Incidence, progression and risk factors of age‐related cataract in Malays: The Singapore Malay Eye Study

Prevalence of cataracts in Iran based on the Persian eye cohort study

The PERSIAN eye cohort study is a population-based study that evaluates the overall prevalence of cataracts and their subtypes (nuclear sclerosis, cortical, and PSC) in Iran. In this study, from January 2015 to September 2021, 16,016 participants over 35 years of age from four provinces who were selected by random cluster sampling were examined. Demographic information, education, socioeconomic status, and place of residence were collected through interviews. The cataract status of the study participants was examined by two experienced ophthalmologists using slit lamp photography. The average age of the study participants was 49.52 ± 9.31 and 8891 (55.5%) were female. The overall prevalence of each type of cataract, nuclear sclerosis, cortical, and PSC was 18.90%, 12.65%, 9.20%, and 3.08%, respectively. The results indicated that the prevalence of any type of cataract (adjusted OR = 0.85, 95% CI: 0.78-0.92, p < 0.001) and NS cataract (adjusted OR = 0.80, 95% CI: 0.73-0.88, p < 0.001) is lower in women. The risk of developing cataracts increased exponentially with aging. The prevalence of any type of cataract and cortical subtype was higher in rural than urban populations. Also, the risk of developing cataracts decreased with an increase in education level and socioeconomic status and some Iranian races such as Arabs, Azari, and Guilak were also at a higher risk of cataracts. The results of this study indicate the importance of a comprehensive regard of cataract as one of the causes of avoidable blindness in Iran due to its higher prevalence than the global average.

Binding with HSP90β, cimifugin ameliorates fibrotic cataracts in vitro and in vivo by inhibiting TGFβ signaling pathways

Fibrotic cataracts, the most frequent complications after phacoemulsification, cannot be cured by drugs in clinic. The primary mechanism underlying the disease is the epithelial-mesenchymal transition (EMT). Cimifugin is a natural monomer component of traditional Chinese medicines. Previous researches have demonstrated the effect of cimifugin inhibiting EMT in the lung. The purpose of this work is to evaluate the impact of cimifugin on EMT in the lens and elucidate its precise mechanism. The pathogenesis of fibrotic cataracts was simulated using TGFβ2-induced cell model of EMT and the injury-induced anterior subcapsular cataract animal model. Through H&E staining and immunofluorescence of mice eyeballs, we discovered that cimifugin can inhibit the expansion of fibrotic lesions in vivo. Furthermore, at mRNA and protein levels, we confirmed that cimifugin can allay EMT of lens epithelial cells (LECs) in vitro and in vivo. Additionally, the inhibition of cimifugin on the activation of TGFβ-related signaling pathways was certified by immunoblot. HSP90β, the target of cimifugin, was predicted by network pharmacology and verified by drug affinity responsive target stability, the cellular thermal shift assay, and microscale thermophoresis. Moreover, co-immunoprecipitation revealed the interaction between HSP90β and TGFβ receptor (TGFβR) II. Together, our findings showed that by weakening the binding of HSP90β and TGFβRII, cimifugin suppressed the TGFβ signaling pathways to alleviate fibrotic cataracts. Cimifugin is a promising medication for the treatment of fibrotic cataracts.

Evaluation of nintedanib efficacy: Attenuating the lens fibrosis in vitro and vivo

PURPOSE

Organ fibrosis is a huge challenge in clinic. There are no drugs for fibrotic cataracts treatments in clinic. Nintedanib is approved by the FDA for pulmonary fibrosis treatments. This study aims to investigate the efficacy and mechanism of nintedanib on fibrotic cataracts.

