Fifteen-Year Cumulative Incidence of Age-Related Macular Degeneration

Effects and Mechanisms of Lutein on Aging and Age-Related Diseases

Aging and age-related diseases are serious public health issues that are receiving growing attention from researchers. Lutein has a critical function in the prevention and management of these issues. Possible mechanisms mainly include suppressing inflammation and oxidative stress, regulating cell activity, and modulating the levels of toxic substances. In this narrative review paper, we sum up the most current developments in the study of the effects of lutein on aging and five age-related diseases (age-related macular degeneration, cataracts, Alzheimer's disease, Parkinson's disease, and osteoporosis), and fundamental mechanisms are reviewed. The bioavailability of lutein and the strategies to improve its bioavailability are discussed. This piece of work can bring a clearer comprehension of the protective effects of lutein against aging and age-related diseases and can be also helpful for developing lutein as functional food and dietary supplements for these age-related diseases.

[Age-related macular degeneration - Part 1: Pathophysiology, classification and diagnostic]

Age-related macular degeneration (AMD) continues to be the most common hereditary disease among older people in the western world. In addition to the clinical examination, multimodal imaging with fluorescein angiography, optical coherence tomography, fundus autofluorescence and fundus photography are crucial for the correct diagnosis and classification. This is particularly important with regard to risk assessment for the development of a late form of the disease. Since the introduction of intravitreal therapy against vascular endothelial growth factor (VEGF), the treatment options for neovascular AMD have increased significantly and the prognosis for patients in terms of maintaining their vision has improved. The hope is to develop stronger and longer-lasting drugs and also to obtain approval for drugs to treat geographic atrophy. It is therefore of great importance to be able to make a quick and correct diagnosis for patients. In this paper we want to present an overview of the pathophysiology, classification and diagnosis of AMD.

The hypothetical molecular mechanism of the ethnic variations in the manifestation of age-related macular degeneration; focuses on the functions of the most significant susceptibility genes

Age-related macular degeneration (AMD) is the leading sight-threatening disease in developed countries. On the other hand, recent studies indicated an ethnic variation in the phenotype of AMD. For example, several reports demonstrated that the incidence of drusen in AMD patients is less in Asians compared to Caucasians though the reason has not been clarified yet. In the last decades, several genome association studies have disclosed many susceptible genes of AMD and revealed that the association strength of some genes was different among races and AMD phenotypes. In this review article, the essential findings of the clinical studies and genome association studies for the most significant genes CFH and ARMS2/HTRA1 in AMD of different races are summarized, and theoretical hypotheses about the molecular mechanisms underlying the ethnic variation in the AMD manifestation mainly focused on those genes between Caucasians and Asians are discussed.

A novel approach for automatic classification of macular degeneration OCT images

Age-related macular degeneration (AMD) and diabetic macular edema (DME) are significant causes of blindness worldwide. The prevalence of these diseases is steadily increasing due to population aging. Therefore, early diagnosis and prevention are crucial for effective treatment. Classification of Macular Degeneration OCT Images is a widely used method for assessing retinal lesions. However, there are two main challenges in OCT image classification: incomplete image feature extraction and lack of prominence in important positional features. To address these challenges, we proposed a deep learning neural network model called MSA-Net, which incorporates our proposed multi-scale architecture and spatial attention mechanism. Our multi-scale architecture is based on depthwise separable convolution, which ensures comprehensive feature extraction from multiple scales while minimizing the growth of model parameters. The spatial attention mechanism is aim to highlight the important positional features in the images, which emphasizes the representation of macular region features in OCT images. We test MSA-NET on the NEH dataset and the UCSD dataset, performing three-class (CNV, DURSEN, and NORMAL) and four-class (CNV, DURSEN, DME, and NORMAL) classification tasks. On the NEH dataset, the accuracy, sensitivity, and specificity are 98.1%, 97.9%, and 98.0%, respectively. After fine-tuning on the UCSD dataset, the accuracy, sensitivity, and specificity are 96.7%, 96.7%, and 98.9%, respectively. Experimental results demonstrate the excellent classification performance and generalization ability of our model compared to previous models and recent well-known OCT classification models, establishing it as a highly competitive intelligence classification approach in the field of macular degeneration.

Targeted 8-arm PEG Nanosystems for Localization of Choroidal Neovascularization Macular Degeneration Model

8-arm PEG (polyethylene-glycol) is a highly promising nanoplatform due to its small size (<10 nm), ease-of-conjugation (many functionalized variants are readily available with "click-like" properties), biocompatibility, and optical inactivity. This study evaluates 8-arm PEG uptake into cells (in vitro) and localization and clearance in vasculature (in vivo) for targeting of choroidal neovascularization in mice, an animal model of macular degeneration. 8-arm PEG nanoparticles were labeled with fluorescein isothiocyanate (FITC) and functionalized in the absence or presence of pentameric Ar-Gly-Asp (RGD; 4 RGD motifs and a PGC linker), one of the most common peptide motifs used for active targeting. In vitro studies show that RGD-conjugated 8-arm PEG nanoparticles exhibit enhanced cellular uptake relative to non-RGD-conjugated control NPs at 34% ± 9%. Laser-induced choroidal neovascularization (CNV) was performed in a mouse model to measure 8-arm PEG localization and clearance to model macular degeneration lesions in vivo. It was determined that both RGD-conjugated and non-RGD-conjugated (nRGD) 8-arm PEG particles localized to CNV lesions, with a half-life around 24 h. In vivo experiments showed that RGD-conjugated nanoparticles exhibited enhanced localization by 15-20% relative to without RGD controls. Exhibiting a high rate of localization and fast clearance relative to larger nanoparticles, targeted 8-arm PEG nanoparticles with a conjugated RGD-peptide could be a promising modality for macular degeneration diagnosis and therapy.

Associations of drusen location with risk factors and incidence of late age-related macular degeneration in the Alienor study

PURPOSE

To test the hypothesis that central drusen location is strongly linked with known Age-related Macular Degeneration (AMD) risk factors and risk of incident late AMD.

METHODS

The Alienor study is a prospective population-based cohort study of residents of Bordeaux, France, followed from 2009 to 2017. On retinal photographs, we defined central drusen as at least one soft drusen (>63 μm) within 500 μm from fovea and pericentral drusen as at least one drusen 500-3000 μm from fovea, in the absence of any central drusen. Late AMD (atrophic and/or neovascular) was diagnosed using multimodal imaging. In total, 481 eyes were included in the analysis: 160 central and 321 pericentral. We investigated associations with systemic (age, sex, smoking, medical prescriptions, plasma concentrations of lipids and nutrients, UV exposure, blood pressure), ocular (retinal thickness, cataract extraction) and genetic risk scores (GRS).

RESULTS

In multivariate logistic regression central drusen were associated with smoking (OR, 2.95 for smoking more than 20 pack-years, p = 0.02), HDL-cholesterol (OR, 1.57 for 1 standard deviation (SD) increase, p = 0.0048), pulse pressure (OR, 0.77 for 1 SD increase, p = 0.04), Age-Related Maculopathy Susceptibility 2 (ARMS2) GRS (OR, 1.42; 95% CI, 1.11-1.83) and complement GRS (OR, 1.55; 95% CI, 1.15-2.10). In Cox modelling, the central location of drusen (at baseline or during the follow-up) was associated with a 4.41-fold increased risk (95% CI,1.98-9.81) for an incident late AMD.

CONCLUSION

Central drusen were strongly associated with AMD risk factors and incident late AMD, suggesting that it represents a key marker for AMD progression.

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.

The quantification of zebrafish ocular-associated proteins provides hints for sex-biased visual impairments and perception

Biochemical differences between sexes can also be seen in non-sexual organs and may affect organ functions and susceptibility to diseases. It has been shown that there are sex-biased visual perceptions and impairments. Abundance differences of eye proteins could provide explanations for some of these. Exploration of the ocular proteome was performed to find sex-based protein abundance differences in zebrafish Danio rerio. A label-free protein quantification workflow using high-resolution mass spectrometry was employed to find proteins with significant differences between the sexes. In total, 3740 unique master proteins were identified and quantified, and 49 proteins showed significant abundance differences between the eyes of male and female zebrafish. Those proteins belong to lipoproteins, immune system, blood coagulation, antioxidants, iron and heme-binding proteins, ion channels, pumps and exchangers, neuronal and photoreceptor proteins, and the cytoskeleton. An extensive literature review provided clues for the possible links between the sex-biased level of proteins and visual perception and impairments. In conclusion, sexual dimorphism at the protein level was discovered for the first time in the eye of zebrafish and should be accounted for in ophthalmological studies. Data are available via ProteomeXchange with identifier PXD033338.

