Retinal vascular abnormalities in neovascular age-related macular degeneration

Histology of type 3 macular neovascularization and microvascular anomalies in treated age-related macular degeneration: a case study

Purpose

To investigate intraretinal neovascularization and microvascular anomalies by correlating in vivo multimodal imaging with corresponding ex vivo histology in a single patient.

Design

A case study comprising clinical imaging from a community-based practice, and histologic analysis at a university-based research laboratory (clinicopathologic correlation).

Participants

A White woman in her 90s treated with numerous intravitreal anti-VEGF injections for bilateral type 3 macular neovascularization (MNV) secondary to age-related macular degeneration (AMD).

Methods

Clinical imaging comprised serial infrared reflectance, eye-tracked spectral-domain OCT, OCT angiography, and fluorescein angiography. Eye tracking, applied to the 2 preserved donor eyes, enabled the correlation of clinical imaging signatures with high-resolution histology and transmission electron microscopy.

Main Outcome Measures

Histologic/ultrastructural descriptions and diameters of vessels seen in clinical imaging.

Results

Six vascular lesions were histologically confirmed (type 3 MNV, n = 3; deep retinal age-related microvascular anomalies [DRAMAs], n = 3). Pyramidal (n = 2) or tangled (n = 1) morphologies of type 3 MNV originated at the deep capillary plexus (DCP) and extended posteriorly to approach without penetrating persistent basal laminar deposit. They did not enter the subretinal pigment epithelium (RPE)-basal laminar space or cross the Bruch membrane. Choroidal contributions were not found. The neovascular complexes included pericytes and nonfenestrated endothelial cells, within a collagenous sheath covered by dysmorphic RPE cells. Deep retinal age-related microvascular anomaly lesions extended posteriorly from the DCP into the Henle fiber and the outer nuclear layers without evidence of atrophy, exudation, or anti-VEGF responsiveness. Two DRAMAs lacked collagenous sheaths. External and internal diameters of type 3 MNV and DRAMA vessels were larger than comparison vessels in the index eyes and in aged normal and intermediate AMD eyes.

Conclusions

Type 3 MNV vessels reflect specializations of source capillaries and persist during anti-VEGF therapy. The collagenous sheath of type 3 MNV lesions may provide structural stabilization. If so, vascular characteristics may be useful in disease monitoring in addition to fluid and flow signal detection. Further investigation with longitudinal imaging before exudation onset will help determine if DRAMAs are part of the type 3 MNV progression sequence.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Volume Rendering of Deep Retinal Age-Related Microvascular Anomalies

PURPOSE

To characterize and distinguish non-neovascular deep retinal age-related microvascular anomalies (DRAMA) from type 3 macular neovascularization (MNV) using volume rendering of OCT and OCT angiography (OCTA).

DESIGN

Retrospective, consecutive case series.

SUBJECTS

Consecutive patients with age-related macular degeneration (AMD) exhibiting de novo non-neovascular abnormalities within the deep vascular plexus (DCP), as detected using high-resolution (High-Res) spectral-domain (SD) and swept-source (SS) OCT or OCTA. Patients with retinal vascular alterations attributable to other disease entities were excluded.

METHODS

Complete ophthalmic examination and multimodal imaging, including confocal fundus photography (CFP), SD-OCT, High-Res SD-OCT and OCTA, and volume-averaged SS-OCTA. The volume renderings of High-Res OCTA and averaged SS-OCTA were used to analyze capillary abnormalities and inflow or outflow connectivity pathways.

MAIN OUTCOME MEASURES

The primary outcomes were the characteristics of capillary abnormalities (number, size, shape, reflectivity, and location) and inflow or outflow connectivity pathways. The secondary outcomes were nearby changes in CFP and structural OCT (hyperreflective foci [HRF], outer retinal atrophy, and retinal pigment epithelium [RPE] atrophy).

