Prevalence of age‐related macular degeneration in Chinese populations worldwide: A systematic review and meta‐analysis

Relationship between CCL2 gene 2518A/G (rs1024611) polymorphism and age-related macular degeneration susceptibility: meta-analysis and trial sequential analysis

PURPOSE

This study aimed to investigate the association between the CC-cytokine ligand-2 (CCL2) 2518A/G (rs1024611) single nucleotide polymorphism (SNP) and susceptibility to age-related macular degeneration (AMD).

METHODS

PubMed, Embase, Web of Science, and other databases were searched for articles published before August 24, 2023. After searching, data extraction, and quality assessment, meta-analysis and trial sequential analysis were conducted using RevMan 5.4, Stata 17.0, and TSA 0.9.5.10 Beta software. Combined OR, P values, and 95% confidence intervals (CIs) were calculated. Sensitivity analysis, subgroup analysis and publication bias assessment were also performed.

RESULTS

Six articles, comprising 1186 cases and 1124 controls, were included. No significant statistical difference was found in six main outcomes. However, due to observed heterogeneity and high sensitivity, subgroup analysis was performed, revealing statistically significant differences across different regions. No significant publication bias was observed. Trial sequential analysis suggested the need for additional follow-up case-control studies to further validate the findings.

CONCLUSION

The CCL2 gene 2518A/G (rs1024611) polymorphism is associated with AMD susceptibility. Among Caucasian populations in West Asia and Europe, the G allele is protective against AMD, whereas in East and South Asia, it poses a risk factor.

Melanin-Like Nanomedicine Functions as a Novel RPE Ferroptosis Inhibitor to Ameliorate Retinal Degeneration and Visual Impairment in Dry Age-Related Macular Degeneration

Ferrous ion accumulation and lethal oxidative stress mediate irreversible retinal pigment epithelial (RPE) cell ferroptosis and subsequent photoreceptor degeneration, a potential key pathogenic factor in the onset of dry age-related macular degeneration (dAMD), causing irreversible vision loss in the global elderly population. However, currently, no effective interventional treatment strategy exists in clinical practice. Herein, lesion site-targeted melanin-like nanoparticles, named ConA-MelNPs, are designed as a novel ferroptosis inhibitor for retinal degenerative diseases. ConA-MelNPs possessed chelating iron ion characteristics, alleviating severe mitochondrial damage caused by oxidative stress and protecting RPE cells from ferroptosis induced by sodium iodate (NaIO3). In a preclinical dAMD mouse model, a single intravitreal injection of ConA-MelNPs yielded significant responses in electroretinograms and visually-driven optomotor responses in visually impaired mice, resisting the challenge posed by secondary NaIO3-induced injuries, with the long-term sustainability of its therapeutic effect. Mechanistically, ConA-MelNPs achieve a therapeutic effect by interrupting the detrimental cascade involving "RPE cell ferroptosis, lethal oxidative stress, and microglial proinflammatory activation," affording the restoration of retinal homeostasis. The synthesized ConA-MelNPs demonstrated good biosafety, with no detected ophthalmic or systemic side effects. Collectively, ConA-MelNPs are proposed as a promising therapeutic option for atrophic retinal diseases such as dAMD.

Proteotranscriptomic analyses reveal distinct interferon-beta signaling pathways and therapeutic targets in choroidal neovascularization

Aim

To investigate the molecular mechanism underlying the onset of choroidal neovascularization (CNV).

Methods

Integrated transcriptomic and proteomic analyses of retinas in mice with laser-induced CNV were performed using RNA sequencing and tandem mass tag. In addition, the laser-treated mice received systemic interferon-β (IFN-β) therapy. Measurements of CNV lesions were acquired by the confocal analysis of stained choroidal flat mounts. The proportions of T helper 17 (Th17) cells were determined by flow cytometric analysis.