METHODS

Drug efficacy was validated through TGFβ2-induced cell models and injury-induced anterior subcapsular cataract (ASC) mice. A slit lamp and the eosin staining technique were applied to access the degree of capsular fibrosis. The CCK-8 assay was used to evaluate the toxicity and anti-proliferation ability of the drug. The cell migration was determined by wound healing assay and transwell assay. The anti-epithelial mesenchymal transition (EMT) and anti-fibrosis efficacy were evaluated by qRT-PCR, immunoblot, and immunofluorescence. The inhibition of nintedanib to signaling pathways was certified by immunoblot.

RESULTS

Nintedanib inhibited the migration and proliferation of TGFβ2-induced cell models. Nintedanib can also repress the EMT and fibrosis of the lens epithelial cells. The intracameral injection of nintedanib can also allay the anterior subcapsular opacification in ASC mice. The TGFβ2/ Smad and non-Smad signaling pathways can be blocked by nintedanib in vitro and in vivo.

CONCLUSION

Nintedanib alleviates fibrotic cataracts by suppressing the TGFβ2/ Smad and non-Smad signaling pathways. Nintedanib is a potential drug for lens fibrosis.

The effects of exposure to solar radiation on human health

This assessment by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the United Nations Environment Programme (UNEP) evaluates the effects of ultraviolet (UV) radiation on human health within the context of the Montreal Protocol and its Amendments. We assess work published since our last comprehensive assessment in 2018. Over the last four years gains have been made in knowledge of the links between sun exposure and health outcomes, mechanisms, and estimates of disease burden, including economic impacts. Of particular note, there is new information about the way in which exposure to UV radiation modulates the immune system, causing both harms and benefits for health. The burden of skin cancer remains high, with many lives lost to melanoma and many more people treated for keratinocyte cancer, but it has been estimated that the Montreal Protocol will prevent 11 million cases of melanoma and 432 million cases of keratinocyte cancer that would otherwise have occurred in the United States in people born between 1890 and 2100. While the incidence of skin cancer continues to rise, rates have stabilised in younger populations in some countries. Mortality has also plateaued, partly due to the use of systemic therapies for advanced disease. However, these therapies are very expensive, contributing to the extremely high economic burden of skin cancer, and emphasising the importance and comparative cost-effectiveness of prevention. Photodermatoses, inflammatory skin conditions induced by exposure to UV radiation, can have a marked detrimental impact on the quality of life of sufferers. More information is emerging about their potential link with commonly used drugs, particularly anti-hypertensives. The eyes are also harmed by over-exposure to UV radiation. The incidence of cataract and pterygium is continuing to rise, and there is now evidence of a link between intraocular melanoma and sun exposure. It has been estimated that the Montreal Protocol will prevent 63 million cases of cataract that would otherwise have occurred in the United States in people born between 1890 and 2100. Despite the clearly established harms, exposure to UV radiation also has benefits for human health. While the best recognised benefit is production of vitamin D, beneficial effects mediated by factors other than vitamin D are emerging. For both sun exposure and vitamin D, there is increasingly convincing evidence of a positive role in diseases related to immune function, including both autoimmune diseases and infection. With its influence on the intensity of UV radiation and global warming, the Montreal Protocol has, and will have, both direct and indirect effects on human health, potentially changing the balance of the risks and benefits of spending time outdoors.

Metabolic Syndrome Is Associated with Cataract in a Large Taiwanese Population Study

