BACKGROUND: Raised intraocular pressure is a risk factor for glaucoma. One treatment option is glaucoma drainage surgery (trabeculectomy). Antimetabolites are used during surgery to reduce postoperative scarring during wound healing. Two agents in common use are mitomycin C (MMC) and 5-Fluorouracil (5-FU).
OBJECTIVES: To assess the effects of MMC compared to 5-FU as an antimetabolite adjunct in trabeculectomy surgery.
SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 October 2015.
SELECTION CRITERIA: We included randomised controlled trials where wound healing had been modified with MMC compared to 5-FU.
DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials and collected data. The primary outcome was failure of a functioning trabeculectomy one year after surgery. Secondary outcomes included mean intraocular pressure at one year. We considered three subgroups: high risk of trabeculectomy failure (people with previous glaucoma surgery, extracapsular cataract surgery, African origin and people with secondary glaucoma or congenital glaucoma); medium risk of trabeculectomy failure (people undergoing trabeculectomy with extracapsular cataract surgery) and low risk of trabeculectomy failure (people who have received no previous surgical eye intervention).
MAIN RESULTS: We identified 11 trials that enrolled 687 eyes of 679 participants. The studies were conducted in the United States, Europe, Asia and Africa. Five studies enrolled participants at low risk of trabeculectomy failure, five studies enrolled participants at high risk of failure, and one study enrolled people with both high and low risk of failure. None of the included trials enrolled participants with combined trabeculectomy/cataract surgery.We considered one study to be at low risk of bias in all domains, six studies to be at high risk of bias in one or more domains, and the remaining four studies to be at an unclear risk of bias in all domains.The risk of failure of trabeculectomy at one year after surgery was less in those participants who received MMC compared to those who received 5-FU, however the confidence intervals were wide and are compatible with no effect (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.30 to 1.00; studies = 11; I(2) = 40%). There was no evidence for any difference between groups at high and low risk of failure (test for subgroup differences P = 0.69).On average, people treated with MMC had lower intraocular pressure at one year (mean difference (MD) -3.05 mmHg, 95% CI -4.60 to -1.50), but the studies were inconsistent (I(2) = 52%). The size of the effect was greater in the high-risk group (MD -4.18 mmHg, 95% CI -6.73 to -1.64) compared to the low-risk group (MD -1.72 mmHg, 95% CI -3.28 to -0.16), but again the test for interaction was not statistically significant (P = 0.11).Similar proportions of eyes treated with MMC lost 2 or more lines of visual acuity one year after surgery compared to 5-FU, but the confidence intervals were wide (RR 1.05, 95% CI 0.54 to 2.06).Adverse events occurred relatively rarely, and estimates of effect were generally imprecise. There was some evidence for less epitheliopathy in the MMC group (RR 0.23, 95% CI 0.11 to 0.47) and less hyphaema in the MMC group (RR 0.62, 95% CI 0.42 to 0.91).None of the studies reported quality of life.Overall, we graded the quality of the evidence as low largely because of risk of bias in the included studies and imprecision in the estimate of effect.
AUTHORS' CONCLUSIONS: We found low-quality evidence that MMC may be more effective in achieving long-term lower intraocular pressure than 5-FU. Further comparative research on MMC and 5-FU is needed to enhance reliability and validity of the results shown in this review. Furthermore, the development of new agents that control postoperative scar tissue formation without side effects would be valuable and is justified by the results of this review.
OBJECTIVE: To assess the efficacy and safety of mytomycin C versus 5-fluorouracil for trabeculectomy. METHODS: We electronically searched the Cochrane Central Register of Controlled Trials (Issue 3, 2008), MEDLINE (1966 to October 2008), EMbase (1947 to October 2008), CMBdisk (1979 to October 2008).We also handsearched relevant conference proceedings. Data were extracted by two reviewers independently using an extraction form. The Cochrane Collaboration’ s RevMan 5.0 software was used for statistical analyses. RESULTS: Nine randomized controlled trials (RCTs) involving 482 participants (495eyes) were identified. The trials enrolled three types of participants (high risk of failure, moderate risk of failure, low risk of failure). As for high risk of failure, compared with mytomycin C, 5-fluorouracil appeared to increase the rate of postoperative complications (RR –5.74, 95%CI –9.91, –1.58). No significant differences were found in postoperative mean intraocular pressure(IOP) (WMD –?2.31, 95%CI –?7.34, 2.71), success rate (RR 1.13, 95%CI 0.91, 1.39) and visual acuity ≥3-line decrease (RR 1.46, 95%CI 0.43, 4.94). As for low risk of failure, there were no significant differences in success rate (RR 1.10, 95%CI 0.99, 1.22) and postoperative complications (RR 1.00, 95%CI –6.21, 8.21). CONCLUSION: In both groups of high risk and low risk of failure, there are no significant differences in postoperative mean IOP and success rate. However, in the group of high risk of failure, compared with 5-fluorouracil, mytomycin C appears to raise the rate of postoperative complications; the rate of reducing the eyes pressure cannot be concluded based on current evidence. However, as the number of the studied cases is rather small and the period of observation is also limited, long-term follow-up of multi-central RCTs with a larger number of cases are still needed before definite conclusions can be made. Further studies are also needed to better determine the pharmacokinetics and cost-effective analyses involving the use of the two agents for glaucoma filtering surgery.