Results

A total of differentially expressed 186 genes (120 up-regulated and 66 down-regulated) and 104 proteins (73 up-regulated and 31 down-regulated) were identified. The gene ontology and KEGG pathway analyses indicated that CNV was mainly associated with immune and inflammatory responses, such as cellular response to IFN-β and Th17 cell differentiation. Moreover, the key nodes of the protein-protein interaction network mainly involved up-regulated proteins, including alpha A crystallin and fibroblast growth factor 2, and were verified by Western blotting. To confirm the changes in gene expression, real-time quantitative PCR was performed. Furthermore, levels of IFN-β in both the retina and plasma, as measured by enzyme-linked immunosorbent assay (ELISA), were significantly lower in the CNV group than in the control group. IFN-β treatment significantly reduced CNV lesion size and promoted the proliferation of Th17 cells in laser-treated mice.

Conclusions

This study demonstrates that the occurrence of CNV might be associated with the dysfunction of immune and inflammatory processes and that IFN-β could serve as a potential therapeutic target.

Effects of visual span on Chinese reading performance in normal peripheral vision

The current study examined the relationships among temporal processing speed, spatial visual span and Chinese character reading speed in normal central and peripheral vision. Maximum reading speed (MRS) and critical print size (CPS) of 26 native Chinese readers (13 young and 13 older adults) were determined at three visual field locations: central vision, 10° left and 10° below fixation using a rapid serial visual presentation (RSVP) task. Temporal processing speed was measured using trigrams of randomly selected Chinese characters presented at a range of exposure durations, while spatial visual span was measured using trigrams presented at different spatial positions. It was found that shorter temporal processing speed and larger spatial visual span were associated with faster MRS at the central and inferior visual field locations, but not at the left of fixation location. As expected, reading and visual span metrics were better in central vision compared to both peripheral locations. In addition, reading, temporal processing, and spatial visual span metrics were better in the young than older subjects (except for similar temporal processing speed at two peripheral locations). The results for central and inferior presentation locations support the hypothesis that temporal processing speed and spatial visual span were associated with Chinese character reading speed. Surprisingly, no correlation was observed for the 10° left of the fixation location, suggesting that the factors affecting reading speed might differ for inferior and lateral peripheral viewing locations.

Exploring challenges to nutrition intervention adherence using COM-B model among patients with wet age-related macular degeneration: a qualitative study

OBJECTIVES

To explore challenges to nutrition intervention adherence using the Capability, Opportunity and Motivation-Behaviour (COM-B) model among wet age-related macular degeneration (AMD) patients. These factors should be considered in the development of potential support and intervention programmes to address these problems.

DESIGN

A qualitative study was conducted with one-to-one and face-to-face interviews with wet AMD patients using a semi-structured question guide. Data were analysed based on COM-B model: capability (physical and psychological), opportunity (physical and social) and motivation (reflective and automatic).

SETTING

Southwest Hospital of Chongqing Province in China.

PARTICIPANTS

A convenient and purposive sample of 24 wet AMD patients were recruited.

RESULTS

The themes and subthemes were identified: psychological capability: (1) insufficient knowledge of nutrition; (2) misconceptions about the disease and treatment; (3) knowledge conflict; physical capability: (1) physical restriction; (2) limited access to nutrition knowledge; physical opportunity: (1) communication between providers and patients; (2) health insurance and extra charges; (3) food environment; social opportunity: (1) stigma of disease; (2) family influence; reflective motivation: (1) self-efficacy; (2) attitude; (3) outcome expectancies; (4) lack of professional support; automatic motivation: (1) difficulties in changing eating habits; (2) mindset.

CONCLUSION

Medical staff should pay much attention to the process of patients' nutrition intervention. In addition, it is also necessary to develop professional and internet-based intervention to modify the dietary behaviour and improve the management skills of the patients.

Potential mechanisms of macular degeneration protection by fatty fish consumption

Age-related macular degeneration (AMD) is a progressive retinal disease that is a leading cause of visual impairment and severe vision loss. The number of people affected by AMD is increasing and constitutes a huge worldwide health problem. The beneficial effects of fish consumption on AMD have been revealed over the past decades, and in this review, we summarizes the beneficial effects of fatty fish on AMD and its mechanism of action. Fatty fish affects the development of AMD by inhibiting neovascularization, interacting with retinal pigment epithelial (RPE) cells, displacing Omega-6, and inducing cellular responses. It is recommended that people at high risk or with moderate or more severe AMD should consider eating more fatty fish in addition to maintaining a healthy lifestyle of weight control and smoking cessation and the need to promote new models of personalized AMD prevention and treatment.

