Longer-acting treatments for neovascular age-related macular degeneration-present and future

Efficacy and safety of dexamethasone versus intravitreal aflibercept implants for macular edema: a systematic review and meta-analysis

BACKGROUND

Macular edema (ME) is a prevalent complication of diabetic retinopathy (DR) and retinal vein occlusion (RVO) that contributes significantly to vision impairment worldwide. This condition is primarily driven by elevated vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines, resulting in the use of anti-VEGF agents such as aflibercept and corticosteroids such as dexamethasone implants. However, evidence comparing the clinical efficacy and safety of these two modalities remains limited.

OBJECTIVES

This systematic review and meta-analysis aimed to compare the safety and efficacy of intravitreal aflibercept injections and dexamethasone implants in ME associated with DR and RVO.

METHOD

The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and registered with PROSPERO (CRD42024577212). A comprehensive search of the PubMed, Cochrane, Web of Science, and Scopus databases was performed until August 30, 2024. Nine studies, involving 572 eyes, were included in the analysis. Key outcomes assessed included Best-Corrected Visual Acuity (BCVA), Central Retinal Thickness (CRT), and Intraocular Pressure (IOP). A random-effects model was applied to the pooled effect size calculations, and heterogeneity was addressed using sensitivity analyses.

RESULTS

Both treatments showed comparable efficacy in improving BCVA and reducing CRT across follow-up intervals. At 3 months, dexamethasone implants demonstrated statistically significant superiority in BCVA improvement (MD = 1.18, 95% CI [0.89, 1.47], P < 0.001) and CRT reduction (MD =  - 62.45 µm, 95% CI [- 85.67, - 39.22], P < 0.001) compared to aflibercept. Similarly, at 12 months, dexamethasone implants maintained greater efficacy in CRT reduction (MD =  - 58.73 µm, 95% CI [- 78.12, - 39.34], P < 0.001). However, dexamethasone implants were associated with an increased IOP at 3 and 6 months (MD = 1.04 mmHg, 95% CI [0.56, 1.52], P < 0.001). No significant differences in IOP were observed between treatments at 12 months.

CONCLUSION

Intravitreal aflibercept injections and dexamethasone implants are effective modalities for the management of ME, with each presenting distinct advantages. Dexamethasone implants minimize the frequency of treatment, while achieving superior outcomes in terms of BCVA and CRT. However, they are also associated with a heightened risk of IOP elevation and cataract formation. Conversely, aflibercept requires more frequent administration, which may result in logistical and financial challenges for patients and health care providers. Therefore, personalized treatment strategies should consider disease severity, comorbidities, and individual preferences. Future research should prioritize patient-centered outcomes, emphasizing quality of life and treatment costs while also investigating condition-specific responses to these therapeutic interventions.

The effect of diabetes on short-term outcomes following epiretinal membrane surgery

PURPOSE

This study aimed to examine the association of diabetes with anatomical and functional outcomes of epiretinal membrane surgery.

METHODS

Consecutive patients who underwent epiretinal membrane surgery between 2017-2021 at Helsinki University Hospital, Finland. Here we examined the association of diabetes, glycemic control, and requirement for insulin medication with surgical outcomes at 1-month.

RESULTS

Included were 214 eyes of 214 patients, with a mean age of 71.2 ± 8.2 years. Among patients with diabetes (n = 45), neither significant differences were observed in anatomical outcomes (- 47.8 ± 72.7 μm vs. - 38.3 ± 103 μm for foveal thickness, p = 0.566 and - 41.6 ± 61.8 μm vs. - 41.7 ± 85.7 μm for central subfield macular thickness, p = 0.996) nor in best-corrected visual acuity (BCVA) gain (0.06 ± 0.22 vs 0.12 ± 0.30 LogMAR units, p = 0.214) compared to those without diabetes. In a multivariate analysis adjusted for age, gender, the existence of preoperative macular cysts, and topical nonsteroidal anti-inflammatory drugs (NSAIDs) use, the results remained consistent. The last preoperative HbA1c levels did not correlate with changes in foveal (Pearson's r = 0.218, p = 0.264) or central subfield macular thickness (r = 0.365, p = 0.056), or with BCVA gain (r = -0.177, p = 0.386). Insulin therapy for diabetes did not associate with the outcomes (p > 0.05 for anatomical and functional comparisons).