Immunogenetic and Environmental Factors in Age-Related Macular Disease

Age-related macular degeneration (AMD) is a chronic disease, which often develops in older people, but this is not the rule. AMD pathogenesis changes include the anatomical and functional complex. As a result of damage, it occurs, in the retina and macula, among other areas. These changes may lead to partial or total loss of vision. This disease can occur in two clinical forms, i.e., dry (progression is slowly and gradually) and exudative (wet, progression is acute and severe), which usually started as dry form. A coexistence of both forms is possible. AMD etiology is not fully understood. Extensive genetic studies have shown that this disease is multifactorial and that genetic determinants, along with environmental and metabolic-functional factors, are important risk factors. This article reviews the impact of heavy metals, macro- and microelements, and genetic factors on the development of AMD. We present the current state of knowledge about the influence of environmental factors and genetic determinants on the progression of AMD in the confrontation with our own research conducted on the Polish population from Kuyavian-Pomeranian and Lubusz Regions. Our research is concentrated on showing how polluted environments of large agglomerations affects the development of AMD. In addition to confirming heavy metal accumulation, the growth of risk of acute phase factors and polymorphism in the genetic material in AMD development, it will also help in the detection of new markers of this disease. This will lead to a better understanding of the etiology of AMD and will help to establish prevention and early treatment.

Ellipsoid Zone Integrity and Visual Function in Dry Age-Related Macular Degeneration

In this longitudinal retrospective image analysis, conducted on patients diagnosed with dry age-related macular degeneration (AMD) and 5 years of follow-up imaging data, the study aimed to investigate the relationship between ellipsoid zone (EZ) integrity on spectral domain optical coherence tomography (SD-OCT) and visual acuity (VA). Using a machine learning-enabled feature extraction tool, quantitative EZ parameters were derived from SD-OCT images. The analysis revealed significant correlations between EZ integrity metrics and VA. Eyes with excellent VA (≥20/25 Snellen) exhibited higher EZ integrity, including less EZ attenuation, thicker ellipsoid zone-retinal pigment epithelium (EZ-RPE) thickness, and higher EZ intensity, in contrast to eyes with worse VA (≤20/40 Snellen). Additionally, eyes with geographic atrophy (GA) in the foveal region displayed compromised EZ integrity compared to those without GA. Notably, baseline EZ integrity metrics were predictive of future VA loss. These findings suggest that quantitative SD-OCT measurements of EZ integrity could potentially detect early changes in dry AMD and serve as valuable indicators for predicting future functional outcomes. Furthermore, these measurements hold promise for use in clinical trial screenings, offering insights into the progression of the disease and its impact on visual acuity. This study underscores the importance of EZ integrity assessment in understanding and managing dry AMD.

Evaluation of Phototoxicity of Short-Wavelength Laser Light Utilizing PCNA Accumulation

In recent years, diseases such as age-related macular degeneration and retinal pigment degeneration caused by excessive exposure to short-wavelength visible light have become significant concerns. With the aim of quantitatively evaluating the toxicity of short-wavelength light, proliferating cell nuclear antigen (PCNA) accumulation at the irradiation site was investigated using live cell imaging techniques to irradiate individual living cells with short-wavelength laser light. By examining the dependency of PCNA accumulation on the irradiation site within the cells and their cell cycle, it was observed that PCNA accumulation occurred only when the cell nucleus of cells in the S phase of the cell cycle was irradiated. We investigated the accumulation of PCNA at the laser irradiation site using laser light at wavelengths of 405 nm and 375 nm, with intensities ranging from 0.5 μW to 9.0 μW. The results confirmed an increase in PCNA accumulation with increasing intensity, and a higher accumulation was observed with laser light irradiation at a wavelength of 375 nm compared to 405 nm. By comparing the PCNA accumulation and 24 h cell viability, we demonstrated the feasibility of quantitatively assessing laser light toxicity through the measurement of PCNA accumulation.

Establishing chronic models of age-related macular degeneration via long-term iron ion overload

Age-related macular degeneration (AMD) is characterized by the degenerative senescence in the retinal pigment epithelium (RPE) and photoreceptors, which is accompanied by the accumulation of iron ions in the aging retina. However, current models of acute oxidative stress are still insufficient to simulate the gradual progression of AMD. To address this, we established chronic injury models by exposing the aRPE-19 cells, 661W cells, and mouse retina to iron ion overload over time. Investigations at the levels of cell biology and molecular biology were performed. It was demonstrated that long-term treatment of excessive iron ions induced senescence-like morphological changes, decreased cell proliferation, and impaired mitochondrial function, contributing to apoptosis. Activation of the mitogen-activated protein kinase (MAPK) pathway and the downstream molecules were confirmed both in the aRPE-19 and 661W cells. Furthermore, iron ion overload resulted in dry AMD-like lesions and decreased visual function in the mouse retina. These findings suggest that chronic exposure to overloading iron ions plays a significant role in the pathogenesis of retinopathy and provide a potential model for future studies on AMD.NEW & NOTEWORTHY To explore the possibility of constructing reliable research carriers on age-related macular degeneration (AMD), iron ion overload was applied to establish models in vitro and in vivo. Subsequent investigations into cellular physiology and molecular biology confirmed the presence of senescence in these models. Through this study, we hope to provide a better option of feasible methods for future researches into AMD.

Incidence and risk factors of age-related macular degeneration in patients with Parkinson's disease: a population-based study

Background and objective

The association between age-related macular degeneration (AMD) and Parkinson' disease (PD) remains unclear. The aim of the present study was to assess the incidence of AMD in patients with PD, elucidate differences by age and sex, and investigate potential risk factors for AMD.

Methods

Data were extracted from the Korean National Health Insurance System database, which covers 97% of the Korean population (2002 through 2019). We calculated the incidence of newly diagnosed AMD in patients with PD and used Cox proportional-hazards models to estimate risk factors for AMD, presenting adjusted hazard ratios (aHR) with 95% confidence intervals (CI).

Results

Of 172,726 patients with PD, 15,800 were newly diagnosed with AMD during the follow-up, including 5,624 men and 10,176 women. The overall incidence of AMD in patients with PD was 13.59 per 1,000 person-years. Stratified by age group and sex, the incidence was higher in women aged 40-69, and conversely higher in men aged 70-89. Risk of AMD was high in older age groups (aHR = 4.36, 95% CI: 3.74-5.09 in the 70 s), female sex (aHR = 1.07, 95% CI: 1.04-1.11), patients with diabetes mellitus (DM) (aHR = 1.14, 95% CI: 1.10-1.18), and patients with hyperlipidemia (aHR = 1.17, 95% CI: 1.13-1.21).

Conclusion

Our findings suggest that the AMD incidence is higher in patients with PD than in the general population, with varying patterns of sex differences across age groups. Particularly, old age, female sex, presence of DM, and hyperlipidemia are potential risk factors. Therefore, clinicians should pay greater attention to AMD in patients with PD.

Denoising OCT videos based on temporal redundancy

The identification of eye diseases and their progression often relies on a clear visualization of the anatomy and on different metrics extracted from Optical Coherence Tomography (OCT) B-scans. However, speckle noise hinders the quality of rapid OCT imaging, hampering the extraction and reliability of biomarkers that require time series. By synchronizing the acquisition of OCT images with the timing of the cardiac pulse, we transform a low-quality OCT video into a clear version by phase-wrapping each frame to the heart pulsation and averaging frames that correspond to the same instant in the cardiac cycle. Here, we compare the performance of our one-cycle denoising strategy with a deep-learning architecture, Noise2Noise, as well as classical denoising methods such as BM3D and Non-Local Means (NLM). We systematically analyze different image quality descriptors as well as region-specific metrics to assess the denoising performance based on the anatomy of the eye. The one-cycle method achieves the highest denoising performance, increases image quality and preserves the high-resolution structures within the eye tissues. The proposed workflow can be readily implemented in a clinical setting.

Age-Related Macular Degeneration, a Mathematically Tractable Disease

A progression sequence for age-related macular degeneration onset may be determinable with consensus neuroanatomical nomenclature augmented by drusen biology and eye-tracked clinical imaging. This narrative review proposes to supplement the Early Treatment of Diabetic Retinopathy Study (sETDRS) grid with a ring to capture high rod densities. Published photoreceptor and retinal pigment epithelium (RPE) densities in flat mounted aged-normal donor eyes were recomputed for sETDRS rings including near-periphery rich in rods and cumulatively for circular fovea-centered regions. Literature was reviewed for tissue-level studies of aging outer retina, population-level epidemiology studies regionally assessing risk, vision studies regionally assessing rod-mediated dark adaptation (RMDA), and impact of atrophy on photopic visual acuity. The 3 mm-diameter xanthophyll-rich macula lutea is rod-dominant and loses rods in aging whereas cone and RPE numbers are relatively stable. Across layers, the largest aging effects are accumulation of lipids prominent in drusen, loss of choriocapillary coverage of Bruch's membrane, and loss of rods. Epidemiology shows maximal risk for drusen-related progression in the central subfield with only one third of this risk level in the inner ring. RMDA studies report greatest slowing at the perimeter of this high-risk area. Vision declines precipitously when the cone-rich central subfield is invaded by geographic atrophy. Lifelong sustenance of foveal cone vision within the macula lutea leads to vulnerability in late adulthood that especially impacts rods at its perimeter. Adherence to an sETDRS grid and outer retinal cell populations within it will help dissect mechanisms, prioritize research, and assist in selecting patients for emerging treatments.