Cataract is the leading cause of blindness worldwide, and metabolic syndrome (MetS) is a known risk factor. In this study, we investigated the association between the risk of cataract with MetS and its components in a large-scale study. Data were derived from the Taiwan Biobank, and 121,380 individuals were included. The NCEP-ATP III criteria modified for use in an Asian population were used to define MetS and its components. The occurrence of cataract was identified through a standardized interview and self-reported questionnaire. Multivariable analysis showed that MetS (OR, 1.129; 95% CI, 1.0175−1.184; p < 0.001), low high-density lipoprotein (HDL)-cholesterol (OR, 1.057; 95% CI, 1.005−1.113; p = 0.032), and hyperglycemia (OR, 1.162; 95% CI, 1.108−1.218; p < 0.001) were significantly associated with cataract. Furthermore, a stepwise increase in the prevalence of cataract corresponding to the number of MetS components was found. The presence of three MetS components (vs. 0; OR, 1.103; 95% CI, 1.024−1.188; p = 0.010), four MetS components (vs. 0; OR, 1.137; 95% CI, 1.040−1.242; p = 0.005), and five MetS components (vs. 0; OR, 1.208; 95% CI, 1.059−1.378; p = 0.005) were significantly associated with cataract. In conclusion, significant associations were found between a high incidence of cataract with MetS and its components, including low HDL-cholesterolemia and hyperglycemia. Further, a stepwise increase in the prevalence of cataract corresponding to the number of MetS components was also found. The results of this study indicate that MetS may increase the development of cataract in Taiwan.

Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2021

The Environmental Effects Assessment Panel of the Montreal Protocol under the United Nations Environment Programme evaluates effects on the environment and human health that arise from changes in the stratospheric ozone layer and concomitant variations in ultraviolet (UV) radiation at the Earth's surface. The current update is based on scientific advances that have accumulated since our last assessment (Photochem and Photobiol Sci 20(1):1-67, 2021). We also discuss how climate change affects stratospheric ozone depletion and ultraviolet radiation, and how stratospheric ozone depletion affects climate change. The resulting interlinking effects of stratospheric ozone depletion, UV radiation, and climate change are assessed in terms of air quality, carbon sinks, ecosystems, human health, and natural and synthetic materials. We further highlight potential impacts on the biosphere from extreme climate events that are occurring with increasing frequency as a consequence of climate change. These and other interactive effects are examined with respect to the benefits that the Montreal Protocol and its Amendments are providing to life on Earth by controlling the production of various substances that contribute to both stratospheric ozone depletion and climate change.

The association between cataract and sleep apnea: a nationwide population-based cohort study

STUDY OBJECTIVES

The association between sleep apnea (SA) and cataract was confirmed in a comprehensive large-scale study. This study aimed to investigate whether SA was associated with increased risk of cataract.

METHODS

The 18-year nationwide retrospective population-based cohort study used data retrieved from the Taiwan National Health Insurance Database. We selected adult patients with a diagnosis of SA, based on diagnostic codes (suspected SA cohort) or on presence of diagnosis after polysomnography (SA cohort), and matched each of them to 5 randomly selected, and age- and sex-matched control participants. The incidence rate of cataract was compared between patients with SA and the controls. The effect of SA on incident cataract was assessed using multivariable Poisson regression and Cox regression analyses.

RESULTS

A total of 6,438 patients in the suspected SA cohort were matched with 32,190 controls (control A cohort), including 3,616 patients in the SA cohort matched with 18,080 controls (control B cohort). After adjusting for age, sex, residency, income level, and comorbidities, the incidence rates of cataract were significantly higher in the SA cohorts than in the corresponding control cohorts. SA was an independent risk factor for incident cataract (adjusted hazard ratio [95% confidence interval]: 1.4 [1.2-1.6]). In patients with SA, elder age, heart disease, chronic pulmonary disease, and diabetes mellitus were independent risk factors for incident cataract.

CONCLUSIONS

Our study revealed a significantly higher risk for developing cataract in patients with SA. Physicians caring for patients with SA should be aware of this ophthalmic complication.

CITATION

Liu P-K, Chang Y-C, Wang N-K, et al. The association between cataract and sleep apnea: a nationwide population-based cohort study. J Clin Sleep Med. 2022;18(3):769-777.

Obesity and risk of age-related eye diseases: a systematic review of prospective population-based studies

BACKGROUND

Obesity is a public health challenge worldwide. The relationship between obesity and age-related eye diseases including cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR) have remained elusive.