CONCLUSIONS

In a cohort of patients who underwent epiretinal membrane surgery, neither the presence of diabetes, nor glycemic control and the use of insulin medication associated with the outcomes.

Multi-Omics Integration With Machine Learning Identified Early Diabetic Retinopathy, Diabetic Macula Edema and Anti-VEGF Treatment Response

Purpose

Identify optimal metabolic features and pathways across diabetic retinopathy (DR) stages, develop risk models to differentiate diabetic macular edema (DME), and predict anti-vascular endothelial growth factor (anti-VEGF) therapy response.

Methods

We analyzed 108 aqueous humor samples from 78 type 2 diabetes mellitus patients and 30 healthy controls. Ultra-high-performance liquid chromatography-high-resolution-mass-spectrometry detected lipidomics and metabolomics profiles. DME patients received ≥3 anti-VEGF treatments, categorized into strong and weak response groups. Machine learning (ML) screened prospective metabolic features, developing prediction models.

Results

Key metabolic features identified in the metabolomics and lipidomics datasets included n-acetyl isoleucine (odds ratio [OR] = 1.635), cis-aconitic acid (OR = 3.296), and ophthalmic acid (OR = 0.836) for DR. For early-DR, n-acetyl isoleucine (OR = 1.791) and decaethylene glycol (PEG-10) (OR = 0.170) were identified as key markers. L-kynurenine (OR = 0.875), niacinamide (OR = 0.843), and linoleoyl ethanolamine (OR = 0.941) were identified as significant indicators for DME. Trigonelline (OR = 1.441) and 4-methylcatechol-2-sulfate (OR = 1.121) emerged as predictors for strong response to anti-VEGF. Predictive models achieved R² values of 99.9%, 97.7%, 93.9%, and 98.4% for DR, early-DR, DME, and strong response groups in the calibration set, respectively, and validated well with R² values of 96.3%, 96.8%, 79.9%, and 96.3%.

Conclusions

This research used ML to identify differential metabolic features from metabolomics and lipidomics datasets in DR patients. It implies that metabolic indicators can effectively predict early disease progression and potential weak responders to anti-VEGF therapy in DME eyes.

Translational Relevance

The identified metabolic indicators may aid in predicting the early progression of DR and optimizing therapeutic strategies for DME.

Intravitreal therapeutic nanoparticles for age-related macular degeneration: Design principles, progress and opportunities

Age-related macular degeneration (AMD) is a leading cause of vision loss in the elderly. The current standard treatment for AMD involves frequent intravitreal administrations of therapeutic agents. While effective, this approach presents challenges, including patient discomfort, inconvenience, and the risk of adverse complications. Nanoparticle-based intravitreal drug delivery platforms offer a promising solution to overcome these limitations. These platforms are engineered to target the retina specifically and control drug release, which enhances drug retention, improves drug concentration and bioavailability at the retinal site, and reduces the frequency of injections. This review aims to uncover the design principles guiding the development of highly effective nanoparticle-based intravitreal drug delivery platforms for AMD treatment. By gaining a deeper understanding of the physiology of ocular barriers and the physicochemical properties of nanoparticles, we establish a basis for designing intravitreal nanoparticles to optimize drug delivery and drug retention in the retina. Furthermore, we review recent nanoparticle-based intravitreal therapeutic strategies to highlight their potential in improving AMD treatment efficiency. Lastly, we address the challenges and opportunities in this field, providing insights into the future of nanoparticle-based drug delivery to improve therapeutic outcomes for AMD patients.