[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.

Discovering the Potential of Natural Antioxidants in Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a multifactorial disease associated with anatomical changes in the inner retina. Despite tremendous advances in clinical care, there is currently no cure for AMD. This review aims to evaluate the published literature on the therapeutic roles of natural antioxidants in AMD. A literature search of PubMed, Web of Science and Google Scholar for peer-reviewed articles published between 1 January 2011 and 31 October 2021 was undertaken. A total of 82 preclinical and 18 clinical studies were eligible for inclusion in this review. We identified active compounds, carotenoids, extracts and polysaccharides, flavonoids, formulations, vitamins and whole foods with potential therapeutic roles in AMD. We evaluated the integral cellular signaling pathways including the activation of antioxidant pathways and angiogenesis pathways orchestrating their mode of action. In conclusion, we examined the therapeutic roles of natural antioxidants in AMD which warrant further study for application in clinical practice. Our current understanding is that natural antioxidants have the potential to improve or halt the progression of AMD, and tailoring therapeutics to the specific disease stages may be the key to preventing irreversible vision loss.

Development and Pilot-Testing of a Patient Decision-Making Aid for Nutrition in Age-Related Macular Degeneration

OBJECTIVE

We described the development and pilot-testing of an application based patient decision-making aid (PDA) for nutrition in age-related macular degeneration (AMD). Alpha-testing and beta-testing were performed to explore the PDA's usability, acceptability, and comprehensibility in the design stage and in "real-life" conditions.

METHODS

A nutrition PDA was developed in this study by a multidisciplinary steering committee that consisted of ophthalmologists, nurses, nutritionists, and methodologists using a systematic development process. The PDA was based on a smartphone native installation and a free-to-use app. First, based on information from literature reviews and focus group interviews for needs assessment, we developed a decision aid prototype. Second, we conducted the alpha testing to explore the acceptability, usability, and comprehensibility of the PDA prototype among 18 AMD patients. Third, a before/after study was conducted to assess changes in the attitudes, risk perceptions, intentions, knowledge, decisional conflicts, and decision self-efficacy of 33 AMD patients.

RESULTS

The alpha test proved that the nutrition PDA is acceptable and usable. In the beta test, after the AMD participants used the PDA, their scores for knowledge [mean = 13.3, standard deviation (SD) = 2.92], attitude (mean = 18.97, SD = 2.19), decision self-efficacy (mean = 23.94, SD = 6.04), and preparation significantly increased (mean = 26.30, SD = 4.90), and their score for decisional conflict significantly decreased (mean = 10.15, SD = 3.66). There was no significant difference in anxiety (mean = 2.64, SD = 1.08) before and after the use of the PDA. The mean score in the system usability scale was above 70 (mean = 72.61; SD = 5.38), which indicates the good usability of the PDA. With regard to the PDA acceptability, the scores for satisfaction with its comprehensibility, satisfaction with its attractiveness, and satisfaction with its emotional support were 5.49 (SD = 1.03), 5.30 (SD = 1.40), and 4.91(SD = 1.07), respectively, which show its adequate acceptability.

CONCLUSION

Our study showed that the nutrition PDA was an acceptable and suitable instrument for AMD patients and fit the values of all its stakeholders. This study is an important step in supporting shared decision-making, which has the potential to provide a more patient-centered and value-based nutrition health system for individuals with different types of AMD.

Management of neovascular age-related macular degeneration: Taiwan expert consensus

Neovascular age-related macular degeneration (nAMD) is a leading cause of irreversible vision loss. The present consensus provides suggestions on diagnosis, evaluation, treatment, and follow-up strategies for nAMD from a panel of 11 practicing ophthalmologists. The experts suggest that the baseline visit for nAMD management should include a comprehensive ophthalmologic examination via a multimodal approach consisting of visual and anatomical evaluation. Patients diagnosed with nAMD should be subjected to treatment with the goal of maintaining visual function while diminishing anatomical disease activity and minimizing treatment burden. Currently, anti-VEGF therapy is the main treatment strategy for nAMD, and evaluation involving comprehensive ophthalmologic examination within 1 month of completion of the loading phase comprising three monthly injections is recommended to guide subsequent management. Either a treat-and-extend or pro re nata regimen can be considered for the maintenance phase of anti-VEGF therapy, and the regimen should be chosen and adjusted according to disease activity, reimbursement criteria, financial burden, and patient preferences. In the event of inactive nAMD or poor treatment outcomes, after thorough evaluation and patient education, anti-VEGF therapy may be stopped. The consensus provides practical nAMD management guidelines for ophthalmologists and fellow healthcare professionals.

