Retinal angiomatous proliferation or retinal anastomosis to the lesion

An Automated Comparative Analysis of the Exudative Biomarkers in Neovascular Age-Related Macular Degeneration, The RAP Study: Report 6

PURPOSE

To investigate differences in volume and distribution of the main exudative biomarkers across all types and subtypes of macular neovascularization (MNV) using artificial intelligence (AI).

DESIGN

Cross-sectional study.

METHODS

An AI-based analysis was conducted on 34,528 OCT B-scans consisting of 281 (250 unifocal, 31 multifocal) MNV3, 55 MNV2, and 121 (30 polypoidal, 91 non-polypoidal) MNV1 treatment-naive eyes. Means (SDs), medians and heat maps of cystic intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachments (PED), and hyperreflective foci (HRF) volumes, as well as retinal thickness (RT) were compared among MNV types and subtypes.

RESULTS

MNV3 had the highest mean IRF with 291 (290) nL, RT with 357 (49) µm, and HRF with 80 (70) nL, P ≤ .05. MNV1 showed the greatest mean SRF with 492 (586) nL, whereas MNV3 exhibited the lowest with 218 (382) nL, P ≤ .05. Heat maps showed IRF confined to the center, whereas SRF was scattered in all types. SRF, HRF, and PED were more distributed in the temporal macular half in MNV3. Means of IRF, HRF, and PED were higher in the multifocal than in the unifocal MNV3 with 416 (309) nL,114 (95) nL, and 810 (850) nL, P ≤ .05. Compared to the non-polypoidal subtype, the polypoidal subtype had greater means of SRF with 695 (718) nL, HRF 69 (63) nL, RT 357 (45) µm, and PED 1115 (1170) nL, P ≤ .05.

CONCLUSIONS

This novel quantitative AI analysis shows that SRF is a biomarker of choroidal origin in MNV1, whereas IRF, HRF, and RT are retinal biomarkers in MNV3. Polypoidal MNV1 and multifocal MNV3 present with higher exudation compared to other subtypes.

Early OCTA Changes of Type 3 Macular Neovascularization Following Brolucizumab Intravitreal Injections

Background and Objectives: Brolucizumab is a novel anti-vascular endothelial growth factor (VEGF), whose efficacy has been shown in the Hawk and Harrier phase 3 clinical studies. The goal of the present case series is to report initial results of brolucizumab intravitreal injections (IVI) on type 3 neovascularization in neovascular age-related macular degeneration (nAMD), evaluated by optical coherence tomography angiography (OCTA). Materials and Methods: This is a bicentric retrospective case series. Patients with newly diagnosed type 3 MNV treated with brolucizumab IVI and at least 6 months follow-up were enrolled. OCTA en face images and B-scans were analyzed for lesions at baseline, 1 month, 3 months, and 6 months. Whenever detectable, lesion area on outer retina and choriocapillaris layers was measured. Results: Twelve eyes of 12 patients were included into the study. The most consistent OCTA sign at baseline was the presence of a vascular tuft in the outer retina (100%). The highest response was achieved at 3 months, with statistically significant decrease in lesion detection in the outer retina, in the choriocapillaris, and outer retinal lesion size. At 6 months, 58% of outer retinal lesions had disappeared. Conclusions: Brolucizumab IVI shows a good short-term efficacy for the treatment of type 3 neovascularizations. Further studies with greater number of patients and longer follow-up are warranted to confirm these findings.

Three-Year Outcomes of Intravitreal Aflibercept Injections for Retinal Angiomatous Proliferation According to Disease Stage

INTRODUCTION

To evaluate the outcomes of intravitreal aflibercept injections for retinal angiomatous proliferation (RAP) according to disease stage.

METHODS

This retrospective chart review included 68 eyes of 53 individuals diagnosed as having RAP and 109 neovascular age-related macular degeneration (nAMD) eyes of 109 patients as controls. All patients received intravitreal injections of aflibercept in a real-world setting. The main outcome measures were the changes in the mean of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) as well as the total number of injections received during the 3-year follow-up period.

