Ab interno trabecular bypass surgery with Schlemm´s canal microstent (Hydrus) for open angle glaucoma

BACKGROUND

Glaucoma is a leading cause of irreversible blindness. A number of minimally-invasive surgical techniques have been introduced as a treatment to prevent glaucoma from progressing; ab interno trabecular bypass surgery with the Schlemm's canal Hydrus microstent is one of them.

OBJECTIVES

To evaluate the efficacy and safety of ab interno trabecular bypass surgery with the Hydrus microstent in treating people with open angle glaucoma (OAG).

SEARCH METHODS

On 7 May 2019, we searched CENTRAL (2019, Issue 5), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov; and the WHO ICTRP.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of the Hydrus microstent, alone or with cataract surgery, compared to other surgical treatments (cataract surgery alone, other minimally-invasive glaucoma device techniques, trabeculectomy), laser treatment, or medical treatment.

DATA COLLECTION AND ANALYSIS

A minimum of three authors independently extracted data from reports of included studies, using a data collection form and analysed data, based on standard Cochrane methods.

MAIN RESULTS

We included three published studies, with 808 people randomised. Two studies had multiple international recruitment centres in the USA and other countries. The third study had several sites based in Europe. All three studies were sponsored by the Hydrus manufacturer Ivantis Inc. All studies included participants with mainly mild or moderate OAG (mean deviation between -3.6 dB (decibel) and -8.4 dB in all study arms), which was controlled with medication in many participants (mean medicated intraocular pressure (IOP) 17.9 mmHg to 19.1 mmHg). There were no concerns regarding allocation concealment bias, but masking of outcome assessors was high or unclear risk in all studies; masking of participants was achieved, and losses to follow-up were not a concern. Two studies compared the Hydrus microstent combined with cataract surgery to cataract surgery alone, in participants with visually significant cataracts and OAG. We found moderate-certainty evidence that adding the Hydrus microstent to cataract surgery increased the proportion of participants who were medication-free from about half to more than three quarters at 12-month, short-term follow-up (risk ratio (RR) 1.59, 95% confidence interval (CI) 1.39 to 1.83; 2 studies, 639 participants; I² = 0%; and 24-month, medium-term follow-up (RR 1.63, 95% CI 1.40 to 1.88; 2 studies, 619 participants; I² = 0%). The Hydrus microstent combined with cataract surgery reduced the medium-term mean change in unmedicated IOP (after washout) by 2 mmHg more compared to cataract surgery alone (mean difference (MD) -2.00, 95% CI -2.69 to -1.31; 2 studies, 619 participants; I² = 0%; moderate-certainty evidence), and the mean change in IOP-lowering drops (MD -0.41, 95% CI -0.56 to -0.27; 2 studies, 619 participants; I² = 0%; low-certainty evidence). We also found low-certainty evidence that adding a Hydrus microstent to cataract surgery reduced the need for secondary glaucoma surgery from about 2.5% to less than 1% (RR 0.17, 95% CI 0.03 to 0.86; 2 studies, 653 participants; I² = 27%; low-certainty evidence). Intraocular bleeding, loss of 2 or more visual acuity (VA) lines, and IOP spikes of 10 mmHg or more were rare in both groups; estimates were imprecise, and included both beneficial and harmful effects. There were no cases of endophthalmitis in either group. No data were available on the proportion of participants achieving IOP less than 21 mmHg, 17 mmHg, or 14 mmHg; health-related quality of life (HRQOL), or visual field progression. One study provided short-term data for the Hydrus microstent compared with the iStent trabecular micro-bypass stent (iStent: implantation of two devices in a single procedure) in 152 participants with OAG (148 in analyses). Use of the Hydrus increased the proportion of medication-free participants from about a quarter to about half compared to those who received iStent, but this estimate was imprecise (RR 1.94, 95% CI 1.21 to 3.11; low-certainty evidence). Use of the Hydrus microstent reduced unmedicated IOP (after washout) by about 3 mmHg more than the iStent (MD -3.10, 95% CI -4.17 to -2.03; moderate-certainty evidence), and the use of IOP-lowering medication (MD -0.60, 95% CI -0.99 to -0.21; low-certainty evidence). Both devices achieved a final IOP < 21 mmHg in most participants (Hydrus microstent: 91.8%; iStent: 84%; RR 1.09, 95% CI 0.97 to 1.23; low-certainty evidence). None of the participants who received the Hydrus microstent (N = 74) required additional glaucoma surgery; two participants who received the iStent (N = 76) did. Few adverse events were found in either group. No data were available on the proportion of participants achieving IOP less than 17 mmHg or 14 mmHg, or on HRQOL.

