Association of blood pressure status with the optic disk structure in non-glaucoma subjects: the Thessaloniki eye study

Deep-learning-based prediction of glaucoma conversion in normotensive glaucoma suspects

BACKGROUND/AIMS

To assess the performance of deep-learning (DL) models for prediction of conversion to normal-tension glaucoma (NTG) in normotensive glaucoma suspect (GS) patients.

METHODS

Datasets of 12 458 GS eyes were reviewed. Two hundred and ten eyes (105 eyes showing NTG conversion and 105 without conversion), followed up for a minimum of 7 years during which intraocular pressure (IOP) was lower than 21 mm Hg, were included. The features of two fundus images (optic disc photography and red-free retinal nerve fibre layer (RNFL) photography) were extracted by convolutional auto encoder. The extracted features as well as 15 clinical features including age, sex, IOP, spherical equivalent, central corneal thickness, axial length, average circumpapillary RNFL thickness, systolic/diastolic blood pressure and body mass index were used to predict NTG conversion. Prediction was performed using three machine-learning classifiers (ie, XGBoost, Random Forest, Gradient Boosting) with different feature combinations.

RESULTS

All three algorithms achieved high diagnostic accuracy for NTG conversion prediction. The AUCs ranged from 0.987 (95% CI 0.978 to 1.000; Random Forest trained with both fundus images and clinical features) and 0.994 (95% CI 0.984 to 1.000; XGBoost trained with both fundus images and clinical features). XGBoost showed the best prediction performance for time to NTG conversion (mean squared error, 2.24). The top three important clinical features for time-to-conversion prediction were baseline IOP, diastolic blood pressure and average circumpapillary RNFL thickness.

CONCLUSION

DL models, trained with both fundus images and clinical data, showed the potential to predict whether and when normotensive GS patients will show conversion to NTG.

Comparing Intraocular Pressure, Ocular Blood Flow, and Retinal Nerve Fiber Layer Thickness in Early and Chronic Hypertensives With Normotensives

PURPOSE

To compare blood pressure (BP), intraocular pressure (IOP), ophthalmic artery flow (OAF) velocity, retinal nerve fiber layer (RNFL) thickness, and visual fields in newly diagnosed hypertension (HT) patients (before treatment), chronic HT (on antihypertensive medications >5 years) and normotensives.

METHODS

A prospective, cross-sectional study at a tertiary care centre in India. Three groups of 45 patients each: group 1 - early HT, group 2 - chronic HT, and Group 3 - normotensives, underwent evaluation of BP, IOP by Goldmann applanation tonometry (GAT), OAF velocity by transcranial doppler (TCD), RNFL analysis by spectral-domain optical coherence tomography (SD-OCT), and visual fields.

RESULTS

The BP was highest in early HT > chronic HT > normotensives (p < 0.001). The IOP of early HT, chronic HT, and normotensives were 15.87 ± 2.19 mmHg, 13.47 ± 1.92 mmHg, and 15.67 ± SD 1.75 mmHg (p < 0.001). The OAF velocity [peak systolic velocity (PSV), end-diastolic velocity (EDV) in cm/sec] was lowest in chronic HT (30.80 ± 7.05, 8.58 ± 1.58) < early HT (35.47 ± 5.34, 10.02 ± 1.74) < normotensives (36.29 ± 4.43, 10.44 ± 2.29), (p < 0.001). The average RNFL thickness was significantly lower in chronic HT (p = 0.022). The PSV, EDV, and MFV showed significant correlation with IOP (r = 0.247, p = 0.004; r = 0.206, p = 0.016; r = 0.266, p = 0.002) and average RNFL thickness (r = 0.309, p= <0.001; r = 0.277, p = 0.001; r = 0.341, p < 0.001).

CONCLUSIONS

Patients with chronic HT demonstrated the lowest retrobulbar flows, IOP and lower RNFL measurements. Lower ocular perfusion may be associated with lower IOP and may be a risk factor for end-organ damage (RNFL) independent of IOP.

The Relevance of Arterial Blood Pressure in the Management of Glaucoma Progression: A Systematic Review

BACKGROUND

Glaucoma is one of the leading causes of global blindness and is expected to co-occur more frequently with vascular morbidities in the upcoming years, as both are aging-related diseases. Yet, the pathogenesis of glaucoma is not entirely elucidated and the interplay between intraocular pressure, arterial blood pressure (BP) and ocular perfusion pressure is poorly understood.

OBJECTIVES

This systematic review aims to provide clinicians with the latest literature regarding the management of arterial BP in glaucoma patients.

METHODS

A systematic search was performed in Medline, Embase, Web of Science and Cochrane Library. Articles written in English assessing the influence of arterial BP and systemic antihypertensive treatment of glaucoma and its management were eligible for inclusion. Additional studies were identified by revising references included in selected articles.

RESULTS

80 Articles were included in this systemic review. A bimodal relation between BP and glaucoma progression was found. Both high and low BP increase the risk of glaucoma. Glaucoma progression was, possibly via ocular perfusion pressure variation, strongly associated with nocturnal dipping and high variability in the BP over 24 h.

CONCLUSIONS

We concluded that systemic BP level associates with glaucomatous damage and provided recommendations for the management and study of arterial BP in glaucoma. Prospective clinical trials are needed to further support these recommendations.

Prevalence of Ocular Hypertension and Other Risk Factors of Open-Angle Glaucoma Among Middle-Aged Adults in Al-Baha City, Saudi Arabia

Background Ocular hypertension (OHT), defined by elevated intraocular pressure (IOP) beyond standard levels, is a predominant risk factor for initiating and exacerbating glaucoma, a collection of progressive optic neuropathies responsible for irreversible vision loss. Given the profound implications for vision care, it is imperative to elucidate the interplay between OHT and glaucoma for effective clinical management. Objective The present study aims to measure IOP levels and identify risk factors associated with glaucoma among middle-aged individuals in Al-Baha City, Saudi Arabia. Methods A cross-sectional study was conducted over a six-month span (January-June 2022) in Al-Baha City. The study cohort comprised adults aged 35 and above attending a glaucoma awareness campaign at King Fahad Hospital, Al-Baha. Parameters such as demographics, socioeconomic status, medical and ocular history, and familial history of eye diseases were collated. Initial ophthalmologic assessments and IOP measurements were performed. Statistical analyses utilized Pearson's Chi-square test for nominal variables. Results The study encompassed 111 participants, 84 (75.7%) of whom were male, and 75 (67.6%) were of Saudi nationality. Notably, 102 (91.9%) reported no family history of glaucoma, 91 (81.1%) indicated no past medical history and 81 (73.0%) were not on any chronic medications. The mean IOP for participants' right and left eyes fluctuated between 18.2-21.5 mmHg and 18.9-22.1 mmHg, respectively. Factors such as age, gender, family history of glaucoma, past medical history, use of chronic medications, and history of ophthalmic surgeries demonstrated a statistically significant correlation with IOP (p<0.05). Conclusion This study highlights a higher prevalence of OHT in females, with several risk factors for OHT and glaucoma identified, such as familial history, vascular diseases, diabetes mellitus, and chronic medication use. Notably, our study did not observe a significant association with age or smoking. These findings emphasize the necessity of regular eye examinations and IOP monitoring, especially in high-risk groups.