RESULTS

The average BCVA and CRT changes in eyes affected by RAP and the controls at 3 years were non-significant. Both populations received a similar number of injections. After 3 years of treatment, patients with RAP had visual decline despite stable anatomical outcomes. Approximately 50% of the eyes with stage II RAP exhibited significant BCVA decline at the end of the third year. Among those eyes that had deteriorated BCVA, persistently worsening BCVA and thinning CRT were observed from year 2 to year 3.

CONCLUSION

Similar to treating nAMD, intensive injections or aggressive treatment strategies are required to treat RAP to achieve optimal visual outcomes in a real-world setting. The response to aflibercept treatment at the second year is associated with the final visual outcome of eyes with stage II RAP lesions.

THE RAP STUDY, REPORT 5: REDISCOVERING MACULAR NEOVASCULARIZATION TYPE 3: Multimodal Imaging of Fellow Eyes over 24 months

Retinal–choroidal anastomosis is an exclusive clinical finding of macular neovascularization Type 3 in eyes with neovascular age-related macular degeneration. Multifocal macular neovascularization Type 3 is usually bilateral, and the lesions develop simultaneously, but when the multifocal phenotype is unilateral, it appears before the development of the unifocal one in the contralateral eye.

To explore the condition of fellow eyes of patients with macular neovascularization Type 3 (MNV3) and to verify whether the retinal–choroidal anastomosis (RCA) develops equally in all MNV types.

Classifying neovascular age-related macular degeneration with a deep convolutional neural network based on optical coherence tomography images

Neovascular age-related macular degeneration (nAMD) is among the main causes of visual impairment worldwide. We built a deep learning model to distinguish the subtypes of nAMD using spectral domain optical coherence tomography (SD-OCT) images. Data from SD-OCT images of nAMD (polypoidal choroidal vasculopathy, retinal angiomatous proliferation, and typical nAMD) and normal healthy patients were analyzed using a convolutional neural network (CNN). The model was trained and validated based on 4749 SD-OCT images from 347 patients and 50 healthy controls. To adopt an accurate and robust image classification architecture, we evaluated three well-known CNN structures (VGG-16, VGG-19, and ResNet) and two customized classification layers (fully connected layer with dropout vs. global average pooling). Following the test set performance, the model with the highest classification accuracy was used. Transfer learning and data augmentation were applied to improve the robustness and accuracy of the model. Our proposed model showed an accuracy of 87.4% on the test data (920 images), scoring higher than ten ophthalmologists, for the same data. Additionally, the part that our model judged to be important in classification was confirmed through Grad-CAM images, and consequently, it has a similar judgment criteria to that of ophthalmologists. Thus, we believe that our model can be used as an auxiliary tool in clinical practice.

MULTIMODAL EVIDENCE OF TYPE 3 NEOVASCULARIZATION IN ENHANCED S-CONE SYNDROME

PURPOSE

To investigate, using multimodal imaging, the anatomy of neovascularization in eyes with enhanced S-cone syndrome.

METHODS

Three eyes with neovascularization, from two patients with enhanced S-cone syndrome, were analyzed using fluorescein angiography, indocyanine-green and optical coherence tomography angiography imaging.

RESULTS

The eyes reported had a demonstrable Type 3 neovascularization with evidence of retinal-retinal anastomoses on fluorescein angiography, indocyanine-green and optical coherence tomography angiography imaging. One eye that was initially without neovascularization, but with chronic macular edema developed a macular hemorrhage. This eye was treated with 8 injections of intravitreal bevacizumab over 29-months resulting in a final fibrovascular lesion. The characteristics of this final lesion share similarities to the two other eyes described. In all eyes and all exams, retinal vessels are observed to communicate with the subretinal fibrovascular lesion.

CONCLUSION

We provide evidence of retinal arteriovenous anastomosis of the superficial retinal plexus to a subretinal neovascular complex in patients with enhanced S-cone syndrome and point to similarities with Type 3 neovascularization in macular telengiectasia Type 2 (MacTel2) and age-related macular degeneration. These findings provide insights into the anatomy of neovascularization in these pathologies and may lead to hypotheses of their etiologies.

