjunctive MMC for primary or revision EN-DCR to augment the surgical success rate, but the results are not completely consistent. To the best of our knowledge, there was no meta-analysis on comparison of success rate of EN-DCR with MMC (MMC group) and endoscopic dacryocystorhinostomy without MMC (control group). Therefore, the aim of this study was to undertake systematic review and meta-analysis to evaluate the efficacy of intraoperative MMC application in EN-DCR surgery and help ophthalmologists to determine whether it is a useful adjuvant in EN-DCR surgery.

Inclusion Criteria:

1. comparative studies;
2. adult patients (> 18 years) with NLDO undergoing primary or revision EN-DCR;
3. all studies included were required to provide the success rates of both MMC and control groups, and the followed up time was more than 6 months.

Exclusion Criteria:

1. studies which did not provide the success rates;
2. studies which included pediatric cases.

Patients were scheduled to undergo endoscopic dacryocystorhinostomy and randomized to with and without MMC