Neovascular Age-Related Macular Degeneration (nAMD): A Review of Emerging Treatment Options

Subretinal fibrosis secondary to neovascular age-related macular degeneration: mechanisms and potential therapeutic targets

Subretinal fibrosis is the end-stage sequelae of neovascular age-related macular degeneration. It causes local damage to photoreceptors, retinal pigment epithelium, and choroidal vessels, which leads to permanent central vision loss of patients with neovascular age-related macular degeneration. The pathogenesis of subretinal fibrosis is complex, and the underlying mechanisms are largely unknown. Therefore, there are no effective treatment options. A thorough understanding of the pathogenesis of subretinal fibrosis and its related mechanisms is important to elucidate its complications and explore potential treatments. The current article reviews several aspects of subretinal fibrosis, including the current understanding on the relationship between neovascular age-related macular degeneration and subretinal fibrosis; multimodal imaging techniques for subretinal fibrosis; animal models for studying subretinal fibrosis; cellular and non-cellular constituents of subretinal fibrosis; pathophysiological mechanisms involved in subretinal fibrosis, such as aging, infiltration of macrophages, different sources of mesenchymal transition to myofibroblast, and activation of complement system and immune cells; and several key molecules and signaling pathways participating in the pathogenesis of subretinal fibrosis, such as vascular endothelial growth factor, connective tissue growth factor, fibroblast growth factor 2, platelet-derived growth factor and platelet-derived growth factor receptor-β, transforming growth factor-β signaling pathway, Wnt signaling pathway, and the axis of heat shock protein 70-Toll-like receptors 2/4-interleukin-10. This review will improve the understanding of the pathogenesis of subretinal fibrosis, allow the discovery of molecular targets, and explore potential treatments for the management of subretinal fibrosis.

Impact of vitreomacular interface on intravitreal Brolucizumab efficacy in age-related macular neovascularization

BACKGROUND

This study aimed to assess the influence of vitreoretinal interface (VRI) on the outcome of Brolucizumab intravitreal injections (IVBr) in patients with age-related macular neovascularization (MNV).

METHODS

40 eyes of 40 patients with active-naive MNV candidates to IVBr were enrolled at the Ophthalmology Clinic of the University "G. d'Annunzio," Chieti-Pescara, Italy. Based on the VRI condition, 20 patients were included in the G0 group (without evidence of VRI alterations), whereas 20 patients were enrolled in the G1 group (with VRI abnormalities). The primary outcome measures were changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SCT), pigment epithelial detachment presence and maximum height (PEDMH), intraretinal fluid (IRF) presence, subfoveal subretinal fluid (SSRF) presence and thickness (SSRFT), subretinal pigment epithelium fluid (SRPEF) presence and SRPEF thickness (SRPEFT).

RESULTS

There were no significant differences in BCVA and SCT between the two groups, although both parameters significantly changed over time (BCVA p 0.005; SCT p < 0.001). No differences in CMT and PEDMH were found between the two groups. SSRF presence showed differences between the two groups at T4 (p 0.044), and IRF presence showed significant differences over time (p 0.008) in favor of MNV eyes without VRI alterations.

CONCLUSIONS

Concomitant vitreomacular interface disease alterations in eyes treated with IVBr for MNV influenced fluid presence with greater persistence of SSRF and IRF compared to MNV eyes without VRI. Nevertheless, the overall macular thickness and visual function were not significantly different between the two groups.

Extent and Topography of Subretinal Drusenoid Deposits Associate With Rod-Mediated Vision in Aging and AMD: ALSTAR2 Baseline

Purpose

In AMD, rod-mediated dark adaptation (RMDA) at 5° eccentricity is slower in eyes with subretinal drusenoid deposits (SDDs) than in eyes without. Here we quantified SDD burden using supervised deep learning for comparison to vision and photoreceptor topography.

Methods

In persons ≥60 years from the Alabama Study on Early Age-Related Macular Degeneration 2, normal, early AMD, and intermediate AMD eyes were classified by the AREDS nine-step system. A convolutional neural network was trained on 55°-wide near-infrared reflectance images for SDD segmentation. Trained graders annotated ground truth (SDD yes/no). Predicted and true datasets agreed (Dice coefficient, 0.92). Inference was manually proofread using optical coherence tomography. The mean SDD area (mm2) was compared among diagnostic groups (linear regression) and to vision (age-adjusted Spearman correlations). Fundus autofluorescence images were used to mask large vessels in SDD maps.

Results

In 428 eyes of 428 persons (normal, 218; early AMD, 120; intermediate AMD, 90), the mean SDD area differed by AMD severity (P < 0.0001): 0.16 ± 0.87 (normal), 2.48 ± 11.23 (early AMD), 11.97 ± 13.33 (intermediate AMD). Greater SDD area was associated with worse RMDA (r = 0.27; P < 0.0001), mesopic (r = -0.13; P = 0.02) and scotopic sensitivity (r = -0.17; P < 0.001). SDD topography peaked at 5° superior, extended beyond the Early Treatment of Diabetic Retinopathy Study grid and optic nerve, then decreased.

Conclusions

SDD area is associated with degraded rod-mediated vision. RMDA 5° (superior retina) probes where SDD is maximal, closer to the foveal center than the rod peak at 3 to 6 mm (10.4°-20.8°) superior and the further eccentric peak of rod:cone ratio. Topographic data imply that factors in addition to rod density influence SDD formation.

Summary of the Therapeutic Options for Patients with Dry and Neovascular AMD

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness worldwide and a severe medical and social problem. The steadily increasing number of patients is related to the aging of the population. So far, many factors affecting the development of AMD have been identified, which can be divided into non-modifiable, including genetic factors, age, and sex, and modifiable or environmental factors, such as smoking, poor diet, and hypertension. Early stages of age-related macular degeneration are characterized by fundus drusen and abnormalities in the retinal pigment epithelium. In late stages, geographic atrophy and choroidal neovascularization (CNV) are observed. The treatment of AMD, especially its advanced forms, is very challenging. Intensive research has made it possible to treat advanced stages of the dry form of AMD with pegcetacoplan and avacincaptad pegol, new drugs approved for use in the US. Pegcetacoplan targets the C3 and avacincaptad pegol targets the C5, the pivotal proteins of the complement cascade. The drugs are administered by intravitreal injection. The gold standard for neovascular AMD (nAMD) consists of intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs such as bevacizumab, ranibizumab, aflibercept, brolucizumab, and faricimab. Treatment can be administered according to the fixed, pro-re-nata, and treat-and-extend regimens. The latter seems to have the best effect on improving visual acuity (VA) and the maximum therapeutic benefit. The search continues for the best ways to deliver intravitreal drugs. Current methods include sustained-release implants and hydrogel platforms for drug release, while the most promising future pathways for treating dry and nAMD are stem cell and gene therapy.