Effect of antihypertensive medications on the risk of open-angle glaucoma

The purpose of this study was to identify the effect of antihypertensive medication on risks of open-angle glaucoma (OAG) among patients diagnosed with hypertension (HTN). A total of 5,195 patients, who were diagnosed with HTN between January 1, 2006 and December 31, 2015, and subsequently diagnosed with OAG, were selected for analysis. For each OAG patient, 5 non-glaucomatous, hypertensive controls were matched (n = 25,975) in hypertension diagnosis date, residential area, insurance type and economic status. Antihypertensive medications were stratified into 5 types: angiotensin converting enzyme inhibitor (ACEi), angiotensin receptor blockers (ARB), calcium channel blockers (CCB), β-blockers and diuretics. Relative risks were calculated. After adjusting for age, sex, body mass index, lifestyle, comorbidities, blood pressure (BP), follow-up duration, and use of other types of antihypertensive drugs, ARB and CCB were found to slightly increase OAG risks (RR 1.1087 (95% CI 1.0293-1.1942); 1.0694 (1.0077-1.1349), respectively). Combinations of ARB with diuretics (1.0893 (1.0349-1.1466)) and CCB (1.0548 (1.0122-1.0991)) also increased OAG risks. The risks for OAG were found to increase by antihypertensive medication use, but the effects appeared to be small. Further studies are necessary to identify the associations of increased BP, medication and therapeutic effect with OAG.

Homocysteine and Glaucoma

Elevated levels of homocysteine (Hcy), a non-proteinogenic amino acid, may lead to a host of manifestations across the biological systems, particularly the nervous system. Defects in Hcy metabolism have been associated with many neurodegenerative diseases including glaucoma, i.e., the leading cause of blindness. However, the pathophysiology of elevated Hcy and its eligibility as a risk factor for glaucoma remain unclear. We aimed to provide a comprehensive review of the relationship between elevated Hcy levels and glaucoma. Through a systemic search of the PubMed and Google Scholar databases, we found that elevated Hcy might play an important role in the pathogenesis of glaucoma. Further research will be necessary to help clarify the specific contribution of elevated Hcy in the pathogenesis of glaucoma. A discovery and conceptual understanding of Hcy-associated glaucoma could be the keys to providing better therapeutic treatment, if not prophylactic treatment, for this disease.

Glaucoma and Systemic Disease

Glaucoma is the leading cause of irreversible blindness in the world. Due to its potential to cause permanent vision loss, it is important to understand how systemic conditions and their respective treatments can be associated with or increase the risk for developing glaucoma. In this review, we examined the literature for up-to-date discussions and provided commentary on glaucoma, its pathophysiology, and associated risk factors. We discuss systemic diseases and the impact, risk, and mechanism for developing glaucoma, including pharmacologically induced glaucoma; inflammatory and auto-immune conditions; infectious, dermatologic, cardiovascular, pulmonary, renal, urologic, neurologic, psychiatric and systemic malignancies: intraocular tumors; as well as pediatric, and genetic conditions. The goal of our discussion of systemic conditions including their commonality, mechanisms, treatments, and associations with developing glaucoma is to emphasize the importance of ocular examinations and follow-up with the multidisciplinary teams involved in the care of each patient to prevent unnecessary vision-loss.

Associations of Midlife and Late-Life Blood Pressure Status With Late-Life Retinal OCT Measures

Purpose

To explore the relationship of long-term blood pressure (BP) patterns with late-life optical coherence tomography (OCT) structural measures reflecting optic nerve health.

Methods

Participants in this community-based cohort study of black and white individuals were part of the Atherosclerosis Risk in Communities study and the nested Eye Determinants of Cognition (EyeDOC) study. Participants had BP measured six times from 1987 to 2017 and were categorized into five BP patterns: sustained normotension; midlife normotension, late-life hypertension (systolic BP [SBP] >140 mmHg or diastolic BP [DBP] >90 mmHg or antihypertensive medication use); sustained hypertension; midlife normotension, late-life hypotension (SBP <90 mmHg or DBP <60 mmHg); and midlife hypertension, late-life hypotension. Multivariable linear regression modeling was used to evaluate associations between BP patterns and late-life OCT ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thickness.

Results

In total, 931 eyes of 931 participants (mean age at EyeDOC visit = 80 years; 63% female; 45% black) were included. Mean GCC and RNFL thicknesses in the sustained normotension pattern were 90.8 ± 10.3 µm and 89.9 ± 11.2 µm versus 89.4 ± 11.9 µm and 90.1 ± 12.2 µm in the sustained hypertension pattern (P > 0.05). Compared to the sustained normotension pattern, no significant differences in GCC or RNFL thickness were found for any anomalous BP pattern.

Conclusions

Assessment of long-term BP status showed no significant associations with late-life OCT structural measures.

Translational Relevance

OCT imaging results in our population-based sample suggest that neither hypertension, even when present in midlife, nor late-life hypotension are significant risk factors for late-life optic nerve damage.

[The effect of systemic antihypertensive drugs on the risk of primary open-angle glaucoma]

Primary open-angle glaucoma (POAG) is a common disease. Elevated blood pressure has been reported as a significant risk factor for the development and progression of POAG.

PURPOSE

The goal of the present study was to test the effect of systemic antihypertensive drugs on the risk of POAG using cis-Mendelian randomization (cis-MR) approach.

MATERIAL AND METHODS

The study involved summary statistics from genome-wide association studies (GWAS) for POAG (15229 cases and 177 473 controls) and from GWAS for systolic blood pressure meta-analysis (757 601 individuals). Drug targets for beta-blockers and for calcium channel blockers and genes coding these targets were identified via DrugBank. Genetic variants within the regions of these genes were selected for the Mendelian randomization analysis.

