Hyperlipidemia, Blood Lipid Level, and the Risk of Glaucoma: A Meta-Analysis

Neuroprotection of the P2X7 receptor antagonist A740003 on retinal ganglion cells in experimental glaucoma

The aim of this study was to explore the neuroprotective effects of the P2X7 receptor antagonist A740003 on retinal ganglion cells (RGCs) in chronic intraocular hypertension (COH) experimental glaucoma mouse model. Bioinformatics was used to analyze the glaucoma-related genes. Western blot, real-time fluorescence quantitative PCR, and immunofluorescence staining techniques were employed to explore the mechanisms underlying the neuroprotective effects of A740003 on RGCs in COH retinas. Bioinformatic analysis revealed that oxidative stress, neuroinflammation, and cell apoptosis were highly related to the pathogenesis of glaucoma. In COH retinas, intraocular pressure elevation significantly increased the levels of translocator protein, a marker of microglial activation, which could be reversed by intravitreal preinjection of A740003. A740003 also suppressed the increased mRNA levels of proinflammatory cytokines interleukin (IL) 1β and tumor necrosis factor α in COH retinas. In addition, although the mRNA levels of anti-inflammatory cytokine IL-4 and IL-10 were kept unchanged in COH retinas, administration of A740003 could increase their levels. The mRNA and protein levels of Bax and cleaved caspase-3 were increased in COH retinas, which could be partially reversed by A740003, while the levels of Bcl-2 kept unchanged in COH retinas with or without the injections of A740003. Furthermore, A740003 partially attenuated the reduction in the numbers of Brn-3a-positive RGCs in COH mice. A740003 could provide neuroprotective roles on RGCs by inhibiting the microglia activation, attenuating the retinal inflammatory response, reducing the apoptosis of RGCs, and enhancing the survival of RGCs in COH experimental glaucoma.

Evaluating the risk of new-onset glaucoma in chronic kidney disease patients: a nationwide cohort study

BACKGROUND

A better understanding of the association between chronic kidney disease (CKD) and glaucoma is required to optimize clinical outcomes. Therefore, this study aimed to investigate the association of chronic kidney disease (CKD) with new diagnoses of glaucoma over time from January 2009 to December 2019.

METHOD

This retrospective propensity-matched cohort study utilizing Taiwanese electronic health records examined the incidence of newly diagnosed glaucoma in patients with and without chronic kidney disease (CKD). The exposure variable was the diagnosis of CKD, identified through diagnostic codes. The primary outcome was the incidence of new-onset glaucoma. Subgroup analyses on glaucoma risk included age, gender, comorbidities, glaucoma subtypes, and dialysis status. Statistical analyses included Kaplan-Meier analysis, Cox proportional hazards models, and Poisson regression models, with the associated hazard ratios and confidence intervals reported.

RESULTS

Seven hundred twenty-three thousand two hundred sixteen patients with CKD (42.3% female; mean [SD] age at index, 66.3 [15.6] years) and 723,216 patients without CKD (42.3% female; mean [SD] age at index, 66.3 [15.7]) were recruited. We showed a significantly increased risk of glaucoma irrespective of subtypes in CKD patients compared to those without CKD (HR: 1.29 [CI: 1.26-1.32], p < 0.001). Kaplan-Meier curves revealed a significantly increased glaucoma risk in both the dialytic subtype and non-dialytic CKD patients when compared to their non-CKD counterparts (p < 0.001). We also showed that all genders (aHR 1.17 [CI: 1.13-1.21] for females vs. aHR 1.39 [CI:1.35-1.43] for males), all ages (< = 49: aHR 1.49 [CI: 1.37-1.62]; 50-59: aHR 1.48 [CI: 1.40-1.56]; 60-69: aHR 1.30 [CI: 1.25-1.6]; 70-79: aHR 1.21 [CI: 1.17-1.26]; > 80: aHR 1.29 [CI: 1.21-1.37]); all income brackets and all urbanization status were associated with significantly increased risk of glaucoma from among the CKD cohort when compared to their respective non-CKD cohort (p < 0.001).

CONCLUSIONS

Our cohort study spanning 12 years showed an elevated glaucoma risk following a CKD diagnosis compared to a frequency-matched non-CKD cohort. Our findings have relevance for the clinical practice of at-risk CKD patients.

TRIAL REGISTRATION

Due to the retrospective nature of the study, no registration was necessary.

Development of a novel scoring system for glaucoma risk based on demographic and laboratory factors using ChatGPT-4

We developed a scoring system for assessing glaucoma risk using demographic and laboratory factors by employing a no-code approach (automated coding) using ChatGPT-4. Comprehensive health checkup data were collected from the Korea National Health and Nutrition Examination Survey. Using ChatGPT-4, logistic regression was conducted to predict glaucoma without coding or manual numerical processes, and the scoring system was developed based on the odds ratios (ORs). ChatGPT-4 also facilitated the no-code creation of an easy-to-use risk calculator for glaucoma. The ORs for the high-risk groups were calculated to measure performance. ChatGPT-4 automatically developed a scoring system based on demographic and laboratory factors, and successfully implemented a risk calculator tool. The predictive ability of the scoring system was comparable to that of traditional machine learning approaches. For high-risk groups with 1-2, 3-4, and 5 + points, the calculated ORs for glaucoma were 1.87, 2.72, and 15.36 in the validation set, respectively, compared with the group with 0 or fewer points. This study presented a novel no-code approach for developing a glaucoma risk assessment tool using ChatGPT-4, highlighting its potential for democratizing advanced predictive analytics, making them readily available for clinical use in glaucoma detection.

Artificial intelligence in therapeutic management of hyperlipidemic ocular pathology

Hyperlipidemia has many ocular manifestations, the most prevalent being retinal vascular occlusion. Hyperlipidemic lesions and occlusions to the vessels supplying the retina result in permanent blindness, necessitating prompt detection and treatment. Retinal vascular occlusion is diagnosed using different imaging modalities, including optical coherence tomography angiography. These diagnostic techniques obtain images representing the blood flow through the retinal vessels, providing an opportunity for AI to utilize image recognition to detect blockages and abnormalities before patients present with symptoms. AI is already being used as a non-invasive method to detect retinal vascular occlusions and other vascular pathology, as well as predict treatment outcomes. As providers see an increase in patients presenting with new retinal vascular occlusions, the use of AI to detect and treat these conditions has the potential to improve patient outcomes and reduce the financial burden on the healthcare system. This article comprehends the implications of AI in the current management strategies of retinal vascular occlusion (RVO) in hyperlipidemia and the recent developments of AI technology in the management of ocular diseases.

Epidemiology and Treatment of Patients With Primary Open Angle Glaucoma in Germany: A Health Claims Data Analysis

PRCIS

Based on a large administrative database of German claims data, our study provides current estimates of the prevalence and incidence of primary open angle glaucoma (POAG) in Germany and describes selected outcomes for prevalent patients with POAG.

PURPOSE

To estimate the prevalence and incidence of POAG in Germany, to describe the patient population in terms of comorbidity burden, routine care, and overall healthcare resource utilization (HCRU) and associated costs, and to describe treatment patterns over time in patients undergoing relevant laser procedures.

MATERIALS AND METHODS

Based on anonymized German claims data, we carried out a retrospective, noninterventional study covering calendar years 2016-2021.

RESULTS

For the adult German population (≥18 y), we estimated a POAG 1-year prevalence of 1.70% and a 1-year incidence of 0.17% in 2018; both increased with age, peaking in 80- to 89-year-olds. Prevalence and incidence were lower in 2020 (1.65% and 0.16%, respectively), the first year of the SARS-CoV-2 pandemic. Most patients solely received topical treatment. Most surgically treated patients underwent laser trabeculoplasty, followed by laser iridotomy, trabeculectomy, and filtration operations with implant. In patients undergoing laser trabeculoplasty, the treatment regimen was nearly unchanged in the second year after, compared with 2 years before the procedure. Multimorbidity was commonly observed; 75.5% of patients had arterial hypertension and 50.0% had disorders of lipoprotein metabolism and other lipidemias, compared with 60.1% and 39.2%, respectively, in an age- and sex-matched control sample.

CONCLUSIONS

Our study provides insights into epidemiology and routine care of POAG in Germany and HCRU in prevalent patients. There was little change in treatment regimens in patients who underwent laser trabeculoplasty, 2 years after the procedure. Most patients were multimorbid highlighting the need for comprehensive care.

Associations Between Life's Essential 8 and Major Ocular Diseases in the American Middle-Aged and Elderly Population

PURPOSE

To explore the correlation between cardiovascular health (CVH) and ocular diseases, given their shared risk factors and biological mechanisms, this study utilizes the newly updated Life's Essential 8 (LE8) algorithm.

DESIGN

A cross-sectional study.

METHODS

This analysis, conducted from February 15 to April 1, 2024, in Changchun, includes data from 4146 participants aged 40 and above, drawn from the National Health and Nutrition Examination Survey database (2005-2008). It covers information on visual health status, dietary habits through interviews, and professional ophthalmological examinations. Participants' CVH status was assessed using the LE8 algorithm, and relationships with major ocular diseases such as retinopathy, cataracts, diabetic retinopathy, glaucoma, and age-related macular degeneration were explored through weighted logistic regression analysis, restricted cubic splines, stratified analysis, and sensitivity analysis.

