The prevalence of age-related maculopathy by geographic region and ethnicity

Pseudoxanthoma elasticum - Genetics, pathophysiology, and clinical presentation

Pseudoxanthoma elasticum (PXE) is an autosomal-recessively inherited multisystem disease. Mutations in the ABCC6-gene are causative, coding for a transmembrane transporter mainly expressed in hepatocytes, which promotes the efflux of adenosine triphosphate (ATP). This results in low levels of plasma inorganic pyrophosphate (PPi), a critical anti-mineralization factor. The clinical phenotype of PXE is characterized by the effects of elastic fiber calcification in the skin, the cardiovascular system, and the eyes. In the eyes, calcification of Bruch's membrane results in clinically visible lesions, including peau d'orange, angioid streaks, and comet tail lesions. Frequently, patients must be treated for secondary macular neovascularization. No effective therapy is available for treating the cause of PXE, but several promising approaches are emerging. Finding appropriate outcome measures remains a significant challenge for clinical trials in this slowly progressive disease. This review article provides an in-depth summary of the current understanding of PXE and its multi-systemic manifestations. The article offers a detailed overview of the ocular manifestations, including their morphological and functional consequences, as well as potential complications. Lastly, previous and future clinical trials of causative treatments for PXE are discussed.

Potential role of CTSS in AMDImmune modulatory and anti-angiogenic effects of cathepsin S knockdown in ARPE-19 cells

We aimed to determine the role of cathepsin S (CTSS) in modulating oxidative stress-induced immune and inflammatory reactions and angiogenesis in age-related macular degeneration. Human retinal pigment epithelium cells line ARPE-19 (immature) were maintained and treated with H2O2. The expression of CTSS, inflammatory cytokines, and complement factors induced by oxidative stress was compared between cells incubated without (control) and with CTSS knockdown (using small interfering ribonucleic acid; siRNA). To evaluate the role of CTSS in angiogenesis, we assayed tube formation using human umbilical vein endothelial cells and conditioned medium from ARPE-19 cells. We also used a mouse model of laser-induced choroidal neovascularization. CTSS levels were higher in ARPE-19 cells treated with H2O2 than in control cells. Oxidative stress-induced CTSS resulted in significantly elevated transcription of nuclear factor kappa B-dependent inflammatory cytokines, complement factors C3a and C5a, membrane attack complex (C5b-9), and C3a and C5a receptors. siRNA-mediated knockdown of CTSS reduced the number of inflammatory signals. Furthermore, oxidative stress-induced CTSS regulated the expression of peroxisome proliferator-activated receptor γ and vascular endothelial growth factor A/Akt serine/threonine kinase family signaling, which led to angiogenesis. Tube formation assays and mouse models of choroidal neovascularization revealed that CTSS knockdown ameliorated angiogenesis in vitro and in vivo. The present findings suggest that CTSS modulates the complement pathway, inflammatory reactions, and neovascularization, and that CTSS knockdown induces potent immunomodulatory effects. Hence, it could be a promising target for the prevention and treatment of early- and late-stage age-related macular degeneration.

Natural products for the treatment of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a chronic retinal disease that significantly influences the vision of the elderly.

PURPOSE

There is no effective treatment and prevention method. The pathogenic process behind AMD is complex, including oxidative stress, inflammation, and neovascularization. It has been demonstrated that several natural products can be used to manage AMD, but systematic summaries are lacking.

STUDY DESIGN AND METHODS

PubMed, Web of Science, and ClinicalTrials.gov were searched using the keywords "Biological Products" AND "Macular Degeneration" for studies published within the last decade until May 2023 to summarize the latest findings on the prevention and treatment of age-related macular degeneration through the herbal medicines and functional foods.

RESULTS

The eligible studies were screened, and the relevant information about the therapeutic action and mechanism of natural products used to treat AMD was extracted. Our findings demonstrate that natural substances, including retinol, phenols, and other natural products, prevent the development of new blood vessels and protect the retina from oxidative stress in cells and animal models. However, they have barely been examined in clinical studies.

CONCLUSION

Natural products could be highly prospective candidate drugs used to treat AMD, and further preclinical and clinical research is required to validate it to control the disease.

Sema4D Knockout Attenuates Choroidal Neovascularization by Inhibiting M2 Macrophage Polarization Via Regulation of the RhoA/ROCK Pathway

Purpose

The aim of this study was to elucidate the role of Sema4D in the pathogenesis of senescence-associated choroidal neovascularization (CNV) and to explore its underlying mechanisms.

Methods

In this study, we utilized a model of laser-induced CNV in both young (3 months old) and old (18 months old) mice, including those with or without Sema4D knockout. The expression and localization of Sema4D in CNV were assessed using PCR, Western blot, and immunostaining. Subsequently, the morphological and imaging examinations were used to evaluate the size of CNV and vascular leakage. Finally, the expression of M2 markers, senescence-related markers, and molecules involved in the RhoA/ROCK pathway was detected.

Results

We found that Sema4D was predominantly expressed in macrophages within CNV lesions, and both the mRNA and protein levels of Sema4D progressively increased following laser photocoagulation, a trend more pronounced in old mice. Moreover, Sema4D knockout markedly inhibited M2 polarization in senescent macrophages and reduced the size and leakage of CNV, particularly in aged mice. Mechanistically, aging was found to upregulate RhoA/ROCK signaling, and knockout of Sema4D effectively suppressed the activation of this pathway, with more significant effects observed in aged mice.

Conclusions

Our findings revealed that the deletion of Sema4D markedly inhibited M2 macrophage polarization through the suppression of the RhoA/ROCK pathway, ultimately leading to the attenuation of senescence-associated CNV. These data indicate that targeting Sema4D could offer a promising approach for gene editing therapy in patients with neovascular age-related macular degeneration.

Technological Perception with Rural and Urban Differentiation and Its Influence on the Quality of Life of Older People with Age-Related Macular Degeneration

The past decade has seen a global increase in population age, especially in developed countries, where aging involves visual diseases such as age-related macular degeneration (AMD), which severely affect quality of life (QoL) and mental health, as well as increase isolation and care costs. This study investigated how persons with AMD perceive the impact of technology use on their QoL, focusing on potential disparities between urban and rural contexts in Spain. Using a cross-sectional observational design, data from the 2020 National Statistics Institute's Disability, Personal Autonomy, and Dependency Situations Survey were analyzed, focusing on QoL aspects based on the WHO items of the WHOQOL-100 scale. The results revealed a generally positive perception of technology among participants, with urban residents perceiving technology's positive impact more favorably. Sex discrepancies in technology perception were also observed, as women exhibited a more positive outlook on technology's influence on QoL. The analysis of QoL aspects, such as 'Visibility', 'Learning', 'Mobility', and 'Domestic life', highlighted distinct challenges faced by rural and urban populations, underscoring the importance of context-specific approaches in technology interventions. However, these perceptions were intertwined with comorbidities, which can exacerbate AMD-related issues. Furthermore, this study explored the role of technology in enhancing QoL among older adults with AMD, examining how it influences daily activities and independence, particularly in the context of AMD management. This study concluded that developing more-inclusive policies tailored to the specific needs of persons with AMD, with special attention to environmental and sex differences, is imperative to enhance the positive impact of technology on their QoL.