RESULTS

From 8 eyes of 8 patients, 2 subtypes of DRAMA were identified: small-diameter perifoveal capillary dilations with hyperreflective walls within the inner nuclear layer (type 1, n = 4) and vascular outpouchings, typically multiple, extending posteriorly into the Henle fiber layer, with reflectivity similar to adjacent normal retinal capillaries (type 2, n = 10). Four eyes had both subtypes of DRAMA. The 3-dimensional visualization of OCTA data demonstrated DRAMA corresponding to the dilations of DCP capillaries without direct inflow or outflow connections to the superficial plexus. Fundus photographs showed circular red dots in 3 eyes, all corresponding to type 1 DRAMA. In all the cases, DRAMA colocalized with HRF. No lesions were found anterior to the areas of the RPE or outer retina atrophy. Asymptomatic intraretinal exudation varied through a follow-up duration of up to 6 years, with no lesions progressing to type 3 MNV.

CONCLUSIONS

In eyes with non-neovascular AMD, DRAMA include 2 types of capillary dilations occurring without the remodeling of the surrounding vascular network. Deep retinal age-related microvascular anomalies can resemble microvascular changes due to other causes and can masquerade as type 3 MNV. Mild intraretinal exudation can vary during follow-up, without progression to type 3 MNV.

Anti-Vascular Endothelial Growth Factor Drug Conbercept-Loaded Peptide Hydrogel Reduced Angiogenesis in the Neovascular Age-Related Macular Degeneration

Age-related macular degeneration (AMD) accounts for 8.7% of the global blindness and neovascular form of AMD (nAMD) occupies a large proportion of severe visual loss and legal blindness caused by AMD with a relatively low incidence rate. Choroidal neovascularization (CNV) is overwhelmingly responsible for the occurrence of nAMD as bleeding and fluid leakage followed by abnormal formation of blood vessels could directly lead to loss of central vision so that reduce the choroidal angiogenesis is an ideal treatment method of nAMD. VEGF is an important cytokine which promote the signaling pathway of angiogenesis and the abnormal expression of VEGF is verified in great many CNV cases. Several anti-VEGF drugs have been widely used in clinical treatments such as ranibizumab, bevacizumab and aflibercept. Conbercept, as an originally developed drug in China, has attracted great attention. For the purpose of better treatment efficacy, our group designed a short chain peptide (Sequence: DDIIIRH-NH₂, M.W.880.99) for controlled drug release to remedy the drawback of the short half-time period. The peptide could self-assembled into a stable 'hydrogel under pH 7.4 condition and the 3D structure was clearly observed in TEM study. Rheological study exhibited its great injectability so that the hydrogel was a material for intravitreal injection. Statistics exhibited that the hydrogel could release approximately 50% of total conbercept. The In vitro experiments showed that either dose-dependent or the time-dependent incubation with peptide would not decrease the cell viability of HREC, revealing that the peptide was biocompatible. The most important is that co-incubation with HREC obviously reduced the HREC proliferation and tube formation induced by VEGF, ensuring its potential for the treatment efficacy of nAMD.

Plexus-specific retinal capillary avascular area in exudative age-related macular degeneration with projection-resolved OCT angiography

OBJECTIVE

To detect the plexus-specific retinal capillary avascular area in exudative age-related macular degeneration (EAMD) with projection-resolved optical coherence tomography angiography (PR-OCTA).

METHODS AND ANALYSIS

In this prospective cross-sectional single centre study, eyes with treatment-naïve EAMD underwent macular 3×3 mm OCTA with AngioVue system. OCTA scans were analysed and processed including three-dimensional projection artefact removal, retinal layer semi-automated segmentation and en face angiogram generation. Automated quantification of extrafoveal (excluding the central 1 mm circle) avascular area (EAA) were calculated on projection-resolved superficial vascular complex (SVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), respectively.

RESULTS

Nineteen eyes with EAMD and 19 age-matched healthy control eyes were included. There was no significant difference between the EAMD and control eyes in terms of age, sex, axial length and mean ocular perfusion pressure (all p>0.05). Compared with control eyes, EAMD eyes had significantly larger EAA in SVC (median 0.125 vs 0.059 mm², p=0.006), ICP (0.016 vs 0.000 mm², p=0.004) and DCP (0.033 vs 0.000 mm², p＜0.001).

CONCLUSION

PR-OCTA showed that EAMD is associated with focal avascular area in all the three retinal vascular plexuses.

Exudative non-neovascular age-related macular degeneration

PURPOSE

To describe the clinical and multimodal imaging (MMI) features of age-related macular degeneration (AMD) eyes presenting with intraretinal exudation and no evidence of neovascularization or structural alterations of native retinal vessels.