RESULTS

After multivariable adjustment, lower LE8 scores showed a significant positive relationship with any ocular disease (odds ratio [OR]: 2.03, 95% confidence interval [CI]: 1.39-2.96, P = .001), any objectively determined ocular disease (OR: 2.24, 95% CI: 1.48-3.38, P < .001), retinopathy (OR: 2.88, 95% CI: 1.89-4.41, P < .001), diabetic retinopathy (OR: 10.23, 95% CI: 3.11-33.61, P < .001), and glaucoma (OR: 2.76, 95% CI: 1.47-5.21, P = .003), with all trends significant (all P < .01). Additionally, lower scores in the behavioral subdomain were significantly correlated with an elevated risk of cataracts (OR: 1.45, 95% CI: 1.03-2.04). Subgroup analyses revealed more pronounced negative correlations between LE8 and retinopathy among females and those suffering from chronic kidney disease.

CONCLUSIONS

A low CVH score was linked to an increased likelihood of ocular diseases in a US-populated-based study. This correlation supports the potential benefits of enhancing cardiovascular wellness to mitigate the development of ocular conditions.

Associations between Statin Use and Glaucoma in the All of Us Research Program

PURPOSE

To investigate associations between statin use and glaucoma in the 2017-2022 All of Us (AoU) Research Program.

DESIGN

Cross-sectional, population-based.

PARTICIPANTS

79,742 adult participants aged ≥ 40 years with hyperlipidemia and with electronic health record (EHR) data in the AoU database.

METHODS

Hyperlipidemia, glaucoma status, and statin use were defined by diagnoses and medication information in EHR data collected by AoU. Logistic regression analysis was performed to evaluate the association between statin use and glaucoma likelihood. Logistic regression modeling was used to examine associations between glaucoma and all covariates included in adjusted analysis. Serum low-density lipoprotein cholesterol (LDL-C) was used to assess hyperlipidemia severity. Analyses stratified by LDL-C level and age were performed.

MAIN OUTCOME MEASURES

Any glaucoma as defined by International Classification of Diseases (ICD) codes found in EHR data.

RESULTS

Of 79,742 individuals with hyperlipidemia in AoU, there were 6,365 (8.0%) statin users. Statin use was associated with increased glaucoma prevalence when compared with statin non-use (adjusted odds ratio [aOR]: 1.13, 95% confidence interval [CI]: 1.01-1.26). Higher serum levels of LDL-C were associated with increased odds of glaucoma (aOR: 1.003, 95% CI: 1.003, 1.004). Statin users had significantly higher LDL-C levels compared to nonusers (144.9 mg/dL versus 136.3 mg/dL, p-value < 0.001). Analysis stratified by LDL-C identified positive associations between statin use and prevalence of glaucoma among those with optimal (aOR = 1.39, 95% CI = 1.05-1.82) and high (aOR = 1.37, 95% CI = 1.09-1.70) LDL-C levels. Age-stratified analysis showed a positive association between statin use and prevalence of glaucoma in individuals aged 60-69 years (aOR = 1.28, 95% CI = 1.05-1.56).

CONCLUSIONS

Statin use was associated with increased glaucoma likelihood in the overall adult AoU population with hyperlipidemia, in individuals with optimal or high LDL-C levels, and in individuals 60-69 years old. Findings suggest that statin use may be an independent risk factor for glaucoma, which may furthermore be affected by one's lipid profile and age.

Breaking Barriers in Behavioral Change: The Potential of Artificial Intelligence-Driven Motivational Interviewing

Patient outcomes in ophthalmology are greatly influenced by adherence and patient participation, which can be particularly challenging in diseases like glaucoma, where medication regimens can be complex. A well-studied and evidence-based intervention for behavioral change is motivational interviewing (MI), a collaborative and patient-centered counseling approach that has been shown to improve medication adherence in glaucoma patients. However, there are many barriers to clinicians being able to provide motivational interviewing in-office, including short visit durations within high-volume ophthalmology clinics and inadequate billing structures for counseling. Recently, Large Language Models (LLMs), a type of artificial intelligence, have advanced such that they can follow instructions and carry coherent conversations, offering novel solutions to a wide range of clinical problems. In this paper, we discuss the potential of LLMs to provide chatbot-driven MI to improve adherence in glaucoma patients and provide an example conversation as a proof of concept. We discuss the advantages of AI-driven MI, such as demonstrated effectiveness, scalability, and accessibility. We also explore the risks and limitations, including issues of safety and privacy, as well as the factual inaccuracies and hallucinations to which LLMs are susceptible. Domain-specific training may be needed to ensure the accuracy and completeness of information provided in subspecialty areas such as glaucoma. Despite the current limitations, AI-driven motivational interviewing has the potential to offer significant improvements in adherence and should be further explored to maximally leverage the potential of artificial intelligence for our patients.

Association of smoking cessation patterns and untreated smoking with glaucoma, cataract, and macular degeneration: a population-based retrospective study

This study aims to assess the association between nicotine replacement therapy (NRT), varenicline, and untreated smoking with the risk of developing eye disorders. We employed a new-user design to investigate the association between NRT use and the incidence of eye disorders by the Taiwan National Health Insurance program. This study included 8416 smokers who received NRT and 8416 smokers who did not receive NRT (control group) matched using propensity scores between 2007 and 2018. After adjustment for relevant factors, a multivariable Cox regression analysis revealed that compared with untreated smokers, NRT use was associated with a significantly reduced risk of macular degeneration (hazard ratio [HR]: 0.34; 95% confidence interval [CI]: 0.13-0.87, P = 0.024). When stratified by dose, short-term NRT use (8-28 defined daily doses) was associated with significantly lower risk of glaucoma (HR: 0.35; 95% CI: 0.16-0.80, P = 0.012) and a trend toward reduced risk of cataract (HR: 0.60; 95% CI: 0.36-1.01, P = 0.053) compared to no treatment. However, these associations were not observed with long-term NRT use. The results of this real-world observational study indicate that NRT use, particularly short-term use, was associated with a lower risk of certain eye disorders compared to no treatment for smoking cessation. Long-term NRT use did not demonstrate the same benefits. Thus, short-term NRT may be a beneficial treatment strategy for reducing the risk of eye disorders in smokers attempting to quit. However, further evidence is required to verify these findings and determine the optimal duration of NRT use.

Environmental exposures to cadmium and lead as potential causes of eye diseases

Humans are exposed to cadmium and lead in various regions of the world daily due to industrial development and climate change. Increasing numbers of preclinical and clinical studies indicate that heavy metals, such as cadmium and lead, play a role in the pathogenesis of eye diseases. Excessive exposure to heavy metals such as cadmium and lead can increase the risk of impaired vision. Therefore, it is essential to better characterize the role of these non-essential metals in disease etiology and progression. This article discusses the potential role of cadmium and lead in the development of age-related eye diseases, including age-related macular degeneration, cataracts, and glaucoma. Furthermore, we discuss how cadmium and lead affect ocular cells and provide an overview of putative pathological mechanisms associated with their propensity to damage the eye.

Neuroprotective Effects of Anti-diabetic Drugs in the Treatment of Patients with Diabetes and Glaucoma or at High Risk for Glaucoma

There is an association between glaucoma and several risk factors and metabolic diseases, such as type 2 diabetes mellitus. Diabetes mellitus leads to neurodegenerative changes, both peripherally and in the brain. This might be a shared pathophysiology and etiology for both glaucoma and diabetes. It is interesting that drugs for the treatment of diabetes seem to have neuroprotective properties independent of their blood sugar reduction. Although prospective, randomized, clinical studies are still missing, particularly metformin and glucagon-like peptide receptor agonists (GLP 1 RA) seem to have neuroprotective effects. Sulphonylureas (e.g., glibenclamide, glimepiride) are still used. They frequently potently reduce blood pressure but may be less neuroprotective. In the present review, the evidence for neuroprotective effects of the different antidiabetic drugs is presented and a possible differential therapy for patients with diabetes and glaucoma, or at high risk of glaucoma, will be discussed.

Regulatory role of cholesterol in modulating actin dynamics and cell adhesive interactions in the trabecular meshwork

The trabecular meshwork (TM) tissue plays a crucial role in maintaining intraocular pressure (IOP) homeostasis. Increased TM contractility and stiffness are directly correlated with elevated IOP. Although cholesterol is known to be a determinant of glaucoma occurrence and elevated IOP, the underlying mechanisms remain elusive. In this study, we used human TM (HTM) cells to unravel the effects of cholesterol on TM stiffness. We achieved this by performing acute cholesterol depletion with Methyl-β-cyclodextrin (MβCD) and cholesterol enrichment/replenishment with MβCD cholesterol complex (CHOL). Interestingly, cholesterol depletion triggered notable actin depolymerization and decreased focal adhesion formation, while enrichment/replenishment promoted actin polymerization, requiring the presence of actin monomers. Using a specific reporter of phosphatidylinositol 4,5-bisphosphate (PIP2), we demonstrated that cholesterol depletion decreases PIP2 levels on the cell membrane, whereas enrichment increases them. Given the critical role of PIP2 in actin remodeling and focal adhesion formation, we postulate that cholesterol regulates actin dynamics by modulating PIP2 levels on the membrane. Furthermore, we showed that cholesterol levels regulate integrin α5β1 and αVβ3 distribution and activation, subsequently altering cell-extracellular matrix (ECM) interactions. Notably, the depletion of cholesterol, as a major lipid constituent of the cell membrane, led to a decrease in HTM cell membrane tension, which was reversed upon cholesterol replenishment. Overall, our systematic exploration of cholesterol modulation on TM stiffness highlights the critical importance of maintaining appropriate membrane and cellular cholesterol levels for achieving IOP homeostasis.

Factors Associated with Increased Intraocular Pressure in Type 2 Diabetes Patients

BACKGROUND

Over one-third of patients living with diabetes will develop ocular disease during their lifetime. The present study analyzes the association between metabolic and anthropometric markers, associated comorbidities, and intraocular pressure (IOP) in patients with type 2 diabetes mellitus (DM).

