Longitudinal changes in global cataract surgery rate inequality and associations with socioeconomic indices

The impact of vitamin E, vitamin B6, and niacin intake on cataract incidence based on NHANES 2005-2008 data

Objective

This investigation aims to elucidate the correlations between dietary intakes of vitamin E, B6, and niacin and the incidence of cataracts, utilizing the comprehensive NHANES 2005-2008 dataset to affirm the prophylactic roles of these nutrients against cataract formation.

Methods

Using data from the NHANES 2005-2008 cycles, this analysis concentrated on 7,247 subjects after exclusion based on incomplete dietary or cataract data. The identification of cataracts was determined through participants' self-reported ophthalmic surgical history. Nutritional intake was gauged using the automated multiple pass method, and the data were analyzed using logistic and quantile regression analyses to investigate the relationship between vitamin consumption and cataract prevalence.

Results

Our analysis identified significant inverse associations between the intake of vitamins E, B6, and niacin and the risk of cataract development. Specifically, higher intakes of vitamin B6 (OR = 0.85, 95% CI = 0.76-0.96, p = 0.0073) and niacin (OR = 0.98, 95% CI = 0.97-1.00, p = 0.0067) in the top quartile were significantly associated with a reduced likelihood of cataract occurrence. Vitamin E intake showed a consistent reduction in cataract risk across different intake levels (OR = 0.96, 95% CI = 0.94-0.99, p = 0.0087), demonstrating a nonlinear inverse correlation.

Conclusion

The outcomes indicate that elevated consumption of vitamin B6 and niacin, in conjunction with regular vitamin E intake, may have the potential to delay or prevent cataract genesis. These results suggest a novel nutritional strategy for cataract prevention and management, advocating that focused nutrient supplementation could be instrumental in preserving eye health and reducing the risk of cataracts. Further research is recommended to validate these findings and establish optimal dosages for maximum benefit.

The burden, causes, and determinants of blindness and vision impairment in Asia: An analysis of the Global Burden of Disease Study

Background

Asia accounts for more than half of the world's population and carries a substantial proportion of the global burden of blindness and vision impairment. Characterising this burden, as well as its causes and determinants, could help with devising targeted interventions for reducing the occurrence of blindness and visual impairment.

Methods

Using the Global Burden of Disease Study 2019 database, we retrieved data on the number of disability-adjusted life years (DALYs); crude and age-standardised rates; and the prevalence (with 95% uncertainty intervals (95%UIs)) of blindness and vision loss due to six causes (age-related macular degeneration, cataracts, glaucoma, near-vision impairment, refractive error, and other vision loss) for Asian countries for the period between 1990 and 2019. We defined DALYs as the sum of the years lost due to disability and years of life lost, and calculated age-standardised figures for the number of DALYs and prevalence by adjusting for population size and age structure. We then evaluated the time trend of the disease burden and conducted subgroup analyses by gender, age, geographic locations, and socio-demographic index (SDI).

Results

In 2019, the DALYs and prevalence of blindness and vision loss had risen by 90.1% and 116% compared with 1990, reaching 15.84 million DALYs (95% UI = 15.83, 15.85) and 506.71 million cases (95% UI = 506.68, 506.74). Meanwhile, the age-standardised rate of DALYs decreased from 1990 to 2019. Cataracts, refractive error, and near vision impairment were the three most common causes. South Asia had the heaviest regional disease burden (age-standardised rate of DALYs = 517 per 100 000 population; 95% UI = 512, 521). Moreover, the burden due to cataracts ranked high in most Asian populations. Being a woman; being older; and having a lower national SDI were factors associated with a greater vision loss burden.

Conclusions

The burden due to vision loss remains high in Asian populations. Cataracts, refractive error, and near vision loss were the primary causes of blindness and vision loss. Greater investment in ocular disease prevention and care by countries with lower socioeconomic status is needed, as well as specific strategies targeting cataract management, women and the elderly.

The Better Operative Outcomes Software Tool (BOOST) Prospective Study: Improving the Quality of Cataract Surgery Outcomes in Low-Resource Settings

PURPOSE

Post-operative vision impairment is common among patients who have undergone cataract surgery in low-resource settings, impacting quality of clinical outcomes and patient experience. This prospective, multisite, single-armed, pragmatic validation study aimed to assess whether receiving tailored recommendations via the free Better Operative Outcomes Software Tool (BOOST) app improved surgical outcomes, as quantified by post-operative unaided distance visual acuity (UVA) measured 1-3 days after surgery.