RESULTS

The effect of a 10-mm Hg decrease in systolic blood pressure caused by calcium channel blockers on the risk of POAG amounted to: odds ratio (OR) 0.90 (95% CI 0.63-1.30, p=0.59). For beta blockers the cis-MR estimated effect on the risk of POAG was OR=0.95 (95% CI 0.34-2.70, p=0.92).

CONCLUSION

The results of the present study do not confirm the hypothesis of causal effect of antihypertensive drugs intake on the risk of developing POAG.

Evidence for Complementary and Alternative Therapies to Treat Glaucoma

Complementary and alternative medicine is used by approximately 5% of patients with glaucoma, and examples include marijuana, Ginkgo biloba extract, bilberry fruit extract, and acupuncture. Systemic marijuana is not beneficial for glaucoma due to the short duration of action, the lack of evidence that it alters disease progression, and its negative side effect profile. Drops that affect the cannabinoid pathway are still being studied. Ginkgo biloba and bilberry fruit extracts have been shown to decrease oxidative stress and improve perfusion of the optic nerve head. However, these findings are inconsistent throughout the literature and the studies are small, which makes the overall evidence weak. There is no evidence that acupuncture alters glaucoma disease progression or causes a sustained decrease in intraocular pressure. In summary, the literature suggests that there are transient and/or theoretical benefits of complementary and alternative medicine for glaucoma care; however, the overall evidence to support their use is weak.

Repurposing Antihypertensive Drugs for the Prevention of Glaucoma: A Mendelian Randomization Study

Purpose

Several antihypertensive drugs have been used for the treatment of glaucoma. However, the effect of hypertension and antihypertensive drugs on glaucoma is still unclear.

Methods

Leveraging large-scale genome-wide association study summary statistics for glaucoma (Ncase = 4737, Ncontrol = 458,196), blood pressure (BP) (N = 422,771), and intraocular pressure (IOP) (N = 31,269), the genetic correlation and causal relationship of genetically assessed IOP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and 12 types of antihypertensive drugs with glaucoma were evaluated using linkage disequilibrium score (LDSC) regression, univariate mendelian randomization (MR), and multivariable MR.

Results

LDSC results showed a suggestive association of glaucoma with SBP (Rg = 0.12, P = 0.0076) and DBP (Rg = 0.17, P = 0.02). In univariate MR, genetically elevated BP in participants was not identified to lead to an increased glaucoma risk (SBP: odds ratio [OR], 1.05 [95% confidence interval {CI}, 0.91-1.21]; P = 0.52; DBP: OR, 1.07 [95% CI, 0.93-1.23]; P = 0.34). The results of univariate MR were replicated in multivariable MR (SBP: OR, 0.95 [95% CI, 0.71-1.29]; P  = 0.75; DBP: OR, 1.13 [95% CI, 0.85-1.51]; P  = 0.41). Furthermore, there was insufficient evidence to suggest that antihypertensive drugs were associated with glaucoma.

Conclusions

Together, controlling BP may not help prevent and treat glaucoma, and antihypertensive drugs may neither treat nor worsen glaucoma.

Translational Relevance

Treating with antihypertensive drugs should not be used as an intervention for patients with glaucoma.

Association Between Dietary Salt Intake and Open Angle Glaucoma in the Thessaloniki Eye Study

PRCIS

In the Thessaloniki Eye Study (TES) incidence phase population, frequent dietary salt intake was potentially associated with increased risk of open angle glaucoma in antihypertensive users.

PURPOSE

The aim was to examine the association between dietary salt intake and glaucoma by antihypertensive use in the TES population.

MATERIALS AND METHODS

The study population included TES incidence phase participants. Dietary salt intake frequency was assessed by self-report. Outcomes included prevalence of any open angle glaucoma (OAG), primary open angle glaucoma (POAG), and pseudoexfoliation (PEX). Covariates included demographics, cardiovascular disease, migraines, diabetes, steroid use, smoking, history of cataract surgery, central corneal thickness, intraocular pressure, blood pressure, and antihypertensive use. Logistic regression was used to examine associations between frequency of salt intake and glaucoma, controlling for covariates and stratified by antihypertensive use.

RESULTS

The study included 1076 participants 80.5±4.4 years old, of whom 518 were female. There were 89/1076 (8.3%) participants with any OAG, 46/789 (5.8%) with POAG, and 287/1030 (27.9%) with PEX. In participants with antihypertensive use, frequent versus never salt intake was associated with increased risk of any OAG [adjusted odds ratio (aOR)=2.65, 95% confidence interval (CI)=1.12, 6.28; n=784] and POAG (aOR=3.59, 95% CI=1.16, 11.11; n=578) overall, and additionally in participants with diastolic blood pressure <90 mm Hg (aOR=2.42, 95% CI=1.00, 5.84; n=735) for OAG. There were no statistically significant adjusted associations between salt intake and PEX, or in participants without antihypertensive use.

CONCLUSIONS

In TES participants assessed for OAG in the prevalence and incidence phases, frequent salt intake may be associated with increased OAG in those who take antihypertensive medication. Further investigation is needed of salt intake and glaucoma in hypertensive individuals.

High Blood Pressure and Intraocular Pressure: A Mendelian Randomization Study

Purpose

To test for causality with regard to the association between blood pressure (BP) and intraocular pressure (IOP) and glaucoma.

Methods

Single nucleotide polymorphisms (SNPs) associated with BP were identified in a genome-wide association study (GWAS) meta-analysis of 526,001 participants of European ancestry. These SNPs were used to assess the BP versus IOP relationship in a distinct sample (n = 70,832) whose corneal-compensated IOP (IOPcc) was measured. To evaluate the BP versus primary open-angle glaucoma (POAG) relationship, additional Mendelian randomization (MR) analyses were conducted using published GWAS summary statistics.

Results

Observational analysis revealed a linear relationship between BP traits and IOPcc, with a +0.28 mm Hg increase in IOPcc per 10-mm Hg increase in systolic BP (95% confidence interval [CI], 0.26-0.29); for diastolic blood pressure (DBP) and pulse pressure (PP), these estimates were +0.41 mm Hg and +0.36 mm Hg, respectively. An inverse-variance weighted MR analysis did not support a causal relationship, as the estimated causal effect was +0.01 mm Hg IOPcc per 10-mm Hg increase in systolic blood pressure (SBP); +0.13 mm Hg IOPcc per 10-mm Hg increase in DBP; and +0.02 mm Hg IOPcc per 10-mm Hg increase in PP (all P > 0.05). With regard to the risk of POAG, MR analyse yielded causal effect estimate of odds ratio = 0.98 (95% CI, 0.92-1.04) per 10-mm Hg increase in SBP. Neither DBP nor PP demonstrated evidence of a causal effect on POAG.