METHODS

This was a retrospective review of the MMI and electronic health records for 3 consecutive patients presenting with unilateral exudative non-neovascular age-related macular degeneration. MMI included confocal color fundus photography (CFP), fundus autofluorescence (FAF), fluorescein angiography (FA), spectral domain optical coherence tomography (SD-OCT), swept-source optical coherence tomography angiography (SS-OCTA), and spectral domain optical coherence tomography angiography (SD-OCTA). Dense B-scan OCTA (DB-OCTA) patterns and implemented image post-processing were used to improve spatial resolution in the OCTA analysis and remove projection artifacts.

RESULTS

Three eyes of 3 patients (1 male and 2 females, ages 72-87) developed intraretinal fluid (IRF) producing retinal edema during regular follow-up for non-neovascular AMD. FA, SS-OCTA, and DB-OCTA demonstrated no evidence of macular neovascularization or discrete retinal vascular abnormalities that could explain the IRF accumulation. Two eyes received intravitreal anti-VEGF therapy and demonstrated prompt resolution of IRF with periodic recurrences over time.

CONCLUSION

Exudative non-neovascular AMD is a novel clinical phenotype characterized by the presence of non-neovascular intraretinal exudation producing macular edema. Differentiating this condition from other manifestations of AMD requires appropriate use of MMI. Further study is needed to assess the clinical impact and optimal management of exudative non-neovascular AMD.

Optical Coherence Tomography Findings (SD-OCT and OCTA) in Early-Stage Type 3 Neovascularization

A 76-year-old male presented with a small hyperreflective density in the outer nuclear layer with subtle retinal pigment epithelium (RPE) elevation and few intraretinal cysts on spectral-domain optical coherence tomography (SD-OCT). Optical coherence tomography angiography (OCTA) confirmed the presence of a tuft-shaped intraretinal neovascular lesion. SD-OCT performed 2 months before showed a smaller RPE elevation at the same location without intraretinal fluid. A 79-year-old male presented with a small hyperreflective density in the outer retina surrounded by scant intraretinal fluid on SD-OCT and a bright vessel on OCTA, suggesting early-stage type 3 neovascularization. SD-OCT performed 2 months before showed a smaller hyperreflectivity at the same location, without intraretinal fluid. An 84-year-old female presented with hyperreflective foci in the outer retina overlying a serous pigment epithelium detachment (PED) with focal RPE disruption on SD-OCT. SD-OCT performed 2 months before showed the same hyperreflective lesion associated with a shallower PED. No neovascular lesions were found on OCTA after six injections of bevacizumab. To conclude, careful evaluation of SD-OCT allows for early detection of type 3 neovascularization at a pre-exudative stage. OCTA may be useful in confirming the presence of intraretinal neovascular lesion and monitoring response to anti-vascular endothelial growth factor agents.

Anti-vascular endothelial growth factor for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to AMD accounts for most cases of AMD-related severe vision loss. Intravitreous injection of anti-vascular endothelial growth factor (anti-VEGF) agents aims to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, to improve vision.

