Geographic atrophy: where we are now and where we are going

Ophthalmologists' awareness of geographic atrophy: An Italian survey including 365 participants

PURPOSE

Geographic atrophy (GA) is a severe complication of age-related macular degeneration (AMD) and leads to irreversible visual decline. To date, no effective treatment is available for GA patients. However, a number of new therapies have recently been approved and several others are in the pipeline. This rapid evolution of prospects for GA patients requires constant updating of ophthalmologists' understanding of GA and its management so as to provide the appropriate treatment. For this reason, Società Italiana di Scienze Oftalmologiche (S.I.S.O.) has designed a specific survey to gauge the position of Italian ophthalmologists in this regard.

METHODS

The three hundred and sixty-five Italian ophthalmologists who agreed to take part received a seventeen-part questionnaire guaranteeing privacy and anonymity. The survey was compiled through an online portal and the results were sent directly to S.I.S.O. ETS. Two graders analyzed the data and recorded the results.

RESULTS

The results showed a high level of self-assessed awareness and understanding of GA, as well as considerable willingness to further improve knowledge of the disease. Most of the participants claimed to have effective rules of conduct in place for managing GA patients, including prompt response, involving a high prevalence of nutraceutical prescriptions and lifestyle recommendations.

CONCLUSIONS

This survey provided an overview of how GA patients are managed in Italy. The Italian ophthalmology community appears to be ready to adopt the upcoming treatments for GA.

Therapeutic innovations for geographic atrophy: A promising horizon

This mini review spotlights the most promising treatments for geographic atrophy, the advanced form of age-related macular degeneration, often resulting in severe and irreversible vision loss. The pathophysiology is complex, and various therapeutic strategies, including anticomplement therapies, gene therapies, cell-based interventions, and artificial intelligence-driven diagnostics are discussed. Anticomplement therapies (antifactors C3 and C5) showed promise in reducing the inflammatory response and the progression of the atrophy. Gene therapies, targeting specific genetic mutations, are under development to correct underlying defects and potentially reverse disease progression. Cell-based therapies are gaining momentum, with early studies indicating encouraging results in the replacement of damaged retinal pigment epithelium cells.

Topographic Clinical Insights From Deep Learning-Based Geographic Atrophy Progression Prediction

Purpose

To explore the contributions of fundus autofluorescence (FAF) topographic imaging features to the performance of convolutional neural network-based deep learning (DL) algorithms in predicting geographic atrophy (GA) growth rate.

Methods

Retrospective study with data from study eyes from three clinical trials (NCT02247479, NCT02247531, NCT02479386) in GA. The algorithm was initially trained with full FAF images, and its performance was considered benchmark. Ablation experiments investigated the contribution of imaging features to the performance of the algorithms. Three FAF image regions were defined relative to GA: Lesion, Rim, and Background. For No Lesion, No Rim, and No Background datasets, a single region of interest was removed at a time. For Lesion, Rim, and Background Shuffled datasets, individual region pixels were randomly shuffled. For Lesion, Rim, and Background Mask datasets, masks of the regions were used. A Convex Hull dataset was generated to evaluate the importance of lesion size. Squared Pearson correlation (r2) was used to compare the predictive performance of ablated datasets relative to the benchmark.

Results

The Rim region influenced r2 more than the other two regions in all experiments, indicating the most relevant contribution of this region to the performance of the algorithms. In addition, similar performance was observed for all regions when pixels were shuffled or only a mask was used, indicating intensity information was not independently informative without textural context.

Conclusions

These ablation experiments enabled topographic clinical insights on FAF images from a DL-based GA progression prediction algorithm.

Translational Relevance

Results from this study may lead to new insights on GA progression prediction.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

The effect of complement C3 or C5 inhibition on geographic atrophy secondary to age-related macular degeneration: A living systematic review and meta-analysis

With the introduction of therapies to treat geographic atrophy (GA), GA management in clinical practice is now possible. A living systematic review can provide access to timely and robust evidence synthesis. This review found that complement factor 3 and 5 (C3 and C5) inhibition compared to sham likely reduces change in square root GA area at 12 months and untransformed GA area at 24 months. There is likely little to no difference in the rate of systemic treatment-emergent adverse events compared to sham. C3 and C5 inhibition, however, likely does not improve best-corrected visual acuity (BCVA) at 12 months, and the evidence is uncertain regarding change in BCVA at 24 months. Higher rates of ocular treatment emergent adverse effects with complement inhibition occur at 12 months and likely at 24 months. Complement inhibition likely results in new onset neovascular age-related macular degeneration at 12 months. This living meta-analysis will continuously incorporate new evidence.

