Anti-vascular endothelial growth factor for neovascular glaucoma

BACKGROUND

Neovascular glaucoma (NVG) is a potentially blinding, secondary glaucoma. It is caused by the formation of abnormal new blood vessels, which prevent normal drainage of aqueous from the anterior segment of the eye. Anti-vascular endothelial growth factor (anti-VEGF) medications are specific inhibitors of the primary mediators of neovascularization. Studies have reported the effectiveness of anti-VEGF medications for the control of intraocular pressure (IOP) in NVG.

OBJECTIVES

To assess the effectiveness of intraocular anti-VEGF medications, alone or with one or more types of conventional therapy, compared with no anti-VEGF medications for the treatment of NVG.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register); MEDLINE; Embase; PubMed; and LILACS to 19 October 2021; metaRegister of Controlled Trials to 19 October 2021; and two additional trial registers to 19 October 2021. We did not use any date or language restrictions in the electronic search for trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of people treated with anti-VEGF medications for NVG.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the search results for trials, extracted data, and assessed risk of bias, and the certainty of the evidence. We resolved discrepancies through discussion.

MAIN RESULTS

We included five RCTs (356 eyes of 353 participants). Each trial was conducted in a different country: two in China, and one each in Brazil, Egypt, and Japan. All five RCTs included both men and women; the mean age of participants was 55 years or older. Two RCTs compared intravitreal bevacizumab combined with Ahmed valve implantation and panretinal photocoagulation (PRP) with Ahmed valve implantation and PRP alone. One RCT randomized participants to receive an injection of either intravitreal aflibercept or placebo at the first visit, followed by non-randomized treatment according to clinical findings after one week. The remaining two RCTs randomized participants to PRP with and without ranibizumab, one of which had insufficient details for further analysis. We assessed the RCTs to have an unclear risk of bias for most domains due to insufficient information to permit judgment.   Four RCTs examined achieving control of IOP, three of which reported our time points of interest. Only one RCT reported our critical time point at one month; it found that the anti-VEGF group had a 1.3-fold higher chance of achieving control of IOP at one month (RR 1.32, 95% 1.10 to 1.59; 93 participants) than the non-anti-VEGF group (low certainty of evidence). For other time points, one RCT found a three-fold greater achievement in control of IOP in the anti-VEGF group when compared with the non-anti-VEGF group at one year (RR 3.00; 95% CI:1.35 to 6.68; 40 participants). However, another RCT found an inconclusive result at the time period ranging from 1.5 years to three years (RR 1.08; 95% CI: 0.67 to 1.75; 40 participants).  All five RCTs examined mean IOP, but at different time points. Very-low-certainty evidence showed that anti-VEGFs were effective in reducing mean IOP by 6.37 mmHg (95% CI: -10.09 to -2.65; 3 RCTs; 173 participants) at four to six weeks when compared with no anti-VEGFs.  Anti-VEGFs may reduce mean IOP at three months (MD -4.25; 95% CI -12.05 to 3.54; 2 studies; 75 participants), six months (MD -5.93; 95% CI -18.13 to 6.26; 2 studies; 75 participants), one year (MD -5.36; 95% CI -18.50 to 7.77; 2 studies; 75 participants), and more than one year (MD -7.05; 95% CI -16.61 to 2.51; 2 studies; 75 participants) when compared with no anti-VEGFs, but such effects remain uncertain. Two RCTs reported the proportion of participants who achieved an improvement in visual acuity with specified time points. Participants receiving anti-VEGFs had a 2.6 times (95% CI 1.60 to 4.08; 1 study; 93 participants) higher chance of improving visual acuity when compared with those not receiving anti-VEGFs at one month (very low certainty of evidence). Likewise, another RCT found a similar result at 18 months (RR 4.00, 95% CI 1.33 to 12.05; 1 study; 40 participants).  Two RCTs reported the outcome, complete regression of new iris vessels, at our time points of interest. Low-certainty evidence showed that anti-VEGFs had a nearly three times higher chance of complete regression of new iris vessels when compared with no anti-VEGFs (RR 2.63, 95% CI 1.65 to 4.18; 1 study; 93 participants). A similar finding was observed at more than one year in another RCT (RR 3.20, 95% CI 1.45 to 7.05; 1 study; 40 participants).  Regarding adverse events, there was no evidence that the risks of hypotony and tractional retinal detachment were different between the two groups (RR 0.67; 95% CI: 0.12 to 3.57 and RR 0.33; 95% CI: 0.01 to 7.72, respectively; 1 study; 40 participants). No RCTs reported incidents of endophthalmitis, vitreous hemorrhage, no light perception, and serious adverse events. Evidence for the adverse events of anti-VEGFs was low due to limitations in the study design due to insufficient information to permit judgments and imprecision of results due to the small sample size. No trial reported the proportion of participants with relief of pain and resolution of redness at any time point.