METHODS

The retrospective study included 87 adult patients with type 2 DM who underwent routine eye examinations and blood/urine tests.

RESULTS

67.9% of the patients had an IOP > 14.5 mmHg and only 41.3% had an HbA1c < 7%. In a multivariate regression analysis, the mean IOP was associated with diabetes duration in subjects with a disease duration < 15 years and an HbA1c < 7% (adjusted R2 = 0.29, p = 0.008). Also, patients with shorter diabetes duration and optimal glucose control had a lower mean IOP than patients with a higher HbA1c (mean IOP 15.1 mmHG vs. 18.9 mmHg, p = 0.04). The patient's age, anthropometric or metabolic markers, associated comorbidities like hypertension (HTN) or retinal angiosclerosis, and diabetes therapies were not associated with IOP in this study.

CONCLUSION

Diabetes progression is directly associated with increased IOP. Avoiding clinical inertia and optimizing glycemic control could prevent or delay the increase of IOP. Routine eye examination should include measuring IOP, not only diabetic retinopathy screening.

Association between dyslipidaemia and dry eye disease: a systematic review and meta-analysis

PURPOSE

To report a systematic review and meta-analysis of the association between dry eye disease (DED) and dyslipidaemia.

METHODS

PubMed, Embase, Web of Science and Cochrane Library were systematically searched from January 2000 to December 2021. We included observational studies to assess the correlation of DED with meibomian gland dysfunction and dyslipidaemia without any language restrictions. The pooled OR with 95% CI was calculated in Stata V.15.

RESULTS

Of 6727 identified studies, 18 studies (21 databases) with a total of 2 663 126 patients were analysed in our meta-analysis. The results showed that DED risk was associated with dyslipidaemia (OR=1.53, 95% CI: 1.41 to 1.66, p=0.001), especially elevated total cholesterol levels (OR=1.57, 95% CI: 1.25 to 1.99, p<0.001), elevated low-density lipoprotein cholesterol levels (OR=1.13, 95% CI: 1.06 to 1.20, p<0.001) and high-density lipoprotein cholesterol levels (OR=1.06, 95% CI: 1.01 to 1.11, p<0.001), but not with serum triglyceride levels. Moreover, having a history of lipid-lowering drug use (OR=1.41, 95% CI: 1.19 to 1.67, p<0.001) was also found to be positively associated with DED risk.

CONCLUSIONS

The findings suggested that dyslipidaemia and lipid-lowering drug use might be associated with an increased risk of DED. More evidence is needed to confirm the findings by prospective studies.

PROSPERO REGISTRATION NUMBER

CRD42022296664.

Primary open-angle glaucoma risk prediction with ABCA1 and LOC102723944 variants and their genotype-phenotype correlations in southern Chinese population

Glaucoma is a leading cause of irreversible visual impairment and blindness worldwide. Previous genome-wide association studies have identified caveolin-1 (CAV1), ATP-binding cassette A1 (ABCA1), and forkhead box C1 (FOXC1) loci associated with primary open angle glaucoma (POAG), a major subtype of glaucoma. This study aimed to fine map the association pattern of FOXC1 locus with POAG and determine the correlations of FOXC1, ABCA1, and CAV1 variants with ocular and lipidemic parameters in southern Chinese population. In total, 1291 unrelated Han Chinese subjects were recruited, including 301 high-tension glaucoma (HTG), 126 normal-tension glaucoma (NTG), and 864 control subjects. Twelve variants in FOXC1 locus, and two variants in ABCA1 and CAV1 genes, were genotyped by TaqMan assays. Genetic risk score and genotype-phenotype correlation analyses were conducted. In the FOXC1 locus, LOC102723944 rs6596830, rather than previously reported rs2745572, showed significant association with POAG (P = 8.61 × 10-4, odds ratio (OR) = 0.75) and HTG (P = 3.68 × 10-3, OR = 0.75). ABCA1 rs2487032 was also significantly associated with POAG (P = 3.00 × 10-5, OR = 0.70) and HTG (P = 2.08 × 10-4, OR = 0.70). Joint analysis showed that carriers of homozygous non-protective alleles of ABCA1 rs2487032 and LOC102723944 rs6596830 had 2.99-fold higher risk of POAG (P = 1.27 × 10-3) when compared to those carrying homozygous non-risk alleles. Patients with POAG carrying ABCA1 rs2487032 G allele had higher HDL cholesterol, and those with LOC102723944 rs6596830 A allele had lower LDL. This study revealed individual and joint association of ABCA1 and LOC102723944 variants with POAG in southern Chinese population. Subjects carrying non-protective alleles had increased risk to POAG, and corresponding genotypes would affect the lipid profiles.

Relationship Between Intraocular Pressure and Age: A Population-Based Study in Nepal

PRCIS

Intraocular pressure (IOP) decreased with age in a population-based study in Nepal, from a mean of 14.1 mm Hg among those 60-64 years old to 13.0 mm Hg among those 80 years old or older.

PURPOSE

Few studies have assessed the distribution of IOP from the Indian subcontinent, despite its large population and high burden of glaucoma. The objective of this study was to assess the distribution of IOP measurements from adults living in a lowland region of Nepal.

METHODS

In a population-based cross-sectional study, all individuals aged 60 years and older from an area of lowland Nepal were invited for an IOP assessment with a rebound tonometer.

RESULTS

Of 160 communities (28,672 people aged ≥60 y) enrolled, 79 (13,808 people aged ≥60 y) were randomly selected for IOP testing. Of those eligible, 10,017 (72.5%) individuals underwent tonometry. Mean IOP decreased monotonically over 5-year age groups, from 14.1 mm Hg (SD: 3.6) among those aged 60-64 years to 13.0 mm Hg (SD: 4.2) among those 80 years or older. The 97.5th percentile IOP measurement was 21.0 mm Hg for all age groups. In adjusted analyses, younger age, self-reported diabetes, and higher population density were each associated with higher IOP, and self-reported cataract surgery was associated with lower IOP.

CONCLUSIONS

Mean IOP was lower among older individuals in Nepal, consistent with many studies from East Asia and in contrast to many studies from western populations. These results suggest that ethnic background might be a consideration when diagnosing ocular hypertension.

Bidirectional Association Between Sudden Sensorineural Hearing Loss and Glaucoma: A Cohort Study

OBJECTIVES

To investigate the bidirectional association between sudden sensorineural hearing loss (SSNHL) and open-angle glaucoma (OAG) over a 12-year follow-up period using nationwide, population-based data.

METHODS

The study was conducted using the National Health Information Database of the National Health Insurance Service (NHIS-NHID), which covered 3.5 million individuals from 2008 to 2019. In Study 1, we evaluated the effect of OAG on SSNHL, and in Study 2, we evaluated the effect of SSNHL on OAG. Participants of the control group were enrolled through "greedy nearest-neighbor" 1:1 propensity score matching.

RESULTS

In Study 1, 26,777 people were included in each group. The hazard ratio (HR) for SSNHL of the OAG group was 1.27 (95% confidence interval [CI], 1.15-1.39). In subgroup analysis, there was significant HR value regarding (old age: 1.17, hyperlipidemia: 1.19). In Study 2, 15,433 people were included in each group. The HR for OAG of the SSNHL group was 1.18 (95% CI, 1.07-1.30). In subgroup analysis, the HRs were significant for old age (2.31), hypertension (1.17), diabetes (1.39), and hyperlipidemia (1.26).

CONCLUSION

Over the 12-year follow-up, we found a bidirectional association between SSNHL and OAG, suggesting a shared pathogenesis.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 133:3169-3177, 2023.

Identification of the novel role of sterol regulatory element binding proteins (SREBPs) in mechanotransduction and intraocular pressure regulation

Trabecular meshwork (TM) cells are contractile and mechanosensitive, and they aid in maintaining intraocular pressure (IOP) homeostasis. Lipids are attributed to modulating TM contractility, with poor mechanistic understanding. In this study using human TM cells, we identify the mechanosensing role of the transcription factors sterol regulatory element binding proteins (SREBPs) involved in lipogenesis. By constitutively activating SREBPs and pharmacologically inactivating SREBPs, we have mechanistically deciphered the attributes of SREBPs in regulating the contractile properties of TM. The pharmacological inhibition of SREBPs by fatostatin and molecular inactivation of SREBPs ex vivo and in vivo, respectively, results in significant IOP lowering. As a proof of concept, fatostatin significantly decreased the SREBPs responsive genes and enzymes involved in lipogenic pathways as well as the levels of the phospholipid, cholesterol, and triglyceride. Further, we show that fatostatin mitigated actin polymerization machinery and stabilization, and decreased ECM synthesis and secretion. We thus postulate that lowering lipogenesis in the TM outflow pathway can hold the key to lowering IOP by modifying the TM biomechanics.

Associations between vision impairment and multimorbidity among older Chinese adults: results from the China health and retirement longitudinal study

BACKGROUND

Although several studies have reported the relationship between vision impairment (VI) and multimorbidity in high-income countries, this relationship has not been reported in low- and middle-income countries. This study aimed to explore the relationship between VI with multimorbidity and chronic conditions among the elderly Chinese population.

METHODS

The cross-sectional analysis was applied to data from the China Health and Retirement Longitudinal Study (CHARLS) in 2018. A total of 8,108 participants ≥ 60 years old were included, and 15 chronic conditions were used in this study. Logistic regression analysis was used to analyze the relationship between VI with multimorbidity and chronic conditions.

