Ranibizumab combined with verteporfin photodynamic therapy in neovascular age-related macular degeneration: year 1 results of the FOCUS Study

Diagnostic accuracy of the Amsler grid and the preferential hyperacuity perimetry in the screening of patients with age-related macular degeneration: systematic review and meta-analysis

OBJECTIVE

To clarify the screening potential of the Amsler grid and preferential hyperacuity perimetry (PHP) in detecting or ruling out wet age-related macular degeneration (AMD).

EVIDENCE ACQUISITION

Medline, Scopus and Web of Science (by citation of reference) were searched. Checking of reference lists of review articles and of included articles complemented electronic searches. Papers were selected, assessed, and extracted in duplicate.

EVIDENCE SYNTHESIS

Systematic review and meta-analysis. Twelve included studies enrolled 903 patients and allowed constructing 27 two-by-two tables. Twelve tables reported on the Amsler grid and its modifications, twelve tables reported on the PHP, one table assessed the MCPT and two tables assessed the M-charts. All but two studies had a case-control design. The pooled sensitivity of studies assessing the Amsler grid was 0.78 (95% confidence intervals; 0.64-0.87), and the pooled specificity was 0.97 (95% confidence intervals; 0.91-0.99). The corresponding positive and negative likelihood ratios were 23.1 (95% confidence intervals; 8.4-64.0) and 0.23 (95% confidence intervals; 0.14-0.39), respectively. The pooled sensitivity of studies assessing the PHP was 0.85 (95% confidence intervals; 0.80-0.89), and specificity was 0.87 (95% confidence intervals; 0.82-0.91). The corresponding positive and negative likelihood ratios were 6.7 (95% confidence intervals; 4.6-9.8) and 0.17 (95% confidence intervals; 0.13-0.23). No pooling was possible for MCPT and M-charts.

CONCLUSION

Results from small preliminary studies show promising test performance characteristics both for the Amsler grid and PHP to rule out wet AMD in the screening setting. To what extent these findings can be transferred to a real clinic practice still needs to be established.

Targeted radiotherapy with gold nanoparticles: current status and future perspectives

Radiation therapy (RT) is the treatment of cancer and other diseases with ionizing radiation. The ultimate goal of RT is to destroy all the disease cells while sparing healthy tissue. Towards this goal, RT has advanced significantly over the past few decades in part due to new technologies including: multileaf collimator-assisted modulation of radiation beams, improved computer-assisted inverse treatment planning, image guidance, robotics with more precision, better motion management strategies, stereotactic treatments and hypofractionation. With recent advances in nanotechnology, targeted RT with gold nanoparticles (GNPs) is actively being investigated as a means to further increase the RT therapeutic ratio. In this review, we summarize the current status of research and development towards the use of GNPs to enhance RT. We highlight the promising emerging modalities for targeted RT with GNPs and the corresponding preclinical evidence supporting such promise towards potential clinical translation. Future prospects and perspectives are discussed.

Fixation stability measurements in patients with neovascular age-related macular degeneration treated with ranibizumab

OBJECTIVE

To evaluate which of 2 measuring units (bivariate contour ellipse area [BCEA] vs Fujii) yields more accurate measurements of fixation stability, obtained using the MP-1 device, in patients with neovascular age-related macular degeneration (nAMD) treated with intravitreal injections of ranibizumab, during a 12-month follow-up period.

DESIGN

Small retrospective, noncomparative, interventional case series.

PARTICIPANTS

A total of 25 eyes in 25 patients (13 males, 12 females; mean age 71.72 ± 7.98 years).

METHODS

All participants were older than 50 years, diagnosed with active subfoveal choroidal neovascularization, had best corrected visual acuity (BCVA) values above 20/100, and all lesion types were included. All patients underwent a loading phase with 3 consecutive intravitreal injections of 0.05 mg ranibizumab at monthly intervals. Patients were retreated after the third injection if they exhibited a 100-μm increase in macular thickness or evidence of intraretinal and/or subretinal fluid and new subretinal hemorrhage, observed with spectral-domain optical coherence tomography and fluorescein angiography. The data collected included BCVA and mean macular sensitivities, BCEA, and fixation patterns, performed at baseline and at months 4 and 12, using the MP-1 device.

RESULTS

The mean total injection number was 5.92 ± 1.18 (minimum 3, maximum 8). Mean BCVA at baseline was 0.55 ± 0.28 logMAR and increased significantly to 0.50 ± 0.33 logMAR. Mean macular sensitivity at baseline was 7.06 ± 4.59 dB and increased significantly to 8.40 ± 4.82. Mean BCEA was 2.19 ± 1.38 deg(2) and decreased significantly to 1.68 ± 1.43 deg(2). Fixation stability patterns, according to the protocol set out by Fujii, did not change significantly during follow-up.

CONCLUSIONS

Compared with Fujii fixation stability patterns, BCEA correlated better with variations in macular sensitivity and BCVA. BCEA can be added to the traditional parameters used to evaluate the efficacy of intravitreal injections in patients with nAMD.

Vitreous inflammation associated with intravitreal anti-VEGF pharmacotherapy

Vascular endothelial growth factor (VEGF) is a potent promoter of angiogenesis involved in a wide variety of physiologic processes. Intravitreal injections targeting VEGF have transformed the treatment of neovascular retinal diseases. Currently, there are four anti-VEGF agents in use: bevacizumab, ranibizumab, pegaptanib, and aflibercept. The success and frequency of anti-VEGF therapy have made the ocular safety profile of these agents of vital importance. This paper focuses on sterile endophthalmitis. In this paper, we compare the incidences of posttreatment sterile endophthalmitis among the four agents, review the mechanism of actions, and discuss the most prevalent hypotheses leading to sterile endophthalmitis.