AUTHORS' CONCLUSIONS

Anti-VEGFs as an adjunct to conventional treatment could help reduce IOP in NVG in the short term (four to six weeks), but there is no evidence that this is likely in the longer term. Currently available evidence regarding the short- and long-term effectiveness and safety of anti-VEGFs in achieving control of IOP, visual acuity, and complete regression of new iris vessels in NVG is insufficient. More research is needed to investigate the effect of these medications compared with, or in addition to, conventional surgical or medical treatment in achieving these outcomes in NVG.

Anti-vascular endothelial growth factor for proliferative diabetic retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is an advanced complication of diabetic retinopathy that can cause blindness. It consists of the presence of new vessels in the retina and vitreous haemorrhage. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. Anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR.

OBJECTIVES

To assess the effectiveness and safety of anti-VEGFs for PDR and summarise any relevant economic evaluations of their use.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov, and the WHO ICTRP. We did not use any date or language restrictions. We last searched the electronic databases on 1 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment, or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments. We excluded studies that used anti-VEGFs in people undergoing vitrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed the risk of bias (RoB) for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 15 new studies in this update, bringing the total to 23 RCTs with 1755 participants (2334 eyes). Forty-five per cent of participants were women and 55% were men, with a mean age of 56 years (range 48 to 77 years). The mean glycosylated haemoglobin (Hb1Ac) was 8.45% for the PRP group and 8.25% for people receiving anti-VEGFs alone or in combination. Twelve studies included people with PDR, and participants in 11 studies had high-risk PDR (HRPDR). Twelve studies were of bevacizumab, seven of ranibizumab, one of conbercept, two of pegaptanib, and one of aflibercept. The mean number of participants per RCT was 76 (ranging from 15 to 305). Most studies had an unclear or high RoB, mainly in the blinding of interventions and outcome assessors. A few studies had selective reporting and attrition bias. No study reported loss or gain of 3 or more lines of visual acuity (VA) at 12 months. Anti-VEGFs ± PRP probably increase VA compared with PRP alone (mean difference (MD) -0.08 logMAR, 95% CI -0.12 to -0.04; I2 = 28%; 10 RCTS, 1172 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may increase regression of new vessels (MD -4.14 mm2, 95% CI -6.84 to -1.43; I2 = 75%; 4 RCTS, 189 eyes; low-certainty evidence) and probably increase a complete regression of new vessels (RR 1.63, 95% CI 1.19 to 2.24; I2 = 46%; 5 RCTS, 405 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP probably reduce vitreous haemorrhage (RR 0.72, 95% CI 0.57 to 0.90; I2 = 0%; 6 RCTS, 1008 eyes; moderate-certainty evidence). Anti-VEGFs ± PRP may reduce the need for vitrectomy compared with eyes that received PRP alone (RR 0.67, 95% CI 0.49 to 0.93; I2 = 43%; 8 RCTs, 1248 eyes; low-certainty evidence). Anti-VEGFs ± PRP may result in little to no difference in the quality of life compared with PRP alone (MD 0.62, 95% CI -3.99 to 5.23; I2 = 0%; 2 RCTs, 382 participants; low-certainty evidence). We do not know if anti-VEGFs ± PRP compared with PRP alone had an impact on adverse events (very low-certainty evidence). We did not find differences in visual acuity in subgroup analyses comparing the type of anti-VEGFs, the severity of the disease (PDR versus HRPDR), time to follow-up (< 12 months versus 12 or more months), and treatment with anti-VEGFs + PRP versus anti-VEGFs alone. The main reasons for downgrading the certainty of evidence included a high RoB, imprecision, and inconsistency of effect estimates.

AUTHORS' CONCLUSIONS

Anti-VEGFs ± PRP compared with PRP alone probably increase visual acuity, but the degree of improvement is not clinically meaningful. Regarding secondary outcomes, anti-VEGFs ± PRP produce a regression of new vessels, reduce vitreous haemorrhage, and may reduce the need for vitrectomy compared with eyes that received PRP alone. We do not know if anti-VEGFs ± PRP have an impact on the incidence of adverse events and they may have little or no effect on patients' quality of life. Carefully designed and conducted clinical trials are required, assessing the optimal schedule of anti-VEGFs alone compared with PRP, and with a longer follow-up.

Anti-vascular endothelial growth factor for diabetic macular oedema: a network meta-analysis

BACKGROUND

Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) modalities can reduce oedema and thereby improve vision and prevent further visual loss. These drugs have replaced laser photocoagulation as the standard of care for people with DMO.

