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.
Mitomycin C (MMC) and 5-fluorouracil (5-FU) are the most frequently utilized adjuvant therapies in trabeculectomy (TRAB), but there is no general consensus as to the direct comparative efficacy and safety of these two adjuvants. In this study, the authors conducted a meta-analysis to compare the efficacy and safety of augmenting TRAB with MMC or 5-FU. A systematic review with meta-analysis was conducted and five randomized controlled clinical trials comparing MMC versus 5-FU as adjunctive therapies were identified, totaling 416 participants. A lower pooled mean IOP and higher complete and qualified success rates were observed in the MMC arm than in the 5-FU arm. Epithelial corneal defects were the unique complication reported more frequently with 5-FU compared to MMC treatment. Compared to TRAB with 5-FU, TRAB with MMC was associated with higher rates of complete and qualified surgical success and was not associated with increased incidences of postoperative complications.
PURPOSE: The aim of this study was to assess the intraoperative application of mitomycin C (MMC) compared to 5-fluorouracil (5-FU) on the outcome of trabeculectomy and to examine the balance of risk and benefit.
METHODS: Pertinent studies were selected through systematic searches of major literature databases, including the Cochrane Library, PubMed, Embase, and Chinese Biomedicine Database. Internet searches of search engines, the professional associations' websites, and the manufacturers' databases were also performed. Clinical controlled trials comparing 5-FU with MMC in trabeculectomy were selected. The primary efficacy measure was the weighted mean difference (WMD) in percentage intraocular pressure reduction (IOPR%) at follow-up end point. The secondary efficacy measure was the relative risk (RR) for "qualified" (with or without medical therapy) success of trabeculectomy at follow-up end point. The third efficacy measure was RR for "complete" (without medical therapy) success of trabeculectomy at follow-up end point. The fourth efficacy measure was RR for adverse events, including wound leak, hypotony, endophalmitis, and shallow anterior chamber (AC). The pooled effects were calculated using the random effects model by RevMan version 5.0 software.
RESULTS: Eight studies enrolling a total of 536 patients were included in the meta-analysis. MMC was associated with significantly more IOPR% compared with 5-FU, with a WMD of 7.09 [95% confidence interval (CI) 1.47-12.70] at follow-up end point (P=0.01). MMC was comparable with 5-FU in qualified success rate, with a RR of 1.09 (0.99-1.20) at follow-up end point (P=0.09). MMC was comparable with 5-FU in complete success rate, with a RR of 1.17 (0.79- 1.75) at follow-up end point (P=0.43). Rates of adverse events did not differ significantly between 5-FU and MMC, with an RR of 0.71 (0.22-2.28) for bleb leakage, 1.40 (0.72-2.72) for hypotony, 1.63 (0.27-9.75) for endophthalmitis, and 0.95 (0.41-2.21) for shallow AC.
CONCLUSIONS: Intraoperative MMC is more effective in lowering IOP in trabeculectomy compared with intraoperative 5-FU, but is comparable with intraoperative 5-FU in both qualified and complete success rate. Intraoperative use of both agents may contribute equally to adverse events.
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.
TOPIC: To analyze the literature pertaining to the techniques used in combined cataract and glaucoma surgery, including the technique of cataract extraction, the timing of the surgery (staged procedure versus combined procedure), the anatomic location of the operation, and the use of antifibrosis agents.
CLINICAL RELEVANCE: Cataract and glaucoma are both common conditions and are often present in the same patient. There is no agreement concerning the optimal surgical management of these disorders when they coexist.
METHODS/LITERATURE REVIEWED: Electronic searches of English language articles published since 1964 were conducted in Pub MED and CENTRAL, the Cochrane Collaboration's database. These were augmented by a hand search of six ophthalmology journals and the reference lists of a sample of studies included in the literature review. Evidence grades (A, strong; B, moderate; C, weak; I, insufficient) were assigned to the evidence that involved a direct comparison of alternative techniques.
RESULTS: The preponderance of evidence from the literature suggests a small (2-4 mmHg) benefit from the use of mitomycin-C (MMC), but not 5-fluorouracil (5-FU), in combined cataract and glaucoma surgery (evidence grade B). Two-site surgery provides slightly lower (1-3 mmHg) intraocular pressure (IOP) than one-site surgery (evidence grade C), and IOP is lowered more (1-3 mmHg) by phacoemulsification than by nuclear expression in combined procedures (evidence grade C). There is insufficient evidence to conclude either that staged or combined procedures give better results or that alternative glaucoma procedures are superior to trabeculectomy in combined procedures.
CONCLUSIONS: In the literature on surgical techniques and adjuvants used in the management of coexisting cataract and glaucoma, the strongest evidence of efficacy exists for using MMC, separating the incisions for cataract and glaucoma surgery, and removing the nucleus by phacoemulsification.
OBJECTIVE: To assess the methodologic quality of published studies of the surgical management of coexisting cataract and glaucoma.
DESIGN: Literature review and analysis.
METHOD: We performed a systematic search of the literature to identify all English language articles pertaining to the surgical management of coexisting cataract and glaucoma in adults. Quality assessment was performed on all randomized controlled trials, nonrandomized controlled trials, and cohort studies. Overall quality scores and scores for individual methodologic domains were based on the evaluations of two experienced investigators who independently reviewed articles using an objective quality assessment form.
MAIN OUTCOME MEASURES: Quality in each of five domains (representativeness, bias and confounding, intervention description, outcomes and follow-up, and statistical quality and interpretation) measured as the percentage of methodologic criteria met by each study.
RESULTS: Thirty-six randomized controlled trials and 45 other studies were evaluated. The mean quality score for the randomized, controlled clinical trials was 63% (range, 11%-88%), and for the other studies the score was 45% (range, 3%-83%). The mean domain scores were 65% for description of therapy (range, 0%-100%), 62% for statistical analysis (range, 0%-100%), 58% for representativeness (range, 0%-94%), 49% for outcomes assessment (range, 0%-83%), and 30% for bias and confounding (range, 0%-83%). Twenty-five of the studies (31%) received a score of 0% in the bias and confounding domain for not randomizing patients, not masking the observers to treatment group, and not having equivalent groups at baseline.
CONCLUSIONS: Greater methodologic rigor and more detailed reporting of study results, particularly in the area of bias and confounding, could improve the quality of published clinical studies assessing the surgical management of coexisting cataract and glaucoma.
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.