Implementation studies of ranibizumab for neovascular age-related macular degeneration

The pathogenesis of AMD is associated with age changes plus pathological changes involving oxidative stress and an altered inflammatory response leading to injury of retinal pigment epithelial cells and the adjacent choroidea and photoreceptor cells. AMD is divided into early, intermediate and advanced AMD. The advanced form of AMD is further divided into non-neovascular AMD and neovascular AMD. The diagnosis of neovascular AMD is based on FA and clinical characteristics of the eyes. The CNV lesions are by their growth pattern divided into type 1 CNV lesions, which grow primarily beneath the RPE, and type 2 CNV lesions, which have penetrated the RPE and evolve within the subretinal space. The natural course of neovascular AMD leads to visual disability in a majority of cases within the first years after onset, primarily caused by the development of subfoveal fibrous tissue and atrophy of the RPE. The prognosis of visual acuity in neovascular AMD has been markedly improved by the introduction of an intravitreal administered VEGF inhibitor (ranibizumab) given on a monthly basis. Treatment with ranibizumab for neovascular AMD was introduced in Denmark in 2006 under a fully reimbursed national healthcare plan. Treatment with ranibizumab is given in a variable dosing regimen that varies from the monthly dosing regimen administered in the studies that led to the approval of ranibizumab for neovascular AMD in Europe. The main objectives of this PhD thesis were to evaluate and potentially improve treatment with ranibizumab in a variable OCT guided regimen for neovascular AMD. Another intension of this PhD thesis was to prepare the conditions for future research to further improve the visual prognosis in neovascular AMD treated with anti-VEGF agents. The first study revealed that vision was improved in eyes with active neovascular AMD treated for 1 year in a variable ranibizumab treatment regimen as compared to PDT and the natural course of the disease. We assumed by comparing our results with other pro re nata regimens based on a monthly reassessment of disease activity that our patients could gain substantial vision if we optimized our frequency of re-examinations. The analysis demonstrated that we could discontinue treatment in patients who had a poor visual acuity during the first 3 months of treatment and that visual outcome could be improved by minimizing the delay from diagnosis of neovascular AMD to first administered ranibizumab injection. This study led to changes in departmental treatment procedures. In the second study, we found that type 2 CNV lesions had a higher hazard ratio as compared to type 1 CNV lesions in developing subfoveal fibrosis. Prominent subfoveal fibrous tissue and fibrous tissue with retinal atrophy led to poorer visual performances in eyes with neovascular AMD after 2 years of treatment as compared with eyes without subfoveal fibrous tissue. In the development of randomized clinical trials designed to address how treatment with VEGF inhibitors can be improved by limiting the growth of subfoveal fibrous tissue or neuroretinal atrophy, it is important to define subgroups of eyes at risk of these pathological changes. The second PhD study has contributed to identify this subgroup of eyes. The third study included in this PhD thesis revealed that the annual incidence rate of AMD-related legally blind persons registered in Denmark has halved during the last decade, with the bulk of the reduction observed after the introduction of ranibizumab for neovascular AMD.

Ranibizumab: a review of its use in the treatment of neovascular age-related macular degeneration

Ranibizumab (Lucentis(®)), an inhibitor of all vascular endothelial growth factor (VEGF) A isoforms, is approved for the intravitreal treatment of neovascular age-related macular degeneration (AMD). In pivotal trials, monthly injections of ranibizumab were superior to verteporfin photodynamic therapy in the treatment of predominantly classic choroidal neovascularization (CNV) due to neovascular AMD (ANCHOR) and sham in the treatment of minimally classic or occult CNV due to neovascular AMD (MARINA). Monthly or less frequent injections of ranibizumab are generally well tolerated and associated with low rates of ocular and systemic serious adverse events (SAEs). Less frequent dosing has been evaluated with the aim of reducing the burden, risk and cost of monthly injections. In the landmark CATT trial, monthly monitoring and retreatment as-needed with ranibizumab was equivalent to monthly treatment in terms of the vision gain at 1 year, but reduced the number of injections (and the related cost) by approximately one-half. In head-to-head comparisons, aflibercept administered bimonthly was noninferior to ranibizumab administered monthly (VIEW 1 and 2), bevacizumab administered monthly was equivalent to ranibizumab administered monthly (CATT), and bevacizumab administered as-needed was equivalent to ranibizumab administered as-needed (CATT). Bevacizumab is widely used (off-label) for economic reasons; while it was less costly than ranibizumab, it was associated with more systemic SAEs. Notwithstanding the availability of other similarly effective anti-VEGF therapies that are approved (aflibercept) or unapproved (bevacizumab), ranibizumab continues to set the standard as regards the totality of evidence from randomized clinical trials demonstrating its efficacy and tolerability (particularly that of the monthly regimen) in the treatment of neovascular AMD.

Bevacizumab in age-related macular degeneration: a randomized controlled trial on the effect of injections every 4 weeks, 6 weeks and 8 weeks

PURPOSE

Several clinical trials have established the efficacy of ranibizumab therapy administered every 4 weeks to treat exudative age-related macular degeneration (ARMD). Bevacizumab appears to be a cost-effective alternative to ranibizumab, although an optimal injection schedule has not yet been determined. In this study, we set out to determine whether bevacizumab treatment in exudative ARMD every 6 or 8 weeks is non-inferior to bevacizumab treatment every 4 weeks.

METHODS

A total of 191 patients with exudative ARMD were randomly assigned to a 1-year continuous regimen of intravitreal bevacizumab every 4 (n = 64), 6 (n = 63) or 8 weeks (n = 64). The primary outcome was visual acuity change after 1 year of treatment.

RESULTS

In all three treatment groups, visual acuity improved between baseline and 1 year. There was no statistically significant difference in the mean change of visual acuity score at 1 year for bevacizumab administered every 4 (1.96 ± 13.70), 6 (1.60 ± 10.98) or 8 weeks (5.98 ± 8.88). Reduction in central retinal thickness was observed in all three study groups. At 1 year, the mean decrease in central foveal thickness ranged from 86 ± 97 μm in the every 6 weeks group to 109 ± 90 μm in the group every 8 weeks group (p = 0.30).

CONCLUSION

At 1 year, bevacizumab administered every 6 or 8 weeks was not inferior to therapy administered every 4 weeks.

Comparisons of outcomes with different intervals between adjunctive ranibizumab and photodynamic therapy for polypoidal choroidal vasculopathy

PURPOSE

To determine the optimal time for administration of intravitreal ranibizumab injections before photodynamic therapy (PDT) as combined therapy to treat polypoidal choroidal vasculopathy (PCV).

DESIGN

Retrospective, comparative, interventional case series.

METHODS

The study included 99 eyes (98 patients) with treatment-naïve subfoveal PCV treated with an intravitreal ranibizumab injection followed by PDT. The combination therapy included 1 ranibizumab injection administered 7 days before PDT (7-day group) or 2 days before PDT (2-day group). All eyes were followed for over 12 months.

RESULTS

Intravitreal ranibizumab was administered 7 days before PDT in 59 eyes and 2 days before PDT in 40 eyes. In the 7-day group, the best-corrected visual acuity (BCVA) did not improve significantly at 3 months (P = .086) or 12 months (P = .259) compared with baseline. In the 2-day group, BCVA improved significantly at 3 months (P < .001) and 12 months (P < .001). The polypoidal lesions regressed completely in 46 eyes (78.0%) in the 7-day group and in 34 eyes (85.0%) in the 2-day group; 38 eyes (64.4%) and 35 eyes (87.5%), respectively, did not require additional treatment, which differed significantly (P = .008) between the 2 groups. Subretinal hemorrhages did not develop in either group within 1 month after the combined therapy.