Efficacy and safety of intravitreal faricimab for neovascular age-related macular degeneration: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to evaluate the visual, anatomical, and safety outcomes of the intravitreal faricimab, a novel vascular endothelial growth factor (VEGF)/angiopoietin-2 (Ang-2) bispecific agent, in neovascular age-related macular degeneration (nAMD) patients. The follow-up times in the included studies ranged from a minimum of 36 weeks to a maximum of 52 weeks. EMBASE, Ovid-Medline, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Scopus, the WHO ICTRP, ClinicalTrial.gov, the EU Clinical Trials Register, and Chinese Clinical Trial Registry (ChiCTR) were searched (The last literature search was performed on August 17, 2023) for randomized controlled trials (RCTs) comparing faricimab with control groups for neovascular age-related macular degeneration (nAMD). The risk of bias for eligible RCTs was independently assessed using the Cochrane Risk of Bias Tool by two authors (W.-T.Y. and C.-S.W.). The meta-analysis was conducted using Review Manager 5.4 software. The mean best corrected visual acuity (BCVA), central subfield thickness (CST), total choroidal neovascularization (CNV) area, and total lesion leakage were analyzed as continuous variables and the outcome measurements were reported as the weighted mean difference (WMD) with a 95% confidence interval (CI). The ocular adverse events and ocular serious adverse events were analyzed as dichotomous variables and the outcome measurements were analyzed as the odds ratios (ORs) with a 95% CI. Random-effects model was used in our study for all outcome synthesizing due to different clinical characteristics. Four RCTs with 1,486 patients were eligible for quantitative analysis. There was no statistically significant difference between intravitreal faricimab and anti-VEGF in BCVA [weighted mean difference (WMD) = 0.47; 95% CI: (- 0.17, 1.11)]. The intravitreal faricimab group showed numerically lower CST [WMD =  - 5.96; 95% CI = (- 7.11, - 4.82)], total CNV area [WMD =  - 0.49; 95% CI = (- 0.68, - 0.30)], and total lesion leakage [WMD =  - 0.88; 95% CI = (- 1.08, - 0.69)] after intravitreal therapy compared with the intravitreal anti-VEGF group. There were no statistically significant differences between intravitreal faricimab and anti-VEGF in ocular adverse events (AEs) [pooled odds ratio (OR) = 1.10; 95% CI = (0.81, 1.49)] and serious adverse events (SAEs) [pooled OR = 0.84; 95% CI = (0.37, 1.90)]. The intravitreal bispecific anti-VEGF/angiopoietin 2 (Ang2) antibody faricimab with a extended injection interval was non-inferior to first-line anti-VEGF agents in BCVA. It was safe and had better anatomical recovery. Large, well-designed RCTs are needed to explore the potential benefit of extended faricimab for nAMD. This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022327450).

Targeting cell-type-specific, choroid-peripheral immune signaling to treat age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness featuring pathogenic neovascularization of the choroidal vasculature (CNV). Although systemic immunity plays a role in AMD, the ocular signals that recruit and activate immune cells remain poorly defined. Using single-cell RNA sequencing, we prospectively profile peripheral blood mononuclear cells from 65 individuals including AMD and controls, which we integrate with existing choroid data. We generate a network of choroid-peripheral immune interactions dysregulated in AMD, including known AMD-relevant gene vascular endothelial growth factor (VEGF) receptor 2. Additionally, we find CYR61 is upregulated in choroidal veins and may signal to circulating monocytes. In mice, we validate that CYR61 is abundant in endothelial cells within CNV lesions neighboring monocyte-derived macrophages. Mechanistically, CYR61 activates macrophage anti-angiogenic gene expression, and ocular Cyr61 knockdown increases murine CNV size, indicating CYR61 inhibits CNV. This study highlights the potential of multi-tissue human datasets to identify disease-relevant and potentially therapeutically modifiable targets.

Accelerated Brain Atrophy, Microstructural Decline and Connectopathy in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) has recently been linked to cognitive impairment. We hypothesized that AMD modifies the brain aging trajectory, and we conducted a longitudinal diffusion MRI study on 40 participants (20 with AMD and 20 controls) to reveal the location, extent, and dynamics of AMD-related brain changes. Voxel-based analyses at the first visit identified reduced volume in AMD participants in the cuneate gyrus, associated with vision, and the temporal and bilateral cingulate gyrus, linked to higher cognition and memory. The second visit occurred 2 years after the first and revealed that AMD participants had reduced cingulate and superior frontal gyrus volumes, as well as lower fractional anisotropy (FA) for the bilateral occipital lobe, including the visual and the superior frontal cortex. We detected faster rates of volume and FA reduction in AMD participants in the left temporal cortex. We identified inter-lingual and lingual-cerebellar connections as important differentiators in AMD participants. Bundle analyses revealed that the lingual gyrus had a lower streamline length in the AMD participants at the first visit, indicating a connection between retinal and brain health. FA differences in select inter-lingual and lingual cerebellar bundles at the second visit showed downstream effects of vision loss. Our analyses revealed widespread changes in AMD participants, beyond brain networks directly involved in vision processing.

AMD and Stem Cell-Based Therapies

Age-related macular degeneration (AMD) is a prevalent and complex disease leading to severe vision loss. Stem cells offer promising prospects for AMD treatment as they can be differentiated into critical retinal cell types that could replace lost host retinal cells or provide trophic support to promote host retinal cell survival. However, challenges such as immune rejection, concerns regarding tumorigenicity, and genomic integrity must be addressed. Clinical trials with stem cell-derived retinal pigment epithelial cells have shown preliminary safety in treating dry AMD, but improvements in manufacturing and surgical techniques cell delivery are needed. Late-stage AMD poses additional hurdles, possibly requiring multi-layered grafts. Advancements in automation technologies and gene correction strategies show potential to enhance iPSC-based therapies. Stem cell-based treatments offer hope for AMD management, but further research and optimization are essential for successful clinical implementation.

Recent Developments in Gene Therapy for Neovascular Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a complex and multifactorial disease and a leading cause of irreversible blindness in the elderly population. The anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the management and prognosis of neovascular AMD (nAMD) and is currently the standard of care for this disease. However, patients are required to receive repeated injections, imposing substantial social and economic burdens. The implementation of gene therapy methods to achieve sustained delivery of various therapeutic proteins holds the promise of a single treatment that could ameliorate the treatment challenges associated with chronic intravitreal therapy, and potentially improve visual outcomes. Several early-phase trials are currently underway, evaluating the safety and efficacy of gene therapy for nAMD; however, areas of controversy persist, including the therapeutic target, route of administration, and potential safety issues. In this review, we assess the evolution of gene therapy for nAMD and summarize several preclinical and early-stage clinical trials, exploring challenges and future directions.

Shedding Light on Photobiomodulation Therapy for Age-Related Macular Degeneration: A Narrative Review

BACKGROUND

Photobiomodulation (PBM) relies on the pathophysiological mechanism whereby red to near-infrared light can target mitochondrial activity and promote ATP synthesis. Preclinical and clinical studies have shown promising results in treating intermediate age-related macular degeneration (AMD), since PBM can produce photochemical reactions in endogenous retinal chromophores. Currently, PBM is approved by the Food and Drug Administration and by the European Medicines Agency for the treatment of intermediate AMD. This narrative review aimed to evaluate the available evidence on the effectiveness and safety of PBM in treating intermediate AMD.

METHODS

A comprehensive search was conducted using the PubMed database, employing the keywords "photobiomodulation" and "age-related macular degeneration." All English-language studies published up to June 2023 were reviewed, and the search was expanded to include relevant references from selected articles. The included publications were analyzed for this review.

RESULTS

The available studies on PBM in AMD demonstrated promising but inconsistent results. PBM showed potential in improving best-corrected visual acuity (BCVA) and contrast sensitivity (CS) in patients with AMD. Some studies also suggested a reduction in AMD lesions, such as drusen volume. However, the long-term efficacy and optimal treatment parameters of PBM in AMD remained to be fully determined due to the limitations of the available studies. These included variations in irradiation techniques, wavelengths, exposure times, and treatment sessions, making it challenging to generalize the effectiveness of PBM. Furthermore, the lack of accurate classification of AMD phenotypes in the available studies hindered the understanding of which phenotypes could truly benefit from this treatment. Finally, the strength of evidence varied among studies, with limited sample sizes, unpublished results, and only three randomized sham-controlled trials.

CONCLUSIONS

Currently, the effectiveness of PBM in promoting drusen resorption or preventing progression to advanced forms of AMD, as observed in the cited studies, remains uncertain.

Relationship between pulsation of posterior vortex vein, choroidal thickness, and choroidal vascular hyperpermeability in polypoidal choroidal vasculopathy

PURPOSE

Posterior vortex vein pulsation on Heidelberg indocyanine green angiography (HRA-IA) video is reported to indicate the presence of congestion in these vessels. This study aimed to determine the relationship between posterior vortex vein pulsation, choroidal thickness, and choroidal vascular hyperpermeability (CVH) in polypoidal choroidal vasculopathy (PCV).

METHODS

Forty-three eyes of 43 patients who had not received previous treatment and were diagnosed with PCV using multimodal imaging were included and retrospectively investigated. On initial visit, presence or absence of pulsation in the posterior vortex vein was analysed using HRA-IA. Subfoveal choroidal thickness (SFCT) was assessed, and patients were divided into the SFCT ≥ 200 μm and < 200 μm (P and NP, respectively) groups. Presence or absence of CVH was investigated using IA in the late phase, and the associations between the three parameters were analysed.