Conclusions

A range of different MR analysis methods provided evidence, in general, that the causal effect of BP on IOP (and POAG) was modest, or even zero. However, interpretation was complicated by SNPs associated with BP potentially having pleiotropic effects on IOP.

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.

Retinal nerve fibre layer thickness measured with SD-OCT in a population-based study: the Handan Eye Study

PURPOSE

To examine the normative profile of retinal nerve fibre layer (RNFL) thickness and ocular parameters based on spectral-domain optical coherence tomography (SD-OCT) and its associations with related parameters among the Chinese population.

METHODS

This population-based cohort Handan Eye Study (HES) recruited participants aged≥30 years. All subjects underwent a standardised ophthalmic examination. Peripapillary RNFL thickness was obtained using SD-OCT. Mixed linear models were adopted to evaluate the correlation of RNFL thickness with ocular parameters as well as systemic factors. R V.3.6.1 software was used for statistical analysis.

RESULTS

3509 subjects (7024 eyes) with the average age of 55.54±10.37 were collected in this analysis. Overall mean RNFL thickness measured was 113.46±10.90 µm, and the thickest quadrant of parapapillary RNFL was the inferior quadrant, followed by the superior quadrant, the nasal quadrant and the temporal quadrant. In the multivariate linear regression model, thinner RNFL thickness was remarkable association with male (p<0.001), older age (p<0.001), increased body mass index (>30, p=0.018), absence of diabetes (p=0.009), history of cataract surgery (p=0.001), higher intraocular pressure (p=0.007), lower spherical equivalent (p<0.001) and increased axial length (p=0.048).

CONCLUSIONS

In non-glaucoma individuals, this difference of RNFL thickness in Chinese population should be noted in making disease diagnoses. Meanwhile, multiple ocular and systemic factors are closely related to the thickness of RNFL. Our findings further emphasise the need to demonstrate ethnic differences in RNFL thickness and the specificity of associated ocular and systemic factors, as well as to develop better normative databases worldwide.

TRIAL REGISTRATION NUMBER

HES was registered in Chinese Clinical Trial Registry website, and the registry number was ChiCTR-EOC-17013214.

Fine Particulate Matter Exposure Levels in Patients with Normal-Tension Glaucoma and Primary Open-Angle Glaucoma: A Population-Based Study from Taiwan

Patients with NTG or POAG with more than one outpatient or discharge diagnosis from the ophthalmology department were included in the study. These data were merged with the PM2.5 data from the Air Quality Monitoring Network for analysis. This was a case−control study, with 1006 participants in the NTG group and 2533 in the POAG group. To investigate fine particulate matter (PM2.5) exposure levels in patients with normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG), patient data were obtained from Taiwan’s Longitudinal Health Insurance Database 2000 for the 2008 to 2013 period. We used a multivariate logic regression model to assess the risk for each participant. The PM2.5 exposure levels were divided into four groups: <25th percentile (Q1), <617 μg/mm3; 25th to 50th percentile (Q2), 617 to 1297 μg/mm3; 50th to 75th percentile (Q3), 1297 to 2113 μg/mm3; and >75th percentile (Q4), >2113 μg/mm3. The results are expressed in terms of odds ratio (OR) and 95% CI. A multiple logistic regression was used to compare the results of the NTG group with those of the POAG group. Compared with the PM2.5 Q1 level, the OR of the PM2.5 Q2 level was 1.009 (95% CI 0.812−1.254), the PM2.5 Q3 level was 1.241 (95% CI 1.241−1.537, p < 0.05), and the PM2.5 Q4 level was 1.246 (95% CI 1.008−1.539, p < 0.05). Our research reveals that compared with POAG, the risk of developing NTG is more closely related with PM2.5 exposure, and PM2.5 has a concentration−dose effect. It is hoped that in the future, in the clinical judgment of NTG and POAG, the level of PM2.5 in the environment can be taken as a risk factor.

Retrobulbar blood flow velocity in systemic lupus erythematosus assessed by color Doppler imaging

OBJECTIVE

To analyze the blood flow in retrobulbar vessels in systemic lupus erythematosus (SLE) by color Doppler imaging (CDI) and to investigate the associations between immunological markers, retinal abnormalities, disease activity, and vascular parameters.

METHODS

We examined 30 patients with SLE who were aged 32.1 ± 11.6 years with a disease duration of 68.0 ± 55.6 months and 30 participants in a control group. The peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistive index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary arteries (PCAs) were determined. Physical and ophthalmic examinations with assessments of immunological markers were performed. All parameters were compared between SLE patients and normal controls while the correlations among parameters were analyzed.

RESULTS

In the SLE group, CDI confirmed blood flow abnormalities in the CRA and PCAs, with significantly lower blood flow velocities and increased RI and PI (p < 0.05). There was a significantly negative correlation between disease duration and EDV in the CRA, PCA, and OA (p = 0.0423, 0.0453, 0.0448). There was also a significant relationship between the SLE Disease Activity Index and the PI of the OA (p = 0.0367). The patients who had received biological agents (Rituximab) had lower EDV in the CRA and PCA (p = 0.0026, 0.028). SLE patients with kidney or CNS involvement had a significant increase in the PI in the OA (p = 0.0287). The PSV and EDV in the CRA were significantly related to creatinine (p = 0.0007 and 0.0418). We also noted a significant decreased EDV in the CRA and an increased RI in the OA among participants positive for anti-dsDNA antibodies (p = 0.0331 and 0.0228).

CONCLUSIONS

Retrobulbar circulatory disturbances were detected in SLE patients by CDI. These findings seem likely to affect smaller vessels like the CRA and PCA. However, the presence of measurable changes in the OA is generally indicative of a coexistent nephropathy or central nervous system (CNS) vasculitis. Creatinine, the disease activity index, being positive for anti-dsDNA, and receiving biological agents were associated with measurable changes on the retrobulbar blood flow.

Blood Pressure and Glaucomatous Progression in a Large Clinical Population

PURPOSE

To investigate the effect of systemic arterial blood pressure (BP) on rates of progressive structural damage over time in glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 7501 eyes of 3976 subjects with glaucoma or suspected of glaucoma followed over time from the Duke Glaucoma Registry.

METHODS

Linear mixed models were used to investigate the effects of BP on the rates of retinal nerve fiber layer (RNFL) loss from spectral-domain OCT (SD-OCT) over time. Models were adjusted for intraocular pressure (IOP), gender, race, diagnosis, central corneal thickness (CCT), follow-up time, and baseline disease severity.