RESULTS

The prevalence of 15 chronic conditions and multimorbidity was higher among the elderly with VI than those without VI. After adjusting for demographic and socioeconomic confounders, 10 chronic conditions were associated with VI (all P < 0.05). Furthermore, positive association was observed between VI and one (odds ratio [OR]: 1.52; 95% confidence intervals [95%CI]: 1.16-2.00; P = 0.002), two (OR: 2.09; 95%CI: 1.61-2.71; P < 0.001), three (OR: 2.87; 95%CI: 2.22-3.72; P < 0.001), four (OR: 3.60; 95%CI: 2.77-4.69; P < 0.001), and five or more (OR: 5.53; 95%CI: 4.32-7.09; P < 0.001) chronic conditions, and the association increased as the number of chronic conditions (P for trend < 0.001). Sensitivity analysis stratified by gender, education, smoking status, and annual per capita household expenditure still found VI to be positively associated with multimorbidity.

CONCLUSIONS

For patients older than 60 years, VI was independently associated with multimorbidity and various chronic conditions. This result has important implications for healthcare resource plans and clinical practice, for example, increased diabetes and kidney function screening for patients with VI.

Chylous aqueous humor caused by hyperlipidemia: A case report and literature review

RATIONALE

Generally, there is no lipoprotein in aqueous humor, and chyle usually exists transiently in the body. Therefore, persistent chylous aqueous humor is rare.

PATIENT CONCERNS

We report a case of a 39-year-old man with persistent milky white appearance over the right eye.

DIAGNOSES

The patient had a history of poorly controlled diabetes for the past 2 years and central retinal vein occlusion of the same eye for the past 2 weeks. The patient's right eye had a uniform milky appearance in the anterior chamber, transparent cornea, and no keratic precipitate in the posterior cornea. Color Doppler ultrasound of the affected eye showed no obvious inflammation in the vitreous cavity. Laboratory tests revealed severe chylemia. The patient was finally diagnosed as chylous aqueous humor.

INTERVENTIONS AND OUTCOMES

After conventional hypolipidemia and hypoglycemia treatment and locally glucocorticoid treatment. The milky white changes in the anterior chamber improved considerably and finally disappeared.

LESSONS

Although the impact of hyperlipidemia on the cardiovascular system and digestive system is well known, its impact on the eyes is often overlooked. We report a rare case of unilateral chylous aqueous humor caused by hyperlipidemia. Through the analysis of this special case, we recommend that ophthalmologists should pay attention to the impact of blood lipid change on eyes.

Risk Factors for Primary Angle-closure Glaucoma: A Systematic Review and Meta-analysis of 45 Studies

SIGNIFICANCE

This study summarized primary angle-closure glaucoma (PACG)-related factors across different dimensions.

OBJECTIVES

This review aimed at systematically summarizing the associated factors of PACG in published literatures.

METHODS

A systematic review and meta-analysis were conducted by searching the electronic databases including PubMed, EMBASE, and Web of Science from their inception to November 2021. The pooled risk estimates of continuous and categorical variables were calculated using weighted mean difference (WMD) and odds ratio (OR; 95% confidence intervals [CIs]), respectively.

RESULTS

We included 45 studies in this review. In the meta-analysis, intraocular pressure (WMD, 3.13; 95% CI, 2.37 to 3.89), anterior chamber depth (WMD, -0.52; 95% CI, -0.70 to -0.34), axial length (WMD, -0.77; 95% CI, -1.26 to -0.28), retinal nerve fiber layer (WMD, -21.23; 95% CI, -30.21 to -12.25), and spherical equivalent (WMD, 1.02; 95% CI, 0.66 to 1.38) were the most common ophthalmic anatomic factors, and lower body weight (WMD, -3.65; 95% CI, -6.48 to -0.82) was the most significant general morphological indicators. The presence of cataract (OR, 3.77; 95% CI, 3.46 to 4.11) and hyperlipidemia (OR, 1.10; 95% CI, 1.02 to 1.20) were significantly associated with PACG. Increased level of triglyceride (WMD, 0.17; 95% CI, 0.06 to 0.27) was associated with PACG. In addition, an association between short-term antidepressant exposure (OR, 1.36; 95% CI, 1.08 to 1.70) and acute angle-closure glaucoma was observed.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

This review identified a few consistent factors related to PACG, providing important information for primary care physicians, general ophthalmologists, and public health professionals to counsel their patients on PACG risks.

The Association between Vascular Abnormalities and Glaucoma-What Comes First?

Glaucoma is a leading cause of irreversible blindness worldwide. While intraocular pressure (IOP) presents a major risk factor, the underlying pathophysiology still remains largely unclear. The correlation between vascular abnormalities and glaucoma has been deliberated for decades. Evidence for a role played by vascular factors in the pathogenesis of glaucomatous neurodegeneration has already been postulated. In addition, the fact that glaucoma causes both structural and functional changes to retinal blood vessels has been described. This review aims to investigate the published evidence concerning the relationship between vascular abnormalities and glaucoma, and to provide an overview of the "chicken or egg" dilemma in glaucoma. In this study, several biomarkers of glaucoma progression from a vascular perspective, including endothelin-1 (ET-1), nitric oxide, vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMPs), were identified and subsequently assessed for their potential as pharmacological intervention targets.

Simvastatin Attenuates Glucocorticoid-Induced Human Trabecular Meshwork Cell Dysfunction via YAP/TAZ Inactivation

PURPOSE

Impairment of the trabecular meshwork (TM) is the principal cause of increased outflow resistance in the glaucomatous eye. Yes-associated protein (YAP) and transcriptional coactivator with PDZ binding motif (TAZ) are emerging as potential mediators of TM cell/tissue dysfunction. Furthermore, YAP/TAZ activity was recently found to be controlled by the mevalonate pathway in non-ocular cells. Clinically used statins block the mevalonate cascade and were shown to improve TM cell pathobiology; yet, the link to YAP/TAZ signaling was not investigated. In this study, we hypothesized that simvastatin attenuates glucocorticoid-induced human TM (HTM) cell dysfunction via YAP/TAZ inactivation.

METHODS

Primary HTM cells were seeded atop or encapsulated within bioengineered extracellular matrix (ECM) hydrogels. Dexamethasone was used to induce a pathologic phenotype in HTM cells in the absence or presence of simvastatin. Changes in YAP/TAZ activity, actin cytoskeletal organization, phospho-myosin light chain levels, hydrogel contraction/stiffness, and fibronectin deposition were assessed.

RESULTS

Simvastatin potently blocked pathologic YAP/TAZ nuclear localization/activity, actin stress fiber formation, and myosin light chain phosphorylation in HTM cells. Importantly, simvastatin co-treatment significantly attenuated dexamethasone-induced ECM contraction/stiffening and fibronectin mRNA and protein levels. Sequential treatment was similarly effective but did not match clinically-used Rho kinase inhibition.

CONCLUSIONS

YAP/TAZ inactivation with simvastatin attenuates HTM cell pathobiology in a tissue-mimetic ECM microenvironment. Our data may help explain the association of statin use with a reduced risk of developing glaucoma via indirect YAP/TAZ inhibition as a proposed regulatory mechanism.

Metabolite and Lipid Biomarkers Associated With Intraocular Pressure and Inner Retinal Morphology: 1H NMR Spectroscopy Results From the UK Biobank

Purpose

The purpose of this study was to assess metabolites associated with intraocular pressure (IOP) and inner retina structure.

Methods

We cross-sectionally assessed 168 non-fasting plasma metabolites measured by nuclear magnetic resonance (NMR) spectroscopy with IOP (n = 28,195), macular retinal nerve fiber layer thickness (mRNFL; n = 10,584), and macular ganglion cell inner plexiform layer thickness (mGCIPL; n = 10,554) in the UK Biobank. We used multiple linear regression models adjusting for various covariates with probit-transformed metabolite levels as predictors for each outcome. Each estimate represents the difference in outcome variable per standard deviation increase in the probit-transformed metabolite values. We used the number of effective (NEF) tests and false discovery rate (FDR) to adjust for multiple comparisons for metabolites and metabolite classes, respectively.

Results

In individual metabolite analysis, multiple amino acids, especially branched-chain amino acids, were associated with lower IOP (-0.12 mm Hg; 95% confidence interval = -0.16 to -0.07; NEF = 2.7E-05). Albumin, 3 hydroxybutyrate, lactate, and several lipids were associated with higher IOP (range = 0.07 to 0.18 mm Hg, NEF = ≤ 0.039). In IOP-adjusted analyses, five HDL-related metabolites were associated with thinner mRNFL (-0.15 microns for all metabolites, NEF = ≤ 0.027), whereas five LDL-related metabolites were associated with thicker mGCIPL (range = 0.17 to 0.20 microns; NEF = ≤ 0.044). In metabolite class analysis, the lipid components of lipoproteins (cholesterol, triglycerides, etc.) were not associated with our outcomes (FDR > 0.2 for all); yet multiple lipoproteins were significantly (FDR < 0.05) associated with all outcomes.

Conclusions

Branched-chain amino acids were associated with lower IOP, HDL metabolites were associated with thinner mRNFL, and LDL metabolites were associated with thicker mGCIPL.