Clinical Pathological Features and Current Animal Models of Type 3 Macular Neovascularization

Type 3 macular neovascularization (MNV3), or retinal angiomatous proliferation (RAP), is a distinct type of neovascular age-related macular degeneration (AMD), which is a leading cause of vision loss in older persons. During the past decade, systematic investigation into the clinical, multimodal imaging, and histopathological features and therapeutic outcomes has provided important new insight into this disease. These studies favor the retinal origin of MNV3 and suggest the involvement of retinal hypoxia, inflammation, von Hippel–Lindau (VHL)–hypoxia-inducible factor (HIF)–vascular endothelial growth factor (VEGF) pathway, and multiple cell types in the development and progression of MNV3. Several mouse models, including the recently built Rb/p107/Vhl triple knockout mouse model by our group, have induced many of the histological features of MNV3 and provided much insight into the underlying pathological mechanisms. These models have revealed the roles of retinal hypoxia, inflammation, lipid metabolism, VHL/HIF pathway, and retinoblastoma tumor suppressor (Rb)–E2F cell cycle pathway in the development of MNV3. This article will summarize the clinical, multimodal imaging, and pathological features of MNV3 and the diversity of animal models that exist for MNV3, as well as their strengths and limitations.

Unaffected fellow eye neovascularization in patients with type 3 neovascularization: Incidence and risk factors

Purpose

To evaluate the incidence and risk factors of neovascularization in unaffected fellow eyes of patients diagnosed with type 3 neovascularization in Korea.

Methods

This retrospective study included 93 unaffected fellow eyes of 93 patients diagnosed with type 3 neovascularization. For initial type 3 neovascularization diagnosis, optical coherence tomography and angiography were conducted. These baseline data were compared between patients with and without neovascularization in their fellow eyes during the follow-up period.

Results

The mean follow-up period was 66.1±31.1 months. Neovascularization developed in 49 (52.8%) fellow eyes after a mean period of 29.5±19.6 months. In the fellow eye neovascularization group, the incidence of soft drusen and reticular pseudodrusen was significantly higher than that in the non-neovascularization group (83.7% vs. 36.5%, p<0.001; 67.3% vs. 40.9%, p = 0.017, respectively), but the choroidal vascularity index (CVI) showed a significantly lower value (60.7±2.0% vs. 61.7±2.5%; p = 0.047). The presence of reticular pseudodrusen was related with the duration from baseline to development of fellow eye neovascularization (p = 0.038).

Conclusion

Neovascularization developed in 52.8% of unaffected fellow eyes. The presence of soft drusen, reticular pseudodrusen, and lower CVI values can be considered risk factors of neovascularization in unaffected fellow eyes of patients with type 3 neovascularization. The lower CVI values suggest that choroidal ischemic change may affect the development of choroidal neovascularization in these patients.

Distinguishing retinal angiomatous proliferation from polypoidal choroidal vasculopathy with a deep neural network based on optical coherence tomography

This cross-sectional study aimed to build a deep learning model for detecting neovascular age-related macular degeneration (AMD) and to distinguish retinal angiomatous proliferation (RAP) from polypoidal choroidal vasculopathy (PCV) using a convolutional neural network (CNN). Patients from a single tertiary center were enrolled from January 2014 to January 2020. Spectral-domain optical coherence tomography (SD-OCT) images of patients with RAP or PCV and a control group were analyzed with a deep CNN. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUROC) were used to evaluate the model's ability to distinguish RAP from PCV. The performances of the new model, the VGG-16, Resnet-50, Inception, and eight ophthalmologists were compared. A total of 3951 SD-OCT images from 314 participants (229 AMD, 85 normal controls) were analyzed. In distinguishing the PCV and RAP cases, the proposed model showed an accuracy, sensitivity, and specificity of 89.1%, 89.4%, and 88.8%, respectively, with an AUROC of 95.3% (95% CI 0.727-0.852). The proposed model showed better diagnostic performance than VGG-16, Resnet-50, and Inception-V3 and comparable performance with the eight ophthalmologists. The novel model performed well when distinguishing between PCV and RAP. Thus, automated deep learning systems may support ophthalmologists in distinguishing RAP from PCV.