RESULTS

Posterior vortex vein pulsation was detected in 24/43 eyes (55%). There were 27 eyes in the P group (mean SFCT, 286 ± 48 μm) and 16 eyes in the NP group (mean SFCT, 143 ± 41 μm). Pulsation was detected in 10 eyes (37%) in the P group and 14 eyes (88%) in the NP group. Incidence of pulsation was significantly higher in the NP group (P < 0.05). There were 17 (40%) patients with CVH-13 (48%) and four (25%) in the P and NP groups, respectively (P = 0.1994). There was no correlation between the presence or absence of pulsation and CVH (P = 0.1994).

CONCLUSION

Congestion of the vortex vein is potentially associated with the pathogenesis of PCV with a thin choroid.

LOW-DOSE SUPPLEMENTATION WITH RETINOL IMPROVES RETINAL FUNCTION IN EYES WITH AGE-RELATED MACULAR DEGENERATION BUT WITHOUT RETICULAR PSEUDODRUSEN

PURPOSE

The aim of this study was to determine the functional impact of oral vitamin A supplementation in patients with intermediate age-related macular degeneration with and without reticular pseudodrusen (RPD) demonstrating dysfunction in dark adaptation.

METHODS

Five patients with intermediate age-related macular degeneration and without RPD (AMD group; mean ± SD age 78.0 ± 4.7 years) and seven with RPD (RPD group; age 74.1 ± 11.2 years) were supplemented with 16,000 IU of vitamin A palmitate for 8 weeks. Assessment at baseline, 4, 8, and 12 weeks included scotopic thresholds, dark adaptation, best-corrected and low luminance visual acuities, and the low-luminance quality of life questionnaire.

RESULTS

In the linear mixed model, rod intercept time improved significantly in the AMD group (mean [95% CI] change -1.1 minutes [-1.8; -0.5] after 4 weeks ( P < 0.001) and -2.2 min [-2.9 to -1.6] after 8 weeks of vitamin A supplementation ( P < 0.001). The dark adaptation cone plateau also significantly improved (i.e., more sensitive cone threshold) at 4 and 8 weeks ( P = 0.026 and P = 0.001). No other parameters improved in the AMD group, and there was no significant improvement in any parameter in the RPD group despite significantly elevated serum vitamin A levels measurable in both groups after supplementation ( P = 0.024 and P = 0.013).

CONCLUSION

Supplementation with 16,000 IU vitamin A, a lower dose than used in previous studies, partially overcomes the pathophysiologic functional changes in AMD eyes. The lack of improvement in the RPD group may indicate structural impediments to increasing vitamin A availability in these patients and/or may reflect the higher variability observed in the functional parameters for this group.

Three-month outcomes of faricimab loading therapy for wet age-related macular degeneration in Japan

This multicenter study aimed to assess the short-term effectiveness and safety of faricimab in treatment-naïve patients with wet age-related macular degeneration (wAMD) in Japan. We retrospectively reviewed 63 eyes of 61 patients with wAMD, including types 1, 2, and 3 macular neovascularization as well as polypoidal choroidal vasculopathy (PCV). Patients received three consecutive monthly intravitreal injections of faricimab as loading therapy. Over these 3 months, visual acuity improved gradually compared to baseline. Moreover, the central foveal thickness decreased significantly at 1, 2, and 3 months compared to baseline (p < 0.0001). At 3 months after initiation of faricimab therapy, a dry macula (defined as absence of intraretinal or subretinal fluid) was achieved in 82% of the eyes. Complete regression of polypoidal lesions was observed in 52% of eyes with PCV. Subfoveal choroidal thickness also decreased significantly at 1, 2, and 3 months compared to baseline (p < 0.0001). Although retinal pigment epithelium tears developed in two eyes, there were no other ocular or systemic complications observed during the 3 months of loading therapy. In conclusion, loading therapy using faricimab resulted in improved visual acuity and retinal morphology in Japanese patients with wAMD without particular safety issues.

A Treat-and-Extend Regimen of Intravitreal Brolucizumab for Exudative Age-Related Macular Degeneration Refractory to Aflibercept: A 12-Month Result

We aimed to investigate whether a treat-and-extend regimen of intravitreal brolucizumab (6.0 mg/0.05 mL) is effective for eyes with exudative age-related macular degeneration (AMD) refractory to aflibercept for 12 months. Sixty eyes from 56 patients receiving brolucizumab for exudative AMD refractory to aflibercept were included. Patients received a mean of 30.1 aflibercept administrations for a mean 67.9-month follow-up. All patients exhibited exudation on optical coherence tomography (OCT) despite regular 4-8 weeks of aflibercept administration. Visit 1 was scheduled at the same interval from the last aflibercept injection to the baseline. The treatment interval was extended or shortened by 1-2 weeks depending on the presence or absence of exudation on OCT. After switching to brolucizumab, the follow-up interval significantly extended at 12 months (before switching: 7.6 ± 3.8 weeks vs. at 12 months: 12.1 ± 6.2 weeks, p = 1.3 × 10^-7). Forty-three percent of the eyes achieved a dry macula at 12 months after switching. However, the best-corrected visual acuity did not improve at any visit. Morphologically, the central retinal thickness and subfoveal choroidal thickness significantly decreased from baseline at 12 months (p = 3.6 × 10^-3 and 1.0 × 10^-3, respectively). Switching to brolucizumab can be considered to extend the treatment interval in eyes with exudative AMD refractory to aflibercept.

Visual impairment due to age-related macular degeneration during 40 years in Finland and the impact of novel therapies

PURPOSE

To evaluate the changes in visual impairment (VI) due to age-related macular degeneration (AMD) during the past 40 years and the impact of novel therapies at population level.

METHODS

In this nationwide register-based study, we assessed the incidence, prevalence, severity, and onset age of VI due to AMD based on the Finnish Register of Visual Impairment data from 1980 to 2019. Our data included 30 016 visually impaired persons with AMD as the main diagnosis for VI. The number of persons treated with intravitreal injections in Finland was obtained from hospital data kept by the Finnish Institute for Health and Welfare.

RESULTS

Between the 1980s and the 2010s, the incidence of reported VI doubled; however, this increase has stagnated in the 2010s. Since 2012, the prevalence of reported VI has decreased. The number of patients treated with intravitreal injections showed a 40-fold increase during 2005-2019. The severity of reported VI has decreased whereas the mean age at the onset of reported VI has increased during the 40 years. The age-adjusted incidence and prevalence of reported VI were significantly higher in females in comparison to males in all decades.

CONCLUSION

Increase in the incidence and prevalence of VI due to AMD in the past decades has stagnated and shifted to older age in the 2010s when therapies for exudative class became commonly available. Furthermore, the prognosis of VI has improved during the past 40 years. These positive trends are likely contributable to improved diagnostic tools, earlier diagnoses, and new therapy options.

Biosimilar versus InnovAtor MoLecule of RAnibizumab in Neovascular Age-Related MaCular DEgeneration (The BALANCE Trial): Real-World Evidence

Purpose

To analyse outcomes of innovator ranibizumab (IRM) (Lucentis) and biosimilar ranibizumab (BRM) (Razumab) in Indian eyes with neovascular age-related macular degeneration (nAMD).

Methods

Retrospective observational study in nAMD patients, who were treated with IRM or BRM (3 loading doses followed by pro re nata (PRN). Primary outcome measures were change in best corrected visual acuity (BCVA) and central macular thickness (CMT) along with safety analysis. Secondary outcomes measures were changes in the subretinal fluid (SRF) and intraretinal fluid (IRF).

Results

Inclusion criteria were satisfied in 164 eyes (60.74%). A total of 87 eyes were treated with IRM, and 77 eyes received BRM. Baseline BCVA was 0.57±0.27 logMAR in IRM group and 0.61±0.25 in the BRM group. At 3, 6, 9, and 12 months BCVA was 0.27±0.22 (p<0.0001), 0.34±0.23 (p<0.0001), 0.39±0.25 (p<0.0001), and 12 months 0.41±0.23 (p<0.0001) in the IRM group and 0.24±0.16 (p<0.0001), 0.27±0.16 (p<0.0001), 0.34±0.17 (p<0.0001), 0.38±0.18 (p<0.0001) in the BRM group. Baseline CMT was 420.39±54.45 μm in IRM group and 407.82±53.07 μm in BRM group. At 3, 6, 9, and 12 months, CMT decreased to 258.28±20.4 μm (p<0.0001), 268.38±19.5 μm (p<0.0001), 269.51±32.41 μm (p<0.0001), and 278.28±16.56 μm (p<0.0001) in the IRM group and 258.84±17.47 μm (p<0.0001), 265.69±17.29 μm (p<0.0001), 273.64±23.13 μm (p<0.0001), and 283.09±19.66 μm (p<0.0001) in the BRM group. Similar improvements in IRF and SRF levels in the patients were noted in both groups. Required number of doses of IRM and BRM was similar over the 12 month period in both groups. A similar profile of adverse events was noted in both the groups.