Optical coherence tomography-derived texture-based radiomics features identify eyes with intraocular inflammation in the HAWK clinical trial

Background and objective

Intravitreal injection of anti-VEGF agents is the first-line treatment for patients with neovascular-age related macular degeneration (nAMD). One unique serious adverse event that may be associated with these agents is intraocular inflammation (IOI). The main purpose of this analysis was to evaluate the potential presence of texture-based radiomics features characterizing heterogeneity within the vitreous compartment of spectral domain optical coherence tomography (SD-OCT) images that may precede or develop in association with IOI and might serve as OCT biomarkers for IOI.

Methods

This is a post-hoc analysis of a subset of cases (N = 67) involving IOI, endophthalmitis, and/or retinal vascular occlusion in the phase 3 HAWK trial. These were investigator determined diagnoses that were also confirmed by the safety review committee. Intraocular inflammation was any signs of inflammation within the eye, endophthalmitis was inflammation associated with presumed infection, and retinal vascular occlusions consisted of intraocular inflammation with concurrent vascular occlusions/vasculitis. Out of 67 eyes, 34 belonged to the Safety group with an IOI event and 33 were propensity-matched Controls. A total of 481 texture-based radiomics features were extracted from the vitreous compartment of the SD-OCT scans at pre-IOI time point (i.e., much earlier than the actual event). Most discriminating five features, selected by the Wilcoxon Rank Sum feature selection were evaluated using Random Forest (RF) classifier on the training set (S t r , N = 47) to differentiate between the two patient groups. Classifier performance was subsequently validated on the independent test set (S t , N = 20). Additionally, the classifier performance in discriminating the Control and Safety group was also validated onS t at the IOI event timepoint.

Results

The RF classifier yielded area under the Receiver Operating Characteristics curve (AUC) of 0.76 and 0.81 onS t using texture-based radiomics features at pre-IOI and event time-point, respectively.

Conclusions

In this analysis, the presence of a pre-IOI safety signal was detected in the form of textural heterogeneity within the vitreous compartment even prior to the actual event being identified by the investigator. This finding may help the clinicians to assess for underlying posterior inflammation.

Genetic Insights into Age-Related Macular Degeneration

One of the major causes of vision impairment among elderly people in developed nations is age-related macular degeneration (AMD). The distinctive features of AMD are the accumulation of extracellular deposits called drusen and the gradual deterioration of photoreceptors and nearby tissues in the macula. AMD is a complex and multifaceted disease influenced by several factors such as aging, environmental risk factors, and a person's genetic susceptibility to the condition. The interaction among these factors leads to the initiation and advancement of AMD, where genetic predisposition plays a crucial role. With the advent of high-throughput genotyping technologies, many novel genetic loci associated with AMD have been identified, enhancing our knowledge of its genetic architecture. The common genetic variants linked to AMD are found on chromosome 1q32 (in the complement factor H gene) and 10q26 (age-related maculopathy susceptibility 2 and high-temperature requirement A serine peptidase 1 genes) loci, along with several other risk variants. This review summarizes the common genetic variants of complement pathways, lipid metabolism, and extracellular matrix proteins associated with AMD risk, highlighting the intricate pathways contributing to AMD pathogenesis. Knowledge of the genetic underpinnings of AMD will allow for the future development of personalized diagnostics and targeted therapeutic interventions, paving the way for more effective management of AMD and improved outcomes for affected individuals.

Repeatability of Rod-Mediated Dark Adaptation Testing in Normal Aging and Early and Intermediate Age-Related Macular Degeneration

PURPOSE

The vulnerability of rod photoreceptors in aging and early and intermediate age-related macular degeneration (AMD) has been well documented. Rod-mediated dark adaptation (RMDA) is a measure of the recovery of light sensitivity in rod photoreceptors following a bright light. Delays in RMDA during early and intermediate AMD have been widely reported. For RMDA's promise as an outcome for trials targeted at early and intermediate AMD to be realized, excellent test-retest reliability, its repeatability, must be established.

METHODS

Test-retest performance in a commonly used RMDA test based on the rod intercept time metric (RIT) was evaluated in participants with early and intermediate AMD and with normal retinal aging with testing approximately 2 weeks apart. The test target was placed at 5° eccentricity superior to the foveal center, an area with maximal rod loss in aging and AMD. Disease severity was identified by a trained and masked grader of fundus photographs using both the AREDS 9-step and Beckman classification systems. Bland-Altman plots and intra-class correlation coefficients (ICC) evaluated repeatability.

RESULTS

The analysis sample consisted of 37 older adults (mean age 76 years, standard deviation 5), with approximately one-third of the sample in each of three groups - normal aging, early AMD, and intermediate AMD. For the total sample, the ICC was 0.98. For individual AMD groups for both AREDS 9-step and Beckman classifications, the ICCs were also very high ranging from 0.82 to 0.99.

CONCLUSION

We demonstrated that RMDA testing using the RIT metric has excellent repeatability when target location is at 5° in studying older adults from normal aging to intermediate AMD, suggesting the reliable use of this functional measure in trials.

Transitioning from Aflibercept to Biosimilar Ranibizumab in Neovascular AMD (The TRANSFORM Trial): A Multicenter Observational Study

Purpose

This study investigates the efficacy of transitioning patients with neovascular age-related macular degeneration (nAMD) from aflibercept (T1) to biosimilar ranibizumab (T2), an approach not previously documented in literature.