AUTHORS' CONCLUSIONS

In people with cataracts and generally mild to moderate OAG, there is moderate-certainty evidence that the Hydrus microstent with cataract surgery compared to cataract surgery alone, likely increases the proportion of participants who do not require IOP lowering medication, and may further reduce IOP at short- and medium-term follow-up. There is moderate-certainty evidence that the Hydrus microstent is probably more effective than the iStent in lowering IOP of people with OAG in the short-term. Few studies were available on the effects of the Hydrus microstent, therefore the results of this review may not be applicable to all people with OAG, particularly in selected people with medically uncontrolled glaucoma, since IOP was controlled with medication in many participants in the included studies. Complications may be rare using the Hydrus microstent, as well as the comparator iStent, but larger studies are needed to investigate its safety.

Acupuncture for glaucoma

BACKGROUND

Glaucoma is a multi-factorial optic neuropathy characterized by an acquired loss of retinal ganglion cells at levels beyond normal age-related loss and corresponding atrophy of the optic nerve. Although many treatments are available to manage glaucoma, patients may seek complementary or alternative medicine approaches such as acupuncture to supplement their regular treatment. The underlying plausibility of acupuncture is that disorders related to the flow of Chi (traditional Chinese concept of vital force or energy) can be managed by stimulating relevant points on the body surface.

OBJECTIVES

To assess the effectiveness and safety of acupuncture compared with other treatments, no treatment, or placebo in patients with glaucoma.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2018, Issue 11); Ovid MEDLINE; Embase.com; the Cumulative Index to Nursing and Allied Health Literature (CINAHL); the Allied and Complementary Medicine Database (AMED); PubMed; Latin American and Caribbean Literature on Health Sciences (LILACS); ZETOC; the metaRegister of Controlled Trials (mRCT); ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP); and the National Center for Complementary and Alternative Medicine (NCCAM) website. We did not use any language or date restrictions in the search for trials. We last searched electronic databases on November 16, 2018, with the exception of NCCAM, which we last searched on July 14, 2010, and the metaRegister of Controlled Trials (mRCT), which we last searched on January 8, 2013. We handsearched Chinese medical journals at Peking Union Medical College Library in April 2007. We searched the Chinese Acupuncture Trials Register, the Traditional Chinese Medical Literature Analysis and Retrieval System (TCMLARS), the Chinese Biological Database (CBM), and the China National Knowledge Infrastructure (CNKI). We last searched Chinese electronic databases on November 19, 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which one arm involved acupuncture treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened results, then extracted the data and assessed risk of bias for eligible trials.