Association between statin use and open-angle glaucoma: a nested case-control study using the Japanese claims database

The association between statins and open-angle glaucoma (OAG) remains controversial. This study investigated the relationship between statins and OAG in Japanese patients with dyslipidemia using the Japanese administrative claims database. A nested case-control study using two models was conducted using the JMDC claims database (01/2005-01/2020). The onset of OAG: index date was defined as the diagnosis of glaucoma, prescription of anti-glaucoma drugs, or surgery of glaucoma. For each case, a maximum of 10 age-, sex-, and calendar year/month-matched controls were randomly selected by risk-set sampling with replacement. The number of statin prescriptions during the exposure assessment period, which was identified as the 12-month (model 1) or 24-month (model 2) periods prior to the index date, was used as an indicator for statin exposure. Adjusted odds ratios (aORs) and 95% confidence interval (CI) were estimated using conditional logistic regression analyses. We identified 375,373 patients with newly diagnosed dyslipidemia. Of these, 6180 cases and 61,792 controls (model 1) and 4153 cases and 41,522 controls (model 2) were selected. Statin use was not identified as a significant risk factor for OAG (model 1: aOR 0.98, 95% CI 0.93-1.03, model 2: aOR 0.97, 95% CI 0.91-1.04). Compared with nonexposure, short-term exposure (< 2 years) to statins was not related to an increased risk of OAG in the Japanese working-age population with dyslipidemia.

Secoisolariciresinol diglucoside and anethole ameliorate lipid abnormalities, oxidative injury, hypercholesterolemia, heart, and liver conditions

Fennel seeds and flaxseed have been traditionally used against many medical ailments due to their medicinal characteristics. The aim of the study was to investigate the health properties of secoisolariciresinol diglucoside (SDG) and anethole from flaxseed and fennel seeds in rats fed with high-fat diet. Histopathological changes in the heart and liver were also examined. Sixty rats were divided into two main groups. Group I (10 rats) was used as a negative control group and fed on the basal diet only. Group II (50 rats) was fed a hypercholesterolemic diet but not given any drugs during the trial for 2 weeks. This group was further divided into five subgroups (10 rats each). One of them was fed on the basal diet and used as a positive control group. However, the other four subgroups were fed on basal diets and anethole (20 mg/kg/day, orally), SDG (20 mg/kg/day, orally), a mixture of anethole + SDG (10 + 10 mg/kg/day, orally), and atorvastatin (10 mg/kg/day, orally) for 6 weeks. Compared to control, treatment with a combination of anethole + SDG showed a significant (p ≤ .05) improvement in serum levels of triglyceride (TG) (137.88 ± 1.61 mg/dL), total cholesterol-(TC) (180.12 ± 8.99 mg/dL), LDL-C (46.40 ± 6.67 mg/dL), VLDL-C (11.81 ± 1.07 mg/dL), aspartate aminotransferase (AST) (75.97 ± 6.92 U/L), alanine aminotransferase (ALT) (34.83 ± 2.17 U/L), alkaline phosphatase (ALP) (130.65 ± 1.05 U/L), and malondialdehyde (MDA) (30.12 ± 1.89 mmol/g), and improved activities of catalase (70.99 ± 3.29 U/g) and superoxide dismutase (SOD) (35.13 ± 2.53 U/dL) enzymes while SDG and anethole group had relatively less impact. Atorvastatin also improved serum levels of triglyceride, total cholesterol, LDL-C, and VLDL-C significantly and rose serum high-density lipoprotein cholesterol (HDL-C) levels considerably meanwhile it had a minor but negative impact on AST, ALT, and ALP, and negligible impact on activities of MDA, CAT, and SOD enzymes compared to the positive control group. The study revealed that combining anethole and SDG may improve dyslipidemia, improve lipid profile, decrease risks of chronic heart diseases, increase HDL-C, and enhance antioxidant enzymes' activities.

Plasma metabolite profile for primary open-angle glaucoma in three US cohorts and the UK Biobank

Glaucoma is a progressive optic neuropathy and a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma is the most common form, and yet the etiology of this multifactorial disease is poorly understood. We aimed to identify plasma metabolites associated with the risk of developing POAG in a case-control study (599 cases and 599 matched controls) nested within the Nurses' Health Studies, and Health Professionals' Follow-Up Study. Plasma metabolites were measured with LC-MS/MS at the Broad Institute (Cambridge, MA, USA); 369 metabolites from 18 metabolite classes passed quality control analyses. For comparison, in a cross-sectional study in the UK Biobank, 168 metabolites were measured in plasma samples from 2,238 prevalent glaucoma cases and 44,723 controls using NMR spectroscopy (Nightingale, Finland; version 2020). Here we show higher levels of diglycerides and triglycerides are adversely associated with glaucoma in all four cohorts, suggesting that they play an important role in glaucoma pathogenesis.

Identification of the novel role of sterol regulatory element binding proteins (SREBPs) in mechanotransduction and intraocular pressure regulation

Trabecular meshwork (TM) cells are highly contractile and mechanosensitive to aid in maintaining intraocular pressure (IOP) homeostasis. Lipids are attributed to modulating TM contractility with poor mechanistic understanding. In this study using human TM cells, we identify the mechanosensing role of the transcription factors sterol regulatory element binding proteins (SREBPs) involved in lipogenesis. By constitutively activating SREBPs and pharmacologically inactivating SREBPs, we have mechanistically deciphered the attributes of SREBPs in regulating the contractile properties of TM. The pharmacological inhibition of SREBPs by fatostatin and molecular inactivation of SREBPs ex vivo and in vivo respectively results in significant IOP lowering. As a proof of concept, fatostatin significantly decreased the SREBPs responsive genes and enzymes involved in lipogenic pathways as well as the levels of the phospholipid, cholesterol, and triglyceride. Further, we show that fatostatin mitigated actin polymerization machinery and stabilization, and decreased ECM synthesis and secretion. We thus postulate that lowering lipogenesis in the TM outflow pathway can hold the key to lowering IOP by modifying the TM biomechanics.

Synopsis

In this study, we show the role of lipogenic transcription factors sterol regulatory element binding proteins (SREBPs) in the regulation of intraocular pressure (IOP). ( Synopsis Figure - Created using Biorender.com ) SREBPs are involved in the sensing of changes in mechanical stress on the trabecular meshwork (TM). SREBPs aid in transducing the mechanical signals to induce actin polymerization and filopodia/lamellipodia formation.SREBPs inactivation lowered genes and enzymes involved in lipogenesis and modified lipid levels in TM.SREBPs activity is a critical regulator of ECM engagement to the matrix sites.Inactivation of SCAP-SREBP pathway lowered IOP via actin relaxation and decreasing ECM production and deposition in TM outflow pathway signifying a novel relationship between SREBP activation status and achieving IOP homeostasis.

Study of the relationship between serum lipid levels and primary open-angle glaucoma

Purpose

To determine the association between serum lipid levels and primary open-angle glaucoma (POAG).

Methods

In this case-control study, 50 patients with POAG documented by clinical tests using standard ophthalmologic equipment and 50 age-matched controls were investigated. Twelve-hour fasting serum lipid profiles, including total cholesterol, serum triglycerides, low-density lipoproteins (LDLs), and high-density lipoproteins (HDLs), were compared between the cases and controls.

Results

The mean age of cases and controls was 62.84 ± 9.68 and 60.12 ± 8.65, respectively (P = 0.65). High total cholesterol levels (>200 mg/dl) were found in 23 cases (46%) and 8 controls (16%); high serum triglyceride levels (>150 mg/dl) were found in 24 cases (48%) and 7 controls (14%); high LDL levels (130 mg/dl) were found in 28 cases (56%) and 9 controls (18%); and low HDL levels (<40 mg/dl) were found in 38 cases (76%) and 30 controls (60%). The mean total cholesterol levels were 205.24 ± 36.90 mg/dl in cases and 177.68 ± 22.56 mg/dl in controls (P < 0.001); the mean serum triglyceride levels were 150.42 ± 49.55 mg/dl and 130.84 ± 23.16 mg/dl, respectively (P = 0.013); and the mean LDL levels were 139.50 ± 31.03 mg/dl and 114.96 ± 17.73 mg/dl, respectively (P < 0.001). The mean cholesterol, triglyceride, and LDL levels were significantly higher in cases than in controls (P < 0.05).

Conclusion

The present study shows that higher proportion of POAG patients have dyslipidemia compared to age-matched controls. Though these findings need to be replicated by others. This study opens new vistas for further studies, such as lowering dyslipidemia, lowering the intra-ocular pressure and incidence of POAG, and whether the use of statins to reduce dyslipidemia affects the progression of POAG.

Effect of Hypercholesterolemia, Systemic Arterial Hypertension and Diabetes Mellitus on Peripapillary and Macular Vessel Density on Superficial Vascular Plexus in Glaucoma

BACKGROUND/AIMS

Vascular factors are involved in the development of glaucoma, including diseases such as hypercholesterolemia (HC), systemic arterial hypertension (SAH), and diabetes mellitus (DM). The aim of this study was to determine the effect of glaucoma disease on peripapillary vessel density (sPVD) and macular vessel density (sMVD) on the superficial vascular plexus, controlling differences on comorbidities such as SAH, DM and HC between glaucoma patients and normal subjects.

METHODS

In this prospective, unicenter, observational cross-sectional study, sPVD and sMVD were measured in 155 glaucoma patients and 162 normal subjects. Differences between normal subjects and glaucoma patients' groups were analyzed. A linear regression model with 95% confidence and 80% statistical power was performed.