Isorhamnetin suppresses the epithelial-mesenchymal transition of the retinal pigment epithelium both in vivo and in vitro through Nrf2-dependent AKT/GSK-3β pathway

Age-related macular degeneration (AMD) is a major cause of blindness in the elderly worldwide. Multiple studies have shown that epithelial-mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of AMD. Isorhamnetin (Isor) is a flavonoid compound that inhibits EMT in tumor cells. However, whether it can also attenuate EMT in the retinal pigment epithelium (RPE) is unknown. Therefore, our study was designed to probe the possible impact of Isor on EMT process in both mouse retina and ARPE-19 cells. C57BL/6 mice were utilized to establish a dry AMD model. Isor and LCZ (a mixture of luteine/β-carotene/zinc gluconate) were administered orally for 3 months. The effects of Isor on the retina were evaluated using fundus autofluorescence, optical coherence tomography, and transmission electron microscopy. Transwell and wound healing assay were employed to assess ARPE-19 cell migration. Western blotting and immunofluorescence were used to measure the protein expressions associated with EMT, Nrf2 and AKT/GSK-3β pathway. The findings indicated that Isor alleviated dry AMD-like pathological changes in vehicle mice retina, inhibited the migration of Ox-LDL-treated ARPE-19 cells, and repressed the EMT processes in vivo and in vitro. Furthermore, Isor activated Nrf2 pathway and deactivated AKT/GSK-3β pathway in both vehicle mice and ARPE-19 cells. Interestingly, when Nrf2 siRNA was transfected into ARPE-19 cells, the inhibitory effect of Isor on EMT and AKT/GSK-3β pathway was attenuated. These results suggested that Isor inhibited EMT processes via Nrf2-dependent AKT/GSK-3β pathway and is a promising candidate for dry AMD treatment.

The Effect of Systemic Parameters and Baseline Characteristics in Short-Term Response Analysis with Intravitreal Ranibizumab in Treatment-Naive Patients with Neovascular Age-Related Macular Degeneration

Anti-vascular endothelial growth factor drugs keep being the main therapy for neovascular age-related macular degeneration (AMD). Possible predictive parameters (demographic, biochemical and/or inflammatory) could anticipate short-term treatment response with ranibizumab. 46 treatment-naive patients were included in a prospective observational study. They underwent three monthly injections of intravitreal ranibizumab for neovascular AMD and the clinical examination was made at baseline and one month after the third injection. Demographic characteristics, co-morbidities and concomitant treatments were recorded at the baseline visit. Biochemical parameters, complete blood count and inflammation biomarkers were also measured at these times. Uric Acid was found to be statistically significant with a one-point difference between good and poor responders in both basal and treated patients, but only in basal parameters was statistical significance reached (p = 0.007 vs. p = 0.071 in treated patients). Cholesterol and inflammatory parameters such as white blood cell count and neutrophils were significantly reduced over time when treated with intravitreal ranibizumab. On the other hand, women seemed to have a worse prognosis for short-term response to intravitreal ranibizumab treatment. Uric acid may help identify possible non-responders before initial treatment with ranibizumab, and cholesterol and white blood cells could be good candidates to monitor short-term response to ranibizumab treatment.

Optical Coherence Tomography Features of Macular Hyperpigmented Lesions without Intraretinal Hyperreflective Foci in Age-Related Macular Degeneration

PURPOSE

To evaluate the optical coherence tomography (OCT) features of hyperpigmented lesions in the absence of intraretinal hyperreflective foci (IHRF) on OCT in eyes with age-related macular degeneration (AMD).

METHODS

We retrospectively analyzed OCT images of eyes with intermediate AMD (iAMD) and macular hyperpigmentation (HP) on color fundus photograph (CFP) but without IHRF on OCT in the corresponding location. The most prominent or definite HP was selected for analysis. The infrared reflectance (IR) image registered with the CFP, and the location corresponding to the HP lesion were defined on the IR image. The location of the HP on the corresponding OCT B-scan was assessed for retinal pigment epithelium (RPE) elevation, acquired vitelliform lesion (AVL), abnormal retinal pigment epithelium + basal lamina (RPE + BL) band reflectivity, RPE + BL band thickening, as well as interdigitation zone (IZ), ellipsoid zone (EZ) and external limiting membrane (ELM) disruption.

RESULTS

49 eyes (39 patients) were included in this study. Forty-six (94%) of the hyperpigmented lesions showed a thickened RPE + BL band. RPE + BL band reflectivity was increased in 37 (76%) of the lesions. RPE + BL band thickening, however, was not correlated with RPE + BL band reflectivity (p-value = 0.31). Either thickening or hyperreflectivity of the RPE + BL band was present in all cases. Twenty (41%) lesions had evidence of ELM disruption, 42 (86%) demonstrated EZ disruption and 48 (98%) had IZ disruption. Five (10%) HPs demonstrated AVL. Among cases with RPE elevation (15 cases, 31%), 10 were classified as drusen, 2 as drusenoid PEDs, and 3 as fibrovascular PEDs.

CONCLUSIONS

Thickening and/or hyperreflectivity of the RPE + BL band commonly correspond to regions of macular hyperpigmentation without IHRF in eyes with iAMD.

Artificial intelligence in retinal imaging: current status and future prospects

INTRODUCTION

The steadily growing and aging world population, in conjunction with continuously increasing prevalences of vision-threatening retinal diseases, is placing an increasing burden on the global healthcare system. The main challenges within retinology involve identifying the comparatively few patients requiring therapy within the large mass, the assurance of comprehensive screening for retinal disease and individualized therapy planning. In order to sustain high-quality ophthalmic care in the future, the incorporation of artificial intelligence (AI) technologies into our clinical practice represents a potential solution.

AREAS COVERED

This review sheds light onto already realized and promising future applications of AI techniques in retinal imaging. The main attention is directed at the application in diabetic retinopathy and age-related macular degeneration. The principles of use in disease screening, grading, therapeutic planning and prediction of future developments are explained based on the currently available literature.

EXPERT OPINION

The recent accomplishments of AI in retinal imaging indicate that its implementation into our daily practice is likely to fundamentally change the ophthalmic healthcare system and bring us one step closer to the goal of individualized treatment. However, it must be emphasized that the aim is to optimally support clinicians by gradually incorporating AI approaches, rather than replacing ophthalmologists.

Relationship between the distribution of intra-retinal hyper-reflective foci and the progression of intermediate age-related macular degeneration

PURPOSE

To assess the relationship between the distribution of intra-retinal hyper-reflective foci (IHRF) on optical coherence tomography (OCT) and progression of intermediate age-related macular degeneration (iAMD) over 2 years.

METHODS

Cirrus OCT volumes of the macula of subjects enrolled in the Amish Eye Study with 2 years of follow-up were evaluated for the presence of iAMD and IHRF at baseline. The IHRF were counted in a series of 5 sequential en face slabs from outer to inner retina. The number of IHRF in each slab at baseline and the change in IHRF from baseline to year 2 were correlated with progression to late AMD at 2 years.

RESULTS

Among 120 eyes from 71 patients with iAMD, 52 eyes (43.3%) of 42 patients had evidence of both iAMD and IHRF at baseline. Twenty-three eyes (19.0%) showed progression to late AMD after 2 years. The total IHRF count increased from 243 at baseline to 604 at 2 years, with a significant increase in the IHRF number in each slab, except for the innermost slab 5 which had no IHRF at baseline or follow-up. The IHRF count increased from 121 to 340 in eyes that showed progression to late AMD. The presence of IHRF in the outermost retinal slabs 1 and 2 was independently associated with a significant risk of progression to late AMD. A greater increase in IHRF count over 2 years in these same slabs 1 and 2 was also associated with a higher risk of conversion to late AMD.

CONCLUSIONS

The risk of progression to late AMD appears to be significantly associated with the distribution and extent of IHRF in the outermost retinal layers. This observation may point to significant pathophysiologic differences of IHRF in inner versus outer layers of the retina.

Epidemiology of geographic atrophy and its precursor features of intermediate age-related macular degeneration

Globally age-related macular degeneration (AMD) is a leading cause of blindness with a significant impact on quality of life. Geographic atrophy (GA) is the atrophic late form of AMD and its prevalence increases markedly with age with around 1 in 5 persons aged 85 and above having GA in at least one eye. Bilateral GA leads to severe visual impairment thus posing a significant burden on patients, careers and health providers. The incidence and prevalence of GA varies across different geographic regions, with the highest rates in those of European ancestry. Although heterogeneity in definitions of GA and reporting strategy can explain some of the discrepancies, the data overall are consistent in showing a lower prevalence in other ethnicities such as those of Asian heritage. This is at present unexplained but thought to be due to the existence of protective factors such as differences in eye pigmentation, diet, environmental exposures and genetic variability. This review covers key aspects of the prevalence and incidence of the ocular precursor features of GA (large drusen, pigmentary abnormalities and reticular pseudo-drusen), the late stage of GA and factors that have been known to be associated with modifying risk including systemic, demographic, environment, genetic and ocular. Understanding the global epidemiology scenario is crucial for the prevention of and management of patients with GA.

