Anti-VEGF Drugs in Age-Related Macular Degeneration: A Focus on Dosing Regimen-Related Safety and Efficacy

Age-related macular degeneration (AMD) is one of the main causes of visual impairment and severe visual loss, and can progress to two advanced forms-neovascularization and atrophic. The field of anti-AMD drugs has undergone huge developments in recent years, from single-target intravitreal administration to current clinical studies with multi-target and non-invasive agents, offering interesting new pharmacological opportunities for the treatment of this disease. Hence, we summarize some of the approved anti-vascular endothelial growth factor (VEGF) drugs for neovascular AMD, especially their structural characteristics, clinical manifestations, dosing regimens, and safety issues of the anti-VEGF drugs highlighted. In addition, advances in atrophic AMD drug research are also briefly described.

Optical coherence tomography imaging biomarkers associated with neovascular age-related macular degeneration: a systematic review

The aim of this systematic literature review is twofold, (1) detail the impact of retinal biomarkers identifiable via optical coherence tomography (OCT) on disease progression and response to treatment in neovascular age-related macular degeneration (nAMD) and (2) establish which biomarkers are currently identifiable by artificial intelligence (AI) models and the utilisation of this technology. Following the PRISMA guidelines, PubMed was searched for peer-reviewed publications dated between January 2016 and January 2022.

POPULATION

Patients diagnosed with nAMD with OCT imaging.

SETTINGS

Comparable settings to NHS hospitals.

STUDY DESIGNS

Randomised controlled trials, prospective/retrospective cohort studies and review articles. From 228 articles, 130 were full-text reviewed, 50 were removed for falling outside the scope of this review with 10 added from the author's inventory, resulting in the inclusion of 90 articles. From 9 biomarkers identified; intraretinal fluid (IRF), subretinal fluid, pigment epithelial detachment, subretinal hyperreflective material (SHRM), retinal pigmental epithelial (RPE) atrophy, drusen, outer retinal tabulation (ORT), hyperreflective foci (HF) and retinal thickness, 5 are considered pertinent to nAMD disease progression; IRF, SHRM, drusen, ORT and HF. A number of these biomarkers can be classified using current AI models. Significant retinal biomarkers pertinent to disease activity and progression in nAMD are identifiable via OCT; IRF being the most important in terms of the significant impact on visual outcome. Incorporating AI into ophthalmology practice is a promising advancement towards automated and reproducible analyses of OCT data with the ability to diagnose disease and predict future disease conversion.

SYSTEMATIC REVIEW REGISTRATION

This review has been registered with PROSPERO (registration ID: CRD42021233200).

Age-Related Macular Degeneration and Its Association With Neurodegenerative Disorders

Age-related macular degeneration (AMD) is a highly prevalent macular condition that primarily affects the older population. It is the primary cause of blindness amongst the elderly population. It is an inflammatory disease that characteristically shows choroidal neovascularization and geographic atrophy. The exact pathomechanism of developing AMD is not known. However, certain factors such as increased age, smoking, genetic factors and certain environmental factors are usually associated with the development of the disease. AMD also involves oxidative stress-mediated destruction of retinal pigment epithelial cells and, consequently, that of retinal photoreceptors. Alzheimer's disease (AD) is a degenerative disorder involving the nervous system that usually affects people aged 65 and over. Both AMD and AD are age-related, degenerative conditions that have several similarities and share many of the same risk factors such as vascular conditions like arteriosclerosis, high blood pressure and obesity. It is believed that the early emergence of the clinical manifestations of AMD and AD may also be significantly influenced by oxidative stress and genetic polymorphism in complement factor H. A common pathogenic pathway between AD and AMD is quite likely. Amyloid-β is an aberrant protein that accumulates within the brains of Alzheimer's patients and appears as plaques on magnetic resonance imaging (MRI). These plaques are a pathognomonic sign of Alzheimer's disease. Similar to this, amyloid-β deposits are reported to build up beneath the retina of AMD patients, which appear as tiny clusters of protein-lipid substances known as drusen. It has also been found that individuals suffering from AMD exhibit an increased chance of developing AD than those with no AMD.