Geographic atrophy: pathophysiology and current therapeutic strategies

Geographic atrophy (GA) is an advanced stage of age-related macular degeneration (AMD) that leads to gradual and permanent vision loss. GA is characterized by the loss of photoreceptor cells and retinal pigment epithelium (RPE), leading to distinct atrophic patches in the macula, which tends to increase with time. Patients with geographic atrophy often experience a gradual and painless loss of central vision, resulting in difficulty reading, recognizing faces, or performing activities that require detailed vision. The primary risk factor for the development of geographic atrophy is advanced age; however, other risk factors, such as family history, smoking, and certain genetic variations, are also associated with AMD. Diagnosis is usually based on a comprehensive eye examination, including imaging tests such as fundus photography, optical coherence tomography (OCT), and fluorescein angiography. Numerous clinical trials are underway, targeting identified molecular pathways associated with GA that are promising. Recent approvals of Syfovre and Izervay by the FDA for the treatment of GA provide hope to affected patients. Administration of these drugs resulted in slowing the rate of progression of the disease. Though these products provide treatment benefits to the patients, they do not offer a cure for geographic atrophy and are limited in efficacy. Considering these safety concerns and limited treatment benefits, there is still a significant need for therapeutics with improved efficacy, safety profiles, and better patient compliance. This comprehensive review discusses pathophysiology, currently approved products, their limitations, and potential future treatment strategies for GA.

Selective drug delivery to the retinal cells: Biological barriers and avenues

Retinal drug delivery is a challenging, but important task, because most retinal diseases are still without any proper therapy. Drug delivery to the retina is hampered by the anatomical and physiological barriers resulting in minimal bioavailability after topical ocular and systemic administrations. Intravitreal injections are current method-of-choice in retinal delivery, but these injections show short duration of action for small molecules and low target bioavailability for many protein, gene based drugs and nanomedicines. State-of-art delivery systems are based on prolonged retention, controlled drug release and physical features (e.g. size and charge). However, drug delivery to the retina is not cell-specific and these approaches do not facilitate intracellular delivery of modern biological drugs (e.g. intracellular proteins, RNA based medicines, gene editing). In this focused review we highlight biological factors and mechanisms that form the basis for the selective retinal drug delivery systems in the future. Therefore, we are presenting current knowledge related to retinal membrane transporters, receptors and targeting ligands in relation to nanomedicines, conjugates, extracellular vesicles, and melanin binding. These issues are discussed in the light of retinal structure and cell types as well as future prospects in the field. Unlike in some other fields of targeted drug delivery (e.g. cancer research), selective delivery technologies have been rarely studied, even though cell targeted delivery may be even more feasible after local administration into the eye.

Investigational drugs inhibiting complement for the treatment of geographic atrophy

INTRODUCTION

Geographic atrophy (GA) is a progressive form of age-related macular degeneration (AMD) that leads to severe visual impairment and central vision loss. Traditional treatment options for GA are limited, highlighting the need for new therapeutic approaches. In recent years, targeting the complement system has emerged as a promising strategy for the treatment of GA.

AREAS COVERED

This expert opinion article reviews the investigational drugs inhibiting the complement cascade for the treatment of GA. Specifically, it focuses on the recent FDA approved pegcetacoplan, a C3 complement inhibitor, and avacincaptad pegol, a C5 complement inhibitor, highlighting their potential efficacy and safety profiles based on clinical trial data.

EXPERT OPINION

FDA approval of intravitreal pegcetacoplan and avacincaptad pegol marks significant progress in the landscape of GA treatment. However, variable results from trials underscore the complex nature of GA and the importance of patient selection. Complement inhibition holds promise, but ongoing research is vital to refine treatment strategies and offer improved outcomes for GA patients.