CONCLUSIONS

Administration of an intravitreal ranibizumab injection 2 days before PDT achieves significantly better visual outcomes and requires fewer additional treatments compared with administration of the injection 7 days before PDT.

Diffusion of technologies for the care of older adults with exudative age-related macular degeneration

PURPOSE

To determine patterns of diffusion of diagnostic tests and therapeutic interventions in the United States through 2010 for patients with newly diagnosed exudative macular degeneration (AMD).

DESIGN

Retrospective longitudinal cohort analysis.

METHODS

SETTING AND PATIENT POPULATION: A total of 23 941 Medicare beneficiaries with exudative AMD newly diagnosed during 1992-2009.

OBSERVATION PROCEDURES

Current Procedural Technology (CPT-4) billing codes were used to identify use of diagnostic tests (optical coherence tomography, fluorescein angiography, and fundus photography) and therapeutic interventions (argon laser photocoagulation, photodynamic therapy, intravitreal corticosteroids, and anti-vascular endothelial growth factor [VEGF] agents) used by these beneficiaries during the first year following diagnosis.

MAIN OUTCOME MEASURES

Rates of use of study diagnostic and therapeutic procedures.

RESULTS

Diffusion was rapid for each successive new diagnostic and treatment modality, with use of newer procedures quickly replacing existing ones. The number of beneficiaries treated with anti-VEGF agents for exudative AMD was considerably greater than for prior innovations, rising from use in 4.0% of beneficiaries in 2004-05 to 62.7% in 2009-10. In each year from first diagnosis years 2006-2009 and in different practice settings, use of bevacizumab exceeded that of ranibizumab (60%-78% vs 33%-47%, respectively). Rates of diffusion of the various therapies were relatively similar in communities throughout the United States irrespective of presence of a major teaching hospital in the vicinity.

CONCLUSIONS

Newer, more effective therapeutic interventions for exudative AMD diffused rapidly throughout the United States, quickly replacing older, less effective interventions. Although improving patient outcomes, rapid diffusion raises important public policy issues for Medicare and other payers to consider.

Drug-induced uveitis

A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates.

Visual outcome of photodynamic therapy for typical neovascular age-related macular degeneration and polypoidal choroidal vasculopathy over 5 years of follow-up

PURPOSE

To evaluate the long-term effects of photodynamic therapy (PDT) on typical neovascular age-related macular degeneration (tAMD) and polypoidal choroidal vasculopathy (PCV).

METHODS

This was a multicenter prospective study of 139 eyes from 136 patients (tAMD: 74 eyes; PCV: 65 eyes) who underwent PDT as the initial treatment. The change in best-corrected visual acuity (BCVA), predictive factors for the BCVA at 60 months, frequency of recurrence, and mean recurrence period were analyzed.

RESULTS

The pre-PDT BCVA and greatest linear dimension (GLD) did not differ between the two groups. The mean BCVA (logMAR) was significantly improved at 6 months post-initial PDT (post-PDT) in the PCV group (-0.11, P = 0.0091). However, at 60 months post-PDT, the mean BCVA was significantly worse than baseline in the tAMD (+0.21, P = 0.0035) and PCV (+0.21, P = 0.0076) groups. Pre-PDT BCVA, age, and GLD were the factors significantly associated with the BCVA at 60 months post-PDT. Although the frequency of recurrence did not significantly differ between the two phenotype groups, the mean recurrence period was significantly longer in the PCV group than in the tAMD group (15.7 vs. 8.6 months, P = 0.0020).

CONCLUSIONS

PDT may not have benefits for visual acuity in cases of tAMD and PCV over 5 years of follow-up.

Cerebrovascular accidents in patients treated for choroidal neovascularization with ranibizumab in randomized controlled trials

PURPOSE

To analyze cerebrovascular accidents (CVAs) pooled from large, randomized, controlled clinical trials of ranibizumab treatment for neovascular age-related macular degeneration.

METHODS

Events in five trials (FOCUS, MARINA, ANCHOR, PIER, and SAILOR) were analyzed using a standard safety monitoring process. Exact methods, stratified by study, were used to test for treatment differences based on odds ratios. A stepwise logistic regression model was fit to classify subjects' risk for CVA based on medical history. Treatment differences in CVA rates at 1 year or 2 years were evaluated within risk groups using stratified exact methods.

RESULTS

Pooled 2-year CVA rates were <3%; odds ratios (95% confidence intervals) for CVA risk were 1.2 (0.4-4.4) for ranibizumab 0.3-mg versus control, 2.2 (0.8-7.1) for 0.5 mg versus control, and 1.5 (0.8-3.0) for 0.5-mg versus 0.3-mg ranibizumab. No substantial increased risk of CVA for 0.5 mg versus 0.3 mg was identified in pooled analyses or any of the individual trials. In pooled analyses, the difference between 0.5-mg ranibizumab and control was larger (7.7 [1.2-177]) among high-risk CVA patients.

CONCLUSION

This analysis provided some evidence, although not definitive, of a potential increased risk of CVA with ranibizumab versus control or with 0.5-mg versus 0.3-mg ranibizumab. Continued monitoring for CVA within clinical trials seems warrented.

Age-related macular degeneration: current treatment and future options

Age-related macular degeneration is the leading cause of visual impairment among older adults in the developed world. Epidemiological studies have revealed a number of genetic, ocular and environmental risk factors for this condition, which can be addressed by disease reduction strategies. We discuss the various treatment options for dry and exudative age-related macular degeneration available and explain how the recommended treatment depends on the exact type, location and extent of the degeneration. Currently, vascular endothelial growth factor (VEGF) inhibition therapy is the best available treatment for exudative age-related macular degeneration but is limited by the need for repeated intravitreal injections. The current treatment regime is being refined through research on optimal treatment frequency and duration and type of anti-VEGF drug. Different modes of drug delivery are being developed and in the future other methods of VEGF inhibition may be used.

Relationship between retinal morphological findings and visual function in age-related macular degeneration

BACKGROUND

We aimed to study the retinal morphological findings associated with exudative age-related macular degeneration (AMD) and their association with visual prognosis.

METHODS

We retrospectively reviewed the medical records of 96 consecutive patients (96 eyes) with exudative AMD. Retinal structural changes were examined using optical coherence tomography (OCT).