METHODS

During the baseline data collection round, surgeons in low and middle-income countries recorded clinical characteristics of 60 consecutive cataract cases in BOOST. Additional data on the causes of poor outcomes from 20 consecutive cases with post-operative UVA of <6/60 (4-12 weeks post-surgery) were entered to automatically generate tailored recommendations for improvement, before 60 additional consecutive cases were recorded during the follow-up study round. Average UVA was compared between cases recorded in the baseline study round and those recorded during follow-up.

RESULTS

Among 4,233 cataract surgeries performed by 41 surgeons in 18 countries, only 2,002 (47.3%) had post-operative UVA 6/12 or better. Among the 14 surgeons (34.1%) who completed both rounds of the study (1,680 cases total), there was no clinically significant improvement in post-operative average UVA (logMAR units ±SD) between baseline (0.50 ± 0.37) and follow-up (0.47 ± 0.36) rounds (mean improvement 0.03, p = 0.486).

CONCLUSIONS

Receiving BOOST-generated recommendations did not result in improved UVA beyond what could be expected from prospective monitoring of surgical outcomes alone. Additional research is required to assess whether targeted support to implement changes could potentiate the uptake of app-generated recommendations and improve outcomes.

Fruit and vegetable intake and the risk of cataract: insights from the UK Biobank study

PURPOSE

A prospective cohort study to investigate the association between fruit and vegetable (F&V) intake and the risk of cataract.

METHODS

We included 72,160 participants who were free of cataract at baseline from the UK Biobank. Frequency and type of F&V intake were assessed using a web-based 24 h dietary questionnaire from 2009 to 2012. Development of cataract during the follow-up was defined by self-report or hospital inpatient records up to 2021. Cox proportional regression models were used to estimate the association between F&V intake and incident cataract.

RESULTS

During a mean follow-up of 9.1 years, 5753 participants developed cataract with a corresponding incidence of 8.0%. After adjusting for multiple demographic, medical and lifestyle covariates, higher intake of F&V were associated with a lower risk of cataract (≥6.5 vs. <2 servings/week: hazards ratio [HR]: 0.82, 95% CI: 0.76 to 0.89; P < 0.0001). Regarding specific types, significant reduced risk of cataract was found for higher intake of legumes (P = 0.0016), tomatoes (≥5.2 vs. <1.8 servings/week: HR: 0.94, 95% CI: 0.88 to 1.00), and apple and pear (>7 vs. <3.5 servings/week: 0.89, 95% CI: 0.83 to 0.94; P < 0.0001), but not for cruciferous vegetables, green leafy vegetables, berry, citrus fruit or melon. Smokers were found to benefit more from F&V intake than former and never smokers. Men also could benefit more from higher vegetable intake than women.

CONCLUSIONS

More F&V intake, especially legumes, tomatoes, apple, and pear, was associated with a lower risk of cataract in this UK Biobank cohort.

Effects of Gold Nanoparticles Phytoreduced with Rutin in an Early Rat Model of Diabetic Retinopathy and Cataracts

Diabetic retinopathy (DR) and cataracts (CA) have an early onset in diabetes mellitus (DM) due to the redox imbalance and inflammation triggered by hyperglycaemia. Plant-based therapies are characterised by low tissue bioavailability. The study aimed to investigate the effect of gold nanoparticles phytoreduced with Rutin (AuNPsR), as a possible solution. Insulin, Rutin, and AuNPsR were administered to an early, six-week rat model of DR and CA. Oxidative stress (MDA, CAT, SOD) was assessed in serum and eye homogenates, and inflammatory cytokines (IL-1 beta, IL-6, TNF alpha) were quantified in ocular tissues. Eye fundus of retinal arterioles, transmission electron microscopy (TEM) of lenses, and histopathology of retinas were also performed. DM was linked to constricted retinal arterioles, reduced endogen antioxidants, and eye inflammation. Histologically, retinal wall thickness decreased. TEM showed increased lens opacity and fibre disorganisation. Rutin improved retinal arteriolar diameter, while reducing oxidative stress and inflammation. Retinas were moderately oedematous. Lens structure was preserved on TEM. Insulin restored retinal arteriolar diameter, while increasing MDA, and amplifying TEM lens opacity. The best outcomes were obtained for AuNPsR, as it improved fundus appearance of retinal arterioles, decreased MDA and increased antioxidant capacity. Retinal edema and disorganisation in lens fibres were still present.