DESIGN AND METHODS

We conducted a systematic review of three electronic databases for longitudinal population-based studies that described associations between measures of obesity including body mass index (BMI), waist-circumference (WC), and waist-to-hip ratio (WHR), and age-related eye diseases.

RESULTS

Our search yielded 1731 articles, of which 14, 10, 16 and 8 articles met our eligibility criteria for cataract, glaucoma, AMD and DR, respectively. BMI-defined obesity was positively associated with incident cataract, incident AMD and incident DR in Western populations, but in Asian populations associations for incident AMD were not significant and associations for incident DR were inverse. WC-defined obesity was associated with incident glaucoma in non-Western populations. WHR-defined obesity but not BMI-defined obesity was associated with the incidence or progression of AMD in two Western studies.

CONCLUSIONS

Overall, we found strong evidence supporting associations between obesity and age-related eye diseases. Further research on the association of abdominal obesity and effect of weight loss and physical activity on age-related eye diseases is warranted to support clinical and public health recommendations.

Metformin alleviates oxidative stress-induced senescence of human lens epithelial cells via AMPK activation and autophagic flux restoration

Cataracts are the leading cause of blindness worldwide owing to the increasing proportion of elderly individuals in the population. The purpose of this study was to investigate whether metformin could alleviate the occurrence and development of age‐related cataract (ARC) and the underlying mechanism. In the present study, we established a senescence model induced by oxidative stress, which was confirmed by measuring β‐galactosidase activity, qRT‐PCR and Western blotting. In addition, we showed that metformin alleviated the oxidative stress‐induced senescence of HLE‐B3 cells via the activation of AMPK. Next, we provided evidence that oxidative stress impaired autophagic flux and induced lysosomal dysfunction. Subsequently, we found that metformin restored autophagic flux that had been impaired by oxidative stress by activating AMPK. Additionally, we found that metformin suppressed HLE‐B3 cell senescence by improving lysosomal function and inactivating mTOR. Furthermore, the inactivation of AMPK, impairment of autophagic flux and lysosomal dysfunction were observed in the human lens epithelium of ARC. In summary, our data suggest that the activation of AMPK may be a potential strategy for preventing ARC, and metformin may be an emerging candidate to alleviate the formation and development of ARC.

LONG-TERM INCIDENCE AND RISK FACTORS OF OCULAR HYPERTENSION FOLLOWING DEXAMETHASONE-IMPLANT INJECTIONS: THE SAFODEX-2 STUDY

PURPOSE

To analyze the incidence, risk factors, and time to onset of ocular hypertension (OHT) after intravitreal injections (IVI) of dexamethasone implant and to evaluate the long-term cumulative probability of intraocular pressure elevation.

METHODS

Eyes of patients having received at least one dexamethasone implant IVI between October 2010 and February 2015 were included in the present study. Ocular hypertension was defined as intraocular pressure > 25 mmHg and/or an increase of 10 mmHg over the follow-up period compared with baseline intraocular pressure.

RESULTS

Four hundred ninety-four eyes were studied in 410 patients. For a total of 1,371 IVI, the incidence of OHT was 32.6% in the study eyes with a mean follow-up period of 30 months (3-62.5) and a median follow-up of 29 months. Pressure-lowering treatment was introduced for 36.9% of eyes. Topical treatment alone was sufficient to manage OHT in 97%. Young age, male sex, uveitis and retinal vein occlusion, and glaucoma treated with a double- or triple-combination topical pressure-lowering medication were found to be risk factors for OHT. The incidence of OHT did not change with an increase in the number of IVI, and there was no cumulative effect, defining by an increase of the incidence of OHT in patients after repeated IVI (P = 0.248).

CONCLUSION

This study confirmed that OHT is of moderate incidence, transient, controlled by topical treatment and provides data on the long-term cumulative probability of intraocular pressure elevation in a large cohort of eyes treated with dexamethasone implant IVI. Repeat injections of dexamethasone implant neither increase nor decrease the risk of OHT.