RESULTS

Parameters with greater effect on sPVD were glaucoma diagnosis, gender, pseudophakia and DM. Glaucoma patients had a sPVD 1.2% lower than healthy subjects (Beta slope 1.228; 95%CI 0.798-1.659, p < 0.0001). Women presented 1.19% more sPVD than men (Beta slope 1.190; 95%CI 0.750-1.631, p < 0.0001), and phakic patients presented 1.7% more sPVD than men (Beta slope 1.795; 95%CI 1.311-2.280, p < 0.0001). Furthermore, DM patients had 0.9% lower sPVD than non-diabetic patients (Beta slope 0.925; 95%CI 0.293-1.558, p = 0.004). SAH and HC did not affect most of the sPVD parameters. Patients with SAH and HC showed 1.5% lower sMVD in the outer circle than subjects without those comorbidities (Beta slope 1.513; 95%CI 0.216-2.858, p = 0.021 and 1.549; 95%CI 0.240-2.858, p = 0.022 respectively.

CONCLUSIONS

Glaucoma diagnosis, previous cataract surgery, age and gender seem to have greater influence than the presence of SAH, DM and HC on sPVD and sMVD, particularly sPVD.

Cholesterol homeostasis regulated by ABCA1 is critical for retinal ganglion cell survival

Genome-wide association studies have suggested a link between primary open-angle glaucoma and the function of ABCA1. ABCA1 is a key regulator of cholesterol efflux and the biogenesis of high-density lipoprotein (HDL) particles. Here, we showed that the POAG risk allele near ABCA1 attenuated ABCA1 expression in cultured cells. Consistently, POAG patients exhibited lower ABCA1 expression, reduced HDL, and higher cholesterol in white blood cells. Ablation of Abca1 in mice failed to form HDL, leading to elevated cholesterol levels in the retina. Counting retinal ganglion cells (RGCs) by using an artificial intelligence (AI) program revealed that Abca1-deficient mice progressively lost RGCs with age. Single-cell RNA sequencing (scRNA-seq) revealed aberrant oxidative phosphorylation in the Abca1-/- retina, as well as activation of the mTORC1 signaling pathway and suppression of autophagy. Treatment of Abca1-/- mice using atorvastatin reduced the cholesterol level in the retina, thereby improving metabolism and protecting RGCs from death. Collectively, we show that lower ABCA1 expression and lower HDL are risk factors for POAG. Accumulated cholesterol in the Abca1-/- retina causes profound aberrant metabolism, leading to a POAG-like phenotype that can be prevented by atorvastatin. Our findings establish statin use as a preventive treatment for POAG associated with lower ABCA1 expression.

Appraising the Effects of Metabolic Traits on the Risk of Glaucoma: A Mendelian Randomization Study

Metabolic traits are associated with the risk of developing glaucoma in observational studies. To assess whether theses associations reflect causality, we conducted a Mendelian randomization (MR) study. Our study included up to 20,906 glaucoma cases and 438,188 controls. Genetic instruments associated with the concerned 11 exposures at the genome-wide significance level were selected from corresponding genome-wide association studies. Summary-level data for glaucoma were obtained from the UK Biobank, the GERA study, and the FinnGen consortium. Univariable and multivariable MR analyses were conducted separately in two populations. Our results showed that higher genetic liability to type 2 diabetes (T2D) was causally and independently associated with an increased risk of glaucoma (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.06-1.16; p = 4.4 × 10^-6). The association for T2D persisted after multivariable adjustment. In addition, higher genetically predicted systolic blood pressure (SBP), fasting glucose (FG), and HbA1c, were also suggestively associated with glaucoma risk. The OR was 1.08 (95% CI, 1.01-1.16; p = 0.035) for SBP, 1.24 (95% CI, 1.05-1.47; p = 0.011) for FG, and 1.28 (95% CI, 1.01-1.61; p = 0.039) for HbA1c. No evidence was observed to support the causal effects of body mass index and blood lipids for glaucoma. This study suggests a causal role for diabetes, as well as possible roles for higher SBP, FG, and HbA1c in the development of glaucoma. Further validation is needed to assess the potential of these risk factors as pharmacological targets for glaucoma prevention.

Association between statin use and the risks of glaucoma in Australia: a 10-year cohort study

SYNOPSIS

In a cohort of middle-aged and elderly Australians, we found that long-term statin use was associated with a higher risk of glaucoma onset. As to subtypes of statins, the increased risk was only found in rosuvastatin users.

PURPOSE

To investigate the relationship between statin use and glaucoma onset in a 10-year longitudinal study.

METHODS

This nested case-control study was based on data from a large-scale cohort of Australians aged over 45 years old. Medication exposure was identified by claims records from the Pharmaceutical Benefits Scheme during the follow-up period (2009-2016). The onset of glaucoma was defined as the people with at least three claims of antiglaucoma medications. Controls matched by age, gender and cardiovascular diseases were selected from participants without prescription of antiglaucoma medications. A conditional logistic regression model was used to assess the association between statin use and glaucoma onset.

RESULTS

The proportion of statin users was higher in the case group (40.5%) than that in the control group (38.4%). After adjusting for baseline characteristics and longitudinal claims records, statin use was not associated with glaucoma onset (OR 1.04, 95% CI 0.97 to 1.11). However, an increased risk of glaucoma onset was observed in participants with a longer duration of statin use (>3 years vs <1 year: OR 1.12, 95% CI 1.04 to 1.21). With respect to specific types of statins, participants taking rosuvastatin were more likely to suffer from glaucoma (OR 1.11, 95%CI 1.01 to 1.22). The use of other statins was not significantly associated with glaucoma onset.

CONCLUSIONS

Long-term statin use was found to be associated with a higher risk of glaucoma onset in this study. Regarding specific types of statins, the increased risk of glaucoma onset was only observed in users of rosuvastatin.

Mendelian randomization analyses in ocular disease: a powerful approach to causal inference with human genetic data

Ophthalmic epidemiology is concerned with the prevalence, distribution and other factors relating to human eye disease. While observational studies cannot avoid confounding factors from interventions, human eye composition and structure are unique, thus, eye disease pathogenesis, which greatly impairs quality of life and visual health, remains to be fully explored. Notwithstanding, inheritance has had a vital role in ophthalmic disease. Mendelian randomization (MR) is an emerging method that uses genetic variations as instrumental variables (IVs) to avoid confounders and reverse causality issues; it reveals causal relationships between exposure and a range of eyes disorders. Thus far, many MR studies have identified potentially causal associations between lifestyles or biological exposures and eye diseases, thus providing opportunities for further mechanistic research, and interventional development. However, MR results/data must be interpreted based on comprehensive evidence, whereas MR applications in ophthalmic epidemiology have some limitations worth exploring. Here, we review key principles, assumptions and MR methods, summarise contemporary evidence from MR studies on eye disease and provide new ideas uncovering aetiology in ophthalmology.

Untargeted lipidomics and metagenomics reveal the mechanism of aspirin eugenol ester relieving hyperlipidemia in ApoE-/- mice

Hyperlipidemia is induced by abnormal lipid metabolism, which can cause the occurrence of cardiovascular diseases and lead to grievous injury to health. Studies showed that AEE had a significant therapeutic effect on hyperlipidemia and is likely to be associated with the up-regulation of cholesterol 7-alpha hydroxylase (CYP7A1), the key enzyme for cholesterol conversion to bile acids, but no research confirmed whether the effect of AEE on hyperlipidemia was related to the gut microbiota and liver lipids. At the same time, more and more studies have shown that gut microbiota and lipids are closely related to hyperlipidemia. Hence, in this study, we investigated the effects of AEE on liver lipids through LC-MS-based untargeted lipidomics and the effects of AEE on gut microbiota based on cecal contents metagenomics by Illumina sequencing in HFD-induced hyperlipidemia ApoE-/- mice at the overall level. The results of lipidomics showed that AEE relieved hyperlipidemia by decreasing the concentration of 10 PEs and 12 SMs in the liver and regulating the pathways of glycerophospholipid metabolic pathway, sphingolipid signaling pathway, and NF-kB signaling pathway. The results of metagenomics concluded that AEE treatment changed the composition of gut microbiota and regulated the functions of lipid transport and metabolism, as well as the metabolism of bile acids and secondary bile acids. The results of the joint analysis between lipidomics and metagenomics showed that the abundance of Verrucomicrobia, Verrucomicrobiales, Candidatus_Gastranaerophilales, and Candidatus_Melainabacteria was significantly positively correlated with the concentration of SM (d18:1/18:0) and PE (16:0/18:1) in the process of AEE alleviating hyperlipidemia in mice. In conclusion, these results suggested that the effect of AEE on hyperlipidemia was closely related to the gut microbiota by the change of bile acids and liver lipids.

Hypermixed Convolutional Neural Network for Retinal Vein Occlusion Classification

Retinal vein occlusion (RVO) is one of the most common retinal vascular diseases leading to vision loss if not diagnosed and treated in time. RVO can be classified into two types: CRVO (blockage of the main retinal veins) and BRVO (blockage of one of the smaller branch veins). Automated diagnosis of RVO can improve clinical workflow and optimize treatment strategies. However, to the best of our knowledge, there are few reported methods for automated identification of different RVO types. In this study, we propose a new hypermixed convolutional neural network (CNN) model, namely, the VGG-CAM network, that can classify the two types of RVOs based on retinal fundus images and detect lesion areas using an unsupervised learning method. The image data used in this study is collected and labeled by three senior ophthalmologists in Shanxi Eye Hospital, China. The proposed network is validated to accurately classify RVO diseases and detect lesions. It can potentially assist in further investigating the association between RVO and brain vascular diseases and evaluating the optimal treatments for RVO.