Real-world visual outcomes of cataract surgery based on population-based studies: a systematic review

BACKGROUND/AIMS

Quantity of cataract surgery has long been an important public health indicator to assess health accessibility, however the quality of care has been less investigated. We aimed to summarise the up-to-date evidences to assess the real-world visual outcomes after cataract surgery in different settings.

METHODS

A systematic review was undertaken in October 2021. Population-based cross-sectional and longitudinal studies reporting vision-related outcomes after cataract surgery published from 2006 onward were included. A meta-analysis was not planned.

RESULTS

Twenty-six cross-sectional studies from low-income and middle-income countries (LMICs) and five cross-sectional studies from high-income countries (HICs) were included. The proportions of participants with postoperative presenting visual acuity (VA) ≥0.32 (20/60) were all over 70% in all HICS studies, but mostly below 70% in LMICS studies, ranging from 29.9% to 80.5%. Significant difference in postoperative VA was also observed within countries. The leading causes for postoperative visual impairment (defined mostly as presenting VA <20/60) mainly included refractive error, ocular comorbidities and surgical complications including posterior capsule opacification, except for one study in Nigeria wherein the leading cause was aphakia. Only four population-based cohort studies were included with 5-20 years of follow-up time, generally demonstrating no significant changes in postoperative visual outcomes during the follow-up.

CONCLUSIONS

We observed large inequality in the visual outcomes and principal causes of visual impairment after cataract surgery among different countries and regions. Structured quality control and enhancement programmes are needed to improve the outcomes of cataract surgery and reduce inequality.

Expression of oxysterols in human lenses: Implications of the sterol pathway in age-related cataracts

Lanosterol, an oxysterol molecule, has been proposed to help maintain lens transparency by inhibiting the formation of protein aggregates. This sterol is produced by the enzyme lanosterol synthase and is part of a metabolic pathway that forms cholesterol as a final step. Abnormalities in lanosterol synthase are responsible for congenital cataracts. The αA-crystallin protein, which acts as a molecular chaperone to lanosterol synthase, has been reported to have anti-protein aggregation, anti-inflammatory and anti-apoptotic properties. In this work, we evaluated the correlation of lanosterol synthase and αA-crystallin in human cataractous lenses with the grade of opacity, as well as the expression of lanosterol synthase, farnesyl DPP, geranyl synthase and squalene epoxidase genes. Lanosterol synthase and αA-crystallin were overexpressed in cataractous lenses as well as farnesyl-DP synthase, squalene epoxidase, lanosterol synthase and geranyl synthase genes in cataratous lenses in comparison with normal lenses. Our data confirm that lanosterol synthase and the sterol pathway are upregulated in cataractous lenses. This argues for a functional role of the oxysterol pathway and its products as an important mediator in the pathogenesis of human cataracts.

Association between Healthy Eating Index-2015 and Age-Related Cataract in American Adults: A Cross-Sectional Study of NHANES 2005-2008

BACKGROUND

Healthy Eating Index-2015 (HEI-2015), a healthy eating pattern proposed by Dietary Guidelines for Americans, is proven to be protective against various diseases. However, whether it is associated with age-related cataracts is unknown.

METHODS

This population-based cross-sectional study included 6395 participants from the National Health and Nutrition Examination Survey (NHANES) in the cycles from 2005 to 2008. HEI-2015 was calculated from 24-h dietary recall interviews, ranging from 0 to 100, and higher HEI-2015 represents better diet quality. Age-related cataract was generated from the questionnaire. The association between HEI-2015 and cataract was assessed with logistic regression models. Propensity score weighting, restricted cubic spline, and subgroup analysis were conducted to further explore the relationship.