Conclusion

Intravitreal injection of IRM and BRM show similar efficacy and safety in Indian eyes with nAMD.

Towards a better understanding of non-exudative choroidal and macular neovascularization

Non-exudative macular and choroidal neovascularization (MNV and CNV) usually refers to the entity of treatment-naïve type 1 neovascularization in the absence of associated signs of exudation. Histopathological studies, dating back in the early 70s, identified the presence of non-exudative MNV, but the first clinical report of this finding was in the late 90s using indocyanine green angiography in eyes with age-related macular degeneration (AMD). With more advanced retinal imaging, there has been an ever increasing appreciation of non-exudative MNV associated with AMD and CNV with other macular disorders. However, consensus regarding the exact definition and the clinical management of this entity is lacking. Furthermore, there may be variation in the imaging features and clinical course suggesting that a spectrum of disease may exist. Herein, we review the large body of published work that has provided a better understanding of non-exudative MNV and CNV in the last decade. The prevalence, multimodal imaging features, clinical course, and response to treatment are discussed to elucidate further key insights about this entity. Based on these observations, this review also proposes a new theory about the origin and course of different sub-types of non-exudative MNV/CNV which can have different etiologies and pathways according to the clinical context of disease.

The role of NAD+ metabolism in macrophages in age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of legal blindness and moderate and severe vision impairment (MSVI) in people older than 50 years. It is classified in various stages including early, intermediate, and late stage. In the early stages, innate immune system, especially macrophages, play an essential part in disease onset and progression. NAD⁺ is an essential coenzyme involved in cellular senescence and immune cell function, and its role in age-related diseases is gaining increasing attention. The imbalance between the NAD⁺ synthesis and consumption causes the fluctuation of intracellular NAD⁺ level which determines the polarization fate of macrophages. In AMD, the over-expression of NAD⁺-consuming enzymes in macrophages leads to declining of NAD⁺ concentrations in the microenvironment. This phenomenon triggers the activation of inflammatory pathways in macrophages, positive feedback aggregation of inflammatory cells and accumulation of reactive oxygen species (ROS). This review details the role of NAD⁺ metabolism in macrophages and molecular mechanisms during AMD. The selected pathways were identified as potential targets for intervention in AMD, pending further investigation.

Does outer retinal layer thickness correlate with the central visual field indices in early dry age-related macular degeneration?

PURPOSE

Age-related macular degeneration (ARMD) is the leading cause of irreversible blindness worldwide and Nepal is one among them. We aimed to determine the relationship between outer retinal layer thickness parameters with central visual field indices in early dry ARMD cases among Nepalese population.

MATERIALS AND METHODS

The subjects for this descriptive, cross-sectional study comprised 40 patients with early dry ARMD from the ophthalmology department of a tertiary level hospital of Nepal. The retinal layer thickness was measured with spectral-domain optical coherence tomography (SD-OCT), and the visual field indices were assessed using the 10-2 protocol of Humphrey visual field analyzer (HFA). Thus, the retinal layer structures correlated with visual field indices among our population.

RESULTS

Among our early dry ARMD population, the foveal threshold (FT) was found to be significantly correlated with retinal pigment epithelium (RPE) elevation (P < 0.01, r = -0.541), outer segment (OS) length (P = 0.02, r = 0.465), and inner segment ellipsoid (ISe) band disruption (P = 0.01, r = -0.499), but not with presence of hyperreflective foci (P = 0.464), RPE thickness (P = 0.612), and central macular thickness (P = 0.214). However, no significant correlation between mean deviation and pattern standard deviation of visual field with retinal layer thickness parameters was identified.

CONCLUSION

In early dry ARMD, a reduced FT is significantly correlated with the integrity of the ISe band, thinning of OS length, and drusen-associated RPE elevation. The results highlight the utility of both SD-OCT retinal layer measurement and central visual field testing by HFA in ARMD to monitor the progression of the disease.

Molecular Genetic Mechanisms in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is among the leading causes of irreversible blindness worldwide. In addition to environmental risk factors, such as tobacco use and diet, genetic background has long been established as a major risk factor for the development of AMD. However, our ability to predict disease risk and personalize treatment remains limited by our nascent understanding of the molecular mechanisms underlying AMD pathogenesis. Research into the molecular genetics of AMD over the past two decades has uncovered 52 independent gene variants and 34 independent loci that are implicated in the development of AMD, accounting for over half of the genetic risk. This research has helped delineate at least five major pathways that may be disrupted in the pathogenesis of AMD: the complement system, extracellular matrix remodeling, lipid metabolism, angiogenesis, and oxidative stress response. This review surveys our current understanding of each of these disease mechanisms, in turn, along with their associated pathogenic gene variants. Continued research into the molecular genetics of AMD holds great promise for the development of precision-targeted, personalized therapies that bring us closer to a cure for this debilitating disease.

Biomarkers as Predictive Factors of Anti-VEGF Response

Age-related macular degeneration is the main cause of irreversible vision in developed countries, and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the current gold standard treatment today. Although anti-VEGF treatment results in important improvements in the course of this disease, there is a considerable number of patients not responding to the standardized protocols. The knowledge of how a patient will respond or how frequently retreatment might be required would be vital in planning treatment schedules, saving both resource utilization and financial costs, but today, there is not an ideal biomarker to use as a predictive response to ranibizumab therapy. Whole blood and blood mononuclear cells are the samples most studied; however, few reports are available on other important biofluid samples for studying this disease, such as aqueous humor. Moreover, the great majority of studies carried out to date were focused on the search for SNPs in genes related to AMD risk factors, but miRNAs, proteomic and metabolomics studies have rarely been conducted in anti-VEGF-treated samples. Here, we propose that genomic, proteomic and/or metabolomic markers could be used not alone but in combination with other methods, such as specific clinic characteristics, to identify patients with a poor response to anti-VEGF treatment to establish patient-specific treatment plans.

Dark Adaptation and Its Role in Age-Related Macular Degeneration

Dark adaptation (DA) refers to the slow recovery of visual sensitivity in darkness following exposure to intense or prolonged illumination, which bleaches a significant amount of the rhodopsin. This natural process also offers an opportunity to understand cellular function in the outer retina and evaluate for presence of disease. How our eyes adapt to darkness can be a key indicator of retinal health, which can be altered in the presence of certain diseases, such as age-related macular degeneration (AMD). A specific focus on clinical aspects of DA measurement and its significance to furthering our understanding of AMD has revealed essential findings underlying the pathobiology of the disease. The process of dark adaptation involves phototransduction taking place mainly between the photoreceptor outer segments and the retinal pigment epithelial (RPE) layer. DA occurs over a large range of luminance and is modulated by both cone and rod photoreceptors. In the photopic ranges, rods are saturated and cone cells adapt to the high luminance levels. However, under scotopic ranges, cones are unable to respond to the dim luminance and rods modulate the responses to lower levels of light as they can respond to even a single photon. Since the cone visual cycle is also based on the Muller cells, measuring the impairment in rod-based dark adaptation is thought to be particularly relevant to diseases such as AMD, which involves both photoreceptors and RPE. Dark adaptation parameters are metrics derived from curve-fitting dark adaptation sensitivities over time and can represent specific cellular function. Parameters such as the cone-rod break (CRB) and rod intercept time (RIT) are particularly sensitive to changes in the outer retina. There is some structural and functional continuum between normal aging and the AMD pathology. Many studies have shown an increase of the rod intercept time (RIT), i.e., delays in rod-mediated DA in AMD patients with increasing disease severity determined by increased drusen grade, pigment changes and the presence of subretinal drusenoid deposits (SDD) and association with certain morphological features in the peripheral retina. Specifications of spatial testing location, repeatability of the testing, ease and availability of the testing device in clinical settings, and test duration in elderly population are also important. We provide a detailed overview in light of all these factors.

[Epidemiological and clinical profile of age-related macular degeneration in Cameroon]

PURPOSE

To determine the epidemiological and clinical characteristics of age-related macular degeneration in patients in Yaoundé.

METHODOLOGY

A multicenter, analytical and cross-sectional study was carried out from March 2017 to June 2018 in four hospitals in the city of Yaoundé. Included were all consenting patients aged at least 40 years with an established diagnosis of AMD both clinically and by imaging. The data were analyzed with CSPro software version 7.0. Chi² and Student's "t" tests in univariate mode and logistic regression in multivariate mode were used with a significance of P≤5%.