Type 3 neovascularisation (retinal angiomatous proliferation) treated with antivascular endothelial growth factor: real-world outcomes at 24 months

Aims

To compare 24 months outcomes of eyes with retinal angiomatous proliferations (RAPs) treated with antivascular endothelial growth factor (anti-VEGF) with a group of controls diagnosed with other neovascular age-related macular degeneration (nAMD) subtypes in a real-world setting.

Methods

Treatment-naïve nAMD eyes that commenced anti-VEGF between January 2006 and November 2015 were identified from a registry of nAMD treatment outcomes. Cases were defined as eyes diagnosed with RAP. Three controls per case were selected among nAMD eyes with non-RAP lesions and matched on baseline visual acuity (VA), year of treatment initiation, anti-VEGF agent first injected and follow-up. Baseline VA was compared with 12 and 24 months VA. Change in VA, number of injections received, proportion of visits with active nAMD and time to first inactivation were compared between RAPs and controls.

Results

157 RAPs and 469 controls were included. Baseline VA (mean (SD)) increased at 12 months (61.4 (15.5) vs 68.7 (14.7) letters, p<0.001) and remained higher (66.6 (17.3) letters) at 24 months (p<0.001) in RAPs. The change from baseline VA (mean(95% CI)) was significantly higher in RAPs than in controls at 12 months (7.3 (5.4 to 9.1) vs 4.1 (2.8 to 5.4) letters, p=0.01) and at 24 months (5.1 (2.8 to 7.3) vs 2.5 (1 to 4) letters, p=0.056). Both groups received a median of 13 injections. RAPs inactivated earlier and were less active than controls (both p<0.001).

Conclusions

RAPs responded well to anti-VEGF, with a significant improvement in VA persisting at 24 months. RAPs had better visual outcomes than controls at 12 and 24 months, tended to inactivate earlier and were less active throughout 2 years follow-up.

[Anti-VEGF therapy resistance in neovascular age-related macular degeneration]

With account to the increase in the elderly population in most of the developed countries, the WHO defines age-related macular degeneration (AMD) as one of the main causes of blindness in the world. A large percentage of disability is accounted for by exudative, or neovascular, form of AMD. Today, a total of 5 anti-VEGF drugs exist that are recommended for treatment of exudative AMD: pegaptanib, ranibizumab, bevacizumab, aflibercept, and conbercept. Despite significant progress in the treatment of neovascular AMD yielded by the introduction into clinical practice of anti-VEGF drugs, some patients report a lack (down to complete lack) of response with standard treatment patterns and even a decrease in treatment efficacy after repeated intravitreal injections.

The Role of Hypoxia, Hypoxia-Inducible Factor (HIF), and VEGF in Retinal Angiomatous Proliferation

In industrialized countries, age-related macular degeneration (AMD) is the leading cause of blindness in elderly people. Hallmarks of the non-neovascular (dry) form of AMD are the formation of drusen and geographic atrophy, whereas the exudative (wet) form of the disease is characterized by invading blood vessels. In retinal angiomatous proliferation (RAP), a special form of wet AMD, intraretinal vessels grow from the deep plexus into the subretinal space. Little is known about the mechanisms leading to intraretinal neovascularization, but age-related changes such as reduction of choroidal blood flow, accumulation of drusen, and thickening of the Bruch's membrane may lead to reduced oxygen availability in photoreceptors. Such a chronic hypoxic situation may induce several cellular response pathways including the stabilization of hypoxia-inducible factors (HIFs) and the production of angiogenic factors, such as vascular endothelial growth factor (VEGF). Here, we discuss the potential contribution of hypoxia and HIFs in RAP disease pathology and in some mouse models for subretinal neovascularization.