Geographic atrophy: Mechanism of disease, pathophysiology, and role of the complement system

Geographic atrophy (GA) is an advanced form of age-related macular degeneration (AMD), characterized by atrophic lesions that first start in the outer retina and progressively expand to cover the macula and the fovea, the center of the macula, leading to irreversible loss of vision over time. GA is distinct from wet or neovascular AMD (nAMD), the other form of advanced AMD. Neovascular AMD is characterized by new invading leaky blood vessels in the macula that can lead to acute vision loss. GA and nAMD may coexist in the same eye. The underlying pathophysiology of GA is complex and thought to involve chronic inflammation due to overactivation of the complement system that leads to the loss of photoreceptors, retinal pigment epithelium (RPE), and the underlying choriocapillaris. The disappearance of these structures appears as sharply demarcated atrophic lesions that are typical of GA. Researchers have reported about 1 million reported cases of GA in the United States, and about 160,000 cases occur per year. The most important risk factors for GA are increasing age and family history. Diagnosis of GA is usually made by using multimodal imaging techniques. Lesions associated with GA are highly heterogeneous, and the growth rate may differ from patient to patient. Despite the progressive nature of GA, the fovea may be spared until much later in the disease, thereby retaining central vision in patients. With time, atrophic lesions may progressively grow to involve the fovea, thereby severely impairing central vision. Vision loss can happen rapidly once the lesions reach the fovea. However, even without the involvement of the fovea, ongoing vision impairment impacting daily life may be present. Median time from GA not involving the center of the fovea (without subfoveal involvement) to GA with lesion boundary affecting the foveal center (subfoveal involvement) ranges from 1.4 to 2.5 years. GA can greatly impact patients' functioning and quality of life and limit their independence by interfering with activities of daily living, including difficulties with reading, driving, watching television, recognizing faces, and being unable to do household chores. No treatments have been available until intravitreal pegcetacoplan was recently approved by the US Food and Drug Administration for GA secondary to AMD. DISCLOSURES: Dr Bakri serves as a consultant to Apellis Pharmaceuticals, as well as AbbVie, Adverum, Eyepoint, iLumen, Iveric Bio, Genentech, Novartis, Outlook Therapeutics, Pixium, Regeneron, Roche, and Regenxbio. Drs Sharp, Luo, and Sarda are employees of Apellis Pharmaceuticals. Dr Bektas and Ms Khan are employees of RTI Health Solutions. Apellis developed and led the concept design of this publication, review and interpretation, approval, and decision to publish. This research was developed under a research contract between RTI Health Solutions and Apellis Pharmaceuticals and was funded by Apellis Pharmaceuticals. This supplement is to describe the disease of geographic atrophy and was funded by Apellis. Apellis Pharmaceuticals has developed Syfovre (pegcetacoplan), the first and only treatment for geographic atrophy.

RANTES (CCL5) in Patients With Geographic Atrophy Age-Related Macular Degeneration

Purpose

A previous study from our research group showed significantly lower levels of RANTES (Regulated upon Activation, Normal T Cell Expressed and Secreted) in patients with intermediate age-related macular degeneration (AMD) compared to control patients with no AMD. The primary aim of this study was to assess levels of RANTES in a cohort of patients with a more advanced form of the disease, geographic atrophy (GA), in comparison with controls.

Methods

The study was conducted on a cohort of patients with GA recruited into a Colorado AMD registry. Cases and controls were defined with multimodal imaging. Plasma levels of the chemokine RANTES were measured using a multiplex assay. A nonparametric (rank-based) regression model was fit to RANTES with a sex by AMD category interaction.

Results

The plasma levels of RANTES were significantly higher in the control group in comparison to the GA AMD group (median [interquartile range]): 10,204 [5799-19,554] pg/mL vs. 5435 [3420-9177] pg/mL, respectively, P < 0.01). When moderated by sex, there was no statistical difference between the male and female GA AMD or the male and female controls.

Conclusions

We found lower level of RANTES in patients with GA AMD compared with controls. This finding is consistent with the findings from our previous intermediate AMD study. However, in contrast to the results of our previous research, when moderated by sex there was no statistical difference between male and female GA patients.

Translational Relevance

The biomarker RANTES is significantly lower in GA AMD patients compared to controls.

Lentiviral Vectors for Ocular Gene Therapy

This review offers the basics of lentiviral vector technologies, their advantages and pitfalls, and an overview of their use in the field of ophthalmology. First, the description of the global challenges encountered to develop safe and efficient lentiviral recombinant vectors for clinical application is provided. The risks and the measures taken to minimize secondary effects as well as new strategies using these vectors are also discussed. This review then focuses on lentiviral vectors specifically designed for ocular therapy and goes over preclinical and clinical studies describing their safety and efficacy. A therapeutic approach using lentiviral vector-mediated gene therapy is currently being developed for many ocular diseases, e.g., aged-related macular degeneration, retinopathy of prematurity, inherited retinal dystrophies (Leber congenital amaurosis type 2, Stargardt disease, Usher syndrome), glaucoma, and corneal fibrosis or engraftment rejection. In summary, this review shows how lentiviral vectors offer an interesting alternative for gene therapy in all ocular compartments.

