Smoking and age-related macular degeneration: biochemical mechanisms and patient support

Potential to improve the burden of age-related macular degeneration: results from the Global Burden of Disease Study 2021

BACKGROUND

Age-related macular degeneration (AMD) is a critical public health issue, requiring prioritized public health strategies.

METHODS

Based on the Global Burden of Disease Study 2021, AMD burden and risk factors were analyzed, considering variables such as sex, age, and location. Age-standardized rates (ASR) were employed to evaluate and compare the burdens across different regions. Frontier analysis was used to determine the lowest achievable burden based on the Sociodemographic Index (SDI), while decomposition analysis revealed factors influencing age-related macular degeneration burden change.

RESULTS

Globally, in 2021, ASR of prevalence and disability-adjusted life years (DALYs) were 94.00 (95% UI 78.32, 114.42) per 100,000 and 6.78 (95% UI 4.70, 9.32) per 100,000 respectively. Additionally, a reduction of smoking exposure to its theoretical minimum risk exposure level (TMREL) would lead to an estimated 10.0% decrease in AMD DALYs in 2021. Frontier analysis suggested that Nepal, Iran (Islamic Republic of), and Nigeria were the top three countries with the most substantial potential for reducing disparities. Decomposition analysis indicated that population growth and aging are the primary driving factors for the increase in AMD DALYs.

CONCLUSIONS

We identify countries and territories with potential for improvement and emphasize the importance of equitable, cost-effective control strategies, particularly tobacco control.

Impact of smoking on ocular health: A systematic review and meta-meta-analysis

PurposeTo provide a comprehensive synthesis of the available evidence on the effects of smoking on ocular health.MethodsDatabases (PubMed, SCOPUS, Web of Science) were searched through December 2024 for systematic reviews and meta-analyses on smoking and ocular disease risk. Meta-analysis quality was assessed using the 16-item A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2.ResultsSixteen studies were included, with 12 qualifying for meta-meta-analysis. Current smokers are 7 to 12 times more likely to develop AMD than non-smokers (Odds Ratio [OR]: 11.93 [95% CI 4.40 to 32.33]; Risk Ratio [RR]: 7.45 [95% CI 4.09 to 13.57]). Past smokers have a seven-fold increased risk (OR: 7.09 [95% CI 4.79 to10.51]). For POAG, current smokers have three times the risk (OR: 3.07 [95% CI 2.07 to 4.54]), and past smokers have three times the risk (OR: 2.64 [95% CI 2.33 to 3.00]). Current smokers are four times more likely to develop cataracts (OR: 4.15 [95% CI 3.35 to 5.15]), while "ever" smokers face a six-fold risk (OR: 5.96 [95% CI 3.21 to 11.04]).ConclusionSmoking is a modifiable risk factor for numerous ocular diseases. Public health efforts and clinical guidelines should emphasize smoking cessation to reduce smoking-related ocular disease incidence and promote ocular health.

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization

Nicotine-induced endoplasmic reticulum (ER) stress in retinal pigment epithelium (RPE) cells is thought to be one pathological mechanism underlying age-related macular degeneration (AMD). ERp29 attenuates tobacco extract-induced ER stress and mitigates tight junction damage in RPE cells. Herein, we aimed to further investigate the role of ERp29 in nicotine-induced ER stress and choroidal neovascularization (CNV). We found that the expression of ERp29 and GRP78 in ARPE-19 cells was increased in response to nicotine exposure. Overexpression of ERp29 decreased the levels of GRP78 and the C/EBP homologous protein (CHOP). Knockdown of ERp29 increased the levels of GRP78 and CHOP while reducing the viability of ARPE-19 cells under nicotine exposure conditions. In the ARPE-19 cell/macrophage coculture system, overexpression of ERp29 decreased the levels of M2 markers and increased the levels of M1 markers. The viability, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were inhibited by conditioned medium from the ERp29-overexpressing group. Moreover, overexpression of ERp29 inhibits the activity and growth of CNV in mice exposed to nicotine in vivo. Taken together, our results revealed that ERp29 attenuated nicotine-induced ER stress, regulated macrophage polarization and inhibited CNV.