N-retinylidene-N-retinylethanolamine degradation in human retinal pigment epithelial cells via memantine- and ifenprodil-mediated autophagy

N-methyl-D-aspartate (NMDA) receptors are ionic glutamine receptors involved in brain development and functions such as learning and memory formation. NMDA receptor inhibition is associated with autophagy activation. In this study, we investigated whether the NMDA receptor antagonists, memantine and ifenprodil, induce autophagy in human retinal pigment epithelial cells (ARPE-19) to remove Nretinylidene- N-retinylethanolamine (A2E), an intracellular lipofuscin component. Fluorometric analysis using labeled A2E (A2E-BDP) and confocal microscopic examination revealed that low concentrations of NMDA receptor antagonists, which did not induce cytotoxicity, significantly reduced A2E accumulation in ARPE-19 cells. In addition, memantine and ifenprodil activated autophagy in ARPE-19 cells as measured by microtubule-associated protein 1A/1B-light chain3-II formation and phosphorylated p62 protein levels. Further, to understand the correlation between memantine- and ifenprodil-mediated A2E degradation and autophagy, autophagy-related 5 (ATG5) was depleted using RNA interference. Memantine and ifenprodil failed to degrade A2E in ARPE-19 cells lacking ATG5. Taken together, our study indicates that the NMDA receptor antagonists, memantine and ifenprodil, can remove A2E accumulated in cells via autophagy activation in ARPE-19 cells.

Causal Effects of Gut Microbiota on Age-Related Macular Degeneration: A Mendelian Randomization Study

Purpose

Recently, the association between gut microbiota and age-related macular degeneration (AMD) through the gut-retina axis has attracted great interest. However, the causal relationship between them has not been elucidated. Using publicly available genome-wide association study summary statistics, we conducted a two-sample Mendelian randomization (MR) analysis to examine the causal relationship between the gut microbiota and the occurrence of AMD.

Methods

The study used a variety of quality control techniques to select instrumental single nucleotide polymorphisms (SNPs) with strong exposure associations. We used a set of SNPs as instrumental variable that were below the genome-wide statistical significance threshold (5 × 10-8). Additionally, a separate group of SNPs below the locus-wide significance level (1 × 10-5) were selected as instrumental variables to ensure a comprehensive conclusion. Inverse variance-weighted (IVW) analysis was the primary technique we used to examine causality in order to confirm the validity of our findings. The MR-Egger intercept test, Cochran's Q test, and leave-one-out sensitivity analysis were used to evaluate the horizontal pleiotropy, heterogeneities, and stability of the genetic variants.

Results

IVW results showed that genus Anaerotruncus (P = 5.00 × 10-3), genus Candidatus Soleaferrea (P = 1.83 × 10-2), and genus unknown id.2071 (P = 3.12 × 10-2) were protective factors for AMD. The Eubacterium oxidoreducens group (P = 3.17 × 10-2), genus Faecalibacterium (P = 2.67 × 10-2), and genus Ruminococcaceae UCG-011 (P = 4.04 × 10-2) were risk factors of AMD. No gut microbiota (GM) taxa were found to be causally related to AMD at the phylum, class, order, and family levels (P > 0.05). The robustness of MR results were confirmed by heterogeneity and pleiotropy analysis. (P > 0.05). We also performed a bidirectional analysis, which showed that genus Anaerotruncus, genus Candidatus Soleaferrea, genus unknown id.2071 and the Eubacterium oxidoreducens group had an interaction with AMD, whereas genus Faecalibacterium showed only a unilateral unfavorable effect on AMD.

Conclusions

We confirmed a causal relationship between AMD and GM taxa, including the Eubacterium oxidoreducens group, Faecalibacterium, Ruminococcaceae UCG-011, Anaerotruncus, and Candidatus Soleaferrea. These strains have the potential to serve as new biomarkers, offering valuable insights into the treatment and prevention of AMD.

Impact of Prophylactic Ranibizumab to Prevent Neovascular Age-Related Macular Degeneration on Eyes With Intermediate Age-Related Macular Degeneration

Purpose

The purpose of this study was to determine the impact of prophylactic ranibizumab (PR) injections given every 3 months in eyes with intermediate nonexudative age-related macular degeneration (AMD) on drusen volume, macular layer thicknesses, and progression of geographic atrophy (GA) area over 24 months in the PREVENT trial.

Methods

This post hoc analysis of the prospective PREVENT trial compared eyes with intermediate AMD randomized to PR versus sham injections to determine rates of conversion to neovascular AMD over 24 months. Drusen area and volume, macular thickness and volume, and retinal layer thicknesses were measured on spectral-domain optical coherence tomography images and analyzed. Masked grading of GA area and subretinal drusenoid deposits (SDDs) using fundus autofluorescence images was performed.

Results

There were no statistical differences in drusen area and volumes between groups, and similar reductions in central subfield thickness, mean cube thickness, cube volume, and retinal sublayer thickness from baseline to 24 months (P = 0.018 to < 0.001), with no statistical differences between groups in any of these anatomic parameters. These findings were not impacted by the presence or absence of SDD. Among the 9 eyes with GA in this study, mean GA growth rate from baseline to 24 months was 1.34 +/- 0.79 mm2/year after PR and 1.95 +/- 1.73 mm2/year in sham-treated eyes (P = 0.49), and similarly showed no statistical difference with square root transformation (P = 0.61).

Conclusions

Prophylactic ranibizumab given every 3 months did not appear to affect drusen volume, macular thinning, or GA progression in eyes with intermediate AMD.

Translational Relevance

This work investigates the impact of PR on progressive retinal degeneration in a clinical trial.

Revisiting Retinal Degeneration Hallmarks: Insights from Molecular Markers and Therapy Perspectives

Visual impairment and blindness are a growing public health problem as they reduce the life quality of millions of people. The management and treatment of these diseases represent scientific and therapeutic challenges because different cellular and molecular actors involved in the pathophysiology are still being identified. Visual system components, particularly retinal cells, are extremely sensitive to genetic or metabolic alterations, and immune responses activated by local insults contribute to biological events, culminating in vision loss and irreversible blindness. Several ocular diseases are linked to retinal cell loss, and some of them, such as retinitis pigmentosa, age-related macular degeneration, glaucoma, and diabetic retinopathy, are characterized by pathophysiological hallmarks that represent possibilities to study and develop novel treatments for retinal cell degeneration. Here, we present a compilation of revisited information on retinal degeneration, including pathophysiological and molecular features and biochemical hallmarks, and possible research directions for novel treatments to assist as a guide for innovative research. The knowledge expansion upon the mechanistic bases of the pathobiology of eye diseases, including information on complex interactions of genetic predisposition, chronic inflammation, and environmental and aging-related factors, will prompt the identification of new therapeutic strategies.

The Choroidal Vascularity Index Versus Optical Coherence Tomography Angiography in the Evaluation of the Choroid with a Focus on Age-Related Macular Degeneration

The choroid is the most vascularized structure of the eye and it is fundamental for the trophism of the outer retina. Its proper functioning and homeostasis represent key points in maintaining normal retinal physiology. Choroidal alterations may be implicated in the development and progression of numerous pathologies; therefore, in-depth studies using imaging techniques can be of crucial relevance to understanding the pathophysiology of retinal-choroidal diseases. The advent of spectral-domain optical coherence tomography (SDOCT) has enabled the non-invasive study of the choroid in vivo and the most recent development, optical coherence tomography angiography (OCTA), allows for the high-resolution visualization of the choriocapillaris and the choroid in regard to vascularization. The choroidal vascularity index (CVI) is a new parameter calculated on SDOCT scans and is defined as the ratio of the luminal area to the total choroidal area. In this review, a study of the choroid using OCTA and CVI will be evaluated in depth and the pros and cons of these two methods will be analyzed, with a particular focus on age-related macular degeneration.

Prevalence of Geographic Atrophy in Advanced Age-Related Macular Degeneration (AMD) in Daily Practice

PURPOSE

To investigate the prevalence of geographic atrophy (GA) in advanced age-related macular degeneration (AMD) and the proportion of eyes that would meet the indication criteria for treatment with the first intravitreal anti-C3 agent (pegcetacoplan).

METHODS

This retrospective cross-sectional study included all AMD patients who visited the Macular-Retina-Centre Oberkassel in 2021. Eyes were classified according to AMD stages. Eyes with GA were divided into two groups regarding foveal involvement. Baseline factors were compared between eyes with foveal GA (FGA) and eyes with non-foveal GA (NFGA) to identify predictive factors for foveal involvement.

RESULTS

A total of 2033 eyes from 1027 patients were included. AMD stage was early in 296 (14.5%) cases, intermediate in 368 (18.1%) cases, and advanced in 1249 (61.4%) cases. A total of 1204 (60%) eyes had GA [932 (77%) FGA and 272 (23%) NFGA], while 125 eyes (27.4% from eyes with advanced dry AMD) met the indication criteria for treatment with intravitreal pegcetacoplan. The proportion of eyes with neovascular AMD was significantly higher in the FGA group compared to the NFGA group [598 (64.2%) vs. 152 (55.8%), p = 0.01].

CONCLUSIONS

At least a quarter of eyes with advanced AMD would be suitable for the upcoming intravitreal pegcetacoplan therapy. Foveal involvement of GA in advanced AMD seems to be more likely in neovascular AMD than in dry AMD.