MAIN OUTCOME MEASURE

Effect of mean arterial pressure (MAP), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) on rates of RNFL loss over time.

RESULTS

A total of 157 291 BP visits, 45 408 IOP visits, and 30 238 SD-OCT visits were included. Mean rate of RNFL change was -0.70 μm/year (95% confidence interval, -0.72 to -0.67 μm/year). In univariable models, MAP, SAP, and DAP during follow-up were not significantly associated with rates of RNFL loss. However, when adjusted for mean IOP during follow-up, each 10 mmHg reduction in mean MAP (-0.06 μm/year; P = 0.007) and mean DAP (-0.08 μm/year; P < 0.001) but not SAP (-0.01 μm/year; P = 0.355) was associated with significantly faster rates of RNFL thickness change over time. The effect of the arterial pressure metrics remained significant after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity, and corneal thickness.

CONCLUSIONS

When adjusted for IOP, lower MAP and DAP during follow-up were significantly associated with faster rates of RNFL loss, suggesting that levels of systemic BP may be a significant factor in glaucoma progression.

Effect of Blood Pressure Reduction on Intraocular Pressure and Ophthalmic Artery Blood Flow Velocity in Hypertension

Purpose: To evaluate the effect of reducing blood pressure (BP) by atenolol and amlodipine on (1) intraocular pressure (IOP) and (2) ophthalmic artery blood flow (OAF) velocity in new hypertensives. Methods: A prospective, observational cohort study conducted at a tertiary care center in India after IRB approval. New hypertensives treated with atenolol 25 mg or amlodipine 5 mg were divided into 2 groups of 30 patients each. BP, IOP by Goldmann applanation tonometry and OAF velocity by transcranial doppler sonography was performed before medication and post medication on day 1, 7, and 30. Results: There was a significant decrease in IOP with both drugs; the effect was greater with atenolol. Atenolol: premedication IOP - 16.06 ± 2.13 mmHg and day 30-12.46 ± 1.94 (22.4%) [P < 0.001], amlodipine: premedication IOP-15.13 ± 2.55 mmHg and day 30- 13.06 ± 2.14 (13.68%) [P < 0.001]. A decrease of 0.5 mmHg in IOP with every 10 mmHg (95% CI: 0.121-0.826, P value = 0.01) decrease in systolic BP was noted after oral atenolol. The OAF peak systolic velocity and mean flow velocity were equally reduced with both drugs (P < 0.001). The end-diastolic velocity, reduced only with atenolol (P = 0.049) but returned to baseline with amlodipine at 1 month. Conclusions: BP reduction by atenolol and amlodipine led to decreases in IOP and OAF velocity, greater with atenolol. The IOP decrease was likely due to reduced blood flow. A slight decrease in the diastolic flow of the ophthalmic artery was noted with atenolol.

Evaluation of putative differences in vessel density and flow area in normal tension and high-pressure glaucoma using OCT-angiography

PURPOSE

To evaluate the putative differences in terms of vessel density and flow area between control (CTRL), high-pressure glaucoma (HPG) and normal tension glaucoma (NTG) subjects at macular and peripapillary level. To assess the correlation between Visual Field Index (VFI), the stage of glaucoma, and optical coherence tomography angiography (OCT-A) parameters.

MATERIAL AND METHODS

In this pilot, prospective study 46 eyes of 46 glaucomatous patients (19 NTG+27 HPG) and 25 control eyes (CTRL) of 25 subjects were recruited. All patients underwent a complete ophthalmologic examination and visual field testing. A 3×3mm volumetric macular scan (Angio Retina [3.0]) and a 4.5×4.5mm diameter peripapillary scan (Angio Disc [4.5]) were performed in the right eye using RTVue-XR Avanti (Optovue, Inc.) OCT-A.

RESULTS

Groups were homogeneous for age (P=0.784) and gender (P=0.623). Among the evaluated optic nerve head (ONH) and macular OCT-A parameters, ONH whole image (P<0.001), inside disc (P=0.021), peripapillary (P<0.001), ONH flow area (P<0.026), macula whole image (P<0.001), fovea (P<0.001), parafovea (P<0.001) showed a significant difference when CTRL group was compared to HPG group at the post hoc test. Similarly, ONH whole image (P<0.001), inside disc (P=0.005), peripapillary (P<0.001), ONH flow area (P<0.026), macula whole image (P<0.001), FOVEA (P<0.001), parafovea (P<0.001) showed a significant difference were CTRL were compared to NTG group. On the contrary, no significant difference was found when NTG and HPG groups were compared. Age was not significantly correlated with any of the OCT-A parameters. The stage of the disease showed a high, significant, correlation with ONH whole image (r=-0.81; P<0.0001), inside disc (r=-0.42; P<0.0001), peripapillary (r=-0.81; P<0.0001), RNFL (r=-0.79; P<0.0001), macula whole image (r=0.56; P<0.0001), fovea (r=-0.78; P<0.0001) and parafovea (r=0.67; P<0.0001). On the contrary, VFI showed a high, significant, correlation with ONH whole image (r=0.77; P<0.0001), inside disc (r=0.39; P=0.0018), peripapillary (r=0.713; P<0.0001), RNFL (r=0.63; P<0.0001), macula whole image (r=-0.39; P=0.0007), fovea (r=0.60; P<0.0001) and parafovea (r=-0.52; P<0.0001).

CONCLUSIONS

Our data support the usefulness of the OCT-A in the common clinical practice for diagnosis, staging, evaluating the progression of the disease as well as for better understanding of its pathogenic mechanisms.

Prevalence Rates and Risk Factors for Primary Open Angle Glaucoma in the Middle East

Glaucoma is a multifactorial disease and a leading cause of irreversible blindness worldwide. Current data has demonstrated the approximate distribution of primary open-angle glaucoma (POAG) in patients of European, African, Hispanic, and Eastern Asian descent. However, a significant gap in the literature exists regarding the prevalence of POAG in Middle Eastern (ME) populations. Current studies estimate ME POAG prevalence based on a European model. Herein we screened 65 total publications on ME prevalence of POAG and specific risk factors using keywords: "glaucoma", "prevalence", "incidence", "risk factor", "Middle East", "Mideast", "Persian", "Far East", as well as searching by individual ME countries through PubMed, Embase, Ovid, Scopus, and Trip searches with additional reference list searches from relevant articles published up to and including March 1, 2021. Fifty qualifying records were included after 15 studies identified with low statistical power, confounding co-morbid ophthalmic diseases, and funding bias were excluded. Studies of ME glaucoma risk factors that identify chromosomes, familial trend, age/gender, socioeconomic status, lifestyle, intraocular pressure, vascular influences, optic disc hemorrhage, cup-to-disc ratio, blood pressure, obstructive sleep apnea, and diabetes mellitus were included in this systematic review. We conclude that the prevalence of POAG in the ME is likely higher than the prevalence rate that European models suggest, with ME specific risk factors likely playing a role. However, these findings are severely limited by the paucity of population-level data in the ME. Well-designed, longitudinal population-based studies with rigorous inclusion and exclusion criteria are ultimately needed to accurately assess the epidemiology and specific mechanistic risk factors of glaucoma in ME populations.