RESULTS

Of the 9,989 patients who were seen during the 16-month study period, 38 met our inclusion criteria - a frequency of 0.4%. The sex ratio was 0.3, and the mean age was 68±11 years. As a function of geographic origin, AMD is more common in patients from the forest and mountain areas. The systemic comorbidities associated recorded were hypertension (47.4%) and diabetes (21.1%). After optical correction, 60 of 76 eyes (78.9%) had useful visual acuity according to WHO criteria, and the rate of blindness was 9.2%. Fundus examination revealed fewer lesions than optical coherence tomography, which demonstrated miliary drusen in 57 (75%) eyes, serous drusen in 27 (35.5%), retinal atrophy in 19 (25%) and neovascularization in 3 (3.9%). The clinical forms were dominated by age-related maculopathy, found in 45 eyes (69.2%), followed by atrophic AMD in 17 (26.2%) and finally by exudative AMD in 3 (4.6%), for a total of 65 out of 76 eyes. Age was related to the risk of MLA and atrophic AMD (P≤0.05).

CONCLUSION

AMD is an uncommon pathology in our setting, predominant in women over the age of 60 years.

Cost-Effectiveness of Conbercept vs. Ranibizumab for Age-Related Macular Degeneration, Diabetic Macular Edema, and Pathological Myopia: Population-Based Cohort Study and Markov Model

Background: With the advent of aging society of China, fundus diseases related to pathological neovascularization, including age-related macular degeneration (AMD), diabetic macular edema (DME), and pathological myopia (PM), have become an increasingly serious medical and health problems. As effective drugs of the treatment, conbercept and ranibizumab have been commonly used and covered by the national basic medical insurance in China. However, the pharmacoeconomic evaluation of conbercept vs. ranibizumab for DME and PM remains lacking. This study would assess the cost-effectiveness of conbercept and ranibizumab for the treatment of AMD, DME, and PM from the perspective of Chinese payers.

Methods: A Markov chain model was constructed based on the visual conditions of the patient indicated by the number of letters in best corrected visual acuity (BCVA). We conducted models based on real-world scenario to calculate the cost per the quality-adjusted life-year (QALY) gained. A 1-year cycle length and a 10-year simulation treatment were applied and the number of injections of conbercept and ranibizumab was assumed to the average number within 10 years. Transition probabilities, costs, utility data, and other parameters were obtained from literature searches. A 3.5% discounting rate was applied for both the costs and utilities.

Results: The incremental cost-effectiveness ratios (ICERs) were more favorable for conbercept than ranibizumab in treatment of AMD, DME, and PM, with associated ICER of 66,669 renminbi (RMB), −258,813 RMB, and −373,185 RMB per QALY gained. Compared with ranibizumab, the incremental effectiveness of conbercept in treatment of AMD, DME, and PM was −0.665 QALYs, 0.215 QALYs, and 0.029 QALYs, respectively. The sensitivity analysis showed the same findings, although the ICER is sensitive to the costs of this program.

Conclusion: Under the current Chinese healthcare setting, conbercept is suitable and cost-effective in treatment of AMD, DME, and PM compared with ranibizumab.

Age-Related Macular Degeneration

A 78-year-old woman presents with vision changes in the right eye for one week. Specifically, she describes central blurring in her vision and bending or waviness in straight lines. She also reports increasing difficulty reading print and often feels that there are blind spots in her vision. How would you diagnose and treat this patient?

The effects of eight serum lipid biomarkers on age-related macular degeneration risk: a Mendelian randomization study

BACKGROUND

Age-related macular degeneration (AMD) is a leading cause of vision loss. Whereas lipids have been studied extensively to understand their effects on cardiovascular diseases, their relationship with AMD remains unclear.

METHODS

Two-sample Mendelian randomization (MR) analyses were performed to systematically evaluate the causal relationships between eight serum lipid biomarkers, consisting of apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), direct low-density lipoprotein cholesterol (LDL-C), lipoprotein A [Lp(a)], triglycerides (TG) and non-HDL cholesterol (non-HDL-C), and the risk of different AMD stages and subtypes. We derived 64-407 genetic instruments for eight serum lipid biomarkers in 419 649 participants of European descent from the UK Biobank cohort. We conducted genome-wide association studies (GWAS) for 12 711 advanced AMD cases [8544 choroidal neovascularization (CNV) and 2656 geographic atrophy (GA) specific AMD subtypes] and 5336 intermediate AMD cases with 14 590 controls of European descent from the International AMD Genomics Consortium.

RESULTS

Higher genetically predicted HDL-C and ApoA1 levels increased the risk of all AMD subtypes. LDL-C, ApoB, CHOL and non-HDL-C levels were associated with decreased risk of intermediate and GA AMD but not with CNV. Genetically predicted TG levels were associated with decreased risk of different AMD subtypes. Sensitivity analyses revealed no evidence for directional pleiotropy effects. In our multivariable MR analyses, adjusting for the effects of correlated lipid biomarkers yielded similar results.

CONCLUSION

These results suggest the role of lipid metabolism in drusen formation and particularly in AMD development at the early and intermediate stages. Mechanistic studies are warranted to investigate the utility of lipid pathways for therapeutic treatment in preventing AMD.

Comparing Fluorescence Lifetime Imaging Ophthalmoscopy in Atrophic Areas of Retinal Diseases

Purpose

Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a non-invasive imaging modality to investigate the human retina. This study compares FLIO lifetimes in different degenerative retinal diseases.

Methods

Included were eyes with retinal pigment epithelium (RPE) and/or photoreceptor atrophy due to Stargardt disease (n = 66), pattern dystrophy (n = 18), macular telangiectasia type 2 (n = 49), retinitis pigmentosa (n = 28), choroideremia (n = 26), and geographic atrophy (n = 32) in age-related macular degeneration, as well as 37 eyes of 37 age-matched healthy controls. Subjects received Heidelberg Engineering FLIO, autofluorescence intensity, and optical coherence tomography imaging. Amplitude-weighted mean FLIO lifetimes (τ_m) were calculated and analyzed.

Results

Retinal FLIO lifetimes show significant differences depending on the disease. Atrophic areas in geographic atrophy and choroideremia showed longest mean FLIO lifetimes. τ_m values within areas of RPE and outer nuclear layer atrophy were significantly longer than within areas with preserved outer nuclear layer (P < 0.001) or non-atrophic areas (P < 0.001).

Conclusions

FLIO is able to contribute additional information regarding differences in chronic degenerative retinal diseases. Although it cannot replace conventional autofluorescence imaging, FLIO adds to the knowledge in these diseases and may help with the correct differentiation between them. This may lead to a more in-depth understanding of the pathomechanisms related to atrophy and types of progression.

Translational Relevance

Differences between atrophic retinal diseases highlighted by FLIO may indicate separate pathomechanisms leading to atrophy and disease progression.

The retinal pigment epithelium: Development, injury responses, and regenerative potential in mammalian and non-mammalian systems

Diseases that result in retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration (AMD), are among the leading causes of blindness worldwide. Atrophic (dry) AMD is the most prevalent form of AMD and there are currently no effective therapies to prevent RPE cell death or restore RPE cells lost from AMD. An intriguing approach to treat AMD and other RPE degenerative diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to become feasible, a deeper understanding of the mechanisms underlying RPE development, injury responses and regenerative potential is needed. In mammals, RPE regeneration is extremely limited; small lesions can be repaired by the expansion of adjacent RPE cells, but large lesions cannot be repaired as remaining RPE cells are unable to functionally replace lost RPE tissue. In some injury paradigms, RPE cells proliferate but do not regenerate a morphologically normal monolayer, while in others, proliferation is pathogenic and results in further disruption to the retina. This is in contrast to non-mammalian vertebrates, which possess tremendous RPE regenerative potential. Here, we discuss what is known about RPE formation during development in mammalian and non-mammalian vertebrates, we detail the processes by which RPE cells respond to injury, and we describe examples of RPE-to-retina and RPE-to-RPE regeneration in non-mammalian vertebrates. Finally, we outline barriers to RPE-dependent regeneration in mammals that could potentially be overcome to stimulate a regenerative response from the RPE.