Brolucizumab Intravitreal Injections for Wet Age-Related Macular Degeneration: Real-Life Study on a Cohort of Italian Patients

Background and Objectives: To report the real-life Brolucizumab therapeutical outcomes of treatment-naïve and non-treatment-naïve eyes with neovascular age-related macular degeneration (nAMD) and to analyze the incidence of therapy-related adverse events. Materials and Methods: A total of 56 eyes of 54 patients diagnosed with nAMD were retrospectively evaluated over a 3-month follow-up. Naïve eyes received a 3-month loading phase, whereas non-naïve eyes were treated with one intravitreal injection + ProReNata scheme. The main outcome measures were best-corrected visual acuity (BCVA) and central retinal thickness (CRT) change. In addition, patients were stratified on the basis of fluid accumulation site, whether intra-retinal (IRF), sub-retinal (SRF), or sub-retinal pigmented epithelium (SRPE), to separately assess the eventual BCVA change in each subgroup. Finally, the incidence of ocular adverse events was evaluated. Results: In naïve eyes, a significant improvement of BCVA (LogMar) was observed at all timepoints from baseline (1 month-Mean Difference (MD): -0.13; 2 months MD: -0.17; 3 months MD: -0.24). In non-naïve eyes, a significant mean change was observed at all timepoints, with the exception of 1-month follow-up (2 months MD: -0.08; 3 months MD: -0.05). CRT significantly changed in both groups at all timepoints at a similar pace within the first two months, with naïve eyes displaying a larger overall thickness decrease at the end of the follow-up (Group 1 = MD: -123.91 µm; Group 2 = MD: -110.33 µm). With respect to the location of the edema, a significant BCVA change was observed in naïve patients with fluid in all three sites at the end of the follow-up (SRPE = MD: -0.13 (p = 0.043); SR = MD: -0.15 (p = 0.019); IR = MD: -0.19 (p = 0.041). Non-naïve patients exhibited significant mean BCVA changes only with respect to SR and IR fluid presence (SRPE = MD: -0.13 (p = 0.152); SR = MD: -0.15 (p = 0.007); IR = MD: -0.06 (p = 0.011). One naïve patient experienced acute-onset anterior and intermediate uveitis which completely resolved after therapy. Conclusions: Brolucizumab was demonstrated to be a safe and efficient alternative in improving both the anatomical and functional parameters of eyes with nAMD in this small, uncontrolled, series of patients.

Incidence of metformin use in patients with age-related macular degeneration versus normal controls: A population-based study in Olmsted County, Minnesota

PURPOSE

The purpose of this study is to compare the use of metformin in patients with both exudative and non-exudative age-related macular degeneration (AMD) versus control populations.

DESIGN

Retrospective review of three age- and sex-matched cohorts from 1/1/2004 to 12/31/2013: patients with exudative AMD, a cohort of dry AMD patients, and a cohort of patients without AMD. The primary endpoint was the incidence of metformin use in all of the cohorts.

RESULTS

There were 1512 patients, with 504 in each of the three cohorts. There was no difference in the prevalence of diabetes between cohorts. Compared to patients with dry AMD, patients with no AMD had increased likelihood of metformin use (p = 0.0168, OR 1.66 (1.09-2.51). There was no difference in the likelihood of metformin use between exudative AMD patients and non-AMD controls.

CONCLUSIONS

There appears to be an increased incidence of metformin use in patients without AMD compared to patients with dry AMD. Metformin's current role in the treatment of anti-aging diseases makes it a plausible target for use in the treatment of AMD, particularly dry AMD.

Trends and disparities in disease burden of age-related macular degeneration from 1990 to 2019: Results from the global burden of disease study 2019

Objectives

This study aims to estimate the trends and disparities in the worldwide burden for health of AMD, overall and by age, sex, socio-demographic index (SDI), region, and nation using prevalence and years lived with disability (YLDs) from Global Burden of Disease (GBD) study 2019.

Methods

This retrospective study presents the prevalent AMD cases and YLDs from 1990-2019, as well as the age-standardized prevalence rate (ASPR) and age-standardized YLD rate (ASYR) of AMD. To measure changes over time, estimated annual percentage changes (EAPCs) of the age-standardized rates (ASRs) were analyzed globally, then studied further by sex, SDI, region, and nation. We included data from the 2019 Global Burden of Disease (GBD) database to examine AMD prevalence and YLDs from 1990-2019 in 204 countries and territories, as well as demographic information such as age, sex, SDI, region, and nation.

Results

Globally, the number of prevalent AMD cases increased from 3,581,329.17 (95% uncertainty interval [UI], 3,025,619.4-4,188,835.7) in 1990 to 7,792,530 (95% UI, 6,526,081.5-9,159,394.9) in 2019, and the number of YLDs increased from 296,771.93 (95% uncertainty interval [UI], 205,462.8-418,699.82) in 1990 to 564,055.1 (95% UI, 392,930.7-789,194.64) in 2019. The ASPR of AMD had a decreased trend with an EAPC of -0.15 (95% confidence interval [CI], -0.2 to -0.11) from 1990 to 2019, and the ASYR of AMD showed a decreased trend with an EAPC of -0.71 (95% confidence interval [CI], -0.78 to -0.65) during this period. The prevalence and YLDs of AMD in adults over 50 years of age showed a significant increase. The prevalence and YLDs of AMD were significantly higher in females than males, overall. The ASPRs and ASYRs in low SDI regions was greater than in high SDI regions from 1990 to 2019. In addition, increases in prevalence and YLDs differed by regions and nations, as well as level of socio-economic development.

Conclusion

The number of prevalent cases and YLDs due to AMD increased over 30 years and were directly linked to age, sex, socio-economic status, and geographic location. These findings can not only guide public health work but also provide an epidemiological basis for global strategy formulation regarding this global health challenge.

Retromode Imaging in Age-Related Macular Degeneration

Background and Objectives: Retromode is a relatively new retinal-imaging technique that is based on the transillumination principle and is obtained with a scanning laser ophthalmoscope that uses light in the infrared spectrum. The laser light penetrates into the deep retinal layers and the choroid. Retromode images are captured with a laterally displaced aperture, and the detector captures only the scattered light. The result is a high-contrast pseudo-three-dimensional image. Age-related macular degeneration (AMD) is a disabling retinal disease. AMD is characterized in its early stage by small and intermediate drusen formation, while the signs of intermediate AMD are large drusen and/or pigmentary abnormalities. Late AMD has two forms, geographic atrophy, which is the advanced form of dry AMD, and wet AMD. Most of the lesions of AMD are located in the outer layers of the retina. This new imaging method can provide a glimpse of the deep retinal layers' topographic changes in a non-invasive, fast, and effective way that can match the other imaging tools available. Materials and Methods: The literature review was performed by searching the PubMed database using the following combination of keywords: retromode imaging and age-related macular degeneration. Relevant images similar to the ones in the literature were identified and used as models. Results: The purpose of this article is to highlight the utility of incorporating retromode imaging into the multimodal evaluation of the retina in patients with AMD and to gather and integrate these findings into a brief but comprehensive paper. Conclusions: Retromode imaging is a good screening, diagnosis, and monitoring tool for patients with AMD.

Role of flavonoids in age-related macular degeneration

A common eye disorder known as age-related macular degeneration (AMD) eventually results in blindness and vision loss. AMD has a complicated and poorly understood aetiology. The main pathological processes associated with AMD include oxidative damage, inflammation, and neovascularization. Flavonoids are naturally occurring bioactive substances with extensive distribution and antioxidant, anti-inflammatory, and neovascularization inhibitory properties. Several in vitro and in vivo AMD-related models pertinent to vision and this ocular ailment have been used to assess the mechanisms of action of various flavonoids. This article will discuss the research progress of flavonoids in AMD, especially the characteristics and mechanism of flavonoids in treating AMD.

Automation of Macular Degeneration Classification in the AREDS Dataset, Using a Novel Neural Network Design

Purpose

To create an ensemble of Convolutional Neural Networks (CNNs), capable of detecting and stratifying the risk of progressive age-related macular degeneration (AMD) from retinal photographs.

Design

Retrospective cohort study.

Methods

Three individual CNNs are trained to accurately detect 1) advanced AMD, 2) drusen size and 3) the presence or otherwise of pigmentary abnormalities, from macular centered retinal images were developed. The CNNs were then arranged in a "cascading" architecture to calculate the Age-related Eye Disease Study (AREDS) Simplified 5-level risk Severity score (Risk Score 0 - Risk Score 4), for test images. The process was repeated creating a simplified binary "low risk" (Scores 0-2) and "high risk" (Risk Score 3-4) classification.

Participants

There were a total of 188,006 images, of which 118,254 images were deemed gradable, representing 4591 patients, from the AREDS1 dataset. The gradable images were split into 50%/25%/25% ratios for training, validation and test purposes.

Main Outcome Measures

The ability of the ensemble of CNNs using retinal images to predict an individual's risk of experiencing progression of their AMD based on the AREDS 5-step Simplified Severity Scale.

Results

When assessed against the 5-step Simplified Severity Scale, the results generated by the ensemble of CNN's achieved an accuracy of 80.43% (quadratic kappa 0.870). When assessed against a simplified binary (Low Risk/High Risk) classification, an accuracy of 98.08%, sensitivity of ≥85% and specificity of ≥99% was achieved.

Conclusion

We have created an ensemble of neural networks, trained on the AREDS 1 dataset, that is able to accurately calculate an individual's score on the AREDS 5-step Simplified Severity Scale for AMD. If the results presented were replicated, then this ensemble of CNNs could be used as a screening tool that has the potential to significantly improve health outcomes by identifying asymptomatic individuals who would benefit from AREDS2 macular supplements.

