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Cochrane Database of Systematic Reviews

Device-modified trabeculectomy for glaucoma

Overview of attention for article published in Cochrane database of systematic reviews, December 2015
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  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (82nd percentile)
  • Average Attention Score compared to outputs of the same age and source

Mentioned by

1 policy source
3 tweeters
3 Wikipedia pages


29 Dimensions

Readers on

122 Mendeley
Device-modified trabeculectomy for glaucoma
Published in
Cochrane database of systematic reviews, December 2015
DOI 10.1002/14651858.cd010472.pub2
Pubmed ID

Xue Wang, Rabeea Khan, Anne Coleman


Glaucoma is an optic neuropathy that leads to vision loss and blindness. It is the second most common cause of irreversible blindness worldwide. The main treatment for glaucoma aims to reduce intraocular pressure (IOP) in order to slow or prevent further vision loss. IOP can be lowered with medications, and laser or incisional surgeries. Trabeculectomy is the most common incisional surgical procedure to treat glaucoma. Device-modified trabeculectomy is intended to improve drainage of the aqueous humor to lower IOP. Trabeculectomy-modifying devices include Ex-PRESS, Ologen, amniotic membrane, expanded polytetrafluoroethylene (E-PTFE) membrane, Gelfilm and others. However, the effectiveness and safety of these devices are uncertain. To assess the relative effectiveness, primarily with respect to IOP control and safety, of the use of different devices as adjuncts to trabeculectomy compared with standard trabeculectomy in eyes with glaucoma. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2014, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to December 2014), EMBASE (January 1980 to December 2014), PubMed (1948 to December 2014), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), 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 search for trials. We last searched the electronic databases on 22 December 2014. We included randomized controlled trials comparing devices used during trabeculectomy with trabeculectomy alone. We also included studies where antimetabolites were used in either or both treatment groups. We used standard procedures expected by Cochrane. We found 33 studies that met our inclusion criteria, of which 30 were published as full-length journal articles and three as conference abstracts. Only five studies have been registered. The 33 studies included a total of 1542 participants with glaucoma, and compared five types of devices implanted during trabeculectomy versus trabeculectomy alone. Five studies reported the use of Ex-PRESS (386 participants), eight studies reported the use of Ologen (327 participants), 18 studies reported the use of amniotic membrane (726 participants), one study reported the use of E-PTFE (60 participants), and one study reported the use of Gelfilm (43 participants). These studies were conducted in North America, South America, Europe, Asia, and the Middle East. Planned participant follow-up periods ranged from three months to five years. The studies were reported poorly which limited our ability to judge risk of bias for many domains. Only two studies explicitly masked outcome assessment so, we rated 31 studies at high risk of detection bias.Low-quality evidence from three studies showed that use of Ex-PRESS compared with trabeculectomy alone may be associated with a slightly lower IOP at one year (mean difference (MD) -1.58 mm Hg, 95% confidence interval (CI) -2.74 to -0.42; 165 eyes). Cataract surgery and hyphema may be less frequent in the Ex-PRESS group than in the trabeculectomy-alone group (cataract surgery: risk ratio (RR) 0.32, 95% CI 0.14 to 0.74, 3 studies, low-quality evidence; hyphema: RR 0.33, 95% CI 0.12 to 0.94, 4 studies, low-quality evidence). The effect of whether Ex-PRESS prevents hypotony was uncertain (RR 0.92, 95% CI 0.63 to 1.33, 2 studies, very low-quality evidence). All these studies received funding from the device manufacturer.Very low-quality evidence from five studies suggests that use of Ologen compared with trabeculectomy alone is associated with slightly higher IOP at one year (MD 1.40 mm Hg, 95% CI -0.57 to 3.38; 177 eyes). The effect of Ologen on preventing hypotony was uncertain (RR 0.75, 95% CI 0.47 to 1.19, 5 studies, very low-quality evidence). Differences between the two treatment groups for other reported complications also were inconclusive.Low-quality evidence from nine studies suggests that use of amniotic membrane with trabeculectomy may be associated with lower IOP at one year compared with trabeculectomy alone (MD -3.92 mm Hg, 95% CI -5.41 to -2.42; 356 eyes). Low-quality evidence showed that use of amniotic membrane may prevent adverse events and complications, such as hypotony (RR 0.40, 95% CI 0.17 to 0.94, 5 studies, low-quality evidence).The report from the only E-PTFE study (60 eyes) showed no important differences for postoperative IOP at one year (MD -0.44 mm Hg, 95% CI -1.76 to 0.88) between the trabeculectomy + E-PTFE versus the trabeculectomy-alone groups. Hypotony was the only postoperative complication observed less frequently in the E-PTFE group compared to the trabeculectomy-alone group (RR 0.29, 95% CI 0.11 to 0.77).The one Gelfilm study reported uncertainty in the difference in IOP and complication rates between the two groups at one year; no further data were provided in the study report. Overall, the use of devices with standard trabeculectomy may help with greater IOP reduction at one-year follow-up than trabeculectomy alone; however, due to potential biases and imprecision in effect estimates, the quality of evidence is low. When we examined outcomes within subgroups based on the type of device used, our findings suggested that the use of an Ex-PRESS device or an amniotic membrane as an adjunct to trabeculectomy may be slightly more effective in reducing IOP at one year after surgery compared with trabeculectomy alone. The evidence that these devices are as safe as trabeculectomy alone is unclear. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices and in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).

Twitter Demographics

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Mendeley readers

The data shown below were compiled from readership statistics for 122 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Unknown 122 100%

Demographic breakdown

Readers by professional status Count As %
Student > Master 24 20%
Student > Bachelor 17 14%
Researcher 14 11%
Student > Ph. D. Student 11 9%
Student > Doctoral Student 10 8%
Other 29 24%
Unknown 17 14%
Readers by discipline Count As %
Medicine and Dentistry 50 41%
Nursing and Health Professions 15 12%
Pharmacology, Toxicology and Pharmaceutical Science 7 6%
Engineering 5 4%
Biochemistry, Genetics and Molecular Biology 4 3%
Other 18 15%
Unknown 23 19%

Attention Score in Context

This research output has an Altmetric Attention Score of 8. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 31 January 2020.
All research outputs
of 16,722,463 outputs
Outputs from Cochrane database of systematic reviews
of 11,578 outputs
Outputs of similar age
of 369,705 outputs
Outputs of similar age from Cochrane database of systematic reviews
of 220 outputs
Altmetric has tracked 16,722,463 research outputs across all sources so far. Compared to these this one has done well and is in the 83rd percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 11,578 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 24.4. This one has gotten more attention than average, scoring higher than 52% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 369,705 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 82% of its contemporaries.
We're also able to compare this research output to 220 others from the same source and published within six weeks on either side of this one. This one is in the 35th percentile – i.e., 35% of its contemporaries scored the same or lower than it.