Exploring Current Molecular Targets in the Treatment of Neovascular Age-Related Macular Degeneration toward the Perspective of Long-Term Agents

Long-lasting anti-vascular endothelial growth factor (anti-VEGF) agents have become an option to reduce treatment frequency, with ongoing research exploring optimal responses and safety profiles. This review delves into molecular targets, pharmacological aspects, and strategies for achieving effective and enduring disease control in neovascular age-related macular degeneration (AMD). The molecular pathways involved in macular neovascularization, including angiogenesis and arteriogenesis, are explored. VEGF, PlGF, Ang-1, and Ang-2 play crucial roles in regulating angiogenesis, influencing vessel growth, maturation, and stability. The complex interplay of these factors, along with growth factors like TGFβ and bFGF, contributes to the pathogenesis of neovascular membranes. Current anti-VEGF therapies, including bevacizumab, ranibizumab, aflibercept, brolucizumab, and faricimab, are discussed with a focus on their pharmacokinetics and clinical applications. Strategies to achieve sustained disease control in AMD involve smaller molecules, increased drug dosages, and novel formulations. This narrative review provides a comprehensive overview of the molecular targets and pharmacological aspects of neovascular AMD treatment.

Accuracy of biomicroscopy, ultrasonography and spectral-domain OCT in detection of complete posterior vitreous detachment

BACKGROUND

To evaluate the accuracy of preoperative biomicroscopy (BM), ultrasonography (US), and spectral domain optical coherence tomography (SD-OCT) to determine complete posterior vitreous detachment (PVD) confirmed by intraoperative findings of triamcinolone acetonide-assisted pars plana vitrectomy (PPV).

METHODS

This prospective study included all consecutive patients admitted for surgical treatment of the epiretinal membrane (ERM) and macular hole (MH). The presence of complete PVD was determined one day before PPV using BM, US, SD-OCT. The preoperative findings were compared to the PVD status determined during PPV.

RESULTS

A total of 123 eyes from 123 patients were included in the study. Indications for PPV included ERM in 57 (46.3%), full thickness macular hole in 57 (46.3%) and lamellar macular hole in 9 (7.3%) patients. Complete PVD during PPV was observed in 18 (31.6%; 95%CI:18.7-49.9) patients with ERM and 13 (19.7%; 95%CI:10.4-33.7) patients with MH. The sensitivity of preoperative BM, US, SD-OCT was 48.4% (95%CI:30.2-66.9), 61.3% (95%CI:42.2-78.2) and 54.8% (95%CI:36.0-72.7) respectively. The specificity of preoperative BM, US, SD-OCT was 81.5% (95%CI:72.1-88.9), 90.2% (95%CI:82.2-95.4) and 85.9% (95%CI:77.0-92.3) respectively. With a prevalence of 25.2% of PVD in our sample the positive predictive value of preoperative BM, US, SD-OCT was 46.9% (95%CI:29.1-65.3), 67.9% (95%CI:47.6-84.1) and 56.7% (95%CI:37.4-74.5) respectively.

CONCLUSION

Preoperative BM, US, and SD-OCT showed relatively low sensitivity but also good specificity in assessing complete PVD. A combination of all three diagnostic methods can provide a good assessment of the vitreoretinal interface state.

Influence of lesion location on lesion reactivation after initial treatment in neovascular age-related macular degeneration

PURPOSE

We aim to evaluate the factors associated with the incidence of lesion reactivation after initial loading injections in patients with neovascular age-related macular degeneration (AMD).

METHODS

This retrospective study included patients diagnosed with treatment-naïve neovascular AMD who received three loading injections of either ranibizumab or aflibercept. After the initial treatment, patients were followed up every 1-2 months during the first year and the follow-up interval was extended to 4 months during the second year. Retreatment was administered on an as-needed basis. The incidence and timing of lesion reactivation at 24 months after diagnosis were identified. In addition, Cox's proportional hazard model was used to evaluate the association of baseline factors with lesion reactivation. Lesion reactivation was defined re-accumulation of subretinal fluid/intraretinal fluid or the development of subretinal/intraretinal hemorrhage.