Mechanistic links between systemic hypertension and open angle glaucoma

Systemic hypertension or hypertension is a very common chronic age-related disease worldwide. It is typically characterised by a sustained elevation of blood pressure, particularly when the systolic blood pressure and/or diastolic blood pressure are of more than 140 mmHg and 90 mmHg, respectively. If hypertension is not well controlled, it may lead to an increased risk of stroke and heart attack. It has been shown that hypertension is linked to various ocular diseases, including cataract, diabetic retinopathy, age-related macular degeneration, and glaucoma. Glaucoma is the leading cause of irreversible blindness worldwide. Primary open angle glaucoma is the most common form of the disease and is usually characterised by an increase in intraocular pressure. This condition, together with normal tension glaucoma, constitutes open angle glaucoma. Systemic hypertension has been identified as a risk factor for open angle glaucoma. It is speculated that blood pressure is involved in the pathogenesis of open angle glaucoma by altering intraocular pressure or ocular blood flow, or both. Recent evidence has shown that both extremely high and low blood pressure are associated with increased risk of open angle glaucoma. Additional pathogenic mechanisms, including increased inflammation likely to be involved in the development and progression of these two diseases, are discussed.

Association between vascular comorbidity and glaucoma progression: A four-year observational study

Glaucoma, one of the significant causes of blindness worldwide, is a chronic optic neuropathy, characterized by progressive loss of retinal ganglion cells and specific perimetric defects. This study aimed to assess the association between the risk of glaucoma progression and different systemic vascular abnormalities. A 4-year prospective study was carried out on 204 patients diagnosed with open-angle glaucoma. Associated systemic vascular pathology was documented in 102 cases. Progression was encountered in 57 (55.9%) patients with vascular comorbidities and only in 10 (9.8%) patients with no associated vascular diseases (OR 13.81, P<0.01). The vascular risk factors associated with glaucoma progression in the study group were diastolic hypotension (OR 5.444, P=0.027), ischemic cardiac disease (OR 5.826; P<0.01), peripheral vasospasm (OR 3.108, P=0.042) and arterial hypertension (OR 2.593, P=0.05). Diabetes was not significantly correlated with progression in the study group, but only patients without diabetic retinopathy were included. This study highlights that systemic comorbidities associated with endothelial lesions, atherosclerosis and hypoperfusion can lead to damage to the retinal nerve fiber layer and the underlying conjunctive tissue.

Apoptosis in health and diseases of the eye and brain

Apoptosis is a form of programmed cell death (PCD) and enables the immunologically silent disposal of senescent or unwanted cells, causing minimal damage to the surrounding environment. Apoptosis can occur via intrinsic or extrinsic pathways that initiate a series of intracellular and extracellular signaling events. This ultimately leads to the clearance of the cell by phagocytes. This normal physiological mechanism may be accelerated in several diseases including those involving the eyes and brain, leading to loss of structure and function. This review presents the role of PCD in the health of the eyes and brain, and the evidence presented for its aberrant role in disease.

Association between metabolic risk factors and optic disc cupping identified by deep learning method

PURPOSE

This study aims to investigate correlation between metabolic risk factors and optic disc cupping and the development of glaucoma.

METHODS

This study is a retrospective, cross-sectional study with over 20-year-old patients that underwent health screening examinations. Intraocular pressure (IOP), fundus photographs, Body Mass Index (BMI), waist circumference (WC), serum triglycerides, serum HDL cholesterol (HDL-C), serum LDL cholesterol (LDL-C), systolic blood pressure (BP), diastolic BP, and serum HbA1c were obtained to analyse correlation between metabolic risk factors and glaucoma. Eye with glaucomatous optic neuropathy(GON) was defined as having an optic disc with either vertical cup-to-disc ratio(VCDR) ≥ 0.7 or a VCDR difference ≥ 0.2 between the right and left eyes by measuring VCDR with deep learning approach.

RESULTS

The study comprised 15,585 subjects and 877 subjects were diagnosed as GON. In univariate analyses, age, BMI, systolic BP, diastolic BP, WC, triglyceride, LDL-C, HbA1c, and IOP were significantly and positively correlated with VCDR in the optic nerve head. In linear regression analysis as independent variables, stepwise multiple regression analyses revealed that age, BMI, systolic BP, HbA1c, and IOP showed positive correlation with VCDR. In multivariate logistic analyses of risk factors and GON, higher age (odds ratio [OR], 1.054; 95% confidence interval [CI], 1.046-1.063), male gender (OR, 0.730; 95% CI, 0.609-0.876), more obese (OR, 1.267; 95% CI, 1.065-1.507), and diabetes (OR, 1.575; 95% CI, 1.214-2.043) remained statistically significant correlation with GON.

CONCLUSIONS

Among the metabolic risk factors, obesity and diabetes as well as older age and male gender are risk factors of developing GON. The glaucoma screening examinations should be considered in the populations with these indicated risk factors.

Autonomic Dysfunction and Blood Pressure in Glaucoma Patients: The Lifelines Cohort Study

Purpose

We investigated relationship of glaucoma with measurements related to autonomic dysfunction, including heart rate variability (HRV) and blood pressure (BP).

Methods

Glaucoma was defined using a questionnaire-based algorithm for 86,841 LifeLines Cohort Study participants. Baseline HRV (root mean square of successive differences [RMSSD]) was calculated from resting electrocardiograms; systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) were oscillometric-based measurements. We used a generalized linear mixed model, adjusted for age, age square, sex, body mass index, and familial relationships to assess the relationship of baseline HRV and BP (continuous and quartiles), hypertension, and antihypertensive medication with glaucoma at follow up (median, 3.8 years).