Association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V polymorphisms with retinal angiomatous proliferation compared with typical age-related macular degeneration: a meta-analysis

PURPOSE

To compare the published results of studies on the genotype association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V in cases diagnosed as retinal angiomatous proliferation (RAP) versus neovascular age-related macular degeneration (AMD) or healthy controls.

METHODS

Heterogeneity of studies was evaluated using Cochran's Q test and I-square index. To modify the heterogeneity in the variables, we used random effects model. Meta-analysis was performed using STATA.

RESULTS

Four studies were included with 1076 neovascular AMD patients, 222 RAP cases, and 2276 control subjects. Pooled overall odds ratios for RAP/AMD were 1.15 (95% CI 0.60-2.18) for GT versus GG, 3.52 (95% CI 1.25-9.91) for TT versus GG ARMS2, 0.98 (95% CI 0.22-4.29) for GA versus AA, 1.00 (95% CI 0.25-4.02) for GG versus AA CFHI62V, 0.57 (95% CI 0.35-0.93) for CT versus TT CFH Y402H, and 0.40 (95% CI 0.22-0.74) for CC versus TT CFH Y402H. Regression analysis showed that ARMS2 TT genotype has a statistically significant effect on RAP versus AMD compared to CFH genotypes (P < 0.001).

CONCLUSION

This meta-analysis disclosed a stronger effect of ARMS2 genotypes in RAP cases compared with CFH Y402H and I62V genotypes.

[Intravitreal ranibizumab for the treatment of retinal angiomatous proliferation]

BACKGROUND

Retinal angiomatous proliferations (RAP) are a subgroup of exsudative or "wet" age-related macular degeneration (wAMD) with devastating reduction of visual acuity in later stages. Intravitreal ranibizumab provides good therapy, but is considered to be less effective than in other choroidal neovascularizations (CNV).

OBJECTIVE

We investigated the efficacy of ranibizumab in late-stage III RAP with retinochoroidal anastomosis compared to the outcome of other CNV lesions.

MATERIALS AND METHODS

The data of all patients with wAMD treated with ranibizumab were retrospectively analyzed. Patients were divided into groups depending on the lesion type into RAP (identified and selected clinically, proven by fluorescein angiography) and CNV lesions (identified by fluorescein angiography only) named occult, minimally and predominantly classic groups. The best-corrected visual acuity (BCVA) was obtained before (at the timepoint "diagnosis"), during (1st, 2nd, and 3rd injection), and after upload ("1st control").

RESULTS

Before first injection, visual acuity decreased in all groups (0.73 to 0.78 logMAR for all CNV, 0.95 to 1.02 logMAR for RAP). During upload there was no further decline in visual acuity but no improvement as well up to the 1st control visit in the RAP group (1.02 to 1.03 logMAR), but a statistically significant increase in all other groups (0.78 to 0.67 logMAR).

CONCLUSION

Treatment of late-stage III RAP with ranibizumab is effective. Stabiliziation of visual acuity can be achieved, but-in contrast to other forms of CNV lesions-no further improvement. Therefore, patients with this special form need to be identified and treated as early as possible.

Resistance to anti-VEGF therapy in neovascular age-related macular degeneration: a comprehensive review

As a progressive chronic disease, age-related macular degeneration (AMD) is the leading cause of irreversible vision impairment worldwide. Experimental and clinical evidence has demonstrated that vascular endothelial growth factor (VEGF) plays a vital role in the formation of choroidal neovascularization. Intravitreal injections of anti-VEGF agents have been recommended as a first-line treatment for neovascular AMD. However, persistent fluid or recurrent exudation still occurs despite standardized anti-VEGF therapy. Patients suffering from refractory or recurrent neovascular AMD may develop mechanisms of resistance to anti-VEGF therapy, which results in a diminished therapeutic effect. Until now, there has been no consensus on the definitions of refractory neovascular AMD and recurrent neovascular AMD. This article aims at clarifying these concepts to evaluate the efficacy of switching drugs, which contributes to making clinical decision more scientifically. Furthermore, insight into the causes of resistance to anti-VEGF therapy would be helpful for developing possible therapeutic approaches, such as combination therapy and multi-target treatment that can overcome this resistance.