Methods

In this multicenter observational study, patients over 50 years of age with nAMD were shifted from intravitreal aflibercept (IVI AFL) to biosimilar ranibizumab (B-RBZ) due to financial constraints. This study employed standardized ophthalmological methods to assess visual acuity (VA), central macular thickness (CMT), and subretinal and intraretinal fluid. Statistical analyses included paired t-tests, Wilcoxon signed-rank tests, and linear regression.

Results

A total of 29 eyes (12 males and 17 females) were analyzed. Mean age was 72.55 ±6.43 years. VA improved significantly during T1, with a mean increase from 55.0 ± 10.2 to 70.0 ± 8.5 ETDRS letters at the switch time point (p < 0.01), then a slight decrease to 62.3 ± 8.9 at 12 months (p < 0.05) was noted during T2. The mean CMT decreased notably from 400 ± 50 to 290 ± 45 μm at the switch. The final CMT at 12 months after switching to B-RBZ was 280 ± 40 μm (p < 0.01). There was a significant decrease in the retinal and intra retinal fluid during T1, followed by a gradual increase during T2. A significant correlation (p < 0.05) was noted between the presence of intraretinal fluid and increased injection frequency of B-RBZ.

Conclusion

The switch from IVI AFL to IVI B-RBZ in patients with nAMD demonstrated efficacy in maintaining the VA and macular anatomy, with some challenges in fluid management.

Hydrogels in Gene Delivery Techniques for Regenerative Medicine and Tissue Engineering

Hydrogels are 3D networks swollen with water. They are biocompatible, strong, and moldable and are emerging as a promising biomedical material for regenerative medicine and tissue engineering to deliver therapeutic genes. The excellent natural extracellular matrix simulation properties of hydrogels enable them to be co-cultured with cells or enhance the expression of viral or non-viral vectors. Its biocompatibility, high strength, and degradation performance also make the action process of carriers in tissues more ideal, making it an ideal biomedical material. It has been shown that hydrogel-based gene delivery technologies have the potential to play therapy-relevant roles in organs such as bone, cartilage, nerve, skin, reproductive organs, and liver in animal experiments and preclinical trials. This paper reviews recent articles on hydrogels in gene delivery and explains the manufacture, applications, developmental timeline, limitations, and future directions of hydrogel-based gene delivery techniques.

Crosstalk Between Microglia and Müller Glia in the Age-Related Macular Degeneration: Role and Therapeutic Value of Neuroinflammation

Age-related macular degeneration (AMD) is a progressive neurodegeneration disease that causes photoreceptor demise and vision impairments. In AMD pathogenesis, the primary death of retinal neurons always leads to the activation of resident microglia. The migration of activated microglia to the ongoing retinal lesion and their morphological transformation from branching to ameboid-like are recognized as hallmarks of AMD pathogenesis. Activated microglia send signals to Müller cells and promote them to react correspondingly to damaging stimulus. Müller cells are a type of neuroglia cells that maintain the normal function of retinal neurons, modulating innate inflammatory responses, and stabilize retinal structure. Activated Müller cells can accelerate the progression of AMD by damaging neurons and blood vessels. Therefore, the crosstalk between microglia and Müller cells plays a homeostatic role in maintaining the retinal environment, and this interaction is complicatedly modulated. In particular, the mechanism of mutual regulation between the two glia populations is complex under pathological conditions. This paper reviews recent findings on the crosstalk between microglia and Müller glia during AMD pathology process, with special emphasis on its therapeutic potentials.

Longitudinal changes in pigment epithelial detachment composition indices (PEDCI): new biomarkers in neovascular age-related macular degeneration

PURPOSE

To evaluate novel, automated biomarkers, pigment epithelial detachment composition indices (PEDCI) in eyes with neovascular age-related macular degeneration (nAMD) undergoing anti-vascular endothelial growth factor (anti-VEGF) therapy through 24 months.

METHODS

Retrospective analysis of 37 eyes (34 patients) with PED associated with nAMD receiving as-needed anti-VEGF treatment was performed. Best-corrected visual acuity (BCVA) and optical coherence tomography images were acquired at a treatment-naïve baseline and 3-, 6-, 12-, 18-, and 24-month visits. Previously validated automated imaging biomarkers, PEDCI-S (serous), PEDCI-N (neovascular), and PEDCI-F (fibrous) within PEDs were measured. ANOVA analysis and Spearman correlation were performed.

RESULTS

Mean BCVA (in logMAR) was 0.60 ± 0.47, 0.45 ± 0.41, 0.49 ± 0.49, 0.61 ± 0.54, 0.59 ± 0.56, and 0.67 ± 0.57 at baseline, 3, 6, 12, 18, and 24 months respectively. Overall, BCVA showed minimal worsening of 0.07 ± 0.54 logMAR (p = 0.07). 13.38 ± 3.77 anti-VEGF injections were given through 24 months. PEDCI-F showed an increase of 0.116, 0.122, 0.036, and 0.006 at months 3, 6, 12, and 18 respectively and a decrease of 0.004 at month 24 (p = 0.03); PEDCI-S showed a decrease of 0.064, 0.130, 0.091, 0.092, and 0.095 at months 3, 6, 12, 18, and 24 respectively (p = 0.16); PEDCI-N showed a decrease of 0.052 at month 3 and an increase of 0.008, 0.055, 0.086, and 0.099 at months 6, 12, 18, and 24 respectively (p = 0.06). BCVA was negatively correlated with PEDCI-F (r = -0.28, p < 0.01), and positively correlated with PEDCI-N (r = 0.28, p < 0.01) and PEDCI-S (r = 0.15, p = 0.03).

CONCLUSION

Longitudinal analysis of PEDCI supports their utility as biomarkers that characterize treatment related effects by quantifying the relative composition of PEDs.

Perspectives on the currently available pharmacotherapy for wet macular degeneration

INTRODUCTION

Wet age-related macular degeneration (w-AMD) is a leading cause of visual impairment globally, with its prevalence expected to rise alongside increasing life expectancy. The current standard treatment involves frequent intravitreal injections of anti-VEGF agents, which although revolutionary, pose significant burdens on both patients and healthcare services.