Design and Characterization of Biomimetic Kerateine Aerogel-Electrospun Polycaprolactone Scaffolds for Retinal Cell Culture

Age-related macular degeneration (AMD) is a retinal disease that affects 196 million people and causes nearly 9% of blindness worldwide. While several pharmacological approaches slow the effects of AMD, in our opinion, cell-based strategies offer the most likely path to a cure. We describe the design and initial characterization of a kerateine (obtained by reductive extraction from keratin proteins) aerogel-electrospun polycaprolactone fiber scaffold system. The scaffolds mimic key features of the choroid and the Bruch's membrane, which is the basement membrane to which the cells of the retinal pigment epithelium (RPE) attach. The scaffolds had elastic moduli of 2-7.2 MPa, a similar range as native choroid and Bruch's membrane. ARPE-19 cells attached to the polycaprolactone fibers, remained viable for one week, and proliferated to form a monolayer reminiscent of that needed for retinal repair. These constructs could serve as a model system for testing cell and/or drug treatment strategies or directing ex vivo retinal tissue formation in the treatment of AMD.

Macular Thickness in Intermediate Age-Related Macular Degeneration Is Influenced by Disease Severity and Subretinal Drusenoid Deposit Presence

Purpose

To investigate how macular thickness varies with intermediate age-related macular degeneration (iAMD) severity and the presence of subretinal drusenoid deposits (SDDs).

Methods

A longitudinal prospective study of 143 participants >50 years of age with no to intermediate AMD who were followed with multimodal imaging and functional testing. Participants were stratified by iAMD severity according to imaging features. Macular thicknesses measurements over the central circles with 1-mm, 3-mm, and 6-mm diameters obtained from ocular coherence tomography imaging were compared across severity categories using cross-sectional (143 eyes) and longitudinal (subset of 77 eyes followed for 4 years) multivariate analyses.

Results

Compared with control eyes without large drusen or SDDs (Group 0), central maculas of lower risk eyes with unilateral large drusen (Group 1) were thicker (P = 0.014), whereas higher risk eyes with SDDs (Group SDD) were thinner (P = 0.02) in cross-sectional multivariate analyses. In longitudinal analyses, maculas with SDDs thinned more rapidly over 4 years relative to control eyes (P = 0.0058), which did not show significant thinning. More rapid central macular thinning was associated with worse baseline best-corrected visual acuity (BCVA) (P = 0.016) and more rapid BCVA decline (P = 0.0059).

Conclusions

Macular thickness in iAMD varies with disease severity, showing small increases in eyes with large drusen and decreases in eyes with SDDs. Active processes possibly related to neuroinflammation and neurodegeneration may be contributory. Longitudinal central macular thickness evaluation is an accessible outcome measure relevant to functional measures and is potentially useful for iAMD interventional studies.

Age-Related Macular Degeneration: Epidemiology and Clinical Aspects

Age-related macular degeneration (AMD) is a degenerative disease of the human retina affecting individuals over the age of 55 years. This heterogeneous condition arises from a complex interplay between age, genetics, and environmental factors including smoking and diet. It is the leading cause of blindness in industrialized countries. Worldwide, the number of people with AMD is predicted to increase from 196 million in 2020 to 288 million by 2040. By this time, Asia is predicted to have the largest number of people with the disease. Distinct patterns of AMD prevalence and phenotype are seen between geographical areas that are not explained fully by disparities in population structures. AMD is classified into early, intermediate, and late stages. The early and intermediate stages, when visual symptoms are typically absent or mild, are characterized by macular deposits (drusen) and pigmentary abnormalities. Through risk prediction calculators, grading these features helps predict the risk of progression to late AMD. Late AMD is divided into neovascular and atrophic forms, though these can coexist. The defining lesions are macular neovascularization and geographic atrophy, respectively. At this stage, visual symptoms are often severe and irreversible, and can comprise profoundly decreased central vision in both eyes. For these reasons, the condition has major implications for individuals and society, as affected individuals may experience substantially decreased quality of life and independence. Recent advances in retinal imaging have led to the recognition of an expanded set of AMD phenotypes, including reticular pseudodrusen, nonexudative macular neovascularization, and subtypes of atrophy. These developments may lead to refinements in current classification systems.

Neovascular Age-Related Macular Degeneration: Therapeutic Management and New-Upcoming Approaches

Age-related macular degeneration (AMD) constitutes a prevalent, chronic, and progressive retinal degenerative disease of the macula that affects elderly people and cause central vision impairment. Despite therapeutic advances in the management of neovascular AMD, none of the currently used treatments cures the disease or reverses its course. Medical treatment of neovascular AMD experienced a significant advance due to the introduction of vascular endothelial growth factor inhibitors (anti-VEGF), which dramatically changed the prognosis of the disease. However, although anti-VEGF therapy has become the standard treatment for neovascular AMD, many patients do not respond adequately to this therapy or experience a slow loss of efficacy of anti-VEGF agents after repeated administration. Additionally, current treatment with intravitreal anti-VEGF agents is associated with a significant treatment burden for patients, caregivers, and physicians. New approaches have been proposed for treating neovascular AMD. Among them, designed ankyrin repeat proteins (DARPins) seem to be as effective as monthly ranibizumab, but with greater durability, which may enhance patient compliance with needed injections.

Choroidal vascularity index determined by binarization of enhanced depth imaging optical coherence tomography images in eyes with intermediate age-related macular degeneration

Purpose

To evaluate choroidal structural changes in patients with intermediate age-related macular degeneration using choroidal vascularity index.

Methods

The eyes of patients with intermediate age-related macular degeneration and controls were evaluated with enhanced depth imaging optical coherence tomography images. Subfoveal choroidal area was segmented into luminal area and stromal area by the binarization technique on enhanced depth imaging optical coherence tomography images using ImageJ software. Choroidal vascularity index was defined as the ratio of luminal area to total circumscribed subfoveal choroidal area.

Results

Fifty-seven eyes with intermediate age-related macular degeneration and 60 healthy control eyes were included in the study. The choroidal vascularity index was computed as 59.53% ± 4.9% in the intermediate age-related macular degeneration group and as 62.7% ± 4.3% in the control group ( p = 0.002). Patients with age-related macular degeneration showed significantly lower values of stromal area and higher values of luminal area compared to control subjects (0.51 ± 0.22 vs 0.87 ± 0.21, p < 0.001 and 0.74 ± 0.22 vs 0.52 ± 0.18, p < 0.001, respectively).

Conclusion

Eyes with intermediate age-related macular degeneration demonstrated reduced choroidal vascularity index compared to healthy eyes. Choroidal vascularity index seems to be a potential non-invasive quantitative method for studying structural changes of the choroid in patients with intermediate age-related macular degeneration.

Genome-wide meta-analysis identifies novel loci associated with age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly population. To accelerate the understanding of the genetics of AMD, we conducted a meta-analysis of genome-wide association studies (GWAS) combining data from the International AMD Genomics Consortium AMD-2016 GWAS (16,144 advanced AMD cases and 17,832 controls), AMD-2013 GWAS (17,181 cases and 60,074 controls), and new data on 4017 AMD cases and 14,984 controls from Genetic Epidemiology Research on Aging study. We identified 12 novel AMD loci near or within C4BPA-CD55, ZNF385B, ZBTB38, NFKB1, LINC00461, ADAM19, CPN1, ACSL5, CSK, RLBP1, CLUL1, and LBP. We then replicated the associations of the novel loci in independent cohorts, UK Biobank (5860 cases and 126,726 controls) and FinnGen (1266 cases and 47,560 control). In general, the concordance in effect sizes was very high (correlation in effect size estimates 0.89), 11 of 12 novel loci were in the expected direction, 5 were associated with AMD at a nominal significance level, and rs3825991 (near gene RLBP1) after Bonferroni correction. We identified an additional 21 novel genes using a gene-based test. Most of the novel genes are expressed in retinal tissue and could be involved in the pathogenesis of AMD (i.e., complement, inflammation, and lipid pathways). These findings enhance our understanding of the genetic architecture of AMD and shed light on the biological process underlying AMD pathogenesis.