Crosstalk Between RPE Cells and Choroidal Endothelial Cells via the ANXA1/FPR2/SHP2/NLRP3 Inflammasome/Pyroptosis Axis Promotes Choroidal Neovascularization

One type of age-related macular degeneration (AMD), neovascular (nAMD), characterized by choroidal neovascularization (CNV), accounts for the majority of the severe central vision impairment associated with AMD. Endothelial cells (ECs) in direct contact with retinal pigment epithelial (RPE) cells are more prone to the pathological angiogenesis involved in CNV. Herein, we investigated the effect of crosstalk between RPE cells and choroidal endothelial cells (CECs) via the ANXA1/FPR2/NLRP3 inflammasome/pyroptosis axis on the development of choroidal neovascularization (CNV) in vitro and in vivo. ANXA1 expression and secretion from ARPE-19 cells were upregulated by hypoxia. FPR2 expression, especially on the plasma membrane, in HCECs was upregulated under hypoxic conditions. ANXA1 secreted from ARPE-19 cells inhibited NLRP3 inflammasome activation and NLRP3 inflammasome-mediated pyroptosis in HCECs by activating the FPR2/SHP2 axis. Moreover, ANXA1 secreted by ARPE-19 cells promoted behaviors of HCECs, including proliferation, migration, and tube formation, by activating the FPR2/SHP2 axis and inhibiting NLRP3 inflammasome-mediated pyroptosis. Inhibiting the upregulated ANXA1/FPR2/SHP2/NLRP3 inflammasome/pyroptosis axis decreased the volume of CNV. Our data suggest that the crosstalk between RPE cells and CECs via the ANXA1/FPR2/NLRP3 inflammasome/pyroptosis axis promotes CNV. This finding could identify a potential target for the prevention and treatment of CNV.

Variations and trends in global disease burden of age-related macular degeneration: 1990-2017

PURPOSE

To evaluate the disease burden of age-related macular degeneration (AMD) and to evaluate the risk factors of disability-adjusted life years (DALY) caused by AMD.

METHODS

Country-specific DALY number, rate and age-standardized rate of AMD were acquired from the Global Burden of Disease Study 2017 database. The Socio-demographic Index (SDI), Human Development Index (HDI), Inequality-adjusted Human Development Index (IA-HDI) and other related data were obtained from published data or shared databases. Regression analysis was conducted to evaluate the correlations between the potential risk factors and the age-standardized DALY rate of AMD.

RESULTS

The DALY number doubled from 1990 to 2017, and DALY rate increased from 4.73 (95% CI: 3.19-6.54) to 6.95 (95% CI: 4.76-9.54). However, change was small after standardizing. Females tended to have severer burden. Disability-adjusted life years (DALY) rates were correlated to annual PM2.5 concentration, gross domestic product (GDP) per capita, population with at least some secondary education (secondary education), glaucoma prevalence and gross national income (GNI) per capita. In SDI model, glaucoma, GDP, healthcare access and quality index (HAQ) and secondary education were associated with disease burden (p < 0.001). In IA-HDI model, cataract, glaucoma, PM2.5, GDP and secondary education were correlated to DALY rates (p < 0.001). In model included four components of HDI, glaucoma, PM2.5, GDP, secondary education, expected years of schooling and life expectancy at birth were associated (p < 0.001).

CONCLUSION

Being female, older age, poor socioeconomic status and less educated are associated with a heavier disease burden of AMD. These findings would provide a basic understanding for policy making on AMD prevention and treatment.

Prevalence of visual impairment among older Chinese population: A systematic review and meta-analysis

Background

To evaluate the prevalence of visual impairment (VI) among elderly Chinese population.