AREAS COVERED

This review explores current and emerging pharmaceutical treatments for w-AMD, focusing on their pharmacokinetics, pharmacodynamics, efficacy, and safety. Promising developments include extending treatment intervals with newer anti-VEGF agents like brolucizumab and faricimab, biosimilars offering cost-effective options, and exploring innovative drug delivery methods such as subretinal gene therapy. Combination therapies, gene therapies, and novel agents like KSI-301 and OPT-302 show potential for improving treatment outcomes and reducing treatment burden.

EXPERT OPINION

While current treatments for w-AMD have significantly advanced with the advent of anti-VEGF therapies, their limitations in terms of treatment burden and incomplete responses have spurred research into diverse alternative approaches. These innovative strategies offer hope for improving patient outcomes and reducing healthcare burdens, suggesting a promising future for w-AMD management.

Intravitreal faricimab for neovascular age-related macular degeneration previously treated with traditional anti-VEGF compounds: a real-world prospective study

BACKGROUND/AIMS

To evaluate the efficacy, safety and durability of intravitreal faricimab in patients with neovascular age-related macular degeneration (nAMD) with unsatisfactory response to traditional anti-vascular endothelial growth factor (anti-VEGF) agents.

METHODS

Single-centre, prospective cohort study of all consecutive patients with nAMD who were switched to intravitreal faricimab from intravitreal ranibizumab or aflibercept, due to unsatisfactory treatment response (maximal fluid-free interval ≤ 8 weeks). Intravitreal faricimab was administered with a loading dose of four 4-weekly injections, followed by an 8-week extension. A treat and extend (T&E) regime was adopted thereafter. Primary outcome was the difference between the maximal fluid-free interval achieved with faricimab, and the one achieved before the switch. Morpho-functional outcomes were also assessed. Secondary outcome was accordance with clinical management when applying faricimab pivotal trial criteria versus our real-world T&E protocol, measured as a proportion.

RESULTS

Twenty-six eyes of 26 patients with a median age of 82 years (range 77-85) were included. Patients were followed for 30.2 weeks (range 26.3-33.1). Maximal fluid-free interval after switch to faricimab (Mdn = 6.0 weeks; IQR = 4-8) was longer than the maximum interval before the switch (Mdn = 4.0 weeks; IQR = 4-4), p < 0.001. Comparing real-world T&E protocol with pivotal trial criteria, 8 (30.8%) eyes received the same clinical management while 18 (69.2%) eyes were kept at a shorter interval when following our T&E protocol. No serious adverse events were recorded.

CONCLUSIONS

Faricimab appears to increase the fluid-free interval and allow extension of dosing interval in patients with nAMD poorly responsive to traditional anti-VEGF drugs.

Laser flare photometry in eyes receiving brolucizumab intravitreal injections for age related macular degeneration

PURPOSE

To measure aqueous flare levels in treatment naïve eyes suffering from wet age- related macular degeneration (wAMD) treated with intravitreal brolucizumab.

METHODS

Patients with treatment naïve wAMD in one eye were prospectively enrolled. Flare levels were measured with laser flare photometry at baseline, 1 day and 1 month after each of the 3 monthly injections during the loading phase.

RESULTS

Twenty-two eyes from 22 patients aged 76.7 ± 6.0 years were enrolled. Flare values were 10.6 ± 3.7 photons/msec at baseline and 12.6 ± 5.8 photons/msec at the last follow up visit, 1 month after the third injection (p = 0.289, repeated measures ANOVA). The mean change in flare after the first injection was 4.2 ± 3.6. photons/msec, 6.6 ± 8.9 photons/msec after the 2nd and 8.6 ± 20.8 photons/msec after the 3rd injection (p = 0.640, repeated measures ANOVA). No patient had clinical signs of intraocular inflammation.

CONCLUSIONS

Eyes receiving brolucizumab injections for wAMD showed similar flare at baseline, during and 1 month after completion of three-monthly intravitreal injections. There was no evidence of subclinical inflammation during the loading phase of brolucizumab based on laser flare photometry measurements.

Hydrogel-Based Therapy for Age-Related Macular Degeneration: Current Innovations, Impediments, and Future Perspectives

Age-related macular degeneration (AMD) is an ocular disease that leads to progressive photoreceptor death and visual impairment. Currently, the most common therapeutic strategy is to deliver anti-vascular endothelial growth factor (anti-VEGF) agents into the eyes of patients with wet AMD. However, this treatment method requires repeated injections, which potentially results in surgical complications and unwanted side effects for patients. An effective therapeutic approach for dry AMD also remains elusive. Therefore, there is a surge of enthusiasm for the developing the biodegradable drug delivery systems with sustained release capability and develop a promising therapeutic strategy. Notably, the strides made in hydrogels which possess intricate three-dimensional polymer networks have profoundly facilitated the treatments of AMD. Researchers have established diverse hydrogel-based delivery systems with marvelous biocompatibility and efficacy. Advantageously, these hydrogel-based transplantation therapies provide promising opportunities for vision restoration. Herein, we provide an overview of the properties and potential of hydrogels for ocular delivery. We introduce recent advances in the utilization of hydrogels for the delivery of anti-VEGF and in cell implantation. Further refinements of these findings would lay the basis for developing more rational and curative therapies for AMD.

Neovascular age-related macular degeneration: disease pathogenesis and current state of molecular biomarkers predicting treatment response-a scoping review

Age-related macular degeneration is a major cause of blindness, and the development of anti-vascular endothelial growth factor (VEGF) intravitreal treatments has revolutionised the management of the disease. At the same time, new challenges and unmet needs arose due to the limitations of the current therapeutic options. Neovascularisation development during the course of the disease has a complex pathogenetic mechanism, and several biomarkers and their association with treatment outcomes have been investigated. We reviewed the relevant literature about neovascularisation development and biomarkers related to response to treatment. Improving our knowledge on the field can improve patient outcomes and offer personalised care.

Long-Acting Ocular Injectables: Are We Looking In The Right Direction?