Results

The odds ratio (OR) of glaucoma was 0.95 (95% confidence interval [CI], 0.92-0.99) per unit increase in log-transformed RMSSD (in ms), indicating that autonomous dysfunction (low HRV) is associated with a higher risk of glaucoma. Per 10-mm Hg increase in BP, we found ORs of 1.03 (95% CI, 1.01-1.05; P = 0.015) for SBP, 1.01 (95% CI, 0.97-1.05; P = 0.55) for DBP, 1.03 (95% CI, 1.00-1.06; P = 0.083) for MAP, and 1.04 (95% CI, 1.01-1.07; P = 0.006) for PP. The OR for the lowest versus highest RMSSD quartile was 1.15 (95% CI, 1.05-1.27; P = 0.003). The ORs for the highest versus second quartile were 1.09 (95% CI, 0.99-1.19; P = 0.091) for SBP and 1.13 (95% CI, 1.02-1.24; P = 0.015) for PP. Glaucoma was more common among hypertensives (OR, 1.25; 95% CI, 1.16-1.35; P < 0.001); among those using angiotensin-converting enzyme (ACE) inhibitors (OR, 1.35; 95% CI, 1.18-1.55; P < 0.001); and among those using calcium-channel blockers (OR, 1.19; 95% CI, 1.01-1.40; P = 0.039).

Conclusions

Low HRV, high SBP, high PP, and hypertension were associated with glaucoma. Longitudinal studies may elucidate if autonomic dysregulation and high BP also predict glaucoma incidence.

Relationship between primary open angle glaucoma and blood pressure

Background: Glaucoma is commonly defined as high intra ocular pressure (≥21 mmHg) with optic neuropathy characterised by progressive loss of retinal ganglion cells which is associated with characteristic structural damage to the optic nerve and visual field loss. There are several studies investigating relation between primary open angle glaucoma (POAG) and both systemic hypertension and especially night hypotension. Our aim was to compare 24-h ambulatory blood pressure variability of patients with glaucoma followed-up in the eye outpatient clinic with that of patients free of glaucoma.Methods: A total of 75 patients were included in the study, 35 in the patient group and 40 in the control group. Both groups were compared for daytime, night-time, and whole day mean systolic and diastolic blood pressure (BP) readings in the ambulatory blood pressure testing.Results: Mean daytime systolic BP of the glaucoma patients was 119.5 ± 11.6 mmHg, and 128.3 ± 15.5 mmHg for control group (p = 0.008). The night-time systolic blood pressure, whole day systolic BP, and mean diastolic BP were significantly lower in patients with glaucoma (p = 0.001, p = 0.001, p = 0.028, respectively). In multiple regression analysis, we identified daytime systolic BP, night-time systolic BP, and whole day systolic BP were independent risk factors for developing glaucoma.Conclusion: If the progression of the disease is noticeable in patients with glaucoma at follow-up, night-time hypotension should be ruled out with ambulatory blood pressure and if this is observed medical treatments used by the patients should be reviewed and necessary measures should be taken.

Ocular blood flow as a clinical observation: Value, limitations and data analysis

Alterations in ocular blood flow have been identified as important risk factors for the onset and progression of numerous diseases of the eye. In particular, several population-based and longitudinal-based studies have provided compelling evidence of hemodynamic biomarkers as independent risk factors for ocular disease throughout several different geographic regions. Despite this evidence, the relative contribution of blood flow to ocular physiology and pathology in synergy with other risk factors and comorbidities (e.g., age, gender, race, diabetes and hypertension) remains uncertain. There is currently no gold standard for assessing all relevant vascular beds in the eye, and the heterogeneous vascular biomarkers derived from multiple ocular imaging technologies are non-interchangeable and difficult to interpret as a whole. As a result of these disease complexities and imaging limitations, standard statistical methods often yield inconsistent results across studies and are unable to quantify or explain a patient's overall risk for ocular disease. Combining mathematical modeling with artificial intelligence holds great promise for advancing data analysis in ophthalmology and enabling individualized risk assessment from diverse, multi-input clinical and demographic biomarkers. Mechanism-driven mathematical modeling makes virtual laboratories available to investigate pathogenic mechanisms, advance diagnostic ability and improve disease management. Artificial intelligence provides a novel method for utilizing a vast amount of data from a wide range of patient types to diagnose and monitor ocular disease. This article reviews the state of the art and major unanswered questions related to ocular vascular anatomy and physiology, ocular imaging techniques, clinical findings in glaucoma and other eye diseases, and mechanistic modeling predictions, while laying a path for integrating clinical observations with mathematical models and artificial intelligence. Viable alternatives for integrated data analysis are proposed that aim to overcome the limitations of standard statistical approaches and enable individually tailored precision medicine in ophthalmology.

The role of intracranial pressure in glaucoma and therapeutic implications

Despite glaucoma being the second leading cause of blindness globally, its pathogenesis remains incompletely understood. Although intraocular pressure (IOP) contributes to glaucoma, and reducing IOP slows progress of the disease, some patients progress despite normal IOP (NTG). Glaucomatous damage causes characteristic cupping of the optic nerve where it passes through the lamina cribrosa. There is evidence that cerebrospinal fluid (CSF) within the optic nerve sheath has a different composition from CSF surrounding the brain. Furthermore, fluctuations in CSF flow into the optic nerve sheath may be reduced by trabeculae within the sheath, and on standing intracranial pressure (ICP) within the sheath is stabilised at around 3 mmHg due to orbital pressure. Blood pressure has been linked both to glaucoma and ICP. These facts have led some to conclude that ICP does not play a role in glaucoma. However, according to stress formulae and Laplace's Law, stress within the lamina cribrosa is dependent on the forces on either side of it, (IOP and ICP), and its thickness. On lying flat at night, ICP between the brain and optic nerve sheath should equalise. Most evidence suggests ICP is lower in glaucoma than in control groups, and that the lamina cribrosa is thinner and more posteriorly displaced in glaucoma. Subjects who have had ICP reduced have developed signs of glaucoma. This review finds most evidence supports a role for low ICP in the pathogenesis of glaucoma. Caffeine, theophylline and vitamin A may increase ICP, and could be new candidates for an oral treatment.

Relationship between ocular risk factors for glaucoma and optic disc rim in normal eyes

AIM

To study relationships between reported risk factors for glaucoma and neuroretinal rim area in normal eyes.

METHODS

The Kumejima study participants, 3762 of the 4632 eligible Kumejima residents 40 years and older, underwent a detailed ocular examination including sequential disc stereo photography. In a randomly chosen eye of a subject whose both eyes met the inclusion criteria, fundus photographs of 2474 ophthalmologically normal eyes of the 2474 subjects were analysed by computer-assisted planimetry to measure the disc, rim and β-peripapillary atrophy (PPA) areas. The rim was divided into the superior and inferior halves by a line connecting the fovea and disc centre.