RESULTS

Initial OCT examination showed cystoid macular edema in 18 eyes (18.8%), fibrin exudate in 56 eyes (58.3%), and hyperreflective foci within the neurosensory retina in 78 eyes (81.3%). Upon initial examination, an external limiting membrane (ELM) line was detected under the fovea in 64 eyes (66.7%). Using Pearson’s correlation analyses, final visual acuity (VA) was correlated with initial VA (r = 0.61, p < 0.001), age (r = 0.34, p < 0.001), initial total foveal thickness (r = 0.41, p < 0.001), presence of hyperreflective foci (r = 0.40, p < 0.001), and detection of a foveal ELM line (r = 0.55, p < 0.001). After multiple regression analysis, final VA correlated with initial VA (r = 0.48, p < 0.001), initial presence of hyperreflective foci (r = 0.23, p = 0.054), and detection of a foveal ELM line (r = 0.36, p = 0.008).

CONCLUSIONS

In eyes with exudative AMD, final VA was most correlated with initial VA. In addition, the initial integrity of the foveal outer retina was partially correlated with the visual prognosis. The initial ELM condition was associated with good final VA, while the initial presence of hyperreflective foci in the foveal neurosensory retina was associated with poor final VA.

Novel automated screening of age-related macular degeneration

PURPOSE

To determine the objective and quantitative hyperspectral parameters for distinguishing between age-related macular degeneration (AMD) and a normal macula.

METHODS

Near-infrared hyperspectral images were taken of 71 eyes of 62 AMD patients with exudative AMD and 21 eyes of 12 control subjects without AMD. The spatial information included a 480 × 321-pixel image in a 50° field located at the ocular fundus and a 720-950-nm-per-pixel reflectance spectrum. Macular vectors were determined as the average spectrum for each macula, and reference vectors were used as average macular vectors for healthy volunteers. Variations in vector length and angle were calculated based on comparison with the reference vector. The AMD differentiation index was a parameter that minimized the plot overlap between AMD patients and controls.

RESULTS

Statistically significant differences between the AMD patients and controls were noted. Receiver-operating characteristic curve analysis revealed an area under the curve of 0.888. The appropriate threshold values were attained for the proposed discrimination index, including 68 % sensitivity, 95 % specificity and 74 % accuracy.

CONCLUSIONS

This study presents a simplified diagnostic index for the determination of age-related macular degeneration based on near-infrared spectra.

Intraocular corticosteroids for posterior segment disease: 2012 update

INTRODUCTION

Diabetic macular edema (DME), cystoid macular edema (CME), age-related macular degeneration (AMD), retinal vascular occlusion (RVO) and uveitis are responsible for severe visual impairment worldwide. In some patients with these conditions, treatment with intraocular corticosteroids may be beneficial. Although off-label use of these agents has occurred for many years, novel agents including preservative-free and sustained-release intravitreal implants are currently being studied in clinical trials (CTs).

AREAS COVERED

This paper reviews the use of CTs for vitreoretinal (VR) diseases including choroidal neovascularization, CME, DME, RVO and posterior uveitis. It also discusses the use of corticosteroids for treating VR disease, including dexamethasone, fluocinolone acetonide, intravitreal implants and triamcinolone acetonide.

EXPERT OPINION

Used alone, intravitreal corticosteroids may benefit disorders such as DME, RVO and uveitis compared with standard therapy. Cases of exudative AMD non-responsive to standard treatment may benefit from combination therapy, including usage of intravitreal corticosteroid injections. Intraoperative use of these agents may aid visualization of retinal structures. Sustained-release intraocular implants have been approved for posterior uveitis and RVO associated with macular edema. In spite of this, most intraocular corticosteroids have a limited duration of action along with significant side effects, including cataract and glaucoma. Currently, intravitreal corticosteroid usage for DME is considered off-label.

Low-fluence photodynamic therapy combinations in the treatment of exudative age-related macular degeneration

AIM

To compare the efficacy of low-fluence photodynamic therapy (PDT) combinations in the treatment of age-related macular degeneration (AMD).

METHODS

Forty-five previously untreated eyes of 45 patients with exudative AMD whose best-corrected visual acuity (BCVA) was ≥0.3 (Snellen) were enrolled. 15 patients in Group I underwent low-fluence PDT (25J/cm(2)-300mW/cm(2)-83sec) and intravitreal pegaptanib combination, 15 patients in Group II underwent PDT (50J/cm(2)-600mW/cm(2)-83sec) and intravitreal pegaptanib combination while, 15 patients in Group III underwent intravitreal pegaptanib monotherapy. Complete ophthalmologic examinations were performed in pre and post treatment visits, and the results were statistically analised. A clinical activity score (CAS) was calculated by using changes in lesion size, amount of hemorrhage, staining pattern in FA and OCT measurement of intra/subretinal fluid. ≤ 3 logMAR lines of decrease in BCVA and decrease in CAS were considered as successful treatment.

RESULTS

The mean age of 19 female (42.2%) and 26 male (57.8%) patients was 72.82±8.02 years. Mean follow-up was 13.93±5.87 months. Lesion type was occult in 28 eyes (62.2%). Treatment success rates according to BCVA assessments were 86.7%, 80%, 60% and mean BCVA decrease were 0.3, 1.0, 2.2 logMAR lines in Group I, II and III, respectively (P>0.05). According to the changes in central macular thickness and CAS, no difference was found among the study groups (P=0.850 and P=0.811, respectively). Patients treated with combination regimens had lower intravitreal injection frequencies (P=0.015).

CONCLUSION

Combination regimen with intravitreal pegaptanib and low-fluence PDT seems to be safe and effective in stabilizing the clinical activity and BCVA in exudative AMD.

Aflibercept: a Potent Vascular Endothelial Growth Factor Antagonist for Neovascular Age-Related Macular Degeneration and Other Retinal Vascular Diseases

Introduction

In the western hemisphere, age-related macular degeneration (AMD) is the leading cause of visual loss in the elderly. Currently approved therapies for AMD include argon laser, photodynamic therapy, and antivascular endothelial growth factor (VEGF) therapy. The index review discusses aflibercept (VEGF Trap-Eye) in the context of current anti-VEGF therapies for neovascular AMD and other retinal vascular diseases. It highlights important differences between VEGF Trap-Eye and currently used anti-VEGF therapies for neovascular AMD; and discusses the efficacy of these treatments utilizing information from landmark clinical trials.

Methods

A systematic search of literature was conducted on PubMed, Science Direct, and Scopus with no limitations of language or years of publication.