The complex anatomy and physiological barriers of the eye make delivering ocular therapeutics challenging. Generally, effective drug delivery to the eye is hindered by rapid clearance and limited drug bioavailability. Biomaterial-based approaches have emerged to enhance drug delivery to ocular tissues and overcome existing limitations. In this review, some of the most promising long-acting injectables (LAIs) in ocular drug delivery are explored, focusing on novel design strategies to improve therapeutic outcomes. LAIs are designed to enable sustained therapeutic effects, thereby extending local drug residence time and facilitating controlled and targeted drug delivery. Moreover, LAIs can be engineered to enhance drug targeting and penetration across ocular physiological barriers.

A Prospective Observational Study on Clinical Profile and Visual Outcomes in Neovascular Age-Related Macular Degeneration

Background and objectives Over the years, several treatment options have been developed for neovascular age-related macular degeneration (AMD), the most notable being intravitreal injections of anti-vascular endothelial growth factor drugs. The rationale for treating neovascular AMD is to preserve and improve central vision, enhance the quality of life for affected individuals, stabilize or improve vision, and prevent further structural damage to the macula. The objective of the present study was to evaluate the clinical course of different disease types of neovascular age-related macular degeneration and their treatment response to anti-vascular endothelial growth factor (anti-VEGF) injections. Methods This prospective observational study was conducted at a tertiary care referral hospital in Eastern India during October 2019 and September 2021. Patients diagnosed with neovascular AMD attending our Outpatient department and retina clinic were recruited for the study. An experienced ophthalmologist examined all patients, meeting the inclusion criteria. The clinical profile, including initial best corrected visual acuity (BCVA), ophthalmoscopic, fluorescein angiographic, and optical coherence tomography (OCT) findings of different patterns of neovascular AMD, were collected and analyzed. Patients were subjected to intravitreal Ranibizumab every month for three months and then on a when-required basis. Visual outcomes were recorded at each follow-up, and a comparison was done between initial and final visual acuity. Descriptive statistics were used for analysis, with p< 0.05 taken as statistically significant. Results A total of 72 patients were included in the study. Fundus fluorescein angiography revealed that 52.78% were classic, 15.28% were minimally classic, and 31.94% were of occult variety. 41.66% of lesions were subfoveal in location, 47.22% were juxtafoveal, and 11.11% lesions were extrafoveal in location. The mean BCVA was Log MAR (Logarithm of the Minimum Angle of Resolution) 1.061±0.25. The average number of intravitreal Ranibizumab injections given to each eye was five. BCVA of patients after the third injection was log MAR 0.818±0.296. There was a significant improvement in mean BCVA from baseline 1.061±0.254 to 0.787±0.317 after the study (p-valve: p<0.05). After the first injection, 49 patients (68.05%) experienced an initial improvement of at least one line, 20 patients (27.77%) did not exhibit any improvement, and 3 patients (4.16%) had a decline of one line in Snellen's visual acuity chart. Over the follow-up period,10 showed improvement in 1 line in the Snellen chart after subsequent injection. At the end of the study, six patients showed no change, and four patients showed deterioration after the completion of injections. No adverse events were noted during the study period. Conclusions Intravitreal Ranibizumab is effective in improving visual outcomes in treatment-naïve individuals with neovascular age-related macular degeneration. The decision for repeat intravitreal anti-VEGF injection should be based on OCT findings of subretinal fluid, pigment epithelial detachment, and cystoid macular edema as an indicator of disease activity. This can also lessen the number of intravitreal injections and morbidity in these patients.

Patterns of Gene Expression, Splicing, and Allele-Specific Expression Vary among Macular Tissues and Clinical Stages of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness, and elucidating its underlying disease mechanisms is vital to the development of appropriate therapeutics. We identified differentially expressed genes (DEGs) and differentially spliced genes (DSGs) across the clinical stages of AMD in disease-affected tissue, the macular retina pigment epithelium (RPE)/choroid and the macular neural retina within the same eye. We utilized 27 deeply phenotyped donor eyes (recovered within a 6 h postmortem interval time) from Caucasian donors (60-94 years) using a standardized published protocol. Significant findings were then validated in an independent set of well-characterized donor eyes (n = 85). There was limited overlap between DEGs and DSGs, suggesting distinct mechanisms at play in AMD pathophysiology. A greater number of previously reported AMD loci overlapped with DSGs compared to DEGs between disease states, and no DEG overlap with previously reported loci was found in the macular retina between disease states. Additionally, we explored allele-specific expression (ASE) in coding regions of previously reported AMD risk loci, uncovering a significant imbalance in C3 rs2230199 and CFH rs1061170 in the macular RPE/choroid for normal eyes and intermediate AMD (iAMD), and for CFH rs1061147 in the macular RPE/choroid for normal eyes and iAMD, and separately neovascular AMD (NEO). Only significant DEGs/DSGs from the macular RPE/choroid were found to overlap between disease states. STAT1, validated between the iAMD vs. normal comparison, and AGTPBP1, BBS5, CERKL, FGFBP2, KIFC3, RORα, and ZNF292, validated between the NEO vs. normal comparison, revealed an intricate regulatory network with transcription factors and miRNAs identifying potential upstream and downstream regulators. Findings regarding the complement genes C3 and CFH suggest that coding variants at these loci may influence AMD development via an imbalance of gene expression in a tissue-specific manner. Our study provides crucial insights into the multifaceted genomic underpinnings of AMD (i.e., tissue-specific gene expression changes, potential splice variation, and allelic imbalance), which may open new avenues for AMD diagnostics and therapies specific to iAMD and NEO.