Subfoveal choroidal thickness after brolucizumab therapy for neovascular age-related macular degeneration: a short-term multicenter study

BACKGROUND/PURPOSE

Observation of choroidal thickness after anti-vascular endothelial growth factor (VEGF) therapy may be important for the ideal management of neovascular age-related macular degeneration (AMD). This study investigated changes in subfoveal choroidal thickness (SCT) during loading doses of intravitreal injections of brolucizumab in eyes with neovascular AMD.

METHODS

This study included 73 eyes of 72 patients with neovascular AMD at five university hospitals in Japan. All 73 eyes underwent three monthly 6.0 mg intravitreal injections of brolucizumab at baseline, 1 month, and 2 months. The SCT at 3 months was evaluated using optical coherence tomography.

RESULTS

The 73 eyes were classified into the treatment-naïve group (43 eyes) and the switched group (30 eyes) that were switched from other anti-VEGF treatments. After three intravitreal injections of brolucizumab, SCT significantly decreased from 236.5 ± 98.8 µm at baseline to 200.4 ± 98.3 µm at 3 months (percent of baseline 84.7%, P < 0.001) in the treatment-naïve group. In the switched group, SCT also significantly decreased from 229.0 ± 113.2 μm at baseline to 216.9 ± 110.2 μm at 3 months (percent of baseline 94.7%, P = 0.039), although the decrease was not as marked compared to that of the treatment-naïve group.

CONCLUSION

Intravitreal injections of brolucizumab for neovascular AMD significantly reduced the SCT in both the treatment-naïve and switched groups. Brolucizumab may cause significant anatomic changes in the choroid, particularly in treatment-naïve AMD eyes, possibly more than that previously reported for other anti-VEGF agents.

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness. The main risk factor is advancing age, with the severity of vision loss ranging from mild to severe. There is a 25% risk of early AMD and 8% risk of late AMD in patients over the age of 75, with the number of cases expected to increase because of the aging population. Diagnosis of the disease requires a dilated fundus examination. Physicians should be aware of the symptoms, risk factors, and treatment options for AMD to refer appropriately for ophthalmologic evaluation. Early detection can be helpful to prevent disease progression.

Current Management of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) remains a leading cause of blindness worldwide. The assessment and management of patients with this condition has evolved in the last decades. In this chapter, current standards for diagnosis, follow-up, and treatment of patients with AMD are reviewed and summarized. Namely, we highlight how current assessment has moved from conventional ophthalmoscopy and fluorescein angiography testing to a multimodal approach, and its important advantages. Alternatives to visual acuity for functional assessment of patients with AMD are also presented. Regarding strategies for follow-up and treatment, we provide specific information for the different stages (i.e., early, intermediate, and late) and forms (for example, choroidal neovascularization and geographic atrophy) of AMD. Specifically, we discuss the relevance and options for self-monitoring and non-pharmacological interventions. Additionally, a summary of the important trials (both on exudative and non-exudative AMD) that have helped inform clinical practice is provided, including data on antiangiogenic agents currently available, and outcomes of the different regimens that have been studied. The influence of advances in imaging on treatment strategies is also discussed.In summary, this chapter is a resource for all clinicians engaged in providing state of the art care for patients with AMD, and can help improve diagnosis, management, and outcomes of individuals with this blinding condition.

Office Examinations–Directed Treatment Paradigms Reduce Travel Burden, Decrease Treatment Cost, and Improve Quality-Adjusted Life-Years for Patients With Exudative Age-Related Macular Degeneration Undergoing Antivascular Endothelial Growth Factor Therapy

Purpose:

In the United States, most intravitreal injections are performed the same day as an office examinations; however, federal agencies and insurance payers suggest these same-day examinations charges are overused and have recommended scrutiny. In this study, we estimate the cost vs benefit to society of same-day office examinations during intravitreal injections for wet age-related macular degeneration (wAMD).