Raised intraocular pressure is a risk factor for glaucoma. One treatment option is glaucoma drainage surgery (trabeculectomy). Antimetabolites are used during surgery to reduce postoperative scarring during wound healing. Two agents in common use are mitomycin C (MMC) and 5-Fluorouracil (5-FU).
OBJECTIVES:
To assess the effects of MMC compared to 5-FU as an antimetabolite adjunct in trabeculectomy surgery.
SEARCH METHODS:
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 2 October 2015.
SELECTION CRITERIA:
We included randomised controlled trials where wound healing had been modified with MMC compared to 5-FU.
DATA COLLECTION AND ANALYSIS:
Two review authors independently selected trials and collected data. The primary outcome was failure of a functioning trabeculectomy one year after surgery. Secondary outcomes included mean intraocular pressure at one year. We considered three subgroups: high risk of trabeculectomy failure (people with previous glaucoma surgery, extracapsular cataract surgery, African origin and people with secondary glaucoma or congenital glaucoma); medium risk of trabeculectomy failure (people undergoing trabeculectomy with extracapsular cataract surgery) and low risk of trabeculectomy failure (people who have received no previous surgical eye intervention).
MAIN RESULTS:
We identified 11 trials that enrolled 687 eyes of 679 participants. The studies were conducted in the United States, Europe, Asia and Africa. Five studies enrolled participants at low risk of trabeculectomy failure, five studies enrolled participants at high risk of failure, and one study enrolled people with both high and low risk of failure. None of the included trials enrolled participants with combined trabeculectomy/cataract surgery.We considered one study to be at low risk of bias in all domains, six studies to be at high risk of bias in one or more domains, and the remaining four studies to be at an unclear risk of bias in all domains.The risk of failure of trabeculectomy at one year after surgery was less in those participants who received MMC compared to those who received 5-FU, however the confidence intervals were wide and are compatible with no effect (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.30 to 1.00; studies = 11; I(2) = 40%). There was no evidence for any difference between groups at high and low risk of failure (test for subgroup differences P = 0.69).On average, people treated with MMC had lower intraocular pressure at one year (mean difference (MD) -3.05 mmHg, 95% CI -4.60 to -1.50), but the studies were inconsistent (I(2) = 52%). The size of the effect was greater in the high-risk group (MD -4.18 mmHg, 95% CI -6.73 to -1.64) compared to the low-risk group (MD -1.72 mmHg, 95% CI -3.28 to -0.16), but again the test for interaction was not statistically significant (P = 0.11).Similar proportions of eyes treated with MMC lost 2 or more lines of visual acuity one year after surgery compared to 5-FU, but the confidence intervals were wide (RR 1.05, 95% CI 0.54 to 2.06).Adverse events occurred relatively rarely, and estimates of effect were generally imprecise. There was some evidence for less epitheliopathy in the MMC group (RR 0.23, 95% CI 0.11 to 0.47) and less hyphaema in the MMC group (RR 0.62, 95% CI 0.42 to 0.91).None of the studies reported quality of life.Overall, we graded the quality of the evidence as low largely because of risk of bias in the included studies and imprecision in the estimate of effect.
AUTHORS' CONCLUSIONS:
We found low-quality evidence that MMC may be more effective in achieving long-term lower intraocular pressure than 5-FU. Further comparative research on MMC and 5-FU is needed to enhance reliability and validity of the results shown in this review. Furthermore, the development of new agents that control postoperative scar tissue formation without side effects would be valuable and is justified by the results of this review.