MAIN RESULTS

We included three completed trials and one ongoing trial in the 2019 update of this review. The three completed trials, conducted in Taiwan and the United States, included participants with glaucoma or intraocular hypertension. The interventions investigated varied across trials. One trial compared auricular acupressure－a non-standard acupuncture technique－with the sham procedure in 33 patients. Another trial compared transcutaneous electrical nerve stimulation (TENS) with a sham procedure in 82 patients. The third trial compared 12 sessions of acupuncture on eye-points versus on non-eye-points in 22 patients. All three trials were rated at high risk of bias for at least one domain. The certainty of evidence across all outcomes was very low due to high risk of bias in at least one contributing study; substantial clinical heterogeneity and methodological heterogeneity; and imprecision of results. One trial reported change in the visual field from baseline without any between-group comparison. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret. All three trials reported data for estimation of reduction of intraocular pressure (IOP). However, time points of IOP measurement varied. For the trial comparing acupressure to a sham procedure, the difference in IOP reduction (measured in mm Hg) is estimated to be -3.70 (95% confidence interval [CI] -7.11 to -0.29) for the right eye and -4.90 (95% CI -8.08 to -1.72) for the left eye at four weeks, and -1.30 mm Hg (95% CI -4.78 to 2.18) for the right eye and -2.30 mm Hg (95% CI -5.73 to 1.13) for the left eye at eight weeks. For the trial comparing TENS to sham treatment, the difference reduction is estimated to be -2.81 (95% CI -3.8 to -1.84) for the right eye and -2.58 (95% CI -3.36 to -1.80) for the left eye immediately after treatment, -2.93 (95% CI -3.72 to -2.13) for the right eye and -3.56 (95% CI -4.35 to 2.78) for the left eye 30 minutes after treatment, and finally -3.61 (95% CI -4.47 to -2.75) for the right eye and -3.61 (95% -4.47 to -2.74) for the left eye. For the trial that compared acupuncture on eye-points versus non-eye-points, 11 out of 22 (50%) participants did not complete the treatment. One trial reported data for estimation of visual acuity. When acupressure is compared to sham treatment, the difference in uncorrected visual acuity (UCVA, measured in logMAR) is estimated to be -0.01 (95% CI -0.24 to 0.22) for the right eye and -0.04 (95% CI -0.27 to 0.19) for the left eye at four months, and -0.03 logMAR (95% CI -0.27 to 0.21) for the right eye and -0.16 logMAR (95% CI -0.43 to 0.11) for the left eye at eight months. The difference in best corrected visual acuity (BCVA) is estimated to be 0.10 (95% CI -0.06 to 0.26) for the right eye and 0 (95% CI -0.14 to 0.14) for the left eye at four months, and -0.04 logMAR (95% CI -0.09 to 0.17) for the right eye and -0.04 logMAR (95% CI -0.18 to 0.10) for the left eye at eight months. One trial reported progression of optic disc damage or nerve fiber layer loss without any between-group comparison. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret. One trial reported adverse events in two patients (out of 22) who experienced needle sensitivity. However, the study did not report between-group comparisons. Because of the quantity of missing data (50%), we did not calculate a between-group comparison, as the quantitative results are difficult to interpret.

AUTHORS' CONCLUSIONS

At this time, it is impossible to draw reliable conclusions from available data to support the use of acupuncture for treatment of patients with glaucoma. Because of ethical considerations, RCTs comparing acupuncture alone with standard glaucoma treatment or placebo are unlikely to be justified in countries where the standard of care has already been established.

Systematic reviews and randomised controlled trials on open angle glaucoma

Evidence for the effectiveness of interventions to prevent the progression of optic nerve damage in open angle glaucoma has evolved over the last 25 years. We describe that evolution through the systematic reviews on various aspects of the topic and how those reviews have highlighted the need for new trials. Though we can be confident that lowering pressure does indeed reduce the risk of progression, we still lack good evidence on the comparative effectiveness of different treatments not so much on lowering pressure but on preventing progression of the disease. This is true for different medicines, types of laser and especially for different surgical interventions. As always there is a need for more research, but this needs to be focussed on key uncertainties using core outcome sets which avoid research waste. Ultimately, our guidelines can be based on sound and comprehensive evidence of effectiveness.

Ab interno trabecular bypass surgery with iStent for open-angle glaucoma

BACKGROUND

Glaucoma is a leading cause of irreversible blindness worldwide. In early stages, glaucoma results in progressive loss of peripheral (side) vision; in later stages, it results in loss of central vision leading to blindness. Elevated intraocular pressure (IOP) is the only known modifiable risk factor for glaucoma. Minimally invasive glaucoma surgical (MIGS) techniques, such as ab interno trabecular bypass surgery with iStent (Glaukos Corporation, Laguna Hills, CA, USA), have been introduced as a new treatment modality for glaucoma. However, the effectiveness of MIGS on keeping people 'drop-free' (i.e. not having to use eye drops to control IOP) and other outcomes is uncertain.