Age-Related Macular Degeneration and Its Association With Neurodegenerative Disorders

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

Effects of systemic drugs on the development and progression of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of severe loss of central vision among people over 50. The pathophysiology of the disease is multifactorial and can be attributed to genetics, aging, inflammation, environmental factors, and lifestyle factors including smoking, diet, obesity, and alcohol consumption. While there is no treatment for dry AMD, the current standard treatment for wet AMD is an intraocular injection of anti-vascular endothelial growth factor-an effective, yet expensive, therapy that requires ongoing treatment. As the aging population continues to grow, and AMD diagnoses continue to rise, new treatments should be explored to reduce vision complications and decrease treatment burdens. Many systemic conditions have progressive pathological changes that may affect AMD, particularly those affecting systemic vasculature like diabetes and cardiovascular status. Consequently, systemic drugs used to treat coexistent systemic diseases may influence some of the pathogenic mechanisms of AMD and lead its progression or delay. In this review we explore the current literature to summarize the findings of the reported effects of antihypertensive, immunosuppressants, cholesterol lowering agents, nonsteroidal anti-inflammatory drugs, dopamine precursors, hypoglycemic agents, and anticoagulants on AMD.

Understanding Inflammation-associated Ophthalmic Pathologies: A Novel 3D Co-culture Model of Monocyte-myofibroblast Immunomodulation

PURPOSE

Inflammation is associated with, and may be causal of, a variety of ophthalmic pathologies. These pathologies are currently difficult to model in vitro because they involve complex interactions between the innate immune system, stromal cells, and other cells that normally maintain ocular tissue homeostasis. Using transscleral drainage channel fibrosis after glaucoma surgery as an example of inflammation-associated ocular fibrosis, we have assessed a simple but novel 3D cell culture system designed to reveal the immunomodulatory impacts of ocular connective tissue cells on monocytes, a major cellular component of the circulating immune system.

METHODS

Primary human Tenon's capsule fibroblasts derived from five unrelated patients were activated into myofibroblasts in 3D collagen matrices under isometric tension, with and without exposure to an inflammatory cytokine-enhanced milieu, and co-cultured with an immortalized human monocyte cell line (THP-1 cells). Quantitative PCR analyses were performed on 8 candidate genes to assess the impacts of inflammatory cytokines on the myofibroblasts and the monocytes in mono-cultures and compared to cells in co-culture to clearly distinguish any co-culture-induced impacts on gene expression.

RESULTS

Our data indicate that both Tenon's capsule myofibroblasts in 3D mono-culture and THP-1 monocytes in suspension mono-culture were responsive to inflammatory cytokine stimuli. Co-culture with Tenon's capsule myofibroblasts significantly modulated the gene expression responses of THP-1 monocytes to inflammatory cytokine stimulation, indicative of an immunomodulatory "feedback" system between these cell types.

CONCLUSION

Our findings provide proof of principle for the use of simple 3D co-culture systems as a means to enhance our understanding of ocular stromal cell interactions with cells of the innate immune system and to provide more informative in vitro models of inflammation-associated ophthalmic pathologies.

Serum miRNA modulations indicate changes in retinal morphology

Background

Age-related macular degeneration (AMD) is the leading cause of vision loss in the developed world and the detection of its onset and progression are based on retinal morphological assessments. MicroRNA (miRNA) have been explored extensively as biomarkers for a range of neurological diseases including AMD, however differences in experimental design and the complexity of human biology have resulted in little overlap between studies. Using preclinical animal models and clinical samples, this study employs a novel approach to determine a serum signature of AMD progression.

Methods

Serum miRNAs were extracted from mice exposed to photo-oxidative damage (PD; 0, 1, 3 and 5 days), and clinical samples from patients diagnosed with reticular pseudodrusen or atrophic AMD. The expression of ~800 miRNAs was measured using OpenArray™, and differential abundance from controls was determined using the HTqPCR R package followed by pathway analysis with DAVID. MiRNA expression changes were compared against quantifiable retinal histological indicators. Finally, the overlap of miRNA changes observed in the mouse model and human patient samples was investigated.

Results

Differential miRNA abundance was identified at all PD time-points and in clinical samples. Importantly, these were associated with inflammatory pathways and histological changes in the retina. Further, we were able to align findings in the mouse serum to those of clinical patients.

Conclusion

In conclusion, serum miRNAs are a valid tool as diagnostics for the early detection of retinal degeneration, as they reflect key changes in retinal health. The combination of pre-clinical animal models and human patient samples led to the identification of a preliminary serum miRNA signature for AMD. This study is an important platform for the future development of a diagnostic serum miRNA panel for the early detection of retinal degeneration.

Visualizing lipid behind the retina in aging and age-related macular degeneration, via indocyanine green angiography (ASHS-LIA)

Age-related macular degeneration (AMD) causes legal blindness in older adults worldwide. Soft drusen are the most extensively documented intraocular risk factor for progression to advanced AMD. A long-standing paradox in AMD pathophysiology has been the vulnerability of Asian populations to polypoidal choroidal vasculopathy (PCV) in the presence of relatively few drusen. Age-related scattered hypofluorescent spots on late phase indocyanine green angiography (ASHS-LIA) was recently proposed as precursors of PCV. Herein, we offer a resolution to the paradox by reviewing evidence that ASHS-LIA indicates the diffuse form of lipoprotein-related lipids accumulating in Bruch's membrane (BrM) throughout adulthood. Deposition of these lipids leads to soft drusen and basal linear deposit (BLinD), a thin layer of soft drusen material in AMD; Pre-BLinD is the precursor. This evidence includes: 1. Both ASHS-LIA and pre-BLinD/BLinD accumulate in older adults and start under the macula; 2. ASHS-LIA shares hypofluorescence with soft drusen, known to be physically continuous with pre-BLinD/BLinD. 3. Model system studies illuminated a mechanism for indocyanine green uptake by retinal pigment epithelium. 4. Neither ASHS-LIA nor pre-BLinD/ BLinD are visible by multimodal imaging anchored on current optical coherence tomography, as confirmed with direct clinicopathologic correlation. To contextualize ASHS-LIA, we also summarize angiographic characteristics of different drusen subtypes in AMD. As possible precursors for PCV, lipid accumulation in forms beyond soft drusen may contribute to the pathogenesis of this prevalent disease in Asia. ASHS-LIA also might help identify patients at risk for progression, of value to clinical trials for therapies targeting early or intermediate AMD.

NMDA Receptor Antagonists Degrade Lipofuscin via Autophagy in Human Retinal Pigment Epithelial Cells

Background and Objectives: Age-related macular degeneration is a slow-progressing disease in which lipofuscin accumulates in the retina, causing inflammation and apoptosis of retinal pigment epithelial (RPE) cells. This study aimed to identify N-methyl-D-aspartate (NMDA) signaling as a novel mechanism for scavenging N-retinylidene-N-retinylethanolamine (A2E), a component of ocular lipofuscin, in human RPE cells. Materials and Methods: A2E degradation assays were performed in ARPE-19 cells using fluorescently labeled A2E. The autophagic activity in ARPE-19 cells was measured upon blue light (BL) exposure, after A2E treatment. Autophagy flux was determined by measuring LC3-II formation using immunoblotting and confocal microscopy. To determine whether autophagy via the NMDA receptor is involved in A2E clearance, ATG5-deficient cells were used. Results: Ro 25-6981, an NR2B-selective NMDA receptor antagonist, effectively cleared A2E. Ro 25-6981 reduced A2E accumulation in the lysosomes of ARPE-19 cells at sub-cytotoxic concentrations, while increasing the formation of LC3-II and decreasing p62 protein levels in a concentration-dependent manner. The autophagic flux monitored by RFP-GFP-LC3 and bafilomycin A1 assays was significantly increased by Ro 25-6981. A2E clearance by Ro 25-6981 was abolished in ATG5-depleted ARPE-19 cells, suggesting that A2E degradation by Ro 25-6981 was mediated by autophagy. Furthermore, treatment with other NMDA receptor antagonists, CP-101,606 and AZD6765, showed similar effects on autophagy activation and A2E degradation in ARPE-19 cells. In contrast, glutamate, an NMDA receptor agonist, exhibited a contrasting effect, suggesting that both the activation of autophagy and the degradation of A2E by Ro 25-6981 in ARPE-19 cells occur through inhibition of the NMDA receptor pathway. Conclusions: This study demonstrates that NMDA receptor antagonists degrade lipofuscin via autophagy in human RPE cells and suggests that NMDA receptor antagonists could be promising new therapeutics for retinal degenerative diseases.