RESULTS

6395 participants were included in the study, with a mean [standard deviation (SD)] age of 48.7 (15.3) years and 3115 (48.7%) being male. HEI-2015 was negatively associated with cataracts after adjusting all covariates included, both as a continuous variable [odds ratio (OR): 0.991, 95% confidence interval (CI): 0.984-0.997, p = 0.006] and quartiles with the highest quartile compared to the lowest (OR: 0.739, 95% CI: 0.559-0.980, p = 0.035). After propensity score weighting, the association remained significant. Restricted cubic spline revealed no non-linear relationship (p for non-linearity 0.085). Subgroup analysis showed that there were no interaction effects.

CONCLUSIONS

Adherence to the healthy eating pattern, HEI-2015, was associated with a lower risk of age-related cataracts.

WHO Vision 2020: Have We Done It?

BACKGROUND

Eye health has widespread implications across many aspects of life, ranging from the individual to the societal level. Vision 2020: The Right to Sight is an initiative that was conceptualised in 1997 and launched in 1999. It was led by the World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB) in response to the increasing prevalence of blindness. Approximately 80% of the causes of blindness were avoidable. Hence, the initiative set out to eliminate the major causes of avoidable blindness. These included cataract, uncorrected refractive error, trachoma, onchocerciasis, and childhood blindness.

METHODS

An electronic literature search was performed using PubMed, MEDLINE and Embase databases to assess the impacts of the Vision 2020 initiative.

RESULTS AND CONCLUSION

The Vision 2020 initiative was ambitious and was essential in catapulting the issue of avoidable blindness in the spotlight and putting it on the global health agenda. The causes of avoidable blindness remain and have not been eliminated. However, there have been noticeable changes in the distribution of the causes of avoidable blindness since the conception of Vision 2020, and this is mainly due to demographic shifts globally. We highlight some of the remaining challenges to acheiving avoidable blindness including, population size, gender disparities in access to eyecare services, and the professional workforce.

Acetyl-11-Keto-Beta Boswellic Acid (AKBA) Protects Lens Epithelial Cells Against H2O2-Induced Oxidative Injury and Attenuates Cataract Progression by Activating Keap1/Nrf2/HO-1 Signaling

Age-related cataract (ARC) is one of the leading blinding eye diseases worldwide. Chronic oxidative stress and the apoptosis of human lens epithelial cells (HLECs) have been suggested to be the mechanism underlying cataract formation. Acetyl-11-keto-β-boswellic acid (AKBA) is a pentacyclic triterpene with antioxidative and antiapoptotic effects. In this study, we investigated the potential effects of AKBA on oxidative-induced HLECs injury and cataract formation. H₂O₂ was used to simulate HLECs oxidative injury in vitro, and Na₂SeO₃ was applied to establish an in vivo cataract model. In our current study, a cell counting kit-8 (CCK-8) assay was performed to evaluate the effects of H₂O₂ and AKBA on cell viability in vitro. Intracellular reactive oxygen species (ROS) levels were measured with the ROS assay to verify the antioxidant capacity of AKBA. Apoptotic cells were detected and measured by TUNEL staining and flow cytometry, and quantitative real-time (qRT)-PCR and Western blotting were applied to examine the transcription and expression of apoptosis-related proteins. Furthermore, immunofluorescence staining was performed to locate factor-erythroid 2-related factor 2 (Nrf2), and the protein levels of Nrf2, kelch-like ECH-associated protein 1 (Keap1) and heme oxygenase-1 (HO-1) were determined by Western blotting. Finally, we observed the degree of lens opacity and performed hematoxylin-eosin (H&E) staining to assess the protective effect of AKBA on cataract formation in vivo. AKBA increased HLECs viability under H₂O₂ stimulation, decreased intracellular ROS levels and alleviated the cell apoptosis rate in vitro. AKBA significantly decreased the expression of caspase-3 and Bax and increased the content of Bcl-2. The results of immunofluorescence and immunohistochemical staining proved that the expression and nuclear translocation of Nrf2 were activated with AKBA treatment in vivo and in vitro. Moreover, computational docking results showed that AKBA could bind specifically to the predicted Keap1/Nrf2 binding sites. After AKBA activation, Nrf2 dissociates from the Nrf2/Keap1 complex, translocates into the nucleus, and subsequently promotes HO-1 expression. In addition, AKBA attenuated lens opacity in selenite-induced cataracts. Overall, these findings indicated that AKBA alleviated oxidative injury and cataract formation by activating the Keap1/Nrf2/HO-1 cascade. Therefore, our current study highlights that AKBA may serve as a promising treatment for ARC progression.