A Population-based Study on the Prevalence and Associated Factors of Age-related Macular Degeneration in Northern Iran the Gilan Eye Study

Purpose: To estimate the prevalence and associated factors of AMD in an Iranian population in 2014.Methods: In this population-based cross-sectional study, a total of 2975 Iranian residents (age: ≥50 years) from the urban and rural areas of Gilan province were included. The prevalence of different grades of AMD was determined using the International Age-Related Maculopathy Epidemiological Study Group grading system.Results: Of 2975 eligible individuals, 2587 (87.0%) subjects participated and 2275 (76.5%) subjects (62.6 ± 8.8 years old) had gradable fundus photographs. Age- and sex-standardized prevalence of early and late AMD based on the 2016 Iran census were 13.2% (95% confidence interval [CI], 10.6-16.2) and 0.7% (95% CI, 0.4-1.3), respectively. In multivariate analysis, each decade increase in age was associated with the adjusted odds of any (adjusted odds ratio [AOR] = 1.31, 95% CI, 1.09-1.56; P = .0031), early (AOR = 1.27, 95% CI, 1.06-1.53; P = .012) and late AMD (AOR = 2.39, 95% CI, 1.08-5.28; P = .031). Hyperopia was identified to be less frequent in late AMD (AOR = 0.20, 95% CI, 0.04-0.80; P = .024). No significant association was found between AMD and sex, smoking, outdoor working, diabetes, hypertension, pseudophakia, hyperlipidemia and myopia.Conclusion: Gilan Eye Study demonstrated the first estimate of age-specific AMD prevalence in Iran being compatible with other WHO regions. With the expected increase in the life expectancy and aging of Iranians, the number of people affected by AMD will be increasing in future. Healthcare policy makers should be advised to provide more efficient eye care services and preventive strategies in this regard.

The Expression of Decidual Protein Induced by Progesterone (DEPP) is Controlled by Three Distal Consensus Hypoxia Responsive Element (HRE) in Hypoxic Retinal Epithelial Cells

Hypoxia affects the development and/or progression of several retinopathies. Decidual protein induced by progesterone (DEPP) has been identified as a hypoxia-responsive gene that may be part of cellular pathways such as autophagy and connected to retinal diseases. To increase our understanding of DEPP regulation in the eye, we defined its expression pattern in mouse and human retina and retinal pigment epithelium (RPE). Interestingly, DEPP expression was increased in an age-dependent way in the central human RPE. We showed that DEPP was regulated by hypoxia in the mouse retina and eyecup and that this regulation was controlled by hypoxia-inducible transcription factors 1 and 2 (HIF1 and HIF2). Furthermore, we identified three hypoxia response elements (HREs) about 3.5 kb proximal to the transcriptional start site that were responsible for hypoxic induction of DEPP in a human RPE cell line. Comparative genomics analysis suggested that one of the three HREs resides in a highly conserved genomic region. Collectively, we defined the molecular elements controlling hypoxic induction of DEPP in an RPE cell line, and provided evidence for an enrichment of DEPP in the aged RPE of human donors. This makes DEPP an interesting gene to study with respect to aging and age-related retinal pathologies.

Using Mendelian randomization to evaluate the causal relationship between serum C-reactive protein levels and age-related macular degeneration

Serum C-reactive protein (CRP), an important inflammatory marker, has been associated with age-related macular degeneration (AMD) in observational studies; however, the findings are inconsistent. It remains unclear whether the association between circulating CRP levels and AMD is causal. We used two-sample Mendelian randomization (MR) to evaluate the potential causal relationship between serum CRP levels and AMD risk. We derived genetic instruments for serum CRP levels in 418,642 participants of European ancestry from UK Biobank, and then conducted a genome-wide association study for 12,711 advanced AMD cases and 14,590 controls of European descent from the International AMD Genomics Consortium. Genetic variants which predicted elevated serum CRP levels were associated with advanced AMD (odds ratio [OR] for per standard deviation increase in serum CRP levels: 1.31, 95% confidence interval [CI]: 1.19-1.44, P = 5.2 × 10^-8). The OR for the increase in advanced AMD risk when moving from low (< 3 mg/L) to high (> 3 mg/L) CRP levels is 1.29 (95% CI: 1.17-1.41). Our results were unchanged in sensitivity analyses using MR models which make different modelling assumptions. Our findings were broadly similar across the different forms of AMD (intermediate AMD, choroidal neovascularization, and geographic atrophy). We used multivariable MR to adjust for the effects of other potential AMD risk factors including smoking, body mass index, blood pressure and cholesterol; this did not alter our findings. Our study provides strong genetic evidence that higher circulating CRP levels lead to increases in risk for all forms of AMD. These findings highlight the potential utility for using circulating CRP as a biomarker in future trials aimed at modulating AMD risk via systemic therapies.

The Experience of Age-related Macular Degeneration

This qualitative article describes the impact of age-related macular degeneration (ARMD) among 15 participants: how a person makes sense of ARMD, the effect of ARMD on the person's quality of life, the psychological disturbances associated with the limitations of ARMD, and the influence of ARMD on social interactions. Such in-depth appreciation of the impact of ARMD will assist in the design of specific and appropriate rehabilitation programs to minimize limitations and enhance participation in people with ARMD.

Safety and tolerability of ranibizumab in uni/bilateral neovascular age-related macular degeneration: 12-month TWEYEs study

Background

To evaluate the safety and tolerability of ranibizumab 0.5 mg in patients with uni/bilateral neovascular age-related macular degeneration (nAMD) and best-corrected visual acuity (BCVA)<2/10 and/or second eye affected, regardless of BCVA.

Methods

In this 12-month, prospective, multicentre, open-label, single arm, pragmatic interventional study, patients (N=941) aged ≥ 50 years were to receive ranibizumab as per approved label, monthly until maximum stable visual acuity (VA) was achieved (initially, three or more injections may be required). Thereafter, patients were to be monitored monthly for VA and treatment was to be resumed if VA was reduced due to disease activity.

Results

Of the 936 patients treated with ranibizumab at least once during the study, 823/113 were unilaterally/bilaterally (not simultaneously) treated. The mean (SD) number of ranibizumab injections during the study was 5.4 (2.9)/10.6 (5.0) injections in uni/bilaterally treated patients. Three systemic drug-related adverse events (AEs) (all serious, all in unilaterally treated patients) and 18 systemic AE of special interest (AESIs) (11 serious, 16/2 in unilaterally/bilaterally treated patients) occurred during the study. The annual incidence rate (AIR) (events/1000 person-years) for systemic drug-related AEs, considering a 15-day/30-day risk period, 11.0/8.5 for unilaterally treated patients. Considering the same risk period, the AIR (events/1000 person-years) for systemic AESIs for unilaterally treated patients was 22.1/19.9. Considering a 30-day risk period, the AIR (events/1000 treated eye-years) of ocular drug-related AEs was 23 and AESIs was 11.5.

Conclusions

The low incidence of AEs and AESIs demonstrated the good safety and tolerability of ranibizumab in unilaterally/bilaterally treated patients with nAMD in this real-world setting.

The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health

This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.

The influence of word frequency on word reading speed when individuals with macular diseases read text

People with central field loss (CFL) use peripheral vision to identify words. Eccentric vision provides ambiguous visual inputs to the processes leading to lexical access. Our purpose was to explore the hypothesis that this ambiguity leads to strong influences of inferential processes, our prediction being that increasing word frequency would decrease word reading time. Individuals with bilateral CFL induced by macular diseases read French sentences displayed with a self-paced reading method. Reading time of the last word of each sentence (target word) was recorded. Each target word (in sentence n) was matched with a synonym word (in sentence n+1) of the same length. When using absolute frequency value (Analysis 1), we found that reading time of target words decreased when word frequency increases, even when controlling for word length. The amplitude of this effect is larger than reported in previous investigations of reading with normal subjects. When comparing the effect of relative frequency (low vs. high) within each pair of synonyms (Analysis 2), results show the same pattern as the one observed in Analysis 1. Our results demonstrate clear-cut frequency effects on word reading time and suggest that inferential processes are stronger in CFL readers than in normally sighted observers. These results might also help design text simplification tools tailored for low-vision patients.

Protective effect of RIPK1-inhibitory compound in in vivo models for retinal degenerative disease

Receptor interacting protein kinase 1 (RIPK1) plays a key role in necroptosis, which is a type of programmed necrosis that is involved in ocular diseases, including glaucoma and dry age-related macular degeneration (AMD). We previously introduced RIPK1-inhibitory compound (RIC), which has biochemical characteristics and a mode of action that are distinct from those of the prototype RIPK1 inhibitor necrostatin-1. The intraperitoneal administration of RIC exerts a protective effect on retinal ganglion cells against a glaucomatous insult. In this study, we examined the protective effect of RIC on retinal pigment epithelium (RPE) against sodium iodate (SI) insult, which is associated with dry AMD pathogenesis. The eye drop administration of RIC that reached on the retina prevented RPE loss in SI-induced retinal degeneration. RIC consistently demonstrated retinal protection in the funduscopy and electroretinogram analyses in SI-injected rabbits and iodoacetic acid-treated mini-pigs. Moreover, the in vivo protective effects of RIC were superior to those of ACU-4429 and doxycycline, which are other medications investigated in clinical trials for the treatment of dry AMD, and RIC did not induce retinal toxicity following topical administration in rats. Collectively, RIC displayed excellent retinal penetration and prevented retinal degeneration in the pathogenesis of dry AMD with a high in vivo efficacy.