Nuclear Receptor Atlases of Choroidal Tissues Reveal Candidate Receptors Associated with Age-Related Macular Degeneration

The choroid is a vulnerable tissue site in the eye, impacted in several blinding diseases including age related macular degeneration (AMD), which is the leading cause of central vision loss in the aging population. Choroidal thinning and choriocapillary dropout are features of the early form of AMD, and endothelial dysfunction and vascular changes are primary characteristics of the neovascular clinical sub-type of AMD. Given the importance, the choroidal endothelium and outer vasculature play in supporting visual function, a better understanding of baseline choroidal signaling pathways engaged in tissue and cellular homeostasis is needed. Nuclear receptors are a large family of transcription factors responsible for maintaining various cellular processes during development, aging and disease. Herein we developed a comprehensive nuclear receptor atlas of human choroidal endothelial cells and freshly isolated choroidal tissue by examining the expression levels of all members of this transcription family using quantitative real time PCR. Given the close relationship between the choroid and retinal pigment epithelium (RPE), this data was cross-referenced with the expression profile of nuclear receptors in human RPE cells, to discover potential overlap versus cell-specific nuclear receptor expression. Finally, to identify candidate receptors that may participate in the pathobiology of AMD, we cataloged nuclear receptor expression in a murine model of wet AMD, from which we discovered a subset of nuclear receptors differentially regulated following neovascularization. Overall, these databases serve as useful resources establishing the influence of nuclear receptor signaling pathways on the outer vascular tissue of the eye, while providing a list of receptors, for more focused investigations in the future, to determine their suitability as potential therapeutic targets for diseases, in which the choroid is affected.

Early Canadian Real-World Experience with Brolucizumab in Anti-Vascular Endothelial Growth Factor-Experienced Patients with Neovascular Age-Related Macular Degeneration: A Retrospective Chart Review

Purpose

To assess early real-world outcomes with brolucizumab in Canadian patients with neovascular age-related macular degeneration (nAMD) for which they previously received ≥1 anti-vascular endothelial growth factor (anti-VEGF) agent(s).

Patients and Methods

This multisite, real-world, retrospective chart review included data from a consecutive sample of 73 patients who received brolucizumab for nAMD after treatment with ≥1 other anti-VEGF agents. The principal reasons for switching to brolucizumab were to extend the treatment interval (51.6% of patients) and to treat persistent macular fluid (34.2%). The primary outcomes were best-corrected visual acuity (BCVA) and the incidence rates of intraocular inflammation (IOI), retinal vasculitis (RV), and retinal vascular occlusion (RVO). Secondary outcomes included central retinal thickness (CRT), injection interval, and presence of intraretinal and subretinal fluid (IRF and SRF). All parameters were measured at baseline until the last treatment visit between April 27, 2020, and August 31, 2021.

Results

Over a mean follow-up of 28 weeks, a nonsignificant mean improvement in BCVA was identified (4.3 [standard deviation (SD) 8.3] letters; P=0.057), with 47.9% experiencing a gain of ≥5 letters. IOI was detected in 3 patients (4.1%), one of whom also developed RV and RVO (1.4%), which is consistent with existing brolucizumab data. Significant reductions were observed in mean CRT (−36.6 μm [SD 56.1 μm]; P=0.0002) and presence of any macular fluid (56.1% [SD 5.6%]; P<0.001), IRF (66.6% [SD 6.3%]; P<0.001), and SRF (62.7% [SD 6.3%]; P<0.001). The mean injection interval increased significantly by 2.1 weeks (SD 2.7; P<0.001).

Conclusion

In the first real-world Canadian analysis, brolucizumab was associated with improvements in functional outcomes in treatment-experienced patients, consistent with other real-world studies. The incidence of IOI, RV, and RVO were in line with the post hoc safety analysis of HAWK and HARRIER data.

Severity of age-related macular degeneration at first presentation in Bhutan: a 3-year national study

Background

Medical services are still developing in Bhutan. There is no published national report on age-related macular degeneration (AMD). We therefore aim to determine the demographic characteristics and severity of AMD at first presentation among Bhutanese patients attending their recently inaugurated vitreoretinal (VR) clinics over a 3-year national survey, and to inform national health policy to develop suitable health program to prevent AMD-related blindness and visual impairment.

Methods

A retrospective cross-sectional consecutive case series study was conducted on all new AMD cases in Bhutan. If a patient presented with asymmetrical AMD, the eye with more severe AMD was considered. If both the eyes had the same severity one eye was chosen randomly. Collection of demographic data and clinical details including diagnostic testing (fundus photography, OCT and fluorescent angiography) and clinical staging were performed.

Results

Of 521 new AMD patients aged 71.9 ± 11.3 years, 306/521 (58.7%) were males (p = 0.005). At their first presentation, 234/521 patients (44.9%) already had late-stage AMD. Importantly, 69/234 patients (29.5%), that is half of total neovascular AMD (nAMD) patients, had disciform scars (DS) which were beyond treatment, and 7/234 patients (3.0%) had geographic atrophy (GA). Seven patients had retinal pigment epithelium tear at presentation. Fourteen of nineteen polypoidal choroidal vasculopathy (PCV) patients were younger than 50 years.

Conclusions

Half of nAMD cases presented as DS not amenable to the treatment. Many potentially treatable nAMD patients had already lost central vision and were legally blind. Young people with PCV losing vision early in life with longer morbidity-affected life and socio-economic burden was concerning. GA and DS cases need visual rehabilitation to improve their QoL. Incorporating a screening program for AMD with effective health education, and maintaining a national AMD Registry, would potentially lower AMD-related blindness and visual impairment.

Retinal abnormalities, although relatively common in sleep clinic patients referred for polysomnography, are largely unrelated to sleep-disordered breathing

Study objectives.

There has been long-standing interest in potential links between obstructive sleep apnea (OSA) and eye disease. This study used retinal photography to identify undiagnosed retinal abnormalities in a cohort of sleep clinic patients referred for polysomnography (PSG) and then determined associations with PSG-quantified sleep-disordered breathing (SDB) severity.

Methods

Retinal photographs (n = 396 patients) were taken of each eye prior to polysomnography and graded according to validated, standardized, grading scales. SDB was quantified via in-laboratory polysomnography (PSG; n = 385) using standard metrics. A questionnaire (n = 259) documented patient-identified pre-existing eye disease. Within-group prevalence rates were calculated on a per patient basis. Data were analyzed using multivariate logistic regression models to determine independent predictors for retinal abnormalities. P < 0.05 was considered significant.

Results

Main findings were (1) 76% of patients reported no pre-existing “eye problems”; (2) however, 93% of patients had at least one undiagnosed retinal photograph-identified abnormality; (3) most common abnormalities were drusen (72%) and peripapillary atrophy (PPA; 47%); (4) age was the most common risk factor; (5) diabetes history was an expected risk factor for retinopathy; (6) patients with very severe levels of SDB (apnea hypopnea index ≥ 50 events/h) were nearly three times more likely to have PPA.

Conclusion

Retinal photography in sleep clinic settings will likely detect a range of undiagnosed retinal abnormalities, most related to patient demographics and comorbidities and, except for PPA, not associated with SDB. PPA may be indicative of glaucoma, and any association with severe SDB should be confirmed in larger prospective studies.

Phase 1B study of the safety and tolerability of the mineralocorticoid fludrocortisone acetate in patients with geographical atrophy

Objective

To evaluate the safety and tolerability of a mineralocorticoid, in a single-dose intravitreal (IVT) injection of 1 mg/0.1 mL and 2 mg/0.1 mL fludrocortisone acetate (FCA) in subjects with geographical atrophy (GA) secondary to age-related macular degeneration.

Methods and Analysis

This phase 1b study was a two-part dose-escalation prospective study. Part 1 involved a single participant treated with 1 mg/0.1 mL and monitored up to 28 days before being reviewed by a safety review committee. Two subsequent participants were then dosed with the same dose. Part 2 involved a single participant dosed with 2 mg/0.1 mL and monitored up to 28 days when a further five participants were dosed. All participants were followed up for 6 months after baseline.

A full ophthalmic assessment was performed at study visits which included GA area, best-corrected visual acuity (BCVA), low-luminance BCVA (LL-BCVA) and intraocular pressure (IOP). Adverse events (AEs) were reported from the first dose of FCA until the end-of-study visit.

Results

There were no serious AEs (ocular or systemic) observed with IVT FCA at either 1 mg/0.1 mL or 2 mg/0.1 mL among nine participants. There was no evidence of increased IOP or cataract development.

Neither BCVA or LL-BCVA changed significantly in the study-eye over the follow-up period (p=0.28 and 0.38, respectively). Mean GA area increased in the study (0.5 mm², p=0.003) and fellow-eyes (0.62 mm², p=0.02) over 6 months. Differences between eyes were not significant (p=0.64), and at the lower end of population norms.

Conclusion

IVT FCA is clinically safe and well tolerated and did not increase IOP.

The Role of Omega-3 and Antioxidant Nutrients in Age-Related Macular Degeneration: A Review Article

Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss worldwide. The cause of the disease is not well explained; studies previse a multifactorial etiology. Various results of studies suggest that omega-3 fatty acids may have beneficial effects in AMD. Besides the omega-3, clinical evidence showed that specific micronutrients (antioxidant vitamins and minerals) protect against AMD. The definition of risk factors for the development and progression of AMD is important for understanding the causes of the disorder and for the determination of its prevention strategies. In this study, the relationship between omega 3 and antioxidant nutrients and the incidence and progression of AMD were evaluated.

The effect of pegcetacoplan treatment on photoreceptor maintenance in geographic atrophy monitored by AI-based OCT analysis

PURPOSE

To investigate the therapeutic effect of intravitreal pegcetacoplan on the inhibition of photoreceptor (PR) loss and thinning in geographic atrophy (GA) on conventional spectral domain-optical coherence tomography (SD-OCT) imaging by deep learning-based automated PR quantification.