RESULTS

A total of 284 patients (173 men and 111 women) were included in the study. The mean age of the patients was 70.5 ± 8.8 years. During the 24-month follow-up period, lesion reactivation was observed in 216 eyes (76.1%) at a mean of 8.2 ± 4.4 months after diagnosis. The incidence of lesion reactivation was 62.5% in extrafoveal macular neovascularization (MNV), 75.0% in juxtafoveal MNV, and 79.5% in subfoveal MNV. The extrafoveal MNV showed significantly lower incidence of lesion reactivation than subfoveal MNV (P = 0.041, hazard ratio = 0.64).

CONCLUSIONS

Extrafoveal MNVs showed a lower incidence of lesion reactivation after initial treatment than subfoveal MNVs. This result should be considered when interpreting the results of clinical trials with different eligibility criteria regarding lesion location.

Clinical Correlation of Retinal Fluid Fluctuation Represented by Fluctuation Index in Wet Age-Related Macular Degeneration: TOWER Study Report 2

Purpose

To explore outcomes and biomarkers associated with retinal fluid instability represented by a new parameter in neovascular age-related macular degeneration (nAMD).

Methods

Patients with treatment-naïve nAMD receiving anti-vascular endothelial growth factor (VEGF) injections for a duration of 1 to 3 years were consecutively reviewed. Fluctuation Index (FI) of each eye, calculated by averaging the sum of differences in 1-mm central subfield thickness between each follow-up from months 3 to 24, was arranged into ascending order from the lowest to the highest and split equally into low, moderate, and high fluctuation groups. Outcomes were analyzed at 24 months.

Results

Of 558 eyes, FI values showed a negative correlation with a degree-response gradient with 24-month visual improvement. After controlling for baseline best-corrected visual acuity and potential confounders, eyes with low fluctuation gained more Early Treatment Diabetic Retinopathy Study letters than those in the moderate and high fluctuation group (Δ, 10.1 and 14.0 letters, respectively). Significant best-corrected visual acuity improvement from baseline to month 24 (11.8 letters) was observed exclusively in the low fluctuation group despite the indifference in the number of injections and types of anti-VEGF drug used among groups. Patients presenting with central subfield thickness of ≥405 µm or intraretinal fluid coinciding with subretinal fluid showed a significant association with foveal thickness instability during the maintenance phase.

Conclusions

Apart from the central subfield thickness values, unstable macular thickening represented by the FI was associated with some baseline features and may contribute to substandard visual outcomes.

Translational Relevance

FI may be a valuable tool for assessing therapeutic adequacy in the treatment of nAMD.

Potential for Treatment Interval Extension in Eyes with nAMD Disease Activity Post Loading Phase in HAWK and HARRIER

INTRODUCTION

The HAWK and HARRIER studies evaluated the efficacy and safety of brolucizumab versus aflibercept in treatment-naïve eyes with neovascular age-related macular degeneration. Based on the study design, brolucizumab-treated eyes adjusted to a q8w regimen because the presence of disease activity (DA) at the end of the matched loading phase (Week 16) could not subsequently extend to a q12w interval. The aim of this post hoc analysis was to assess subsequent DA in this subgroup to determine the potential for interval extensions during the first year of treatment.

METHODS

Pooled data from the brolucizumab 6 mg arms and aflibercept arms of HAWK and HARRIER were included. Presence of DA was determined by the masked investigator based on their assessment of functional and anatomical parameters measured by optical coherence tomography. DA was compared at DA assessments, conducted at Weeks 16, 20, 32, and 44; fluid was also assessed at the primary analysis at Week 48.

RESULTS

Fewer brolucizumab- (22.8%) than aflibercept-treated (32.2%) eyes had DA at the first DA assessment at Week 16. In eyes with investigator-identified DA at Week 16, BCVA change from baseline to Week 96 was comparable between treatment arms. Fewer brolucizumab- than aflibercept-treated eyes had DA at each subsequent DA assessment in Year 1: 31.8% vs 39.1% (Week 20), 27.3% vs 43.5% (Week 32), and 17.3% vs 31.2% (Week 44). Fewer eyes treated with brolucizumab than aflibercept had intraretinal and/or subretinal fluid: 35.3% vs 43.5% (Week 20), 55.8% vs 69.6% (Week 32), 30.0% vs 43.1% (Week 44), and 48.6% vs 68.6% (Week 48).