Through the Smoke: An In-Depth Review on Cigarette Smoking and Its Impact on Ocular Health

Smoking is a widespread and pervasive habit, impacting health across various care settings, including acute care, subacute care, home-based care, and long-term care. Smoking is a serious global public health concern that has been related to many chronic diseases. However, the effect of smoking on eye disorders has been less studied. Cigarette smoke contains a complex mixture of harmful constituents, including nicotine and toxic chemicals, which permeate the bloodstream, affecting ocular tissues. The oxidative stress and inflammation induced by smoking are central to its detrimental effects on ocular health. Age-related macular degeneration (AMD), a leading cause of vision loss, exhibits a strong association with smoking. Research consistently demonstrates that smokers face a heightened risk of both early and advanced AMD. Cataracts, another prevalent ocular condition, develop earlier and progress more rapidly in smokers. The oxidative stress on the lens and reduced antioxidants among smokers contribute to the increased severity of cataracts. Moreover, the health of the eyes may be compromised by smoking-related chemicals that reduce blood flow and/or hasten thrombus formation in ocular capillaries thus increasing the chance of acquiring glaucoma, cataracts, AMD, and Graves' eye disease. Beyond individual health concerns, the societal implications of smoking on ocular health are substantial, including increased healthcare costs and diminished quality of life for affected individuals. Understanding the underlying mechanisms can provide insights into potential therapeutic interventions for preventing and managing smoking-related ocular damage. Given the global prevalence of smoking, raising awareness about the ocular risks associated with smoking is crucial for promoting eye health. The review underscores the urgent need for comprehensive anti-smoking initiatives and smoking cessation programs to alleviate the burden of ocular diseases associated with smoking.

Untargeted metabolomics for uncovering plasma biological markers of wet age-related macular degeneration

Wet age-related macular degeneration (wAMD) causes central vision loss and represents a major health problem in elderly people. Here we have used untargeted metabolomics using UHPLC-MS to profile plasma from 127 patients with wAMD (67 choroidal neovascularization (CNV) and 60 polypoidal choroidal vasculopathy (PCV)) and 50 controls. A total of 545 biochemicals were detected. Among them, 17 metabolites presented difference between patients with wAMD and controls. Most of them were oxidized lipids (N=6, 35.29%). Comparing to controls, 28 and 18 differential metabolites were identified in patients with CNV and PCV, respectively. Two metabolites, hyodeoxycholic acid and L-tryptophanamide, were differently distributed between PCV and CNV. We first investigated the genetic association with metabolites in wet AMD (CFH rs800292 and HTRA1 rs10490924). We identified six differential metabolites between the GG and AA genotypes of CFH rs800292, five differential metabolites between the GG and AA genotypes of HTRA1 rs10490924, and four differential metabolites between the GG and GA genotypes of rs10490924. We selected four metabolites (cyclamic acid, hyodeoxycholic acid, L-tryptophanamide and O-phosphorylethanolamine) for in vitro experiments. Among them, cyclamic acid reduced the activity, inhibited the proliferation, increased the apoptosis and necrosis in human retinal pigment epithelial cells (HRPECs). L-tryptophanamide affected the proliferation, apoptosis and necrosis in HRPECs, and promoted the tube formation and migration in primary human retinal endothelial cells (HRECs). Hyodeoxycholic acid and O-phosphorylethanolamine inhibited the tube formation and migration in HRECs. The results suggested that differential metabolites have certain effects on wAMD pathogenesis-related HRPECs and HRECs.

Lack of association between three common genetic variations of XPC and susceptibility to age-related macular degeneration, a preliminary study

Background

Numerous association studies have indicated that genetic alterations in genes involved in DNA repair processes are associated with the risk of age-related macular degeneration (ARMD). There is no published study on the relationship between common xeroderma pigmentosum complementation group C (XPC, MIM 613208) polymorphisms and susceptibility to ARMD. The aim of this study is to determine whether three common (Ala499Val, Lys939Gln, and PAT) genetic variants of XPC are associated with the risk of developing ARMD. A total of 120 ARMD patients and 118 healthy controls were included in the study. Genotyping analyses were carried out by PCR-based methods.

Results

Our analysis revealed that there was no relationship between the XPC polymorphisms and susceptibility to ARMD. In both case and control groups, strong linkage disequilibrium existed between three common (Ala499Val, Lys939Gln, and PAT) genetic polymorphisms of XPC. Statistical analysis showed no association between the haplotypes and the risk of ARMD.

Conclusions

The present data indicated that the common polymorphisms of XPC are not susceptible genetic variations for ARMD.