OBJECTIVES

• To investigate ocular and systemic effects of, and quality of life associated with, intravitreous injection of three anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) versus no anti-VEGF treatment for patients with neovascular AMD• To compare the relative effects of one of these anti-VEGF agents versus another when administered in comparable dosages and regimens SEARCH METHODS: To identify eligible studies for this review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (searched January 31, 2018); MEDLINE Ovid (1946 to January 31, 2018); Embase Ovid (1947 to January 31, 2018); the Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 31, 2018); the International Standard Randomized Controlled Trials Number (ISRCTN) Registry (www.isrctn.com/editAdvancedSearch - searched January 31, 2018); ClinicalTrials.gov (www.clinicaltrials.gov - searched November 28, 2018); and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en - searched January 31, 2018). We did not impose any date or language restrictions in electronic searches for trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or versus a control treatment (e.g. sham treatment, photodynamic therapy), in which participants were followed for at least one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We compared outcomes using risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 16 RCTs that had enrolled a total of 6347 participants with neovascular AMD (the number of participants per trial ranged from 23 to 1208) and identified one potentially relevant ongoing trial. Six trials compared anti-VEGF treatment (pegaptanib, ranibizumab, or bevacizumab) versus control, and 10 trials compared bevacizumab versus ranibizumab. Pharmaceutical companies conducted or sponsored four trials but funded none of the studies that evaluated bevacizumab. Researchers conducted these trials at various centers across five continents (North and South America, Europe, Asia, and Australia). The overall certainty of the evidence was moderate to high, and most trials had an overall low risk of bias. All but one trial had been registered prospectively.When compared with those who received control treatment, more participants who received intravitreous injection of any of the three anti-VEGF agents had gained 15 letters or more of visual acuity (risk ratio [RR] 4.19, 95% confidence interval [CI] 2.32 to 7.55; moderate-certainty evidence), had lost fewer than 15 letters of visual acuity (RR 1.40, 95% CI 1.27 to 1.55; high-certainty evidence), and showed mean improvement in visual acuity (mean difference 6.7 letters, 95% CI 4.4 to 9.0 in one pegaptanib trial; mean difference 17.8 letters, 95% CI 16.0 to 19.7 in three ranibizumab trials; moderate-certainty evidence) after one year of follow-up. Participants treated with anti-VEGF agents showed improvement in morphologic outcomes (e.g. size of CNV, central retinal thickness) compared with participants not treated with anti-VEGF agents (moderate-certainty evidence). No trial directly compared pegaptanib versus another anti-VEGF agent and followed participants for one year; however, when compared with control treatments, ranibizumab and bevacizumab each yielded larger improvements in visual acuity outcomes than pegaptanib.Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same RCTs compared the same regimens with respect to gain of 15 or more letters of visual acuity (RR 0.95, 95% CI 0.81 to 1.12; high-certainty evidence) and loss of fewer than 15 letters of visual acuity (RR 1.00, 95% CI 0.98 to 1.02; high-certainty evidence); results showed similar mean improvement in visual acuity (mean difference [MD] -0.5 letters, 95% CI -1.5 to 0.5; high-certainty evidence) after one year of follow-up, despite the substantially lower cost of bevacizumab compared with ranibizumab. Reduction in central retinal thickness was less among bevacizumab-treated participants than among ranibizumab-treated participants after one year (MD -11.6 μm, 95% CI -21.6 to -1.7; high-certainty evidence); however, this difference is within the range of measurement error, and we did not interpret it to be clinically meaningful.Ocular inflammation and increased intraocular pressure (IOP) after intravitreal injection were the most frequently reported serious ocular adverse events. Researchers reported endophthalmitis in less than 1% of anti-VEGF-treated participants and in no cases among control groups. The occurrence of serious systemic adverse events was comparable across anti-VEGF-treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to show a meaningful difference between groups (evidence of low- to moderate-certainty). Investigators rarely measured and reported data on visual function, quality of life, or economic outcomes.

AUTHORS' CONCLUSIONS

Results of this review show the effectiveness of anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; studies show that ranibizumab and bevacizumab improved visual acuity in some eyes that received these agents and were equally effective. Available information on the adverse effects of each medication does not suggest a higher incidence of potentially vision-threatening complications with intravitreous injection of anti-VEGF agents compared with control interventions; however, clinical trial sample sizes were not sufficient to estimate differences in rare safety outcomes. Future Cochrane Reviews should incorporate research evaluating variable dosing regimens of anti-VEGF agents, effects of long-term use, use of combination therapies (e.g. anti-VEGF treatment plus photodynamic therapy), and other methods of delivering these agents.

Microvascular abnormalities secondary to radiation therapy in neovascular age-related macular degeneration: findings from the INTREPID clinical trial

PURPOSE

To report the incidence and features of retinal microvascular abnormalities (MVAs) occurring secondary to stereotactic radiotherapy (SRT) in a randomised double-masked sham-controlled clinical trial at 21 European sites.

METHODS

Two hundred and thirty participants with neovascular age-related macular degeneration (AMD) treated with at least three intravitreal antivascular endothelial growth factor (anti-VEGF) injections prior to enrolment, and demonstrating a continuing need for re-treatment.