OBJECTIVES

The 2014 update of this review found high-quality evidence of benefit with antiangiogenic therapy with anti-VEGF modalities, compared to laser photocoagulation, for the treatment of DMO.The objective of this updated review is to compare the effectiveness and safety of the different anti-VEGF drugs in preserving and improving vision and quality of life using network meta-analysis methods.

SEARCH METHODS

We searched various electronic databases on 26 April 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any anti-angiogenic drug with an anti-VEGF mechanism of action versus another anti-VEGF drug, another treatment, sham or no treatment in people with DMO.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods for pair-wise meta-analysis and we augmented this evidence using network meta-analysis methods. We focused on the relative efficacy and safety of the three most commonly used drugs as interventions of direct interest for practice: aflibercept and ranibizumab, used on-label; and off-label bevacizumab.We collected data on three efficacy outcomes (gain of 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letters; mean change in best-corrected visual acuity (BCVA); mean change in central retinal thickness (CRT)), three safety outcomes (all severe systemic adverse events (SSAEs); all-cause death; arterial thromboembolic events) and quality of life.We used Stata 'network' meta-analysis package for all analyses. We investigated the risk of bias of mixed comparisons based on the variance contribution of each study, having assigned an overall risk of bias to each study.

MAIN RESULTS

Twenty-four studies included 6007 participants with DMO and moderate vision loss, of which two studies randomised 265 eyes of 230 participants and one was a cross-over study on 56 participants (62 eyes) that was treated as a parallel-arm trial. Data were collected on drugs of direct interest from three studies on aflibercept (975 eyes), eight studies on bevacizumab (515 eyes), and 14 studies on ranibizumab (1518 eyes). As treatments of indirect interest or legacy treatment we included three studies on pegaptanib (541 eyes), five studies on ranibizumab plus prompt laser (557 eyes), one study on ranibizumab plus deferred laser (188 eyes), 13 studies on laser photocoagulation (936 eyes) and six studies on sham treatment (793 eyes).Aflibercept, bevacizumab and ranibizumab were all more effective than laser for improving vision by 3 or more lines after one year (high-certainty evidence). Approximately one in 10 people improve vision with laser, and about three in 10 people improve with anti-VEGF treatment: risk ratio (RR) versus laser 3.66 (95% confidence interval (CI) 2.79 to 4.79) for aflibercept; RR 2.47 (95% CI 1.81 to 3.37) for bevacizumab; RR 2.76 (95% CI 2.12 to 3.59) for ranibizumab. On average there was no change in visual acuity (VA) with laser after one year, compared with a gain of 1 or 2 lines with anti-VEGF treatment: laser versus aflibercept mean difference (MD) -0.20 (95% CI -0.22 to -0.17) logMAR; versus bevacizumab MD -0.12 (95% CI -0.15 to -0.09) logMAR; versus ranibizumab MD -0.12 (95% CI -0.14 to -0.10) logMAR. The certainty of the evidence was high for the comparison of aflibercept and ranibizumab with laser and moderate for bevacizumab comparison with laser due to inconsistency between the indirect and direct evidence.People receiving ranibizumab were less likely to gain 3 or more lines of VA at one year compared with aflibercept: RR 0.75 (95% CI 0.60 to 0.94), moderate-certainty evidence. For every 1000 people treated with aflibercept, 92 fewer would gain 3 or more lines of VA at one year if treated with ranibizumab (22 to 148 fewer). On average people receiving ranibizumab had worse VA at one year (MD 0.08 logMAR units, 95% CI 0.05 to 0.11), moderate-certainty evidence; and higher CRT (MD 39 µm, 95% CI 2 µm to 76 µm; low-certainty evidence). Ranibizumab and bevacizumab were comparable with respect to aflibercept and did not differ in terms of VA: RR of gain of 3 or more lines of VA at one year 1.11 (95% CI 0.87 to 1.43), moderate-certainty evidence, and difference in change in VA was 0.00 (95% CI -0.02 to 0.03) logMAR, moderate-certainty evidence. CRT reduction favoured ranibizumab by -29 µm (95% CI -58 µm to -1 µm, low-certainty evidence). There was no evidence of overall statistical inconsistency in our analyses.The previous version of this review found moderate-certainty evidence of good safety of antiangiogenic drugs versus control. This update used data at the longest available follow-up (one or two years) and found that aflibercept, ranibizumab and bevacizumab do not differ regarding systemic serious adverse events (SSAEs) (moderate- or high-certainty evidence). However, risk of bias was variable, loop inconsistency could be found and estimates were not precise enough on relative safety regarding less frequent events such as arterial thromboembolic events or death (low- or very low-certainty evidence).Two-year data were available and reported in only four RCTs in this review. Most industry-sponsored studies were open-label after one year. One large publicly-funded study compared the three drugs at two years and found no difference.