Results

Preclinical studies have shown that VEGF Trap-Eye binds to VEGF-A with a higher affinity than other anti-VEGF molecules; and that it also binds to placental growth factor (PlGF). In clinical trials, VEGF Trap-Eye has been shown to be as effective in the treatment of neovascular AMD as other anti-VEGF therapies and possibly to have a longer duration of drug activity.

Conclusion

VEGF Trap-Eye has enhanced the treatment options currently available for the management of neovascular AMD. The comparable efficacy of VEGF Trap-Eye (to other anti-VEGF agents) coupled with its longer dosing interval may decrease the number of annual office visits for patients with AMD and their caregivers.

Canadian expert consensus: optimal treatment of neovascular age-related macular degeneration

BACKGROUND

New therapeutic approaches, particularly anti-vascular endothelial growth factor (anti-VEGF) therapies, prevent, and in some cases reverse, vision damage caused by age-related macular degeneration (AMD). Unequal access to care across Canada remains a problem for many retina specialists and their patients.

OBJECTIVE

To develop a consensus concerning the management of patients with exudative age-related macular degeneration (AMD).

DESIGN

Consensus document.

PARTICIPANTS

Ten Canadian retina specialists.

METHODS

The development of a consensus among Canadian experts concerning optimal treatment of AMD began with a review of the clinical evidence, daily practices, existing guidelines, and current national and international approvals and policies. The experts met on June 29, 2010, in Quebec City to discuss their findings and to propose strategies for consensus.

RESULTS

The result of this expert panel is a consensus proposal for Canadian ophthalmologists and retina specialists who are treating patients with or at risk for developing neovascular AMD.

CONCLUSIONS

The consensus provides guidelines to aid retina specialists in managing exudative AMD. Currently, ranibizumab is the only agent with sufficient Level I evidence and a Health Canada-approved indication for the treatment of wet AMD. Bevacizumab has been shown to be noninferior in preserving and improving visual acuity when compared to ranibizumab. Potential safety differences between the 2 drugs remain to be elucidated. The positioning of ranibizumab in this therapeutic area will be further defined as additional data for existing and emerging therapies become available. Until then, this agent remains the therapy of choice for individuals with neovascular AMD.

Recent Patents on Emerging Therapeutics for the Treatment of Glaucoma, Age Related Macular Degeneration and Uveitis

Advancements in the field and rising interest among pharmaceutical researchers have led to the development of new molecules with enhanced therapeutic activity. Design of new drugs which can target a particular pathway and/or explore novel targets is of immense interest to ocular pharmacologists worldwide. Delivery of suitable pharmacologically active agents at proper dose (within the therapeutic window) to the target tissues without any toxicity to the healthy ocular tissues still remain an elusive task. Moreover, the presence of static and dynamic barriers to drug absorption including the corneal epithelium (lipophilic), corneal and scleral stroma (hydrophilic), conjunctival lymphatics, choroidal vasculature and the blood-ocular barriers also pose a significant challenge for achieving therapeutic drug concentrations at the target site. Although many agents are currently available, new compounds are being introduced for treating various ocular diseases. Deeper understanding of the etiology and complex mechanisms associated with the disease condition would aid in the development of potential therapeutic candidates. Novel small molecules as well as complex biotechnology derived macromolecules with superior efficacy, safety and tolerability are being developed. Therefore, this review article provides an overview of existing drugs, treatment options, advances in emerging therapeutics and related recent patents for the treatment of ocular disorders such as glaucoma, age related macular degeneration (AMD) and uveitis.

Efficacy of combined photodynamic therapy and intravitreal bevacizumab injection versus photodynamic therapy alone in polypoidal choroidal vasculopathy

PURPOSE

To compare the efficacy of combined photodynamic therapy (PDT) and optical coherence tomography-guided intravitreal bevacizumab injection versus PDT alone for the treatment of polypoidal choroidal vasculopathy.

METHODS

The medical records of 39 patients with symptomatic polypoidal choroidal vasculopathy who received combination therapy with PDT and intravitreal bevacizumab injections or PDT monotherapy were retrospectively reviewed. Best-corrected visual acuity, number of treatments, and optical coherence tomography and angiographic findings were compared between the two patient groups.

RESULTS

In the PDT monotherapy group (n = 19), the mean number of PDTs was 1.89, whereas in the combined therapy group (n = 20), mean 1.30 times of PDT and 2.90 times of intravitreal bevacizumab injection were performed during the 12 months of follow-up. The number of PDTs was significantly different between the 2 groups (P = 0.032). At 12 months, the mean improvement in best-corrected visual acuity was 3.0 lines in the combined group and 1.6 lines in the PDT monotherapy group. At 12 months, improved vision by ≥ 3 lines was achieved in 55.0% in the combined therapy group and 36.8% in the PDT monotherapy group.

CONCLUSION

Combined PDT and bevacizumab therapy effectively treated polypoidal choroidal vasculopathy with fewer PDTs compared with PDT alone during the 1 year of follow-up. Combined treatment appeared to result in better visual acuity, but a larger scale study is required to draw a definite conclusion.

Interventions for age-related visual problems in patients with stroke

BACKGROUND

The prevalence of eye problems increases with age and, consequently, so does the level of visual impairment. As the incidence of stroke also increases with age, a significant proportion of stroke patients will have age-related visual problems. It is possible that the effect of interventions for age-related visual problems may differ in the population of stroke patients compared to the wider population of older people. The interaction between the problems arising directly from stroke and those arising directly from age-related visual problems will be complex. Interventions for age-related visual problems may also be affected by the presence of other stroke-related co-morbidities. Consequently, the nature and outcome of interventions for age-related visual problems may be different in patients with stroke.

OBJECTIVES

The aim of this review is to determine if interventions for age-related visual problems improve functional ability following stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (March 2011), the Cochrane Eyes and Vision Group Trials Register (December 2009) and nine electronic bibliographic databases including: the Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), MEDLINE (1950 to February 2011), EMBASE (1980 to February 2011), CINAHL (1982 to February 2011), AMED (1985 to February 2011) and PsycINFO (1967 to February 2011). We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts.

SELECTION CRITERIA

Randomised trials in adults after stroke, where the intervention is specifically targeted at assessing, treating or correcting age-related visual problems, or improving the ability of the patient to cope with visual impairment. Primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, visual acuity, visual field, visual function, balance, falls, depression and anxiety, discharge destination/residence after stroke, quality of life and social isolation, adverse events and death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts and planned to extract data and appraise trials. We planned that assessment of methodological quality would be undertaken for allocation concealment, blinding of outcome assessor, method of dealing with missing data and other potential sources of bias.