INTERVENTIONS

16 Gy, 24 Gy or sham SRT. All three groups received pro re nata anti-VEGF injections if the lesion was judged to be active at review visits. Colour fundus images from baseline and 6 months and fluorescein angiograms from baseline and annual visits were graded for measures of morphological outcome and safety using a prespecified protocol with accompanying definitions to distinguish RT-related MVA from non-specific retinal vessel abnormalities that are known to occur in neovascular AMD. The main outcome measure was MVA detected by months 12, 24 and 36 after enrolment.

RESULTS

The frequency of MVAs in the combined SRT arms was 0% in year 1, 13.1% in year 2 and 30.3% in year 3. The area of MVA was small and the mean change in visual acuity in year 2 was similar in a subset of SRT eyes with MVAs, versus those without MVAs. MVA was considered to have possibly contributed to vision loss in 2 of 18 cases with MVA in year 2, and 5 of 37 cases in year 3.

CONCLUSION

Treatment with SRT is associated with development of subtle MVAs that have little or no impact on visual outcome. These findings can help clinicians recognise the retinal MVAs that occur in response to SRT.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY CHANGES IN EARLY TYPE 3 NEOVASCULARIZATION AFTER ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT

PURPOSE

To investigate the morphologic changes on optical coherence tomography angiography (OCTA) of treatment-naive Type 3 neovascularization secondary to exudative age-related macular degeneration after 1 year of anti-vascular endothelial growth factor therapy.

METHODS

Consecutive patients diagnosed with treatment-naive early-stage Type 3 neovascularization were enrolled in this retrospective study. All patients underwent color fundus photographs/MultiColor (Heidelberg Engineering) imaging, fluorescein angiography, indocyanine green angiography, structural spectral domain OCT, and OCTA Optovue RTVue XR Avanti (Optovue) at baseline, and repeated OCTA and structural spectral domain OCT at Month 12. Qualitative analysis of the 3 × 3 OCTA examinations at baseline and Month 12 was then compared, to assess changes after anti-vascular endothelial growth factor therapy.

RESULTS

A total of 15 treatment-naive eyes of 15 consecutive patients were included in the analysis. At 12-month follow-up after pro-re-data anti-vascular endothelial growth factor therapy (5.75 ± 1.48 injections of ranibizumab, and injections of 6.33 ± 1.21 of aflibercept), OCTA demonstrated persistence of the deep capillary plexus abnormalities in 13/15 eyes. In the outer retina and choriocapillaris, the initial lesion became undetectable in 7/15 cases, accompanied by choriocapillaris atrophy. The abnormal vascular complex persisted in the form of a tuft-shaped lesion in the outer retinal segmentation in 9/15 eyes, which in the choriocapillaris segmentation was associated with sub-retinal pigment epithelium neovascularization in 8 cases.

CONCLUSION

Optical coherence tomography angiography showed that the tuft-shaped abnormal outer retinal lesion, frequently associated with a small clew-like flow signal in the choriocapillaris, after 1 year of anti-vascular endothelial growth factor therapy, either becomes undetectable or develops sub-retinal pigment epithelium neovascularization.

A retrospective cohort study in patients with tractional diseases of the vitreomacular interface (ReCoVit)

Purpose

To assess how vitreomacular adhesion (VMA), vitreomacular traction (VMT), and macular holes (MH) evolve, and to assess visual acuity outcomes associated with different management strategies for each subgroup.

Methods

Retrospective, single-center, observational study of 400 patients (556 eyes) who presented with optical coherence tomography (OCT) findings related to tractional diseases of the vitreomacular interface (187 with bilateral disease). The outcomes measured include prevalence of symptoms, rates of disease stabilization, spontaneous resolution, and disease progression necessitating surgical intervention. Size of VMA/VMT was not measured.

Results

Vision loss and metamorphopsia were the leading causes for referral. Patients were followed for a mean of 10.9 months (median 6.9 months). Spontaneous resolution occurred in 22.7 % (46/203) of eyes with VMT and in 7.3 % (9/124) of eyes with VMA (P < .001). In the former group, 34.1 % (14 eyes) showed improved visual acuity (P = .001). During follow-up, 11.3 % (14/124) of eyes with VMA showed disease progression; six (4.8 %) developed a macular hole. Eleven of the 203 eyes with VMT (5.4 %) developed a macular hole; 52 of 203 eyes with VMT (25.6 %) had disease progression that resulted in patients opting for pars plana vitrectomy (PPV). Of the eyes with VMA, 4.8 % (6/124) had disease progression resulting in patients opting for PPV.