AUTHORS' CONCLUSIONS

Anti-VEGF drugs are effective at improving vision in people with DMO with three to four in every 10 people likely to experience an improvement of 3 or more lines VA at one year. There is moderate-certainty evidence that aflibercept confers some advantage over ranibizumab and bevacizumab in people with DMO at one year in visual and anatomic terms. Relative effects among anti-VEGF drugs at two years are less well known, since most studies were short term. Evidence from RCTs may not apply to real-world practice, where people in need of antiangiogenic treatment are often under-treated and under-monitored.We found no signals of differences in overall safety between the three antiangiogenic drugs that are currently available to treat DMO, but our estimates are imprecise for cardiovascular events and death.

Anti-vascular endothelial growth factor for control of wound healing in glaucoma surgery

BACKGROUND

Trabeculectomy is performed as a treatment for glaucoma to lower intraocular pressure (IOP). The surgical procedure involves creating a channel through the wall of the eye. However scarring during wound healing can block this channel which will lead to the operation failing. Anti-vascular endothelial growth factor (VEGF) agents have been proposed to slow down healing response and scar formation.

OBJECTIVES

To assess the effectiveness of anti-VEGF therapies administered by subconjunctival injection for the outcome of trabeculectomy at 12 months follow-up and to examine the balance of benefit and harms when compared to any other anti-scarring agents or no additional anti-scarring agents.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2015), EMBASE (January 1980 to November 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 12 November 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of anti-VEGF therapies administered by subconjunctival injection compared to any other anti-scarring agents or no additional anti-scarring agents (no treatment or placebo) in trabeculectomy surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome was successful trabeculectomy at 12 months after surgery which was defined as achieving a target IOP (usually no more than 21 mm Hg) without any additional intervention. Other outcomes included: qualified success (achieving target IOP with or without additional intervention), mean IOP and adverse events.

MAIN RESULTS

We included five RCTs (175 participants, 177 eyes) that met the inclusion criteria in this review.One trial conducted in Iran (37 participants, 37 eyes) compared anti-VEGF (bevacizumab 0.2 mg) versus control (sham injection) in people with refractory glaucoma. We judged this study to be at low risk of bias.The primary outcome of this review was not reported; mean IOP at three months was 15.1 mm Hg (standard deviation 1.0) in both anti-VEGF and control groups.Four trials compared anti-VEGF to mitomycin C (MMC) (138 particpants, 140 eyes). These studies were conducted in India, Iran, Turkey and the USA. The anti-VEGF agent used in these four trials was bevacizumab 2.5 mg (two trials), bevacizumab 1.25 mg three times and ranibizumab 0.5 mg. Two trials were at high risk of bias in two domains and one trial was at high risk of bias in four domains.Only one of these trials reported the primary outcome of this review (42 participants, 42 eyes). Low quality evidence from this trial showed that people receiving bevacizumab 2.5 mg during primary trabeculectomy were less likely to achieve complete success at 12 months compared to people receiving MMC but the confidence interval (CI) was wide and compatible with increased chance of complete success for anti-VEGF (risk ratio (RR) 0.71, 95% CI 0.46 to 1.08), Assuming that approximately 81% of people receiving MMC achieve complete success, the anticipated success using anti-VEGF agents would be between 37.2% and 87.4%. The same trial suggested no evidence for any difference in qualified success between bevacizumab and MMC (RR 1.00, 95% CI 0.87 to 1.14, moderate quality evidence). Two trials of primary trabeculectomy provided data on mean IOP at 12 months; one trial of bevacizumab 2.5 mg and one trial of ranibizumab 0.5 mg. Mean IOP was 1.86 mm Hg higher (95% CI 0.15 to 3.57) in the anti-VEGF groups compared to the MMC groups (66 people, low quality evidence). Data were reported on wound leak, hypotony, shallow anterior chamber and endophthalmitis, but these events occurred rarely and currently there are not enough data available to detect any differences, if any, between the two treatments.

AUTHORS' CONCLUSIONS

The evidence is currently of low quality which is insufficient to refute or support anti-VEGF subconjunctival injection for control of wound healing in glaucoma surgery. The effect on IOP control of anti-VEGF agents in glaucoma patients undergoing trabeculectomy is still uncertain, compared to MMC.Further RCTs of anti-VEGF subconjunctival injection in glaucoma surgery are required, particularly compared to sham treatment with at least 12 months follow-up.