MAIN RESULTS

We considered 7357 titles, 460 abstracts and 85 full papers. We identified no studies for inclusion in this review.

AUTHORS' CONCLUSIONS

There are no implications for practice arising from this review. Evidence relating to the management of patients (from the general population) with age-related visual problems is available from other Cochrane reviews and is likely to be the best evidence available for making treatment decisions about individual patients. Subgroup analyses within these reviews to explore the effect of interventions for age-related visual problems in patients with stroke are recommended. We recommend that the objectives and selection criteria for this Cochrane review are amended and clarified prior to any future updates.

New Approach of Anti-VEGF Agents for Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of visual loss in older population. Angiogenesis is an important factor associated with the development of CNV due to AMD. Treatment of CNV with intravitreal anti-VEGF monotherapy is currently the standard of care. However, not all patients respond to monotherapy, and modified anti-VEGF treatment regimen and combination therapy may target reducing treatment frequency or improving visual outcome. This paper reviews the many clinical trials that have been performed utilizing several treatment regimens. While many trials have shown that this variable therapy is justifiable, further study is required to determine correct regimens and dosage.

Vascular complications and diabetes: current therapies and future challenges

Diabetic retinal complications, including macular edema (DME) and proliferative diabetic retinopathy (PDR), are the leading cause of new cases of blindness among adults aged 20–74. Chronic hyperglycemia, considered the underlying cause of diabetic retinopathy, is thought to act first through violation of the pericyte-endothelial coupling. Disruption of microvascular integrity leads to pathologic consequences including hypoxia-induced imbalance in vascular endothelial growth factor (VEGF) signaling. Several anti-VEGF medications are in clinical trials for use in arresting retinal angiogenesis arising from DME and PDR. Although a review of current clinical trials shows promising results, the lack of large prospective studies, head-to-head therapeutic comparisons, and potential long-term and systemic adverse events give cause for optimistic caution. Alternative therapies including targeting pathogenic specific angiogenesis and mural-cell-based therapeutics may offer innovative solutions for currently intractable clinical problems. This paper describes the mechanisms behind diabetic retinal complications, current research supporting anti-VEGF medications, and future therapeutic directions.

Experimental study on the photodynamic treatment of choroidal neovasculization with nanophthalocyanine photosensitizer

AIM

To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs).

METHODS

Two types of photosensitizers, G(1)-ZnPc(COOH)(8) and G(1)-ZnPc(COOH)(8)/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (△Ψm) were conducted on HRPE and HRECs after initial uptake of the two drugs.

RESULTS

Both photosensitizers demonstrated an improvement of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G(1)-ZnPc(COOH)(8)/m showed a better CNV closure effect versus G(1)-ZnPc(COOH)(8) (P<0.05). A significant difference (P<0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs (P>0.05). Both photosensitizers showed cytotoxicity on HRPE, but G(1)-ZnPc(COOH)(8)/m induced a lower cell viability.

CONCLUSION

G(1)-ZnPc(COOH)(8)/m mediated PDT is better than G(1)-ZnPc(COOH)(8) in CNV closure and also have the advantage of fast metabolism leading to less side effect.

One-year results of photodynamic therapy combined with intravitreal ranibizumab for exudative age-related macular degeneration

Purpose. To evaluate the effects of photodynamic therapy (PDT) combined with intravitreal injection of ranibizumab (IVR) for exudative age-related macular degeneration (AMD). Methods. Retrospective case series. Thirty eight eyes of 38 patients with exudative AMD underwent combined therapy consisting first of IVR, followed by PDT within a week and the second IVR at 1 month. All patients were followed up for more than 12 months. The best corrected visual acuity (BCVA) and central macular thickness (CMT) were examined. Results. The mean number of IVR and PDT sessions were 2.9 ± 1.3 and 1.1 ± 0.3, respectively. The mean BCVA and CMT were significantly improved to 0.38 logMAR units (P < 0.01) and 240 μm (P < 0.01) at 12 months, respectively. Thirty-six of 38 eyes (94.8%) improved or maintained BCVA at 12 months. Conclusion. PDT combined with IVR for exudative AMD was effective at improving visual acuity and CMT with a low recurrence rate for 12 months.

Meta-analysis of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents: causative organisms and possible prevention strategies

PURPOSE

To report the rates of endophthalmitis and the spectrum of causative organisms after intravitreal injection of anti-vascular endothelial growth factor agents and possible prevention strategies.

METHODS

Meta-analysis of the U.S. literature from 2005 to 2009 reporting endophthalmitis bacterial isolates after intravitreal injection of anti-vascular endothelial growth factor agents and comparison with reports of endophthalmitis bacterial isolates after intraocular surgery in the United States.

RESULT

Endophthalmitis after intravitreal injection occurred in 52 of 105,536 injections (0.049%) (95% confidence interval [CI], 0.038-0.065%). Among 50 cases of endophthalmitis with bacterial culture isolates, 24 (48.0% [95% CI, 34.8-61.5%]) were culture negative and 26 (52% [95% CI, 38.5-65.2%]) were culture positive. Among the 26 culture-positive isolates, causative organisms were coagulase-negative Staphylococcus in 17 cases (65.4% [95% CI, 46.0-80.6%]), Streptococcus species in 8 cases (30.8% [95% CI, 16.5-50.2%]), and Bacillus cereus in 1 case (3.8% [95% CI, 0.9-19.0%]). Streptococcus species were significantly more frequent after intravitreal injection than after intraocular surgery in the Endophthalmitis Vitrectomy Study (29 of 226 isolates, 9.0% [95% CI, 6.3-12.6%], P = 0.005), a report on clear corneal cataract surgery endophthalmitis (6 of 73 isolates, 8.2% [95% CI, 3.9-16.8%], P = 0.022), and a report on postvitrectomy endophthalmitis with no cases of Streptococcus species.

CONCLUSION

Streptococcal isolates are approximately three times more frequent after intravitreal anti-vascular endothelial growth factor injection than after intraocular surgery. Strategies to consider minimizing oropharyngeal droplet transmission may include avoiding talking, coughing, and sneezing or wearing surgical masks.

Endophthalmitis following intravitreal injections

BACKGROUND

To report the clinical features, culture results, management and visual outcome of patients with endophthalmitis following intravitreal injections.

METHODS

Retrospective review of all patients with suspected endophthalmitis after intravitreal injections treated with intravitreal antibiotics (teicoplanin and ciprofloxacin) at a referral centre between January 2003 and December 2010.