OBJECTIVES

To assess the effectiveness and safety of ab interno trabecular bypass surgery with iStent (or iStent inject) for open-angle glaucoma in comparison to conventional medical, laser, or surgical treatment.

SEARCH METHODS

Cochrane Eyes and Vision's Information Specialist searched the following databases on 17 August 2018: the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register; 2018, Issue 7), MEDLINE Ovid, Embase Ovid, the ISRCTN registry, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We applied no date or language restrictions. We searched the reference lists of reports from included studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that had compared iStent or iStent inject to medical therapy, laser treatment, conventional glaucoma surgery (trabeculectomy), or other MIGS procedures. We included RCTs that had compared iStent or iStent inject in combination with phacoemulsification to phacoemulsification alone.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened search results, assessed risk of bias, and extracted data from reports of included RCTs using an electronic data collection form.

MAIN RESULTS

We included seven RCTs (765 eyes of 764 participants; range per study 33 to 239 participants) that evaluated iStent in people with open-angle glaucoma. We also identified 13 studies that are ongoing or awaiting publications of results. Most participants in the included studies were women (417/764 (55%) participants) and older age (age range: 49 to 89 years). We assessed most trials at unclear or high risk of bias: four trials did not clearly report the method of generating the random sequence or concealing allocation; five were unmasked, open-label studies, which we assessed at high risk of bias for performance and detection bias. All seven trials were funded by the Glaukos Corporation. We graded the certainty of evidence as very low.Four RCTs compared iStent in combination with phacoemulsification to phacoemulsification alone. The summary estimate which we derived from two of the four RCTs suggested that participants in the iStent in combination with phacoemulsification group were 1.38 times more likely to be drop-free between six and 18 months than those in the phacoemulsification alone group (risk ratio (RR) 1.38, 95% confidence interval (CI) 1.18 to 1.63, I² = 67%). Data from two RCTs also suggested that iStent in combination with phacoemulsification compared to phacoemulsification alone may have offered a small reduction in number of IOP-lowering drops (mean difference (MD) -0.42 drops, 95% CI -0.60 to -0.23). It is uncertain whether there was any difference in terms of mean reduction in IOP from baseline (no meta-analysis).Two RCTs compared treatment with iStent to medical therapy; one of the two trials used the iStent inject. We determined the two trials to be clinically and methodologically heterogeneous and did not conduct a meta-analysis; however, the investigators of both trials reported that over 90% of participants in the treatment groups were drop-free compared to no participants in the medical therapy groups at six to 18 months.One RCT compared treatment with one versus two versus three iStents. There was no difference in terms of participants who were drop-free at 36 months or less; however, at longer follow-up (i.e. at 42 months) participants in the one iStent treatment were less likely to be drop-free than those in the two iStent (RR 0.51, 95% CI 0.34 to 0.75) or three iStent (RR 0.49, 95% CI 0.34 to 0.73) treatment groups. The study did not report the mean change in number of IOP-lowering drops.The type and timing of complications reported varied by RCTs. Similar proportions of participants who underwent treatment with iStent in combination with phacoemulsification and who underwent phacoemulsification alone needed secondary glaucoma surgery. None of RCTs reported findings related to quality of life.

AUTHORS' CONCLUSIONS

There is very low-quality evidence that treatment with iStent may result in higher proportions of participants who are drop-free or achieving better IOP control, in the short, medium, or long-term. Results from the 13 studies with results not yet available may clarify the benefits of treatment of people with iStent. Additionally, future MIGS studies should consider measuring quality of life and outcomes that reflect people's ability to perform vision-dependent activities.