Methods

All population-based studies on VI prevalence among elderly Chinese populations were searched and only studies with clear definitions of diagnosis were selected. Meta-analysis methods were used to estimate the pooled prevalence and its 95% confidence interval (95%CI) of moderate and severe visual impairment (MSVI) and blindness both by presenting visual acuity (PVA) and best corrected visual acuity (BCVA). Subgroup analysis of gender, district, geographical location, age, education level and examined year were also conducted.

Results

72 studies with 465 039 individuals were included and analyzed. Using PVA, the pooled prevalence of MSVI is 10.9% (95% CI = 9.4%-12.6%) and blindness is 2.2% (95% CI = 1.8%-2.8%), while prevalence of MSVI and blindness by BCVA was 5.4% (95% CI = 4.6%-6.2%) and 2.2% (95% CI = 1.9%-2.5%), respectively. Females, rural residents, older age and lower educational level were risk factors for MSVI and blindness.

Conclusions

VI causes a great health burden among Chinese populations, particularly affecting female subjects, subjects dwelling in rural area, older subjects and subjects with lower educational level.

Autophagy Genes for Wet Age-Related Macular Degeneration in a Finnish Case-Control Study

Age-related macular degeneration is an eye disease that is the main cause of legal blindness in the elderly in developed countries. Despite this, its pathogenesis is not completely known, and many genetic, epigenetic, environmental and lifestyle factors may be involved. Vision loss in age-related macular degeneration (AMD) is usually consequence of the occurrence of its wet (neovascular) form that is targeted in the clinic by anti-VEGF (vascular endothelial growth factor) treatment. The wet form of AMD is associated with the accumulation of cellular waste in the retinal pigment epithelium, which is removed by autophagy and the proteosomal degradation system. In the present work, we searched for the association between genotypes and alleles of single nucleotide polymorphisms (SNPs) of autophagy-related genes and wet AMD occurrence in a cohort of Finnish patients undergoing anti-VEGF therapy and controls. Additionally, the correlation between treatment efficacy and genotypes was investigated. Overall, 225 wet AMD patients and 161 controls were enrolled in this study. Ten SNPs (rs2295080, rs11121704, rs1057079, rs1064261, rs573775, rs11246867, rs3088051, rs10902469, rs73105013, rs10277) in the mTOR (Mechanistic Target of Rapamycin), ATG5 (Autophagy Related 5), ULK1 (Unc-51-Like Autophagy Activating Kinase 1), MAP1LC3A (Microtubule Associated Protein 1 Light Chain 3 α), SQSTM1 (Sequestosome 1) were analyzed with RT-PCR-based genotyping. The genotype/alleles rs2295080-G, rs11121704-C, rs1057079-C and rs73105013-T associated with an increased, whereas rs2295080-TT, rs2295080-T, rs11121704-TT, rs1057079-TT, rs1057079-T, rs573775-AA and rs73105013-C with a decreased occurrence of wet AMD. In addition, the rs2295080-GG, rs2295080-GT, rs1057079-TT, rs11246867-AG, rs3088051-CC and rs10277-CC genotypes were a positively correlated cumulative number of anti-VEGF injections in 2 years. Therefore, variability in autophagy genes may have an impact on the risk of wet AMD occurrence and the efficacy of anti-VEGF treatment.

Short-Term Results of Switch from Conbercept to Bevacizumab or Ranibizumab in Eyes with Persistent Neovascular Age-Related Macular Degeneration

Purpose

To study the short-term anatomical and functional outcomes in patients with neovascular age-related macular degeneration (nAMD) who were previously treated with conbercept and switched to ranibizumab or bevacizumab due to persistent activity.

Methods

This retrospective single-arm study included nAMD patients who were followed up for at least three months after switching from at least 3 monthly intravitreal conbercept injections to bevacizumab or ranibizumab for persistent choroidal neovascularization (CNV) activity. The demographic data, treatments, best-corrected visual acuity (BCVA), central macular thickness (CMT), and the height of pigmented epithelial detachment (PED) before and after switching were recorded and analyzed.