RESULTS

Nineteen cases that had aqueous or vitreous biopsy were identified. Nine had negative culture. Ten had positive culture; Staphylococcus species in 4/10, Streptococcus species in 4/10, E. coli in 1/10 and gram-negative bacilli in 1/10. Symptoms developed within the first 48 hours in all. One of ten culture-positive cases had no pain on presentation, while 5/9 patients with negative culture reported pain. Initial treatment consisted of intravitreal antibiotics in all cases, 6/19 cases required a second intravitreal antibiotic injection, 4/19 underwent vitrectomy as secondary therapy. At the last follow up, 7/19 patients had visual acuity of 6/18 or better, 9/19 had visual acuity of 6/60 or worse.

CONCLUSION

The overall numbers of patients with endophthalmitis following intravitreal injections has risen dramatically over the past years. In contrast to earlier reports of multicentre studies, outcome of patients is relatively poor in the current treatment settings. We did not find clinical features useful in identifying cases with negative culture.

Effects of combination therapy with verteporfin photodynamic therapy and ranibizumab in patients with age-related macular degeneration

PURPOSE

This open-label, prospective, small-scale study investigated the benefits of same-day verteporfin and intravitreal ranibizumab in patients with predominantly classic, minimally classic or occult subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration.

METHODS

Patients received verteporfin at baseline and at month 3, if leakage persisted. Ranibizumab (0.5 mg) was given at baseline and months 1, 2 and 3, and thereafter at monthly intervals if required. Same-day ranibizumab was given ≥ 1 hr after verteporfin.

RESULTS

Fifteen patients [11 male, four female; mean age 75.5 years (range 54-94 years)] were treated. At day 360, mean visual acuity (VA) had improved by 10.9 letters. An increase of ≥ 15 and ≥ 30 letters (i.e. ≥ 3 and ≥ 6 lines) was observed in seven (47%) patients and one patient (7%), respectively. Mean central retinal thickness (CRT) decreased by 85 μm. At days 7, 14 and 30, CNV perfusion was absent in 14/15 patients. Mean lesion area had reduced from baseline by 23.1% at day 120, 25.5% at day 180 and 23.6% at day 360. There were no visual safety concerns and intraocular pressures remained normal. Only two serious adverse events were recorded over the 12-month period, and neither was considered to be related to treatment.

CONCLUSION

Same-day verteporfin plus ranibizumab improved VA, reduced CRT, prevented CNV perfusion and reduced lesion area safely over 12 months. Further investigation is warranted to confirm whether this combination improves long-term vision and reduces the need for retreatment.

Review of combination therapies for neovascular age-related macular degeneration

While angiogenesis is one of the factors associated with the development of CNV due to age-related macular degeneration (AMD), inflammation and oxidative stress also appear to play a role. Treatment of CNV with intravitreal anti-vascular endothelial growth factor monotherapy is currently the standard of care. However, not all patients respond to monotherapy, and combination therapy may target the CNV through multiple mechanisms, thus reducing treatment frequency or improving visual outcome. Photodynamic therapy (with regular or reduced fluence), as well as intravitreal steroids are used in combination with anti-VEGF therapy. This paper reviews the many clinical trials that have been performed utilizing several combinations of double and triple therapy. While combination therapy is biologically justifiable, further study is required to determine correct combinations and dosage.

Combined treatment of photodynamic therapy and bevacizumab for choroidal neovascularization secondary to age-related macular degeneration

Purpose

To evaluate the outcome of a combined photodynamic therapy and intravitreal injection of bevacizumab in choroidal neovascularization secondary to age-related macular degeneration.

Methods

Photodynamic therapy (PDT) was administered to 28 eyes followed by 3 consecutive bevacizumab injections. Patients were followed-up for more than 12 months. At baseline, 1, 3, 6, and 12 months post PDT, visual acuity (VA) and central macular thickness were measured using optical coherence tomography.

Results

The mean VA was significantly improved from logarithm of the minimal angle of resolution 0.86 at baseline to 0.69 at 1 month (p = 0.011), 0.63 at 3 months (p = 0.003), 0.64 at 6 months (p = 0.004) and 0.60 at 12 months (p < 0.001). Central macular thickness decreased significantly from 328.3 µm at baseline to 230.0 µm at 6 months and 229.9 µm at 1 year (p < 0.001). Reinjection mean number was 0.4 for 6 months and 0.8 for 12 months. By 1 year, retreatment was performed in 10 eyes (36%).

Conclusions

PDT combined with three consecutive intraviteal bevacizumab injections was effective in improving VA and reducing central macular thickness.

Treatment of age-related macular degeneration: focus on ranibizumab

Ranibizumab, a humanized antigen-binding fragment (Fab) that binds all isoforms of VEGF-A, significantly slows down loss of vision and causes significant visual improvement in many patients with choroidal neovascularization (CNV) due to exudative age-related macular degeneration (AMD). These benefits of intravitreal ranibizumab apply to all angiographic subtypes of neovascular AMD and across all lesion sizes when the drug is injected at monthly intervals as shown in two pivotal phase III trials (ANCHOR and MARINA). The results from the PrONTO study suggest that less frequent treatment with ranibizumab through a variable dosing regimen dependent on optical coherence tomography (OCT) findings is a treatment option that results in comparably favorable visual outcomes. Currently, it is unclear whether combination therapy of ranibizumab with photodynamic therapy (PDT) provides any significant advantage over ranibizumab monotherapy (FOCUS trial); however, the combination of PDT and ranibizumab may decrease the need for frequent retreatment. This question will be addressed in the SUMMIT trial. Therapy with ranibizumab is generally very well tolerated with a low rate of seriously adverse ocular events or systemic side-effects. The advent of vascular endothelial growth factor (VEGF) inhibitors has revolutionized the therapy of neovascular AMD. Ranibizumab at the moment appears to be the most effective approved treatment for neovascular AMD.

Combined treatment of exudative age related macular degeneration with photodynamic therapy and intravitreal triamcinolone

Choroidal neovascularization (CNV) secondary to age related macular degeneration is among the leading causes of legal blindness in developed countries. Photodynamic therapy (PDT) with verteporfin induces CNV closure causing little damage to healthy tissue, but the need to re-treat may lead to low final visual acuity at an unacceptable cost. The association of intravitreous triamcinolone or antiangiogenic drugs with PDT has been used in order to reduce these limitations of the therapy. The combination of PDT and intravitreous triamcinolone, its complications and outcome at one and two-year follow-up are discussed.