Endoscopic cyclophotocoagulation (ECP) for open angle glaucoma and primary angle closure

BACKGROUND

Glaucoma is a leading cause of irreversible blindness. A number of minimally invasive surgical techniques have been introduced as a treatment to prevent glaucoma progressing. Among them, endoscopic cyclophotocoagulation (ECP) is a cyclodestructive procedure developed by Martin Uram in 1992.

OBJECTIVES

To evaluate the efficacy and safety of ECP in people with open angle glaucoma (OAG) and primary angle closure whose condition is inadequately controlled with drops.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 12 July 2018.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of ECP compared to other surgical treatments (other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment. We also planned to include trials where these devices were combined with phacoemulsification compared to phacoemulsification alone.

DATA COLLECTION AND ANALYSIS

Two review authors planned to independently extract data from reports of included studies using a data collection form and analyse data based on methods expected by Cochrane. Our primary outcome was proportion of participants who were drop-free (not using eye drops). Secondary outcomes included mean change in IOP; proportion of participants who achieved an IOP of 21 mmHg or less, 17 mmHg or less or 14 mmHg or less; and proportion of participants experiencing intra- and postoperative complications, We planned to measure all outcomes in the short-term (six to 18 months), medium-term (18 to 36 months), and long-term (36 months onwards).

MAIN RESULTS

We found one ongoing study that met our inclusion criteria (ChiCTR-TRC-14004233). The study compares combined phacoemulsification with ECP to phacoemulsification alone in people with primary angle closure glaucoma. The primary outcome is intraocular pressure (IOP) and number of IOP-lowering drugs. A total of 50 people have been enrolled. The study started in February 2014 and the trialists have completed recruitment and are in the process of collecting data.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the effects of ECP for OAG and primary angle closure. Properly designed RCTs are needed to assess the medium and long-term efficacy and safety of this technique.

Subconjunctival draining minimally-invasive glaucoma devices for medically uncontrolled glaucoma

BACKGROUND

Glaucoma is a leading cause of irreversible blindness. Subconjunctival draining minimally-invasive glaucoma devices such as the Xen gelatin implant and InnFocus stent have been introduced as a treatment to prevent glaucoma progressing.These implants provide a channel to allow aqueous humour from the anterior chamber of the eye to drain into the subconjunctival space on the surface of the eye thus reducing intraocular pressure (IOP) and mimicking the mechanism of the most commonly undertaken glaucoma surgery, trabeculectomy.

OBJECTIVES

To evaluate the efficacy and safety of subconjunctival draining minimally-invasive glaucoma devices in treating people with open angle glaucoma and ocular hypertension whose condition is inadequately controlled with drops.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2018, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 10 July 2018.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of Xen gelatin implant or InnFocus MicroShunt to other surgical treatments (other minimally-invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment. We also planned to include trials where these devices were combined with phacoemulsification compared to phacoemulsification alone.

DATA COLLECTION AND ANALYSIS

We planned to have two review authors independently extract data from reports of included studies using a data collection form and analyse data based on methods expected by Cochrane. Our primary outcome was mean change in IOP. Secondary outcomes included proportion of participants who were drop-free; proportion of participants who achieved an IOP of 21 mmHg or less, 17 mmHg or less or 14 mmHg or less; and proportion of participants experiencing intra- and postoperative complications. We planned to measure all outcomes in the short-term (six to 18 months), medium-term (18 to 36 months), and long-term (36 months onwards).

MAIN RESULTS

We found no completed RCTs that met our inclusion criteria. We found one ongoing study (NCT01881425). The study compares InnFocus MicroShunt to trabeculectomy in people with primary open angle glaucoma. The primary outcome is greater than 20% IOP reduction from baseline to 12 months' follow-up. A total of 889 people aged between 40 and 85 years have been enrolled. The estimated study completion date is November 2019.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the effects of subconjunctival draining minimally-invasive glaucoma devices for medically uncontrolled open angle glaucoma. Properly designed RCTs are needed to assess the medium- and long-term efficacy and safety of this technique.