Toll-like receptor 3 gene regulates cataract-related mechanisms via the Jagged-1/Notch signaling pathway

Epithelial-melancholy transition (EMT) is the main cause of organ fibrosis and a common pathogenetic mechanism in most cataracts. This study aimed to explore the molecular mechanism of Toll-like receptor (TLR)-3 in the occurrence and development of post-cataract EMT and to provide new ideas for the prevention and treatment of posterior capsule opacification (PCO). In the presence or absence of TLR3, the human lens epithelial cell (LEC) line, SRA01/04, was treated with the transforming growth factor (TGF)-β2. Cell counting kit-8 (CCK-8) and Transwell assays were used to analyze the cell proliferation, migration, and invasion. The expression levels of proteins and RNAs were detected by western blotting and quantitative polymerase chain reaction (qPCR) experiments. Functional gain and loss studies showed that TLR3 regulates the proliferation, migration, and invasion of LECs and EMT induced by TGF-β2. Moreover, TLR3 regulates the expression of Jagged-1, Notch-1, and Notch-3 These findings indicate that TLR3 prevents the progression of lens fibrosis by targeting the Jagged-1/Notch signaling pathway to regulate the proliferation, migration, and invasion of LECs, and TGF-β2-induced EMT. Therefore, the TLR3-Jagged-1/Notch signaling axis may be a potential therapeutic target for the treatment of fibrotic cataracts.

Socio-economic disparity in visual impairment from cataract

AIM

To investigate the association of visual impairment from cataract with human development index (HDI) by years lived with disability (YLDs).

METHODS

Published data on national age-standardized YLD rates caused by cataract and national HDIs in 2019 were obtained. Age-standardized YLD rates from 1990 to 2019 were analyzed to explore cataract burden among patients with different income levels. Age-standardized YLD rates in different HDI groups were compared by different degrees of visual impairment. Association between national age-standardized YLD rates and HDI in 2019 was analyzed.

RESULTS

The age-standardized YLD rates of populations with visual impairment or blindness due to cataract declined from 1990 to 2019, especially among those with lower middle income. Multiple comparison tests revealed that countries with low HDI had significantly higher age-standardized YLD rates of blindness due to cataract than those with high and very high HDI (P<0.001). The age-standardized YLD rates of populations with blindness (β=-0.588, P<0.001), severe vision loss (β=-0.378, P<0.001), and moderate vision loss (β=-0.389, P<0.001) inversely correlated with HDI.

CONCLUSION

Age-standardized YLD rates caused by cataract have declined since 1990. The burden of visual impairment due to cataract inversely correlate with national socioeconomic development and is more concentrated in countries with low HDI than those with high HDI, especially among the blind. These findings highlight the need to provide additional cataract services and cataract surgery coverage to developing countries to decrease the burden of avoidable blindness caused by cataract.

Decomposition of Economic Inequality in Cataract Surgery Using Oaxaca Blinder Decomposition: Tehran Geriatric Eye Study (TGES)

Purpose: The aim of this study was to investigate economic inequality in cataract surgery and to decompose it into its determinants using Oaxaca-Blinder decomposition.Methods: The Tehran Geriatric Eye Study is a population-based cross-sjal study that was done on individuals above 60 years using stratified cluster random sampling. All subjects underwent full optometric, slit lamp, and fundoscopic examinations. Then, after pupil dilation, the history of cataract surgery, including PC and AC IOL, was determined.Results: The age and sex-standardized prevalence of cataract surgery was 33.51% (95% CI: 31.45 to 35.62). Cataract surgery had a significant positive association with age (OR: 14.06; p < .001 for >80 vs 60-64 years) and a significant inverse association with education level (OR: 0.55, p: 0.006 for college education vs being illiterate) and economic status (OR: 0.64, p: 0.003 for rich vs poor). A significant difference was found in cataract surgery between the rich and poor (26.22%) disfavoring the poor (p < .001). The explained and unexplained portions comprised 95.99% and 4.01% of the difference (p < .001 and p = .336, respectively). Among study variables, age (p < .001), education (p = .003), economic status (p = .002), insurance (p = .011), and eye examination (p < .001) were significant determinants of inequality in the explained portion.Conclusion: There was a marked difference in the prevalence of cataract surgery between the rich and poor that was mostly caused by the explained portion. Age, economic status, and education had the largest effects on increasing the inequality and history of eye examination by an ophthalmologist and insurance coverage had the largest effects on reducing this inequality.