Results

A total of 64 eyes of 64 patients were included with a mean follow-up of 9.6 ± 3.0 months. The average number of injections of conbercept was 3.6 ± 0.8 (range, 3–5) before switching. 18 eyes were switched to bevacizumab, and the other 46 eyes were switched to ranibizumab. After switching, mean BCVA slowly improved from 0.73 ± 0.48 to 0.64 ± 0.41 (p=0.0132) at one month after the last intravitreal injection of ranibizumab or bevacizumab during the mean follow-up of 4.4 ± 2.0 months. One month after switching, the mean CMT decreased significantly from 294.9 ± 121.8 μm to 230.9 ± 107.0 μm (p < 0.0001) and kept stable during the follow-up. There was a significant reduction of maximum PED height (mPEDH) at the first month after switching (from 384.3 ± 340.3 μm to 287.2 ± 245.2 μm, p=0.0018) and kept stable during the follow-up. The mean PED height at foveal center (cPEDH) showed a regression over time after switching (from 169.3 ± 230.6 μm to 130.5 ± 180.2 μm, p=0.0227) and also kept stable during the follow-up. The proportion of patients with IRF was slightly increased but not statistically significant before switching. After switching, this proportion decreased significantly from 96.9% to 81.3% at one month after the first intravitreal injection of ranibizumab or bevacizumab (p=0.0086). The proportion of patients with SRF did not change significantly before and after switching. The mean decrease of mPEDH and cPEDH at the last follow-up after switching was significantly larger in the IVR subgroup than in the IVB subgroup (p=0.023 and 0.010).

Conclusion

Our results indicate that switching from intravitreal conbercept injections to bevacizumab or ranibizumab can lead to significant improvement of CMT, PED, and IRF and slight improvement of BCVA in a short period of time for persistent nAMD patients.

Prevalence of myopic macular degeneration worldwide: a systematic review and meta-analysis

PURPOSE

To investigate the prevalence of myopic macular degeneration (MMD) in the global population.

METHODS

All published literature of population-based studies on MMD prevalence worldwide were searched and only those with clear definitions to diagnose and classify MMD lesions by standardised grading methods were selected. Meta-analysis methods were used to calculate the pooled prevalence of MMD and its 95% CI in a random-effects model. The prevalence of MMD lesions would also be reported, together with the subgroup analysis of age, region and gender. Correlation between MMD prevalence and spherical equivalent levels and axial length were also evaluated.

RESULTS

12 studies with 58 558 subjects were included in this meta-analysis. The pooled prevalence of MMD in the world population was 2.1% (95% CI: 1.3% to 3.3%). In the subgroup analysis, people with the following characteristics were at higher risk of developing MMD: female, urban life, living in Asia, older age, longer axial length and severer myopia.

CONCLUSIONS

MMD is a serious public health concern worldwide, particularly in subjects who are women, subjects living in urban areas, subjects living in Asia, and subjects with longer axial lengths and severer myopia. Further studies from other continents/ethnicities are needed for comprehensive estimates of the prevalence of MMD globally.

Toll-like receptor 4 gene polymorphisms rs4986790 and rs4986791 and age-related macular degeneration susceptibility: a meta-analysis

Background: Several studies have investigated two single nucleotide polymorphisms (SNPs) (rs4986790 and rs4986791) of toll-like receptor 4 (TLR4) and age-related macular degeneration (AMD) susceptibility. However, their results varied. Here, we performed a systematic review and meta-analysis to investigate the association between these two SNPs and AMD susceptibility.Materials and Methods: We searched the PubMed and Web of Science databases for articles indexed up to July 20, 2019. Studies investigating the association between TLR4 polymorphisms rs4986790 (Asp299Gly) and rs4986791 (Thr399Ile) and AMD susceptibility were included in this systematic review. The results of the included studies were pooled with allele contrast, recessive, dominant and overdominant models. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Egger's test was used to evaluate publication bias.Results: Six studies with 9 cohorts were included in this systematic review and meta-analysis. The recessive and overdominant models showed that rs4986790 was significantly associated with AMD susceptibility, with odds ratios (ORs) of 0.73 and 1.41, respectively. By contrast, rs4986791 was not associated with AMD susceptibility. No publication bias was observed for either rs4986791 or rs4986790.Conclusion: The current evidence supports the hypothesis that rs4986790 but not rs4986791 is associated with AMD susceptibility.