One-year result of aflibercept treatment on age-related macular degeneration and predictive factors for visual outcome

PURPOSE

To investigate the efficacy of periodic injection of aflibercept in each subtype of age-related macular degeneration (AMD) and to explore the predictive factors for visual outcome in clinical settings.

DESIGN

Prospective nonrandomized interventional case series.

METHODS

Patients with AMD were recruited and were administered aflibercept injections once a month for 3 months followed by once every 2 months for 8 months. The logarithm of the minimal angle of resolution (logMAR) at 12 months and improvement of vision from baseline were compared among polypoidal choroidal vasculopathy (PCV), retinal angiomatous proliferation (RAP), and typical AMD. Regression rate of polypoidal lesions was assessed. We also performed regression analysis with logMAR at 12 months as the dependent variable.

RESULTS

The study sample consisted of 98 patients: 46 had typical AMD, 42 had PCV, and 10 had RAP. Mean logMAR improved from 0.36 to 0.21 in 12 months. While there was no difference in visual improvement between typical AMD and PCV, final logMAR was better in PCV (0.32 ± 0.09 vs 0.08 ± 0.04, P = .016). Thirty-nine PCV patients underwent follow-up angiography, and regression of polyps was observed in 27 cases (69.2%). Multiple regression analysis showed that the presence of external limiting membrane (ELM), smaller greatest linear dimension, and the presence of polypoidal lesion were associated with better visual outcome (R(2) = 0.53, P = 2.73 × 10(-14)).

CONCLUSIONS

Periodic injection of aflibercept is effective for PCV as well as for typical AMD. The statuses of ELM, greatest linear dimension, and polypoidal lesion are predictive for visual outcome.

Pigment epithelial detachment followed by retinal cystoid degeneration leads to vision loss in treatment of neovascular age-related macular degeneration

PURPOSE

Intravitreal antiangiogenic therapy is the major therapeutic breakthrough in neovascular age-related macular degeneration (AMD). Optical coherence tomography (OCT) is the leading diagnostic tool, but solid criteria for optimal therapeutic outcomes are lacking. A comprehensive analysis of structure/function correlations using Food and Drug Administration- and European Medicines Agency-approved substances and fixed and flexible regimens was performed.

DESIGN

Post hoc analysis of a prospective, randomized multicenter clinical trial including 189 study sites.

PARTICIPANTS

A total of 1240 patients with active neovascular AMD.

METHODS

Participants received intravitreal ranibizumab or aflibercept. A fixed regimen was used for 48 weeks followed by a flexible regimen until week 96. At monthly intervals, best-corrected visual acuity (BCVA) was measured and retinal morphology was assessed by standardized OCT, including intraretinal cysts (IRCs), subretinal fluid (SRF), and pigment epithelial detachment (PED), presenting with a width ≥400 μm or a height of ≥200 μm. Results were correlated for each regimen, feature, and time.

MAIN OUTCOME MEASURES

The BCVA outcomes in relation to retinal pathomorphology based on noninferiority for all treatment arms.

RESULTS

In neovascular AMD, only IRC at baseline and persistent through week 12 had a negative impact on BCVA. With therapeutic intervention, exudative features such as IRC and SRF resolved rapidly in 74% of eyes, whereas PED responded only slowly with 38%. Independent of the type of regimen, fixed or flexible, retinal morphology correlated tightly with visual function. Intraretinal cysts consistently showed the lowest BCVA gains with either regimen or substance. With the switch from a fixed to a flexible pro re nata (PRN) regimen, progressive visual loss occurred exclusively in the group with primary PED presenting as the hallmark of neovascular activity and was induced by secondary formation of IRC in the neurosensory retina.