DESIGN

Post-hoc analysis of a prospective, multicenter, randomized, sham-controlled, masked phase II trial investigating the safety and efficacy of pegcetacoplan for the treatment of GA due to age-related macular degeneration.

PARTICIPANTS

Study eyes of 246 patients, randomized 1:1:1 to monthly (AM), bimonthly (AEOM) and sham (SM) treatment.

METHODS

We performed fully automated, deep learning-based segmentation of retinal pigment epithelium (RPE) loss and PR thickness on SD-OCT volumes acquired at baseline, month 2, 6 and 12. The difference in the change of PR loss area was compared between treatment arms. Change in PR thickness adjacent to the GA borders and in the whole 20 degrees scanning area was compared between treatment arms.

MAIN OUTCOME MEASURES

Square root transformed PR loss area in μm or mm, PR thickness in μm, PR loss/RPE loss ratio.

RESULTS

A total of 31,556 B-Scans of 644 SD-OCT volumes of 161 study eyes (AM: 52, AEOM: 54, SM: 56) were evaluated from baseline to month 12. Comparison of mean change in PR loss area revealed statistically significantly less growth in the AM group at month 2, 6 and 12 compared to SM (-41μm ± 219 vs. 77μm ± 126, p=0.0004; -5μm ± 221 vs. 156μm ± 139, p<0.0001; 106μm ± 400 vs. 283μm ± 226 p=0.0014). PR thinning was significantly reduced under monthly treatment compared to sham within the GA junctional zone as well as throughout the 20 degrees area. A trend towards greater inhibition of PR loss compared to RPE loss was observed under therapy.

CONCLUSIONS

Distinct and reliable quantification of PR loss using deep learning-based algorithms offers an essential tool to evaluate therapeutic efficacy in slowing disease progression. PR loss and thinning are reduced by intravitreal complement C3 inhibition. Automated quantification of PR loss/maintenance based on OCT images is an ideal approach to reliably monitor disease activity and therapeutic efficacy in GA management in clinical routine and regulatory trials.

Assessment of patient education materials for age-related macular degeneration

Purpose

Age‐related macular degeneration (AMD) is a leading cause of vision loss. It is helpful for patients living with AMD to understand the prognosis, risk factors and management of their condition. Online education materials are a popular and promising channel for conveying this knowledge to patients with AMD. However, the quality of these materials—particularly with respect to qualities such as ‘understandability’ and ‘actionability’—is not yet known. This study assessed a collection of online materials about AMD based on these qualities of ‘understandability’ and ‘actionability’.

Methods

Online education materials about AMD were sourced through Google from six English‐speaking nations: Australia, New Zealand, USA, UK, Ireland and Canada. Three Australian/New Zealand trained and registered optometrists participated in the grading of the ‘understandability’ and ‘actionability’ of online education materials using the Patient Education Materials Assessment Tool (PEMAT).

Results

This study analysed a total of 75 online materials. The mean ‘understandability’ score was 74% (range: 38%–94%). The ‘understandability’ PEMAT criterion U11 (calling for a summary of the key points) scored most poorly across all materials. The mean ‘actionability’ score was 49% (range: 0%–83%). The ‘actionability’ PEMAT criterion A26 (using ‘visual aids’ to make instructions easier to act on) scored most poorly across all materials.

Conclusion

Most education materials about AMD are easy to understand, but difficult to act on, because of a lack of meaningful visual aids. We propose future enhancements to AMD education materials—including the use of summaries, visual aids and a habit tracker—to help patients with AMD improve their understanding of disease prognosis, risk factors and eye assessment schedule requirements.

The Amyloid Precursor Protein Plays Differential Roles in the UVA Resistance and Proliferation of Human Retinal Pigment Epithelial Cells

Background:

Age-related macular degeneration (AMD) can be characterised by degeneration of retinal pigment epithelial (RPE) cells and the accumulation, in retinal drusen deposits, of amyloid beta-peptides proteolytically derived, by secretases, from the amyloid precursor protein (APP). Ultraviolet (UV) light exposure is a risk factor for the development of AMD.

Objectives:

In the current study, we investigated whether APP and/or its proteolysis are linked to the UVA resistance or proliferation of ARPE-19 human RPE cells.

Methods:

Cell viability was determined, following UVA exposure, with prior small interfering RNA-mediated APP depletion or secretase inhibitor treatments. APP levels/proteolysis were analysed by immunoblotting. Cells were also grown in the presence/absence of secretase inhibitors to assess their effects on longer-term culture growth. Finally, the effects of APP proteolytic fragments on ARPE-19 cell proliferation were monitored following co-culture with human embryonic kidney cells stably over-expressing these fragments.

Results:

Endogenous APP was depleted following UVA irradiation and β-secretase, but not α- secretase, and the processing of the protein was reduced. Experimental APP depletion or γ-secretase (but not α- or β-secretase) inhibition ablated the detrimental effect of UVA on cell viability. In contrast, α-secretase, and possibly γ-secretase but not β-secretase activity, appeared to promote the longer-term proliferation of ARPE-19 cells in the absence of UVA irradiation.

Conclusions:

There are clear but differential links between APP expression/proteolysis and the proliferation and UVA resistance of ARPE-19 cells indicating that the protein should be investigated further in relation to the identification of possible drug targets for the treatment of AMD.

A multimodal deep learning system to distinguish late stages of AMD and to compare expert vs. AI ocular biomarkers

Within the next 1.5 decades, 1 in 7 U.S. adults is anticipated to suffer from age-related macular degeneration (AMD), a degenerative retinal disease which leads to blindness if untreated. Optical coherence tomography angiography (OCTA) has become a prime technique for AMD diagnosis, specifically for late-stage neovascular (NV) AMD. Such technologies generate massive amounts of data, challenging to parse by experts alone, transforming artificial intelligence into a valuable partner. We describe a deep learning (DL) approach which achieves multi-class detection of non-AMD vs. non-neovascular (NNV) AMD vs. NV AMD from a combination of OCTA, OCT structure, 2D b-scan flow images, and high definition (HD) 5-line b-scan cubes; DL also detects ocular biomarkers indicative of AMD risk. Multimodal data were used as input to 2D-3D Convolutional Neural Networks (CNNs). Both for CNNs and experts, choroidal neovascularization and geographic atrophy were found to be important biomarkers for AMD. CNNs predict biomarkers with accuracy up to 90.2% (positive-predictive-value up to 75.8%). Just as experts rely on multimodal data to diagnose AMD, CNNs also performed best when trained on multiple inputs combined. Detection of AMD and its biomarkers from OCTA data via CNNs has tremendous potential to expedite screening of early and late-stage AMD patients.

Prophylactic Ranibizumab to Prevent Neovascular Age-Related Macular Degeneration in Vulnerable Fellow Eyes: A Randomized Clinical Trial

PURPOSE

To determine whether prophylactic ranibizumab prevents the development of neovascular age-related macular degeneration (nAMD) in eyes with intermediate AMD for patients with pre-existing nAMD in their contralateral eye.

DESIGN

Multicenter randomized clinical trial.

PARTICIPANTS

Adults aged 50 and older with intermediate AMD (multiple intermediate drusen [≥ 63 μm and <125 μm] or ≥1 large drusen [≥125 μm] and pigmentary changes) in the study eye and nAMD in the contralateral eye.

INTERVENTION

Intravitreal ranibizumab injection (0.5 mg) every 3 months for 24 months or sham injection.

MAIN OUTCOME MEASURES

Conversion to nAMD over 24 months (primary). Change in best-corrected visual acuity from baseline to 24 months (secondary).

RESULTS

Among 108 enrolled participants (54 [50%] in each group), all except two were non-Hispanic Whites, 61 participants (56%) were female, and the mean age was 78 years. The mean baseline visual acuity was 77.7 letters (Snellen equivalent 20/32). The rate of conversion to nAMD over 24 months was 7 of 54 eyes (13%) in both groups (ranibizumab vs. sham hazard ratio=0.91 [95% CI, 0.32-2.59], P=.86). At 24 months, the cumulative incidence of nAMD adjusted for loss to follow-up was 14% (95% CI, 4%-23%) in the ranibizumab group and 15% (95% CI, 4%-25%) in the sham group. At 24 months, the mean change in visual acuity from baseline was -2.1 letters (standard deviation, 5.4) with ranibizumab and -1.4 letters (standard deviation, 7.7) with sham (adjusted difference=-0.8 [95% CI, -3.7 to 2.2], P=.63). The proportion of eyes that lost at least 10 letters of visual acuity from baseline at 24 months was 2 of 39 (5%) with ranibizumab and 4 of 40 (10%) with sham. There were no serious ocular adverse events in either group.

CONCLUSIONS

Quarterly dosing of 0.5 mg ranibizumab in eyes with intermediate AMD did not reduce the incidence of nAMD as compared to sham injections; however, the study was likely underpowered given the 95% confidence interval, and a clinically meaningful effect cannot be excluded. There also was no effect on visual acuity at 24 months. Other strategies to reduce neovascular conversion in these vulnerable eyes are needed.