Exogenous administration of hydrogen sulfide alleviates homocysteine induced inflammation in ARPE-19 cells

Plasma homocysteine (Hcy) is an independent risk factor for Age related macular degeneration (AMD) and an inducer of inflammation. Homocysteine catabolism releases hydrogen sulfide (H₂S). H₂S has controversial effects on inflammation. In this study we have analysed the endogenous and exogenous H₂S in modulating inflammation using adult retinal pigment epithelial (ARPE-19) cells as an in vitro model for AMD. ARPE-19 cells were treated with various concentrations of Hcy (15, 30 and 50 μM) for 3 h. Expression of Hcy transulfuration genes (CBS, CSE) by qPCR and western blot. H₂S levels were measured using Free Radical Analyzer System (WPI, USA). The inflammatory markers (IL-6 and IL-8) were evaluated using real-time PCR and ELISA. Hcy exposure increased CBS protein expression, hydrogen sulfide levels and pro-inflammatory cytokines, modulating CBS by silencing did not alter H₂S levels, but inhibition of CSE with PAG inhibited H₂S production and decreased cytokine (IL-6 and IL-8) levels. On the contrary exogenous supply of hydrogen sulfide with NaHS and by compound 1c showed anti-inflammatory effects even in the presence of Hcy. This study shows that exogenous delivery of H₂S decreases inflammation in retinal pigment epithelial cells on exposure to Hcy in ARPE-19 cells.

Results of patients with neovascular age-related macular degeneration managed by a treat-extend-stop protocol without recurrence

PURPOSE

To assess vision, injection quantity, initial lesion size, and final anatomic status in patients with nAMD completing the treat-extend-stop (TES) protocol.

METHODS

Patients with nAMD received ≥ 3 monthly anti-VEGF injections followed by 1-2 week injection interval extensions, with intra/subretinal fluid resolution on SD-OCT, to 12 weeks. With quiescent disease, and 2 quarterly injections, patients were monitored alone beginning at 4 weeks extending by 1-2 week intervals until quarterly monitoring.

RESULTS

Eighty-eight of 143 eyes with nAMD completed the TES protocol without disease recurrence. Sixteen (18.2%) developed sub-foveal geographic atrophy (GA), 25 (28.4%) developed fibrovascular scarring (FV) and 47 (53.4%) developed regressed choroidal neovascularization (rCNV) with 16.9 ± 13.3 average injections between the 3 groups which was not statistically significant. Average treatment time was 30.3 ± 26.1 months and subsequent follow-up was 23.2 ± 19.8 months. Average lesion size for FV was 18.77 ± 10.8mm² vs. GA at 12.00 ± 9.99mm² vs. regressed CNV at 7.12 ± 6.5mm² (p < 0.05). Pre, post, and final vision for GA was 39.6 letters (20/160) vs. 32.7 letters (20/200 + 2, p = 0.4725) vs. 25.0 letters (20/320, p = 0.0865); FV was 22.4 letters (20/400 + 2) vs. 11.6 letters (20/640, p = 0.0351) vs. 11.0 letters (20/640 + 1, p = 0.0226), and rCNV was 56.4 letters (20/80 + 1) vs. 69.5 letters (20/40, p < 0.001) vs. 67.3 letters (20/40-2, p = 0.0016). In the rCNV group, 17/46 eyes gained ≥ 3 lines and 30/46 eyes achieved ≥ 20/40 vision. Non-central GA expanded 0.226 ± 0.126 mm vs. 0.225 ± 0.098 mm during and after treatment completion over 24 months (p = 0.99).

CONCLUSIONS

Central GA or FV portends worse visual outcomes vs. rCNV after cessation of therapy. Anti-VEGF therapy may not affect the rate of GA expansion. Final anatomic character and location are key determinants of final vision.

Potential of Telomerase in Age-Related Macular Degeneration-Involvement of Senescence, DNA Damage Response and Autophagy and a Key Role of PGC-1α

Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.