Multiomics analysis reveals the mechanical stress-dependent changes in trabecular meshwork cytoskeletal-extracellular matrix interactions

Trabecular meshwork (TM) tissue is subjected to constant mechanical stress due to the ocular pulse created by the cardiac cycle. This brings about alterations in the membrane lipids and associated cell–cell adhesion and cell–extracellular matrix (ECM) interactions, triggering intracellular signaling responses to counter mechanical insults. A loss of such response can lead to elevated intraocular pressure (IOP), a major risk factor for primary open-angle glaucoma. This study is aimed to understand the changes in signaling responses by TM subjected to mechanical stretch. We utilized multiomics to perform an unbiased mRNA sequencing to identify changes in transcripts, mass spectrometry- (MS-) based quantitative proteomics for protein changes, and multiple reaction monitoring (MRM) profiling-based MS and high-performance liquid chromatography (HPLC-) based MS to characterize the lipid changes. We performed pathway analysis to obtain an integrated map of TM response to mechanical stretch. The human TM cells subjected to mechanical stretch demonstrated an upregulation of protein quality control, oxidative damage response, pro-autophagic signal, induction of anti-apoptotic, and survival signaling. We propose that mechanical stretch-induced lipid signaling via increased ceramide and sphingomyelin potentially contributes to increased TM stiffness through actin-cytoskeleton reorganization and profibrotic response. Interestingly, increased phospholipids and diacylglycerol due to mechanical stretch potentially enable cell membrane remodeling and changes in signaling pathways to alter cellular contractility. Overall, we propose the mechanistic interplay of macromolecules to bring about a concerted cellular response in TM cells to achieve mechanotransduction and IOP regulation when TM cells undergo mechanical stretch.

The Association between Serum Lipids and Intraocular Pressure in 2 Large United Kingdom Cohorts

PURPOSE

Serum lipids are modifiable, routinely collected blood test features associated with cardiovascular health. We examined the association of commonly collected serum lipid measures (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides) with intraocular pressure (IOP).

DESIGN

Cross-sectional study in the UK Biobank and European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohorts.

PARTICIPANTS

We included 94 323 participants from the UK Biobank (mean age, 57 years) and 6230 participants from the EPIC-Norfolk (mean age, 68 years) cohorts with data on TC, HDL-C, LDL-C, and triglycerides collected between 2006 and 2009.

METHODS

Multivariate linear regression adjusting for demographic, lifestyle, anthropometric, medical, and ophthalmic covariables was used to examine the associations of serum lipids with corneal-compensated IOP (IOPcc).

MAIN OUTCOME MEASURES

Corneal-compensated IOP.

RESULTS

Higher levels of TC, HDL-C, and LDL-C were associated independently with higher IOPcc in both cohorts after adjustment for key demographic, medical, and lifestyle factors. For each 1-standard deviation increase in TC, HDL-C, and LDL-C, IOPcc was higher by 0.09 mmHg (95% confidence interval [CI], 0.06-0.11 mmHg; P < 0.001), 0.11 mmHg (95% CI, 0.08-0.13 mmHg; P < 0.001), and 0.07 mmHg (95% CI, 0.05-0.09 mmHg; P < 0.001), respectively, in the UK Biobank cohort. In the EPIC-Norfolk cohort, each 1-standard deviation increase in TC, HDL-C, and LDL-C was associated with a higher IOPcc by 0.19 mmHg (95% CI, 0.07-0.31 mmHg; P = 0.001), 0.14 mmHg (95% CI, 0.03-0.25 mmHg; P = 0.016), and 0.17 mmHg (95% CI, 0.06-0.29 mmHg; P = 0.003). An inverse association between triglyceride levels and IOP in the UK Biobank (-0.05 mmHg; 95% CI, -0.08 to -0.03; P < 0.001) was not replicated in the EPIC-Norfolk cohort (P = 0.30).

CONCLUSIONS

Our findings suggest that serum TC, HDL-C, and LDL-C are associated positively with IOP in 2 United Kingdom cohorts and that triglyceride levels may be associated negatively. Future research is required to assess whether these associations are causal in nature.

Daytime Lipid Metabolism Modulated by CLOCK Gene Is Linked to Retinal Ganglion Cells Damage in Glaucoma

Lipid metabolism is intimately linked to circadian mechanisms and light signaling. Deteriorated photic transduction because of retinal ganglion cell (RGC) loss occurring with glaucoma progression reduces perceived light amplitude, causing circadian disruption. To investigate associations with RGCs, total cholesterol (TC), its low-density (LDL-C) and high-density (HDL-C) fractions, and triglycerides (TG) were measured, under a controlled meal regimen, during daytime hours in 114 patients diagnosed with primary open-angle glaucoma (POAG). RGC damage was assessed by high-definition optical coherence tomography (HD-OCT). Analysis of eight clock, clock-related, and melatonin receptor gene polymorphisms was performed on 19 patients. RGC loss was associated with changes in lipid metabolism in a time-dependent manner. Morning (08:00) values of HDL-C (r = 0.613, p < 0.0001) and TG (r = 0.568, p < 0.0001) correlated positively with RGC global loss, while LDL-C at 08:00 had a weak correlation (r = 0.235; p = 0.012) but showed a strong correlation in the evening (20:00) (r = 0.533, p < 0.0001). The morning–evening gradients (MEGs, changes at 20:00 versus 08:00) in TC and LDL-C changed sign from a negative to a positive association in patients exceeding the 15% two-eye mean GLV threshold. MEG (LDL-C higher in the evening than in the morning) was positive only in POAG patients with the CLOCK_3111 TT genotype.

Statin Use in Relation to Intraocular Pressure, Glaucoma, and Ocular Coherence Tomography Parameters in the UK Biobank

Purpose

The purpose of this study was to evaluate the relationship between statin use and glaucoma-related traits.

Methods

In a cross-sectional study, we included 118,153 UK Biobank participants with data on statin use and corneal-compensated IOP. In addition, we included 192,283 participants (8982 cases) with data on glaucoma status. After excluding participants with neurodegenerative diseases, 41,638 participants with macular retinal nerve fiber layer thickness (mRNFL) and 41,547 participants with macular ganglion cell inner plexiform layer thickness (mGCIPL) were available for analysis. We examined associations of statin use with IOP, mRNFL, mGCIPL, and glaucoma status utilizing multivariable-adjusted regression models. We assessed whether a glaucoma polygenic risk score (PRS) modified associations. We performed Mendelian randomization (MR) experiments to investigate associations with various glaucoma-related outcomes.

Results

Statin users had higher unadjusted mean IOP ± SD than nonusers, but in a multivariable-adjusted model, IOP did not differ by statin use (difference = 0.05 mm Hg, 95% confidence interval [CI] = -0.02 to 0.13, P = 0.17). Similarly, statin use was not associated with prevalent glaucoma (odds ratio [OR] = 1.05, 95% CI = 0.98 to 1.13). Statin use was weakly associated with thinner mRNFL (difference = -0.15 microns, 95% CI = -0.28 to -0.01, P = 0.03) but not with mGCIPL thickness (difference = -0.12 microns, 95% CI = -0.29 to 0.05, P = 0.17). No association was modified by the glaucoma PRS (Pinteraction≥ 0.16). MR experiments showed no evidence for a causal association between the cholesterol-altering effect of statins and several glaucoma traits (inverse weighted variance P ≥ 0.14).

Conclusions

We found no evidence of a protective association between statin use and glaucoma or related traits after adjusting for key confounders.

Blood pressure control and glaucoma risk in postmenopausal women: an analysis from the Women's Health Initiative

OBJECTIVE

Individuals with elevated systolic blood pressure (BP) or low diastolic BP, whether or not on antihypertensive treatment, may be at higher risk for developing glaucoma. We aimed to investigate BP levels in relation to glaucoma risk in a large cohort of postmenopausal women.

METHODS

Prospective follow-up of 101,447 postmenopausal women without prior history of glaucoma enrolled in the Women's Health Initiative Study. BP was measured in-clinic at baseline and after 3 years using standardized procedures. Antihypertensive medication use was determined by drug inventory at baseline and year 3. Women self-reported incident newly diagnosed glaucoma annually. Hazard ratios (HRs) and 95% confidence intervals were estimated using Cox proportional hazards analyses adjusting for demographic, medical history, and lifestyle covariates.

RESULTS

During a mean follow-up of 4.7 years, we documented 7,514 glaucoma cases. Among women not on antihypertensive treatment, those with systolic BP ≥ 140 mm Hg or diastolic BP ≥80 mm Hg were not at higher risk of developing glaucoma (HR 0.97, 95% confidence intervals 0.88-1.08 and HR 1.00 [0.93-1.08], respectively), compared with women with a systolic BP < 120 mm Hg or a diastolic BP 60 to <80 mm Hg. Among women on antihypertensive treatment, neither systolic BP ≥ 140 mm Hg nor diastolic BP ≥80 mm Hg was associated with an increased glaucoma risk (HR 0.89 [0.79-1.00] and HR 0.97 [0.90-1.05], respectively). A diastolic BP <60 mm Hg was not associated with a higher risk compared with a diastolic BP 60 to <80 mm Hg.

CONCLUSIONS

BP control is not associated with an increased or decreased glaucoma risk in postmenopausal women.

Associations of statin use with the onset and progression of open-angle glaucoma: A systematic review and meta-analysis

Background

Statins, the first-line therapy for hyperlipidemia, have received considerable attention as candidates for glaucoma treatments given its neuroprotective effects. In this systematic review and meta-analysis, we intended to assess the association of statin use with the onset and progression of open-angle glaucoma (OAG).

Methods

Databases including PubMed, Embase and Web of Science Core Collection were searched for longitudinal studies reporting the association between statin use and OAG onset or progression on Feb 3, 2021. A meta-analysis was performed for the association between statin use and OAG onset. Relative risks (RRs) with 95% confidential intervals (CIs) were retrieved from included studies and pooled using random-effects models. Potential risks of bias were evaluated by the Newcastle-Ottawa Quality Assessment Scale for all eligible studies. This study had been registered on PROSPERO (CRD 42021232172).