Thrombospondin-1 proteomimetic polymers exhibit anti-angiogenic activity in a neovascular age-related macular degeneration mouse model

Neovascular age-related macular degeneration (nAMD) is the leading cause of blindness in the developed world. Current therapy includes monthly intraocular injections of anti-VEGF antibodies, which are ineffective in up to one third of patients. Thrombospondin-1 (TSP1) inhibits angiogenesis via CD36 binding, and its down-regulated expression is negatively associated with the onset of nAMD. Here, we describe TSP1 mimetic protein-like polymers (TSP1 PLPs). TSP1 PLPs bind CD36 with high affinity, resist degradation, show prolonged intraocular half-lives (13.1 hours), have no toxicity at relevant concentrations in vivo (40 μM), and are more efficacious in ex vivo choroidal sprouting assays compared to the peptide sequence and Eylea (aflibercept), the current standard of care anti-VEGF treatment. Furthermore, PLPs exhibit superior in vivo efficacy in a mouse model for nAMD compared to control PLPs consisting of scrambled peptide sequences, using fluorescein angiography and immunofluorescence. Since TSP-1 inhibits angiogenesis by VEGF-dependent and independent mechanisms, TSP1 PLPs are a potential therapeutic for patients with anti-VEGF treatment-resistant nAMD.

Age-related macular degeneration: care of the patient in the community setting

The aim of this article is to explain age-related macular degeneration (AMD) and how it impacts on the wellbeing of patients in the community setting. It explores the anatomy and physiology associated with AMD, its symptoms and treatment, and goes on to discuss related nursing care.

Diagnosis and Management of Patients With Geographic Atrophy Secondary to Age-Related Macular Degeneration: A Delphi Consensus Exercise

Geographic atrophy (GA) is a progressive and irreversible retinal disease with no comprehensive recommendations for diagnosis or monitoring. We used a Delphi approach to determine consensus in key areas around diagnosis and management of GA. A steering committee of eight retina specialists developed two sequential online surveys administered to eye care professionals (ECPs). Consensus was defined as agreement by ≥ 75% of respondents. Up to 177 ECPs from eight countries completed one or both surveys. Consensus was achieved in several topics related to diagnostic imaging, including the use of optical coherence tomography, and the urgent need for treatments and beneficial interventions to reduce the associated burden. Currently, low-vision aids and smoking cessation are considered the most beneficial interventions. We demonstrate consensus for diagnosis and management of patients with GA including best practices in patient identification and monitoring, and unmet needs. [Ophthalmic Surg Lasers Imaging Retina 2023;54:589-598.].

Innovative Strategies for Drug Delivery to the Ocular Posterior Segment

Innovative and new drug delivery systems (DDSs) have recently been developed to vehicle treatments and drugs to the ocular posterior segment and the retina. New formulations and technological developments, such as nanotechnology, novel matrices, and non-traditional treatment strategies, open new perspectives in this field. The aim of this mini-review is to highlight promising strategies reported in the current literature based on innovative routes to overcome the anatomical and physiological barriers of the vitreoretinal structures. The paper also describes the challenges in finding appropriate and pertinent treatments that provide safety and efficacy and the problems related to patient compliance, acceptability, effectiveness, and sustained drug delivery. The clinical application of these experimental approaches can help pave the way for standardizing the use of DDSs in developing enhanced treatment strategies and personalized therapeutic options for ocular pathologies.

Impact of an immersive, interactive medical education initiative on guideline-based retinal disease management knowledge/competence and effectual practice change

BACKGROUND

Retinal diseases, including wet or dry age-related macular degeneration, diabetic macular edema, and diabetic retinopathy (DR), are underdiagnosed and undertreated in the United States. Clinical trials support the effectiveness of anti-vascular endothelial growth factor (anti-VEGF) therapies for several retinal conditions, but real-world data suggest underuse by clinicians, resulting in patients experiencing poorer visual outcomes over time. Continuing education (CE) has demonstrated effectiveness at changing practice behaviors, but more research is needed to understand whether CE can help address diagnostic and treatment gaps.

METHODS

This test and control matched pair analysis examined pre-/post-test knowledge of retinal diseases and guideline-based screening and intervention among 10,786 healthcare practitioners (i.e., retina specialists, ophthalmologists, optometrists, primary care providers, diabetes educators, pharmacists/managed care specialists, and other healthcare providers, such as registered nurses, nurse practitioners, and physician assistants) who participated in a modular, interactive CE initiative. An additional medical claims analysis provided data on practice change, evaluating use of VEGF-A inhibitors among retina specialist and ophthalmologist learners (n = 7,827) pre-/post-education, compared to a matched control group of non-learners. Outcomes were pre-/post-test change in knowledge/competence and clinical change in application of anti-VEGF therapy, as identified by the medical claims analysis.

RESULTS

Learners significantly improved knowledge/competence scores on early identification and treatment, identifying patients who could benefit from anti-VEGF agents, using guideline-recommended care, recognizing the importance of screening and referral, and recognizing the importance of early detection and care for DR (all P-values = 0.003 to 0.004). Compared with matched controls, learners' incremental total injections for anti-VEGF agents for retinal conditions increased more after the CE intervention (P < 0.001); specifically, there were 18,513 more (new) anti-VEGF injections prescribed versus non-learners (P < 0.001).

CONCLUSIONS

This modular, interactive, immersive CE initiative resulted in significant knowledge/competence gains among retinal disease care providers and changes in practice-related treatment behaviors (i.e., appropriate consideration and greater incorporation of guideline-recommended anti-VEGF therapies) among participating ophthalmologists and retina specialists compared to matched controls. Future studies will utilize medical claims data to show longitudinal impact of this CE initiative on treatment behavior among specialists and impact on diagnosis and referral rates among optometrists and primary care providers who participate in future programming.

Targeting angiogenesis in oncology, ophthalmology and beyond

Angiogenesis is an essential process in normal development and in adult physiology, but can be disrupted in numerous diseases. The concept of targeting angiogenesis for treating diseases was proposed more than 50 years ago, and the first two drugs targeting vascular endothelial growth factor (VEGF), bevacizumab and pegaptanib, were approved in 2004 for the treatment of cancer and neovascular ophthalmic diseases, respectively. Since then, nearly 20 years of clinical experience with anti-angiogenic drugs (AADs) have demonstrated the importance of this therapeutic modality for these disorders. However, there is a need to improve clinical outcomes by enhancing therapeutic efficacy, overcoming drug resistance, defining surrogate markers, combining with other drugs and developing the next generation of therapeutics. In this Review, we examine emerging new targets, the development of new drugs and challenging issues such as the mode of action of AADs and elucidating mechanisms underlying clinical benefits; we also discuss possible future directions of the field.