CONCLUSION

These findings indicate that, in eyes that still had DA 8 weeks after the final dose of loading phase, brolucizumab-treated eyes had improved fluid resolution and higher potential for treatment interval extension than aflibercept-treated eyes during the first year of treatment.

Novel Approaches in the Drug Development and Delivery Systems for Age-Related Macular Degeneration

The number of patients with ocular disorders has increased due to contributing factors such as aging populations, environmental changes, smoking, genetic abnormalities, etc. Age-related macular degeneration (AMD) is one of the common ocular disorders which may advance to loss of vision in severe cases. The advanced form of AMD is classified into two types, dry (non-exudative) and wet (exudative) AMD. Although several therapeutic approaches are explored for the management of AMD, no approved therapy can substantially slow down the progression of dry AMD into the later stages. The focus of researchers in recent times has been engaged in developing targeted therapeutic products to halt the progression and maintain or improve vision in individuals diagnosed with AMD. The delivery of anti-VEGF agents using intravitreal therapy has found some success in managing AMD, and novel formulation approaches have been introduced in various studies to potentiate the efficacy. Some of the novel approaches, such as hydrogel, microspheres, polymeric nanoparticles, liposomes, implants, etc. have been discussed. Apart from this, subretinal, suprachoroidal, and port delivery systems have also been investigated for biologics and gene therapies. The unmet potential of approved therapeutic products has contributed to several patent applications in recent years. This review outlines the current treatment options, outcomes of recent research studies, and patent details around the novel drug delivery approach for the treatment of AMD.

Intralenticular Ozurdex injection in an eye with thicker lens and the therapeutic effect maintained for 15 months

Introduction

To report a case of accidental intralenticular Ozurdex injection in an eye with thicker lens. During the follow-up period of 15 months, the therapeutic effect of intralenticular Ozurdex was maintained.

Case description

Ozurdex was accidently injected into the lens of an eye with uveitis, and the lens thickness was measured to be 5.70 mm. The uveitis was under good control, and no significant development of cataract was observed until 7 months after the intralenticular Ozurdex injection. Then due to the outbreak of COVID-19, follow-up was suspended. Fifteen months after the injection, the patient returned to the doctor. At this time, significant cataract development was observed, whereas uveitis was still under good control. Accordingly, cataract surgery and Ozurdex extraction were performed. Two months after surgery, a mild recurrence of uveitis occurred.

Conclusions

A thicker lens might be an important risk factor for accidental intralenticular Ozurdex injections. However, after intralenticular Ozurdex injection, the development of cataract was slow, and Ozurdex could still have a therapeutic effect on uveitis in this case. Thus, immediate surgery might be unnecessary for certain accidental intralenticular Ozurdex injection cases, and a follow-up strategy could be chosen to maintain the effect of Ozurdex.

Metformin therapy as a strategy to compensate anti-VEGF resistance in patients with diabetic macular edema