Methods:

An Excel spreadsheet was used to model different antivascular endothelial growth factor treatment scenarios for wAMD, including automatic treatment, injection series' treat and extend (T&E), and as-needed treatment, with increasing same-day examinations in the order listed. Treatment parameters were estimated using US population statistics, published literature, and Centers for Medicare & Medicaid Services, provider utilization data. Costs and benefits were compared for the 4 treatment scenarios.

Results:

Although yearly examinations and optical coherence tomography costs were higher for injection series, T&E, and as-needed protocols compared with automatic treatment, our model predicts reduced yearly injection and travel costs for those same treatment scenarios also, saving $2.9 billion (injection series), $7.2 billion (T&E), and $6.1 billion (as-needed) annually for the US population. Same-day injections accounted for 21%, 8%, and 9% of the savings, respectively, because of reduced travel burden. Furthermore, early detection of wAMD in the fellow eye during office examinations allows for a 1.8, 2.1, and 2.5 quality-adjusted life-year benefit, respectively.

Conclusions:

Office examinations–directed antivascular endothelial growth factor therapy for wAMD reduces travel and treatment expenses and improves screening of the fellow eye, resulting in robust cost savings and quality-adjusted life-year benefit for the US population.

Definition of indicators of appropriateness in the management of neovascular age-related macular degeneration: An expert opinion

Wet age-related macular degeneration is a chronic condition culminating, in most cases, in blindness. The introduction of anti-angiogenic agents in 2006 has represented a major breakthrough in the treatment of the disease, but timely and effective treatment with regular follow-up and monitoring is mandatory to stabilize and preserve visual acuity. In clinical practice, however, appropriate therapy provision is frequently challenged by economic and organizational issues that result in suboptimal visual outcomes and increased incidence of legal blindness. International Guidelines have defined a diagnostic and therapeutic pathway to ensure the best practice in wet age-related macular degeneration management, but reference parameters to evaluate and compare the performance of Retina Centers are lacking. To address the appropriateness of wet age-related macular degeneration management in Italy, a multidisciplinary panel of ten experts gathered in three meetings. They defined three sets of indicators and relative benchmark values that each Center should comply with to ensure patients optimal care already from the first access: (a) clinical intervention indicators, to determine the possible Center’s deviation from the diagnostic and therapeutic pathway; (b) outcome indicator, to evaluate the socioeconomic impact of the healthcare systems’ performance; (c) management indicators, to test the size of the gap between the Center’s supply and demand. Once the indicators have been analyzed, healthcare systems can plan actions to improve appropriateness and monitor their effects. However, to put this in practice, a concerted effort by all parts involved in healthcare provision is required, together with adequate systems to analyze clinical and administrative documentation.

Advances in Biodegradable Nano-Sized Polymer-Based Ocular Drug Delivery

The effective delivery of drugs to the eye remains a challenge. The eye has a myriad of defense systems and physiological barriers that leaves ocular drug delivery systems with low bioavailability profiles. This is mainly due to poor permeability through the epithelia and rapid clearance from the eye following administration. However, recent advances in both polymeric drug delivery and biomedical nanotechnology have allowed for improvements to be made in the treatment of ocular conditions. The employment of biodegradable polymers in ocular formulations has led to improved retention time, greater bioavailability and controlled release through mucoadhesion to the epithelia in the eye, amongst other beneficial properties. Nanotechnology has been largely investigated for uses in the medical field, ranging from diagnosis of disease to treatment. The nanoscale of these developing drug delivery systems has helped to improve the penetration of drugs through the various ocular barriers, thus improving bioavailability. This review will highlight the physiological barriers encountered in the eye, current conventional treatment methods as well as how polymeric drug delivery and nanotechnology can be employed to optimize drug penetration to both the anterior and posterior segment of the eye.