Through the Eyes of Patients: Understanding Treatment Burden of Intravitreal Anti-VEGF Injections for nAMD Patients in Norway

Purpose

Patients with neovascular age-related macular degeneration (nAMD) are treated with frequent intravitreal injections to maintain vision. The treatment frequency impacts the life of patients and caregivers and poses a major capacity challenge for Norwegian ophthalmic clinics. The purpose of this survey was to document patient-reported outcomes on how the disease and the treatment impact nAMD patients in Norway.

Methods

Norwegian nAMD patients voluntarily completed the survey. The patients reported the time spent on each treatment appointment, the need for caregiver support, treatment intervals, and the emotional impact of the treatment. There was no active selection of patients to the survey. Respondents had to confirm the nAMD diagnosis prior to submitting the response. All data was included in the analysis as submitted by the respondents. This survey was market research involving anonymous patient data, and no participants were identifiable.

Results

In total, 130 patients responded to the survey. The majority of patients reported to receive nine or more injections per year (48.8%), and many patients needed caregiver support for every treatment appointment (37.7%). Patients reported to be anxious one day (25.4%), two days (8.5%), one week (10.8%) or more than one week (3.1%) prior to treatment. The week before the treatment, 33.1% of patients reported to be stressed and 15.4% struggled to sleep. The majority of patients reported the treatment as uncomfortable (54.6%) or as somewhat painful (26.2%). The results on yearly number of injections, time used each treatment day and need for caregiver support suggested a variation between Norwegian hospital regions.

Conclusions

This survey uncovers how treatment with intravitreal injections represents a substantial burden for Norwegian patients with nAMD. Future research on how the treatment burden impacts nAMD patients may lead to more patient-centered care and help guide treatment decisions. New treatments with longer intervals between injections are likely to both reduce the treatment burden and improve capacity in ophthalmology clinics.

Nanofiber-coated implants: Development and safety after intravitreal application in rabbits

Intravitreal injections are the preferred choice for drug administration to the posterior segment of the eye. However, the required frequent injections may cause complications to the patient and low adherence to the treatment. Intravitreal implants are able to maintain therapeutic levels for a long period. Biodegradable nanofibers can modulate drug release and allow the incorporation of fragile bioactive drugs. Age-related macular degeneration is one of the world major causes of blindness and irreversible vision loss. It involves the interaction between VEGF and inflammatory cells. In this work we developed nanofiber-coated intravitreal implants containing dexamethasone and bevacizumab for simultaneously delivery of these drugs. The implant was successfully prepared and the efficiency of the coating process was confirmed by scanning electron microscopy. Around 68% of dexamethasone was released in 35 days and 88% of bevacizumab in 48hs. The formulation presented activity in the reduction of vessels and was safe to the retina. It was not observed any clinical or histopathological change, neither alteration in retina function or thickness by electroretinogram and optical coherence tomography during 28 days. The nanofiber-coated implants of dexamethasone and bevacizumab may be considered as a new delivery system that can be effective for the treatment of AMD.

Melatonin Inhibits VEGF-Induced Endothelial Progenitor Cell Angiogenesis in Neovascular Age-Related Macular Degeneration

Neovascular age-related macular degeneration (AMD) is described as abnormal angiogenesis in the retina and the leaking of fluid and blood that generates a huge, dark, blind spot in the center of the visual field, causing severe vision loss in over 90% of patients. Bone marrow-derived endothelial progenitor cells (EPCs) contribute to pathologic angiogenesis. Gene expression profiles downloaded from the eyeIntegration v1.0 database for healthy retinas and retinas from patients with neovascular AMD identified significantly higher levels of EPC-specific markers (CD34, CD133) and blood vessel markers (CD31, VEGF) in the neovascular AMD retinas compared with healthy retinas. Melatonin is a hormone that is mainly secreted by the pineal gland, and is also produced in the retina. Whether melatonin affects vascular endothelial growth factor (VEGF)-induced EPC angiogenesis in neovascular AMD is unknown. Our study revealed that melatonin inhibits VEGF-induced stimulation of EPC migration and tube formation. By directly binding with the VEGFR2 extracellular domain, melatonin significantly and dose-dependently inhibited VEGF-induced PDGF-BB expression and angiogenesis in EPCs via c-Src and FAK, NF-κB and AP-1 signaling. The corneal alkali burn model demonstrated that melatonin markedly inhibited EPC angiogenesis and neovascular AMD. Melatonin appears promising for reducing EPC angiogenesis in neovascular AMD.

Increased efficacy of dietary supplement containing wax ester-rich marine oil and xanthophylls in a mouse model of dry macular degeneration

Age-related macular degeneration (AMD) is nowadays considered among the retinal diseases whose clinical management lacks established treatment approaches, mainly for its atrophic (dry) form. In this respect, the use of dietary patterns enriched in omega-3 and antioxidant xanthophylls has emerged as a promising approach to counteract dry AMD progression although the prophylactic potential of omega-3 of fish origin has been discussed. Whether enriched availability of omega-3 and xanthophylls may increase the effectiveness of diet supplementation in preventing dry AMD remains to be fully established. The present study aims at comparing the efficacy of an existing orally administered formulation based on lutein and fish oil, as a source of omega-3, with a novel formulation providing the combination of lutein and astaxanthin with Calanus oil (COil), which contains omega-3 together with their precursors policosanols. Using a mouse model of dry AMD based on subretinal injection of polyethylene glycol (PEG)-400, we assessed the comparative efficacy of both formulations on PEG-induced major hallmarks including oxidative stress, inflammation, glial reactivity and outer retinal thickness. Dietary supplementation with both mixtures has been found to exert a significant antioxidant and anti-inflammatory activity as reflected by the overall amelioration of the PEG-induced pathological hallmarks. Noteworthy, the formulation based on COil appeared to be more protective than the one based on fish oil, presumably because of the higher bioavailability of omega-3 in COil. These results support the use of dietary supplements combining omega-3 and xanthophylls in the prevention and treatment of AMD and suggest that the source of omega-3 might contribute to treatment efficacy.