Diabetic macular edema (DME) is the complication of diabetic retinopathy, the leading cause of vision loss among diabetic patients. Metformin is the main antidiabetic treatment. It is preferable for its great anti-angiogenic and anti-inflammatory effects. Anti-vascular endothelial growth factor (VEGF) therapy is the preferable treatment for DME despite its lack of convincing results in some patients. To assess whether the combination of metformin and anti-VEGF drugs may decrease the risk of anti-VEGF resistance among DME patients. We included DME patients with a central retinal thickness (CRT) ≥ 250 μm who consecutively underwent at least 3 anti-VEGF therapies from January 1, 2020, to December 30, 2021. Anti-VEGF resistance was defined as persistent macular edema with decreased CRT ≤ 25% after 3 anti-VEGF injections. 109 patients were considered for this research, of whom 65 (59.6%) were resistant to anti-VEGF therapy. The mean CRT of the non-metformin group decreased from 344.88 ± 129.48 to 318.29 ± 123.23 (20.85%) and from 415.64 ± 144.26 to 277.11 ± 99.25 (31.51%) (P = .031) in the metformin group. Moreover, the metformin group had fewer resistant patients than the non-metformin, 24 (45.3%) versus 41 (73.2%). Furthermore, a considerable gain in visual acuity was observed in both groups, with a BCVA gain of 40.41% in the metformin group and 39.9% in the non-metformin group. Metformin may be combined with an anti-VEGF drug to minimize the risk of anti-VEGF resistance among DME patients. Moreover, it can serve to design effective therapeutic deliveries.

Intraprocedural OCT monitoring of the immediate treatment response during indocyanine green angiography-guided laser therapy of teleangiectatic capillaries in diabetic macular edema

In this retrospective study the morphological response of teleangiectatic capillaries (TCs) to focal laser treatment and the functional and morphological outcome after Indocyanine green angiography (ICGA)-guided laser therapy was evaluated. TCs in eyes with diabetic macular edema (DME) were treated with laser therapy. The immediate and subsequent reaction of the TCs lumina to direct photocoagulation was monitored with customized OCT single scans. Additionally, patients were treated with intravitreal anti-VEGF as needed. 12 eyes of 9 patients with treatment naive (6 eyes) and pretreated (6 eyes) DME were followed-up for a mean of 24 months (± 8.1SD). Best-corrected visual acuity improved from 0.25 logMar (± 0.2SD) to 0.12 (± 0.10SD; p = 0.06) at each patient’s last visit. During laser treatment a darkening of the TCs lumina was achieved in 91.3% of lesions. All these lesions fully resolved, whereas TCs, which showed no darkening of their lumen in OCT persisted and required re-treatment with laser. Additional anti-VEGF injections were indicated in only one eye (8.3%). The darkening of the TCs lumina visible in OCT might provide an image-biomarker that indicates successful coagulation of aneurysmatic lesions. Consequently, a significant functional and morphological improvement with need for anti-VEGF treatment in only one eye, was achieved.

Information concerning the registration of the trial: date of registration: 11th of december, 2019. Trial registration number: 107/2019.

Aqueous proteins help predict the response of patients with neovascular age-related macular degeneration to anti-VEGF therapy

BackgroundTo reduce the treatment burden for patients with neovascular age-related macular degeneration (nvAMD), emerging therapies targeting vascular endothelial growth factor (VEGF) are being designed to extend the interval between treatments, thereby minimizing the number of intraocular injections. However, which patients will benefit from longer-acting agents is not clear.MethodsEyes with nvAMD (n = 122) underwent 3 consecutive monthly injections with currently available anti-VEGF therapies, followed by a treat-and-extend protocol. Patients who remained quiescent 12 weeks from their prior treatment entered a treatment pause and were switched to pro re nata (PRN) treatment (based on vision, clinical exam, and/or imaging studies). Proteomic analysis was performed on aqueous fluid to identify proteins that correlate with patients' response to treatment.ResultsAt the end of 1 year, 38 of 122 eyes (31%) entered a treatment pause (≥30 weeks). Conversely, 21 of 122 eyes (17%) failed extension and required monthly treatment at the end of year 1. Proteomic analysis of aqueous fluid identified proteins that correlated with patients' response to treatment, including proteins previously implicated in AMD pathogenesis. Interestingly, apolipoprotein-B100 (ApoB100), a principal component of drusen implicated in the progression of nonneovascular AMD, was increased in treated patients who required less frequent injections. ApoB100 expression was higher in AMD eyes compared with controls but was lower in eyes that develop choroidal neovascularization (CNV), consistent with a protective role. Accordingly, mice overexpressing ApoB100 were partially protected from laser-induced CNV.FundingThis work was supported by the National Eye Institute, National Institutes of Health grants R01EY029750, R01EY025705, and R01 EY27961; the Research to Prevent Blindness, Inc.; the Alcon Research Institute; and Johns Hopkins University through the Robert Bond Welch and Branna and Irving Sisenwein professorships in ophthalmology.ConclusionAqueous biomarkers could help identify patients with nvAMD who may not require or benefit from long-term treatment with anti-VEGF therapy.