Efficacy, safety and visual outcomes of cataract surgeries performed during blindness prevention programs in different locations in Kenya

PURPOSE

To determine the visual outcomes achieved in terms of efficacy and safety during high-volume cataract surgery programs in different locations in Kenya.

METHODS

Eight hundred eighty-one eyes of 849 patients underwent extracapsular cataract extraction with intraocular lens implantation in a retrospective, observational, consecutive cohort study on patients who underwent cataract surgery in five programs that a Spanish non-governmental organization conducted between 2013 and 2019 for the prevention of blindness in different geographical areas of Kenya: Thika, Athi River, Kissi, Bagavathi, and Nakuru. The programs were carried out by Spanish and Kenyan surgeons working together.

RESULTS

Mean age was 66.81 ± 14.47 years. Fifty-one percent of the operated eyes (447 eyes) were women. 94% of patients belonged to six ethnic groups. The mean uncorrected distance visual acuity (UDVA) before surgery was 1.98 ± 0.98 logMAR (20/2000), which changed to 0.82 ± 0.68 logMAR (20/150) 3 months after surgeries. The corrected distance visual acuity (CDVA) was 0.4 ± 0.53 logMAR (20/50) 3 months after surgery, 77.5% of the patients had good visual outcomes, and 6.3% had poor outcomes. Preoperative UDVAs were significantly different with respect to the different geographical areas (Kruskal-Wallis; p < 0.001). The most common intraoperative complication was posterior capsule rupture (incidence, 4.2%, 37 of 881), and the most serious complication was expulsive hemorrhage (incidence, 0.1%, 1 of 881).

CONCLUSIONS

Cataract programs performed in a middle-income country with the proper technique and standardized protocols of action improved the visual outcome of the patients. Dissimilar baseline status was found in different areas regarding preoperative visual acuities. Training programs of local surgeons should be reinforced.

Survey report on keratoplasty in China: A 5-year review from 2014 to 2018

To provide the general information on corneal transplantation (CT) in China, China Cornea Society designed a questionnaire on CT from 2014 to 2018 and entrusted it to 31 committee members for implementation of the survey nationwide. This article presents the results of the survey and compares the indicators used in the survey and those in the annual statistical report released by the Eye Bank Association of America (EBAA). The number of corneal transplantations completed by the 64 hospitals from 2014 to 2018 was respectively 5377, 6394, 7595, 8270 and 8980, totally 36,616 (22,959 male and 13,657 female). The five largest hospitals by the number of corneal transplantations completed 15,994 surgeries in total, accounting for 43.68% of all the surgeries performed in the 64 hospitals. The most common indication for corneal transplantations was corneal leukoma (7683, 20.98%), followed by bacterial keratitis (4209, 11.49%), corneal dystrophies (4189, 11.44%), keratoconus (3578, 9.77%) and corneal perforation (2839, 7.75%). The main surgical techniques were penetrating keratoplasty (PK) (19,896, 54.34%), anterior lamellar keratoplasty (ALK) (13,869, 37.88%). The proportion of PK decreased from 57.97% in 2014 to 52.88% in 2018 while the proportion of ALK increased from 36.04% in 2014 to 37.92% in 2018. The geographical distribution of keratoplasties performed in China is unbalanced. PK and ALK were the main techniques of CT and corneal leukoma, bacterial keratitis and corneal dystrophies were the main indications for CT in China.

Are we advancing universal health coverage through cataract services? Protocol for a scoping review

INTRODUCTION

Universal health coverage (UHC) includes the dimensions of equity in access, quality services that improve health and protection against financial hardship. Cataract continues to be the leading cause of blindness globally, despite cataract surgery being an efficacious intervention. The aim of this scoping review is to map the nature, extent and global distribution of data on cataract services for UHC in terms of equity, access, quality and financial protection.