Two-year outcome of treat-and-extend aflibercept after ranibizumab in age-related macular degeneration and polypoidal choroidal vasculopathy patients

Background

The purpose of the study was to evaluate the 2-year outcome and predictive factors of treat-and-extend aflibercept in patients with eyes affected by typical neovascular age-related macula degenelation (t-AMD) or polypoidal choroidal vasculopathy (PCV), who were switched from ranibizumab.

Patients and methods

The patients underwent three monthly aflibercept injections and subsequent administration following the treat-and-extend protocol. Sixty-two eyes of 62 patients were reviewed retrospectively. R statistical software was used for statistical analysis.

Results

Twenty-two eyes were t-AMD and the remaining 40 eyes were PCV. There was no significant difference in the logarithm of the minimal angle of resolution visual acuity (VA) between baseline and 2 years after switching to aflibercept (0.40 vs 0.40; P=0.99). Multivariate analyses suggested that the following factors were significantly correlated with better VA at 2 years after switching to aflibercept: patients with PCV, the absence of intraretinal fluid at baseline, and better VA at baseline.

Conclusion

In conclusion, VA was maintained and there was an anatomical improvement at 2 years in patients with t-AMD and PCV who were switched from ranibizumab to treat-and-extend aflibercept. PCV patients showed more favorable visual outcomes and less injections at 2 years compared to t-AMD patients. Intraretinal fluid and VA at baseline were predictors of VA at 2 years.

Correlation of Color Fundus Photograph Grading with Risks of Early Age-related Macular Degeneration by using Automated OCT-derived Drusen Measurements

We evaluated automated OCT-derived drusen volume measures in a population-based study (n = 4,512) aged ≥40 years, and its correlation with conventional color fundus photographs (CFP)-derived early AMD features. Participants had protocol-based assessment to capture medical and ocular history, genotyping for SNPs in CFH, ARMS2, and CETP, CFP-based AMD grading and automated drusen volume based on SD-OCT using built-in software (Cirrus OCT advanced RPE analysis software). Significantly fewer eyes with early AMD features (drusen, hyperpigmentation, soft or reticular drusen) had drusen volume = 0 mm³ (p < 0.001). In eyes with drusen volume > 0 mm³, increasing AMD severity was associated with increase in drusen volume (correlation coefficient 0.17, p < 0.001). However 220 (59.14%) of 372 participants with AMD based on CFP grading had drusen volume = 0 mm³. Factors associated with drusen volume included age (OR 1.42 per 5 years, 95% confidence interval [CI] 2.76, 4.48), systolic blood pressure (OR1.00, 95% CI 1.00, 1.01), ethnic Malay (OR 1.54, 95% CI 1.29, 1.83) and Chinese (OR 1.66, 95% CI 1.37, 2.01) compared to Indian. The ARMS2 rs10490924 T allele was associated with increased drusen volume in subjects with AMD (multivariable adjusted OR1.54, 95% CI 1.08, 2.19). Automated OCT-derived drusen volume is correlated with CFP-based AMD grading in many, but not all subjects. However the agreement is not good. These two modalities provide complementary information and should be incorporated into future studies.

HDL-cholesterol levels and risk of age-related macular degeneration: a multiethnic genetic study using Mendelian randomization

Background

Dyslipidemia, particularly high-density lipoprotein cholesterol (HDL-C), has recently been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss. However, epidemiological studies have yielded conflicting results.

Methods

We investigated the causal role of plasma lipid levels in AMD in multiethnic populations comprising 16 144 advanced AMD cases and 17 832 controls of European descent, together with 2219 cases and 5275 controls of Asian descent, using Mendelian randomization in three models. Model 1 is a conventional meta-analysis which does not account for pleiotropy of instrumental variable (IV) effects. Model 2 is a univariate, inverse variance weighted regression analysis that accounts for potential unbalanced pleiotropy using MR-Egger method. Finally, Model 3 is a multivariate regression analysis that addresses pleiotropy by MR-Egger method and by adjusting for effects on other lipid traits.

Results

A 1 standard deviation (SD) higher HDL-cholesterol level was associated with an odds ratio (OR) for AMD of 1.17 (95% confidence interval: 1.07–1.29) in Europeans (P = 6.88 × 10^–4) and of 1.58 (1.24–2.00) in Asians (P = 2.92 × 10^–4) in Model 3. The corresponding OR estimates were 1.30 (1.09–1.55) in Europeans (P = 3.18 × 10^–3) and 1.42 (1.11—1.80) in Asians (P = 4.42 × 10^–3) in Model 1, and 1.21 (1.11–1.31) in Europeans (P = 3.12 × 10^–5) and 1.51 (1.20–1.91) in Asians (P = 7.61 × 10^–4) in Model 2. Conversely, neither LDL-C (Europeans: OR = 0.96, P = 0.272; Asians: OR = 1.02, P = 0.874; Model 3) nor triglyceride levels (Europeans: OR = 0.91, P = 0.102; Asians: OR = 1.06, P = 0.613) were associated with AMD. We also assessed the association between lipid levels and polypoidal choroidal vasculopathy (PCV) in Asians, a subtype of AMD, and found a similar trend for association of PCV with HDL-C levels.

Conclusions

Our study shows that high levels of plasma HDL-C are causally associated with an increased risk for advanced AMD in European and Asian populations, implying that strategies reducing HDL-C levels may be useful to prevent and treat AMD.

Extended HLA-G haplotypes in patients with age-related macular degeneration

The study aims to determine if genetic polymorphisms in the human leukocyte antigen (HLA)-G gene are associated with age-related macular degeneration (AMD). HLA-G is important for immunological tolerance, and it is also known to have angiogenic effects. Polymorphisms in the 5'-upstream regulatory region (URR) and 3'-untranslated region (UTR) of HLA-G have been associated with a number of diseases, especially with respect to a 14 bp insertion/deletion (ins/del) polymorphism in the 3'UTR. Full gene sequencing was performed on a cohort of 146 AMD patients and 63 healthy controls aged 60 years or older and HLA-G haplotypes were determined. Analyses were performed on a publicly available gene expression dataset from the NCBI GEO database (accession number GSE29801) from which expression data for HLA-G, -C and -A were extracted. Analysis of the GEO dataset showed that both HLA-G and -C was expressed in the back of the eye and that expression was upregulated in the macular area of AMD. No differences were observed between patients and controls when analysing the distribution of haplotypes in the HLA-G promoter, coding region, 3'UTR or the 14 bp ins/del polymorphism of the 3'UTR. The increased expression of HLA-G in the macula of AMD patients indicates a role of HLA-G in the micro environment as part of the AMD pathogenesis. This is supported by the expression of HLA-C, which has previously been shown to play a role in AMD. The HLA-G haplotype distribution did not display any differences between AMD patients and controls. This article is protected by copyright. All rights reserved.

Six-Year Incidence and Risk Factors of Age-Related Macular Degeneration in Singaporean Indians: The Singapore Indian Eye Study

We aimed to determine the 6-year incidence and risk factors of age-related macular degeneration (AMD) in first and second generations of Singaporean Indians. Baseline examination was conducted in 2007-9 and 6-year propsective follow-up examination of this Indian population in 2013-5. All participants underwent interviews with questionnaires and comprehensive medical and eye examinations. Incidence was age-standardized to Singaporean 2010 census. Risk factors associated with AMD incidence were assessed and compared between first and second generations of immigrants. Among 2200 persons who participated in the follow-up examination (75.5% response rate), gradable fundus photographs were available in 2105. The 6-year age-standardized incidences of early and late AMD were 5.26% and 0.51% respectively. Incident early AMD was associated with cardiovascular disease history (HR 1.59, 95% CI 1.04-2.45), underweight body mass index (BMI) (HR 3.12, 95% CI 1.37-7.14) (BMI of <18.5 vs 18.51-25 kg/m2), heavy alcohol drinking (HR 3.14 95% CI 1.25-7.89) and ARMS2 rs3750847 homozygous genetic loci carrier (HR 2.52, 95% CI 1.59-3.99). We found a relatively low incidence of early AMD in this Singaporean Indian population compared to Caucasian populations. Both first and second-generation Indian immigrants have similar incidence and risk factor patterns for early AMD.