Association between Retinal Thickness Variability and Visual Acuity Outcome during Maintenance Therapy Using Intravitreal Anti-Vascular Endothelial Growth Factor Agents for Neovascular Age-Related Macular Degeneration

Previous studies based on clinical trial data have demonstrated that greater fluctuations in retinal thickness during the course of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy for neovascular age-related macular degeneration (nAMD) is associated with poorer visual acuity outcomes. However, it was unclear whether similar findings would be observed in real-world clinical settings. This study aimed to evaluate the association between retinal thickness variability and visual outcomes in eyes receiving anti-VEGF therapy for nAMD using pro re nata treatment regimen. A total of 64 eyes which received intravitreal anti-VEGF therapy (bevacizumab, ranibizumab or aflibercept) for the treatment of nAMD were evaluated. Variability in spectral-domain optical coherence tomography (OCT) central subfield thickness (CST) was calculated from the standard deviation (SD) values of all follow-up visits after three loading doses from month 3 to month 24. Eyes were divided into quartiles based on the OCT CST variability values and the mean best-corrected visual acuity values at 2 years were compared. At baseline, the mean ± SD logMAR visual acuity and CST were 0.59 ± 0.39 and 364 ± 113 µm, respectively. A significant correlation was found between CST variability and visual acuity at 2 years (Spearman's ρ = 0.54, p < 0.0001), indicating that eyes with lower CST variability had better visual acuity at 2 years. Eyes with the least CST variability were associated with the highest mean visual acuity improvement at 2 years (quartile 1: +9.7 letters, quartile 2: +1.1 letters, quartile 3: -2.5 letters, quartile 4: -9.5 letters; p = 0.018). No significant difference in the number of anti-VEGF injections was found between the four CST variability quartile groups (p = 0.21). These findings showed that eyes undergoing anti-VEGF therapy for nAMD with more stable OCT CST variability during the follow-up period were associated with better visual outcomes. Clinicians should consider adopting treatment strategies to reduce CST variability during the treatment course for nAMD.

Ocular Therapeutics and Molecular Delivery Strategies for Neovascular Age-Related Macular Degeneration (nAMD)

Age-related macular degeneration (AMD) is the leading cause of vision loss in geriatric population. Intravitreal (IVT) injections are popular clinical option. Biologics and small molecules offer efficacy but relatively shorter half-life after intravitreal injections. To address these challenges, numerous technologies and therapies are under development. Most of these strategies aim to reduce the frequency of injections, thereby increasing patient compliance and reducing patient-associated burden. Unlike IVT frequent injections, molecular therapies such as cell therapy and gene therapy offer restoration ability hence gained a lot of traction. The recent approval of ocular gene therapy for inherited disease offers new hope in this direction. However, until such breakthrough therapies are available to the majority of patients, antibody therapeutics will be on the shelf, continuing to provide therapeutic benefits. The present review aims to highlight the status of pre-clinical and clinical studies of neovascular AMD treatment modalities including Anti-VEGF therapy, upcoming bispecific antibodies, small molecules, port delivery systems, photodynamic therapy, radiation therapy, gene therapy, cell therapy, and combination therapies.