METHODS AND ANALYSIS

The search will be constructed by an Information Specialist and undertaken in MEDLINE, Embase and Global Health databases. We will include all published non-interventional primary research studies and systematic reviews that report a quantitative assessment of access, equity, quality or financial protection of cataract surgical services for adults at the subnational, national, regional or global level from population-based surveys or routinely collected health service data since 1 January 2000 and published through to February 2020.Screening and data charting will be undertaken using Covidence systematic review software. Titles and abstracts of identified studies will be screened by two authors independently. Full-text articles of potentially relevant studies will be obtained and reviewed independently by two authors against the inclusion criteria. Any discrepancies between the authors will be resolved by discussion, and with a third author as necessary. A data charting form will be developed and piloted on three studies by three authors and amendments made as necessary. Data will be extracted by two reviewers independently and summarised narratively and using maps.

ETHICS AND DISSEMINATION

Ethical approval was not sought as the scoping review will only use published and publicly accessible data. The review will be published in an open access peer-reviewed journal. A summary of the results will be developed for website posting, stakeholder meetings and inclusion in the ongoing Lancet Global Health Commission on Global Eye Health.

Long Noncoding RNA NEAT1 Regulates TGF-β2-Induced Epithelial-Mesenchymal Transition of Lens Epithelial Cells through the miR-34a/Snail1 and miR-204/Zeb1 Pathways

The aim of this study was to explore whether the long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1)/miR-34a/Snail1 and NEAT1/miR-204/Zeb1 pathways are involved in epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs). Primary human LECs (HLECs) were separated and cultured. Our results identified that TGF-β2 induces NEAT1 overexpression in a dose-dependent manner and a time-dependent manner. Additionally, TGF-β2 induced downregulation of E-cadherin and upregulation of fibronectin in primary HLECs through a NEAT1-dependent mechanism. Microarray analysis showed that NEAT1 overexpression inhibited the miR-34a and miR-204 levels in the LECs. The expression of miR-34a and miR-204 was decreased, and the levels of Snail1 and Zeb1 were elevated in human posterior capsule opacification- (PCO-) attached LECs and the LECs obtained from anterior subcapsular cataract (ASC) by quantitative RT-PCR (qRT-PCR). Mechanistic studies revealed that NEAT1 negatively regulates miR-34a or miR-204, and miR-34a or miR-204 directly targets Snail1 or Zeb1 by luciferase assay and RNA-binding protein immunoprecipitation assay, respectively. Overall, the NEAT1/miR-34a/Snail1 and NEAT1/miR-204/Zeb1 pathways are involved in TGF-β2-induced EMT of HLECs. In summary, TGF-β2 induces NEAT1 overexpression, which in turn suggests that NEAT1 acts as a ceRNA targeting Snail1 or Zeb1 by binding miR-34a or miR-204, and promotes the progression of EMT of LECs.

2',3'-Cyclic-nucleotide 3'-phosphodiesterase contributes to epithelial-mesenchymal transition of lens epithelial cells through the notch signalling pathway

Objectives

Fibrosis is a complex process involved in multiple diseases that result in organ injury and failure. Cataract, one common form of ocular fibrosis, is a main cause of blindness worldwide, and surgery may be the only cure. In this regard, epithelial‐mesenchymal transition (EMT) of lens epithelial cells (LECs) is the primary cause of anterior subcapsular cataract (ASC). This study aimed to investigate the mechanism by which 2',3'‐cyclic‐nucleotide 3'‐phosphodiesterase (CNPase) regulates the function of EMT in LECs.

Materials and Methods

A mouse model of ASC was used to observe the expression of CNPase in the lens and correlate its expression changes with lens EMT. Furthermore, the effects of CNPase on cell migration and cell proliferation were evaluated by transwell migration, wound healing and EdU staining assays. Finally, Western blotting and immunofluorescence were used to assess the mechanical properties potentially involved in the regulation of EMT by CNPase.

Results

The expression of CNPase was upregulated in LECs during the EMT process in mice with ASC. Notably, CNPase significantly promoted the proliferation, migration and EMT of LECs in vitro. Interestingly, the EMT‐promoting mechanism of CNPase may be achieved by targeting the Notch signalling pathway.

Conclusions

Considering the involvement of EMT in ASC, both CNPase and the Notch signalling pathway may be therapeutic targets for the treatment of cataracts.