Resvega, a Nutraceutical Preparation, Affects NFκB Pathway and Prolongs the Anti-VEGF Effect of Bevacizumab in Undifferentiated ARPE-19 Retina Cells

Age-related macular degeneration (AMD) is an irreversible chronic degenerative pathology that affects the retina. Despite therapeutic advances thanks to the use of anti-vascular endothelial growth factor (VEGF) agents, resistance mechanisms have been found to accentuate the visual deficit. In the present study, we explored whether a nutraceutical formulation composed of omega-3 fatty acids and resveratrol, called Resvega®, was able to disrupt VEGF-A secretion in human ARPE-19 retina cells. We found that Resvega® inhibits VEGF-A secretion through decreases in both the PI3K-AKT-mTOR and NFκB signaling pathways. In NFκB signaling pathways, Resvega® inhibits the phosphorylation of the inhibitor of NFκB, IκB, which can bind NFκB dimers and sequester them in the cytoplasm. Thus, the NFκB subunits cannot migrate to the nucleus where they normally bind and stimulate the transcription of target genes such as VEGF-A. The IκB kinase complex (IKK) is also affected by Resvega® since the nutraceutical formulation decreases both IKKα and IKKβ subunits and the IKKγ subunit which is required for the stimulation of IKK. Very interestingly, we highlight that Resvega® could prolong the anti-angiogenic effect of Avastin®, which is an anti-VEGF agent typically used in clinical practice. Our results suggest that Resvega® may have potential interest as nutritional supplementation against AMD.

Age-Related Macular Degeneration: Epidemiology, Pathophysiology, Diagnosis, and Treatment

The greatest global root of irremediable amaurosis in the venerable is age-related macular degeneration (AMD), a complex eye condition. Clinically, AMD is characterized as being in an early stage to late stage and initially affects the macula, which is the center of the retina (advanced AMD). Age-related cellular and metabolic imbalance are made worse by the creation of excessive amounts of free radical species, which causes mitochondrial malfunction. As a result, in AMD-affected eyes, the deprivation of melanocytes, confection, and eventually atrophy within the retinal tissue are caused by the continued proliferation of oxidative stress caused by systemic antioxidant capacity depletion.

In the urbanized, industrialized world, age-related macular degeneration (AMD) is one of the major causes of central vision loss in the older age group. Although several causes and mechanisms for the dysfunction and degeneration of the retinal pigment epithelium (RPE) have previously been identified, the condition’s symptoms are still not fully understood. Etiopathogenesis is still not entirely understood. As a result, the RPE fails, allowing an accumulation of aberrant misfolded proteins, due to the loss of anatomical control over oppression, altered homeostasis, dysfunctional lipid homeostasis, and failure of mitochondria.

Due to the multitude of interconnected processes, numerous complicated therapy combinations will probably be the best option to deliver the best visual outcomes; these combinations will vary depending on the kind and degree of the condition being treated. Undoubtedly, this will lead to the development of customized preventative medications and, hopefully, the revelation of a potential cure. All the mechanisms involved in the etiology of AMD should be continuously probed to create covariates for other contemporaneous or future problems.

Ranibizumab port delivery system: a clinical perspective

Age-related macular degeneration (AMD) represents a leading cause of blindness worldwide. Neovascular AMD (nAMD) is a subtype of AMD most frequently treated with intravitreal anti-vascular endothelial growth factor (aVEGF) injections, which has allowed for patients to maintain vision that would have otherwise been lost. However, the need for frequent intravitreal injections for optimal results poses a risk for undertreatment in nAMD patients due to the high treatment burden associated with current aVEGF therapy. Many novel agents and pathways are being explored and targeted for less burdensome treatment options, one of which is the ranibizumab port delivery system (PDS). The PDS is a surgically implanted, refillable device that allows for the sustained release of ranibizumab, a widely used aVEGF agent, into the vitreous cavity. Positive results non-inferior to monthly ranibizumab injections in both phase II and phase III clinical trials allowed for FDA approval of the device with refill intervals of 6 months, which represents the longest approved treatment interval to date for nAMD therapy. This article reviews the need for a durable nAMD treatment option in real-world practice, the clinical trial and extension study data for the PDS, the risk of adverse events and safety profile of the PDS and the potential clinical role of the PDS in answering the real-world needs of nAMD treatment. In addition, other pipeline sustained-treatment modalities are discussed in the context of ongoing clinical trials.

Challenges in Age-Related Macular Degeneration: From Risk Factors to Novel Diagnostics and Prevention Strategies

Age-related macular degeneration (AMD) is a chronic multifactorial eye disease representing the primary cause of vision loss in people aged 60 years and older. The etiopathogenesis of the disease remains uncertain, with several risk factors contributing to its onset and progression, such as genotype, aging, hypertension, smoking, overweight, and low dietary intake of carotenoids. Since the aging populations of the industrialized world are increasing rapidly, the impact of AMD in the socio-economical life-developed countries is expected to increase dramatically in the next years. In this context, the benefits of prevention and early disease detection for prompt and effective treatment can be enormous to reduce the social and economic burden of AMD. Nutritional and lifestyle changes, including dietary intake of xanthophyll pigments, such as lutein and zeaxanthin, no smoking, and regular exercise, are known to protect from risk of AMD progression from early to advanced disease stages. In this review, we present the clinical outcomes of a pilot study on trans-scleral iontophoresis delivery of lutein in patients with AMD. Topical delivery of lutein directly to the macula may provide a more efficient method for enriching the macular pigment and for achieving greater patient compliance to therapy than oral administration and thus enhancing prevention strategies. Modern diagnostic methodologies shall address the major problem of accurately detecting the risk of transition from intermediate AMD to advanced AMD stages. Adaptive optics retinal imaging and resonance Raman spectroscopy are two highly promising technologies for the objective assessment of patients with AMD. In this review, we present some of their clinical applications for collecting quantitative measurements of retinal cellular changes and macular content of xanthophyll pigments, respectively. In conclusion, there is great expectation that technological advancements in AMD management will deliver improved screening, therapeutic prevention, and diagnostic systems in the coming decade through a pro-active strategy of “treatment for prevention” that will aim to reduce the global burden of vision loss caused by AMD in the elderly.