Current and emerging therapies for the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in the industrialized world. In the last few decades, the mainstay of treatment for choroidal neovascularization (CNV) due to AMD has been thermal laser photocoagulation. In the last decade, photodynamic therapy with verteporfin extended treatment for more patients. While both of these treatments have prevented further vision loss in a subset of patients, improvement in visual acuity is rare. Anti-vascular endothelial growth factor A (VEGF) therapy has revolutionized the treatment of AMD-related CNV. Pegaptanib, an anti-VEGF aptamer prevents vision loss in CNV, although the performance is similar to that of photodynamic therapy. Ranibizumab, an antibody fragment and bevacizumab, a full-length humanized monoclonal antibody against VEGF have both shown promising results with improvements in visual acuity with either agent. VEGF trap, a modified soluble VEGF receptor analogue, binds VEGF more tightly than all other anti-VEGF agents and has also shown promising results in early trials. Other treatment strategies to decrease the effect of VEGF have used small interfering ribonucleic acid (RNA) to inhibit VEGF production and VEGF receptor production. Steroids, including anecortave acetate in the treatment and prevention of CNV, have shown promise in controlled trials. Receptor tyrosine kinase inhibitors, such as vatalanib, inhibit downstream effects of VEGF, and have been effective in the treatment of CNV in early studies. Squalamine lactate inhibits plasma membrane ion channels with downstream effects on VEGF, and has shown promising results with systemic administration. Other growth factors, including pigment epithelium-derived growth factor that has been administered via an adenoviral vector has shown promising initial results. In some patients ciliary neurotrophic factor is currently being studied for the inhibition of progression of geographic atrophy. Combination therapy has been investigated, and may prove to be more effective in the management of AMD-associated CNV. Ongoing and future studies will be crucial for optimizing the treatment of patients with AMD.

A systematic review of the efficacy and safety outcomes of anti-VEGF agents used for treating neovascular age-related macular degeneration: comparison of ranibizumab and bevacizumab

OBJECTIVE

To systematically review ocular and systemic events in treatment of wet age-related macular degeneration (AMD) with anti-vascular endothelial growth factor antibodies, ranibizumab and bevacizumab, and to provide a detailed perspective of their differences on clinical use, efficacy and safety.

RESEARCH DESIGN AND METHODS

This review was based on a 2010 PubMed literature search performed using two separate terms: 'lucentis' OR 'ranibizumab' AND 'age-related macular degeneration' OR 'AMD' or 'avastin' OR 'bevacizumab' AND 'age-related macular degeneration' OR 'AMD'. A clinical diagnosis of wet AMD was defined by the authors of the trial reports. Clinical studies that met Level I or Level II evidence criteria were considered for review.

FINDINGS

Eight large, randomized, controlled trials of ranibizumab (Level I) included 1,485 patients (range 162-716) and four open-label studies of ranibizumab (Level II) included 4,484 patients (range 32-4,300). Six studies (one Level I, five Level II) of bevacizumab included 424 patients (range 28-165). All demonstrated improvements in visual acuity. Only one study (Level II) compared the efficacy of ranibizumab and bevacizumab. Adverse ocular and systemic safety events occurring during the study were prospectively recorded for ranibizumab, irrespective of their suspected relationship to study treatments. Only three of six bevacizumab studies reported details of adverse ocular or systemic events. There was extensive Level I and Level II evidence to support both the efficacy and safety of ranibizumab in wet AMD. Data suggest that bevacizumab provides efficacy in wet AMD, but the safety profile of intravitreal bevacizumab remains to be established.

CONCLUSION

In contrast to ranibizumab, current safety data for bevacizumab are incomplete and not yet robust. If the medical community remains committed to using intravitreal bevacizumab, it is critical to establish that it has an acceptable safety profile, supported by evidence-based medicine. Considerable further research is warranted to achieve this.

Ranibizumab versus bevacizumab for the treatment of neovascular age-related macular degeneration

PURPOSE OF REVIEW

This paper reviews the recent literature regarding the effectiveness, efficacy and safety of intravitreal bevacizumab as compared with ranibizumab for the treatment of neovascular age-related macular degeneration (nAMD).

RECENT FINDINGS

Numerous randomized clinical trials have demonstrated the safety and efficacy of ranibizumab for the treatment of nAMD. Bevacizumab, developed, labeled and approved for the management of colorectal cancer, has been used off-label for the management of nAMD. However, given its lower cost and effectiveness, it is commonly used for many cases of nAMD. Recent clinical trials have demonstrated similar effectiveness between the two compounds in terms of visual acuity and central macular thickness. However, emerging data have suggested that these two compounds may have different ocular and systemic adverse event profiles; bevacizumab has been linked to both a higher risk of severe intraocular inflammation and a higher risk of incident arterial thromboembolic events. This incremental risk for both ocular and systemic adverse events may have an impact on the incremental cost-effectiveness ratio derived from health economic models that directly compare one anti-vascular endothelial growth factor (VEGF) compound to the other.

SUMMARY

Numerous clinical trials, including the Comparison of AMD Treatment Trial, are underway examining the comparative efficacy of ranibizumab versus bevacizumab for the treatment of nAMD. While these studies may demonstrate clinical noninferiority of one anti-VEGF compound over another, they may not be adequately powered to detect important differences in ocular and systemic safety. Large-scale, appropriately powered safety studies need to be conducted to evaluate differences in safety.

Preclinical aspects of anti-VEGF agents for the treatment of wet AMD: ranibizumab and bevacizumab

Three anti-vascular endothelial growth factor (VEGF) therapies are currently used for the treatment of patients with wet age-related macular degeneration (AMD): pegaptanib, ranibizumab, and bevacizumab. Ranibizumab is an antibody fragment approved for the treatment of wet AMD. Bevacizumab is a full-length antibody registered for use in oncology but unlicensed for wet AMD. However, it is used off-label worldwide not only for wet AMD but also for various other ocular diseases associated with macular edema and abnormal vessel growth. We consider aspects of ranibizumab and bevacizumab in relation to their molecular characteristics, in vitro and in vivo properties, and preclinical safety data. Before 2009, most studies described the short-term toxicity of bevacizumab in multiple cell types of the eye. Since 2009, an increasing number of studies have compared the properties of ranibizumab and bevacizumab and investigated their impact on retinal cell functioning. Compared with bevacizumab, ranibizumab neutralizes VEGF better at low concentrations, maintains efficacy for longer, and has a higher retinal penetration and potency. Studies in animals demonstrate ranibizumab to be better localized to the injected eye, whereas bevacizumab appears to have a greater effect in the fellow eye. In humans, a localized and systemic effect has been reported for both molecules. In conclusion, overlapping yet distinct pharmacological properties of ranibizumab and bevacizumab indicate that safety or efficacy data from one cannot be extrapolated to the other.