CONCLUSIONS

The efficacy of antiangiogenic therapy in neovascular AMD is strongly determined by morphologic features. The subretinal pigment epithelium lesion underlying PED appears to be the primary indicator for progressive disease activity, whereas secondary cystoid degeneration is the most relevant imaging marker for visual function. Clinically, PED emerged as trigger for consecutive vision loss in PRN treatment.

Treating the untreatable patient: current options for the management of treatment-resistant neovascular age-related macular degeneration

Anti-vascular endothelial growth factor (anti-VEGF) agents represent the current standard of care for neovascular age-related macular degeneration (nAMD). Although effective in a majority of cases, a significant proportion of patients have persisting retinal exudation despite regular anti-VEGF therapy. This exudation is considered to produce poorer visual outcomes in these patients. Some of these patients may have misdiagnosed nAMD variants such as polypoidal choroidal vasculopathy; however, the majority of these eyes have what has been termed treatment-resistant nAMD. Currently, the best way to care for these patients is uncertain. Here, we review the evidence for different approaches to the management of treatment-resistant nAMD, including high-dose anti-VEGF therapy, combination regimes and switching of anti-VEGF agents, and discuss possible therapeutic approaches for patients with treatment-resistant nAMD.

Clinical characteristics and current treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is a multifactorial degeneration of photoreceptors and retinal pigment epithelium. The societal impact is significant, with more than 2 million individuals in the United States alone affected by advanced stages of AMD. Recent progress in our understanding of this complex disease and parallel developments in therapeutics and imaging have translated into new management paradigms in recent years. However, there are many unanswered questions, and diagnostic and prognostic precision and treatment outcomes can still be improved. In this article, we discuss the clinical features of AMD, provide correlations with modern imaging and histopathology, and present an overview of treatment strategies.

Genomic aspects of age-related macular degeneration

Age-related macular degeneration (AMD) is a major late-onset posterior eye disease that causes central vision to deteriorate among elderly populations. The predominant lesion of AMD is the macula, at the interface between the outer retina and the inner choroid. Recent advances in genetics have revealed that inflammatory and angiogenic pathways play critical roles in the pathophysiology of AMD. Genome-wide association studies have identified ARMS2/HTRA1 and CFH as major AMD susceptibility genes. Genetic studies for AMD will contribute to the prevention of central vision loss, the development of new treatment, and the maintenance of quality of vision for productive aging.

Resistance to antivascular endothelial growth factor treatment in age-related macular degeneration

Age-related macular degeneration (AMD) is the main cause of visual impairment and blindness in people aged over 65 years in developed countries. Vascular endothelial growth factor (VEGF) is a positive regulator of angiogenesis and its proven role in the pathological neovascularization in wet AMD has provided evidence for the use of anti-VEGF agents as potential therapies. In this study, we review the literature for the possible causes of failure after treatment with anti-VEGF agents and attempt to propose an algorithm of suggestive actions to increase the chances of successful management of such difficult cases.

Neovascular age-related macular degeneration: decision making and optimal management

AIM

To review the decision-making processes and dilemmas in the delivery of services for neovascular age-related macular degeneration (nAMD) and describe its optimal management.

METHODS

Review of literature and presentation of illustrative cases.

RESULTS

Guidelines are available to aid commissioners and providers of services but with important gaps in advice. Increasing awareness of variants and diseases that mimic nAMD means that clinicians need to carefully assess lesions at presentation, using stereo imaging, fluorescein and indocyanine green angiography, and new generation optical coherence tomography. Current evidence supports the use of ranibizumab as first-line therapy. Evidence is unclear on the most appropriate treatment regime, especially in protocols relying on clinician-determined re-treatment. Current consensus recommends initiation with monthly injections for 3 months followed by maintenance comprising regular monthly visits with clinician-determined re-treatment. Further evidence on treatment protocols and the comparison with bevacizumab is awaited.

CONCLUSIONS

Owing to incomplete evidence base health professionals face a large number of controversies and dilemmas in care pathways for patients with nAMD. Treatment should be delivered against protocols developed locally in a systematic manner with consensus and a cautious approach to change.