Conclusions

Better visual acuity outcomes were found in eyes with spontaneous resolution compared to the other groups. Spontaneous resolution of VMT and VMA was rare, whereas disease progression resulting in PPV was more common.

Effects of Vitreomacular Adhesion on Age-Related Macular Degeneration

Herein, we review the association between vitreomacular adhesion (VMA) and neovascular age-related macular degeneration (AMD). Meta-analyses have shown that eyes with neovascular AMD are twice as likely to have VMA as normal eyes. VMA in neovascular AMD may induce inflammation, macular traction, decrease in oxygenation, sequestering of vascular endothelial growth factor (VEGF), and other cytokines or may directly stimulate VEGF production. VMA may also interfere with the treatment effects of anti-VEGF therapy, which is the standard treatment for neovascular AMD, and releasing VMA can improve the treatment response to anti-VEGF treatment in neovascular AMD. We also reviewed currently available methods of relieving VMA.

Anti-vascular endothelial growth factor for neovascular age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to neovascular AMD accounts for most AMD-related severe vision loss. Anti-vascular endothelial growth factor (anti-VEGF) agents, injected intravitreally, aim to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, improve vision.

OBJECTIVES

To investigate: (1) the ocular and systemic effects of, and quality of life associated with, intravitreally injected anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) for the treatment of neovascular AMD compared with no anti-VEGF treatment; and (2) the relative effects of one anti-VEGF agent compared with another when administered in comparable dosages and regimens.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to March 2014), EMBASE (January 1980 to March 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 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 used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 27 March 2014.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or a control treatment (e.g., sham treatment or photodynamic therapy). All trials followed participants for at least one year.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We analyzed outcomes as risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 12 RCTs including a total of 5496 participants with neovascular AMD (the number of participants per trial ranged from 28 to 1208). One trial compared pegaptanib, three trials ranibizumab, and two trials bevacizumab versus controls; six trials compared bevacizumab with ranibizumab. Four trials were conducted by pharmaceutical companies; none of the eight studies which evaluated bevacizumab were funded by pharmaceutical companies. The trials were conducted at various centers across five continents (North and South America, Europe, Asia and Australia). The overall quality of the evidence was very good, with most trials having an overall low risk of bias.When compared with control treatments, participants who received any of the three anti-VEGF agents were more likely to have gained 15 letters or more of visual acuity, lost fewer than 15 letters of visual acuity, and had vision 20/200 or better after one year of follow up. Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same regimens were compared in the same RCTs, despite the substantially lower cost for bevacizumab compared with ranibizumab. No trial directly compared pegaptanib with other anti-VEGF agents; however, when compared with controls, ranibizumab or bevacizumab yielded larger improvements in visual acuity outcomes than pegaptanib.Participants treated with anti-VEGFs showed improvements in morphologic outcomes (e.g., size of CNV or central retinal thickness) compared with participants not treated with anti-VEGF agents. There was less reduction in central retinal thickness among bevacizumab-treated participants than among ranibizumab-treated participants after one year (MD -13.97 μm; 95% confidence interval (CI) -26.52 to -1.41); however, this difference is within the range of measurement error and we did not interpret it as being clinically meaningful.Ocular inflammation and increased intraocular pressure after intravitreal injection were the most frequently reported serious ocular adverse events. Endophthalmitis was reported in fewer than 1% of anti-VEGF treated participants; no cases were reported in control groups. The occurrence of serious systemic adverse events was comparable across anti-VEGF-treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to detect a meaningful difference between groups. Data for visual function, quality of life, and economic outcomes were sparsely measured and reported.

AUTHORS' CONCLUSIONS

The results of this review indicate the effectiveness of anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; ranibizumab and bevacizumab were also shown to improve visual acuity. The information available on the adverse effects of each medication do not suggest a higher incidence of potentially vision-threatening complications with intravitreal injection compared with control interventions; however, clinical trial sample sizes may not have been sufficient to detect rare safety outcomes. Research evaluating variable dosing regimens with anti-VEGF agents, effects of long-term use, combination therapies (e.g., anti-VEGF treatment plus photodynamic therapy), and other methods of delivering the agents should be incorporated into future Cochrane reviews.