LRG1 Expression Is Elevated in the Eyes of Patients with Neovascular Age-Related Macular Degeneration

Leucine-rich a-2-glycoprotein 1 (LRG1) is a candidate therapeutic target for treating the neovascular form of age-related macular degeneration (nvAMD). In this study we examined the expression of LRG1 in eyes of nvAMD patients. Choroidal neovascular membranes (CNVMs) from patients who underwent submacular surgery for retinal pigment epithelium-choroid graft transplantation were collected from 5 nvAMD patients without any prior intravitreal anti-VEGF injection, and from six patients who received intravitreal anti-VEGF injections before surgery. As controls free of nvAMD, retina sections were obtained from the eyes resected from a patient with lacrimal sac tumor and from a patient with neuroblastoma. CNVMs were immunostained for CD34, LRG1, and α-smooth muscle actin (α-SMA). Aqueous humor samples were collected from 58 untreated-naïve nvAMD patients prior to the intravitreal injection of anti-VEGF and 51 age-matched cataract control patients, and LRG1 concentration was measured by ELISA. The level of LRG1 immunostaining is frequently high in both the endothelial cells of the blood vessels, and myofibroblasts in the surrounding tissue of CNVMs of treatment-naïve nvAMD patients. Furthermore, the average concentration of LRG1 was significantly higher in the aqueous humor of nvAMD patients than in controls. These observations provide a strong experimental basis and scientific rationale for the progression of a therapeutic anti-LRG1 monoclonal antibody into clinical trials with patients with nvAMD.

Neovascular age-related macular degeneration at treatment intervals of 14 weeks or greater

BACKGROUND

We assessed the proportion of eyes with neovascular age-related macular degeneration (nAMD) in routine clinical practice that reach ≥14 week treatment intervals and their outcomes.

METHOD

We analysed data from the Fight Retinal Blindness! (FRB!) Project database, a prospectively designed registry of 'real-world' outcomes. Treatment-naive eyes starting vascular endothelial growth factor (VEGF) inhibitors for nAMD from 1st January 2006 were included. Eyes were defined to have reached the ≥14 week treatment interval if they received ≥2 consecutive injections at treatment intervals of ≥14 week but not exceeding 26 weeks. Outcomes were reported in a subgroup of eyes that had 12 months of follow-up from reaching this interval.

RESULTS

Of the 3907 treatment-naïve eyes that started treatment during the identified periods on a treat-and-extend regimen and received at least 8 injections over the first 2 years, 402 (10%) eyes received at least 2 consecutive injections at an interval of ≥14 week during their follow-up. Fifty-two percent of these eyes maintained vision to 12 months, however only 40% stayed at this interval and 25% of the lesions reactivated.

CONCLUSION

We found that only 10% of eyes with nAMD were extended beyond a 13-week injection interval and that over half had returned to a shorter interval by 12 months. Eyes that stayed at this extended treatment interval maintained stable vision. More data on the outcomes of eyes treated with intervals longer than 3 months are required to establish whether emerging VEGF inhibitors provide a more sustained effect than the currently available drugs.

Brolucizumab: a novel anti-VEGF humanized single-chain antibody fragment for treating w-AMD

INTRODUCTION

Wet age-related macular degeneration (w-AMD) represents the leading cause of visual impairment in the elderly in the developed countries. Intravitreal antivascular endothelial growth factor (VEGF) drugs are currently considered as the first-line treatment option for treating w-AMD; however, the frequent injection intervals have lit the way to investigate novel anti-VEGF agents allowing a more extended treatment regimen. Brolucizumab is a single-chain antibody fragment targeting all the isoforms of VEGF-A. Phase III HAWK and HARRIER trials have shown a longer durability and superior anatomical outcomes as compared with the standard of care by adopting a quarterly regimen for treating w-AMD. Brolucizumab has been approved in Europe, USA, and Japan for the management of w-AMD.

AREAS COVERED

This article presents an overview of w-AMD and investigates the progress of brolucizumab through clinical trials. It offers insights into where brolucizumab may be placed in the current market of anti-VEGF agents and its potential advantages over the previous molecules adopted for treating w-AMD.

EXPERT OPINION

The possibility of administering brolucizumab with more dilated treatment intervals represents an important advantage to decrease the treatment burden and improve patient compliance. Brolucizumab represents a possible drug switching option in non-responding patients to other anti-VEGF drugs.