Findings

515,788 participants (mean age 68.7 years, 62.3% female) from ten studies were included in the systematic review of the association between statin use and OAG onset, and 26,347 OAG patients (mean age 67.3 years, 52.2% female) from seven studies were included for the association between statin use and OAG progression. Potential risks of bias were detected in 12 studies, which were mainly attributed to selection and confounding bias. In addition, 515,600 participants from eight studies were included in the meta-analysis which collectively showed that statin use was associated with a reduced risk of OAG onset (Pooled RR: 0.95; 95%CI: 0.93-0.98; I2=0.199;). No significant heterogeneity or publication bias was found for studies included in the meta-analysis. There were inconsistent evidences for the association between statin use and OAG progression.

Interpretation

Statin use is associated with a slightly lower risk of OAG onset based on existing evidences from longitudinal observational studies, the association between statin use and OAG progression remains inconclusive. The included evidences were typically weak due to poor study design and under-powered studies. Current findings should be interpreted cautiously and still need to be validated in further research.

Funding

The National Key R&D Program of China (2018YFC0116500), Science and Technology Planning Project of Guangdong Province (2013B20400003), the China Postdoctoral Science Foundation (2019TQ0365), the National Natural Science Foundation of China (82000901 and 82101171).

Genetic Risk of Cardiovascular Disease Is Associated with Macular Ganglion Cell-Inner Plexiform Layer Thinning in an Early Glaucoma Cohort

PURPOSE

To evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma.

DESIGN

Prospective, observational genetic association study.

PARTICIPANTS

Multicohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort.

METHODS

A cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell-inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group.

MAIN OUTCOME MEASURES

Spectral-domain OCT and Humphrey Visual Field (HVF) change.

RESULTS

After accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18-2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12-1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05-1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16-2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24-1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95-1.33; P = 0.179) comparable with that of the normative population.

CONCLUSIONS

This study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases.

Relationship between Using Fibrate and Open-Angle Glaucoma in Hyperlipidemic Patients: A Population-Based Cohort Study

Background: This study aimed to investigate the associated risk between using fibrate and open-angle glaucoma (OAG) in hyperlipidemic patients from the National Health Insurance Research Database (NHIRD). Methods: We collected data over a 16-year period from the NHIRD, and used the Fisher’s exact test and Pearson chi-square test to analyze variables. Adjusted hazard ratios (aHR) were used to examine the risk factors for disease development. We applied Kaplan–Meier analysis to compare the cumulative incidence of OAG. Results: A total of 10,011 patients using fibrate were enrolled in the study cohort, and 40,044 patients not using fibrate were enrolled in the control cohort. The incidence of OAG was lower in the study cohort than in the control cohort (aHR = 0.624, p = 0.007). The overall incidence of OAG was 463.02 per 100,000 person-years in the study cohort and 573.65 per 100,000 person-years in the control cohort. We used the Kaplan–Meier method to calculate the cumulative risk of developing OAG. The results revealed that after using fibrate for over seven years, the study cohort had a greatly lower rate of developing OAG than the control cohort (log-rank test p = 0.050). Conclusions: Our studies showed that using fibrate for over seven years may lead to a lower risk of OAG in patients with hyperlipidemia. Nevertheless, further prospective studies that comprehensively investigate the relationship between using fibrate and OAG are needed.

Clinical Practice Management of Primary Open-Angle Glaucoma in the United States: An Analysis of Real-World Evidence

PURPOSE

To investigate clinical management of primary open-angle glaucoma (POAG) in the United States using real-world evidence and to examine healthcare resource utilization (HCRU), medication adherence/persistence, and procedure use.

DESIGN

A cross-sectional, retrospective analysis of Optum's de-identified Market Clarity Dataset (July 1, 2013-December 31, 2019).

PATIENTS AND METHODS

Patients ≥18 years with POAG diagnosis and continuous enrollment for 1-year pre- and post-index were eligible and categorized into four mutually exclusive cohorts: CH1, treated with antiglaucoma medication(s) only; CH2, underwent glaucoma procedure(s) only; CH3, treated with antiglaucoma medication(s) and underwent procedure(s); and CH4, received no treatment for POAG. Adherence and persistence with antiglaucoma medications, and disease-specific HCRU were analyzed. Pairwise two-sample comparisons and multivariate regressions were conducted.

RESULTS

Examined 232,572 eligible patients (CH1=60,895; CH2=4330; CH3=6027; CH4=161,320). Prostaglandin analogs were most prescribed antiglaucoma medications (CH1: 69.7%; CH3: 62.7%), of which latanoprost was most common (CH1: 51.3%; CH3: 46.1%). Disease-specific office visits occurred in 26.3%, 78.2%, 75.0%, 23.8%, and surgical services visits occurred in 3.8%, 36.3%, 42.5%, 3.3%, in CH1-CH4, respectively. Adherence was higher (medication possession ratio: 47.1% vs 39.4%; P<0.0001), and more patients remained persistent across 1-year post-index period in CH1 vs CH3 (25.4% vs 16.1%; P<0.0001). Positive predictors of medication persistence included being female, ≥55 years, and history of dyslipidemia or thyroid disease (all P≤0.0003).

CONCLUSION

Overall, 70% POAG patients might not have received antiglaucoma treatment. Since POAG is a slowly progressive blinding disease, the lack of antiglaucoma treatment and suboptimal adherence/persistence with medications are of major concerns. Targeted screening and educational approaches are needed to improve POAG management.

Risk of Glaucoma Associated with Components of Metabolic Disease in Taiwan: A Nationwide Population-Based Study

PURPOSE

This retrospective cohort study was conducted to determine the glaucoma risk associated with metabolic disease (MetD) using insurance claims data of Taiwan.

METHODS

From the database, we identified patients with newly diagnosed hypertension, diabetes and/or hyperlipidemia from the years 2000 to 2002 as the MetD cohort (N = 42,036) and an age-gender-diagnosis-date matched control cohort without MetD with a two-fold sample size than that of the MetD cohort. Both cohorts were followed until the development of glaucoma, death, or withdrawal, until 31 December 2013. The incidence of glaucoma, and the Cox method estimated hazard ratio (HR) of glaucoma were calculated. Results showed that the incidence of glaucoma was two-fold higher in the MetD cohort than in the controls (1.99 versus 0.99 per 1000 person-years), with an adjusted HR of 1.66 (95% CI: 1.50-1.85). The glaucoma incidence was higher in patients with diabetes than those with hypertension and hyperlipidemia (2.38 versus 1.95 and 1.72 per 1000 person-years, respectively). The incidence increased to 5.67 per 1000 person-years in patients with all three comorbidities, with an aHR of 4.95 (95% CI: 2.35-10.40). We also found higher incidence rates of primary open-angle glaucoma and primary angle-closure glaucoma with aHRs of 2.03 and 1.44, respectively. It was concluded that glaucoma risk increased with the number of MetD. Health providers need to monitor patients with MetD to prevent glaucoma.

High-Density Lipoprotein 3 Cholesterol and Primary Open-Angle Glaucoma: Metabolomics and Mendelian Randomization Analyses

PURPOSE

We hypothesized that the effect of blood lipid-related metabolites on primary open-angle glaucoma (POAG) would differ according to specific lipoprotein particles and lipid sub-fractions. We investigated the associations of blood levels of lipoprotein particles and lipid sub-fractions with POAG.

DESIGN

Cross-sectional study.

PARTICIPANTS

Individuals recruited for the baseline visit of the population-based Singapore Epidemiology of Eye Disease study (n = 8503).

METHODS

All participants underwent detailed standardized ocular and systemic examinations. A total of 130 blood lipid-related metabolites were quantified using a nuclear magnetic resonance metabolomics platform. The analyses were conducted in 2 stages. First, we investigated whether and which lipid-related metabolites were directly associated with POAG using regression analyses followed by Bayesian network modeling. Second, we investigated if any causal relationship exists between the identified lipid-related metabolites, if any, and POAG using 2-sample Mendelian randomization (MR) analysis. We performed genome-wide association studies (GWAS) on high-density lipoprotein (HDL) 3 cholesterol (after inverse normal transformation) and used the top variants associated with HLD3 cholesterol as instrumental variables (IVs) in the MR analysis.

MAIN OUTCOME MEASURE

Primary open-angle glaucoma.

RESULTS

Of the participants, 175 (2.1%) had POAG. First, a logistic regression model showed that total HDL3 cholesterol (negatively) and phospholipids in very large HDL (positively) were associated with POAG. Further analyses using a Bayesian network analysis showed that only total HDL3 cholesterol was directly associated with POAG (odds ratio [OR], 0.72 per 1 standard deviation increase in HDL3 cholesterol; 95% confidence interval [CI], 0.61-0.84), independently of age, gender, intraocular pressure (IOP), body mass index (BMI), education level, systolic blood pressure, axial length, and statin medication. Using 5 IVs identified from the GWAS and with the inverse variance weighted MR method, we found that higher levels of HDL3 cholesterol were associated with a decreased odds of POAG (OR, 0.91; 95% CI, 0.84-0.99, P = 0.021). Other MR methods, including weighted median, mode-based estimator, and contamination mixture methods, derived consistent OR estimates. None of the routine lipids (blood total, HDL, or low-density lipoprotein [LDL] cholesterol) were associated with POAG.

CONCLUSIONS

Overall, these results suggest that the relationship between HDL3 cholesterol and POAG might be causal and specific, and that dysregulation of cholesterol transport may play a role in the pathogenesis of POAG.