RESULTS

The disc, superior and inferior halves rim and β-PPA areas averaged 2.53±0.50 (SD), 0.82±0.15, 0.84±0.16 and 0.45±0.66 mm². After adjustment for other systemic and ocular factors including age, disc and β-PPA areas, disc-fovea distance (p=0.013, 0.016) correlated positively and intraocular pressure (IOP) (p=0.004, 0.006) and axial length (AL) (p<0.000, 0.004) negatively with the superior and inferior halves rim area, respectively; central corneal thickness (CCT) (p=0.008) and mean blood pressure (mBP) (p=0.020) correlated positively and male gender (p=0.012) negatively only with the superior half rims.

CONCLUSIONS

Besides previously reported risk factors for glaucoma such as age or IOP, thinner CCT, lower mBP and male gender were newly found to significantly correlate with smaller rim area only in the superior half disc, and a greater disc-fovea distance with greater superior and inferior half rim areas in normal adult eyes.

Factors Associated With Retinal Vessel Diameters in an Elderly Population: the Thessaloniki Eye Study

Purpose

To identify the factors associated with retinal vessel diameters in the population of the Thessaloniki Eye Study.

Methods

Cross-sectional population-based study (age ≥ 60 years). Subjects with glaucoma, late age-related macular degeneration, and diabetic retinopathy were excluded from the analyses. Retinal vessel diameters were measured using the IVAN software, and measurements were summarized to central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole to venule ratio (AVR).

Results

The analysis included 1614 subjects. The hypertensive group showed lower values of CRAE (P = 0.033) and AVR (P = 0.0351) compared to the normal blood pressure (BP) group. On the contrary, the group having normal BP under antihypertensive treatment did not have different values compared to the normal BP group. Diastolic BP (per mm Hg) was negatively associated with CRAE (P < 0.0001) and AVR (P < 0.0001), while systolic BP (per mm Hg) was positively associated with CRAE (P = 0.001) and AVR (P = 0.0096). Other factors significantly associated included age, sex, alcohol, smoking, cardiovascular disease history, ophthalmic medication, weight, and IOP; differences were observed in a stratified analysis based on BP medication use.

Conclusions

Our study confirms previous reports about the association of age and BP with vessel diameters. The negative correlation between BP and CRAE seems to be guided by the effect of diastolic BP as higher systolic BP is independently associated with higher values of CRAE. The association of BP status with retinal vessel diameters is determined by diastolic BP status in our population. Multiple other factors are also independently associated with retinal vessel diameters.

Relationship between optical perfusion pressure and systemic blood pressure on glaucoma: Case-control study

AIM:

To investigate the relationship between blood pressure (BP), ocular perfusion pressure (OPP), intraocular pressure (IOP) and open angle glaucoma (OAG) in Primary Open Angle Glaucoma (POAG) patients and normal population.

DESIGN:

Cross-sectional observation study.

MATERIALS AND METHODS:

Hospital-based, case control cross-sectional study conducted on 150 patients, of which 75 people were included in the control group and 75 people in the glaucoma group. The diagnosis of cases was based on disc evaluation, gonioscopy, perimetry and applanation tonometry. Systolic and diastolic blood pressure (SBP and DBP) was measured with a Mercury Sphygmomanometer. Mean ocular perfusion pressure (MOPP) = ⅔ (mean arterial pressure − IOP), where mean arterial pressure (MAP) = DBP + ⅓ (SBP − DBP), systolic perfusion pressure (SPP) = SBP – IOP and diastolic perfusion pressure (DPP) = DBP − IOP was calculated.

RESULTS:

DBP, OPP, SPP and DPP showed positive association with POAG. There is positive correlation between IOP and SBP, DBP and there is a negative correlation between IOP, OPP, SPP and DPP. Lower OPP was strongly associated with an increased risk for POAG, with a relative risk of 6.27 and the odds ratio of 0.075 for those with OPP less than 50 mmHg. Similarly, a low DPP less than 55 mmHg were also associated with increased risk for POAG with relative risk of 5.3 and the odds ratio of 0.020.

CONCLUSION:

Low MOPP and low DPP show strong association with increased prevalence of POAG and are independent risk factors for OAG.

Prevalence, incidence, and risk factors of primary open-angle glaucoma - a cohort study based on longitudinal data from a German public health insurance

Background

This study estimates the prevalence and incidence rates of primary open -angle glaucoma (POAG) as well as risk factors based on a dataset from the largest German health insurance company.

Methods

A random sample of 250,000 persons at age 50+ of the Allgemeine Ortskrankenkasse (AOK) from 2010 to 2013 was used. Selected risk factors of POAG incidence were analyzed using multivariate Cox proportional hazard models.

Results

The age-standardized prevalence of POAG at age 50+ in 2010 was 2.79% (95%-CI: 2.72–2.85%). The age-standardized total incidence rate was 0.38 (0.36–0.39) per 100 person-years. Sex differences were significant for total prevalence and total incidence rates, with higher prevalence and incidence rates for women compared to men. The Cox model revealed a strong age effect, a significantly 19% higher incidence for women (p ≤ 0.001), injuries of the eye and orbit (175%, p ≤ 0.001), degeneration of iris and ciliary body (155%, p = 0.022), myopia (155%, p ≤ 0.001), retinal vascular occlusions (134%, p ≤ 0.001), hypertension (13%, p ≤ 0.001) and diabetes mellitus (23%, p ≤ 0.001).

Conclusion

Health claims data are an important data source for estimating POAG occurrence and help overcome the problems of small sample sizes. These results may help to understand the causal pathways of POAG and to develop intervention strategies to increase the awareness of patients and physicians with the aim of reducing POAG incidence.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6935-6) contains supplementary material, which is available to authorized users.

Effect of systemic antihypertensives on change in intraocular pressure after initiating topical prostaglandins for primary open-angle glaucoma

Purpose

There is a limited understanding of factors that influence the efficacy of topical glaucoma medication. Our study is a long-term, case–control analysis of how systemic antihypertensive (anti-HTN) medications influence the change in IOP after initiating prostaglandin (PG) drop therapy.

Materials and methods

A retrospective chart review of 3,781 patients was performed on patients with a diagnosis of glaucoma suspect that progressed to primary open-angle glaucoma (POAG) by ICD-9 codes over a 10-year period. Inclusion criteria consisted of the following: 1) progression from preglaucoma to glaucoma diagnosis in a time span of ≥6 months; 2) two visual fields recorded between these dates; 3) initial average IOP of both eyes of ≥21 mmHg; and 4) initiation of topical PG therapy alone. IOP (in mmHg) was measured at initiation of PG drops and at next visit.

Results

One hundred eleven patients were qualified for analysis. Patients not on anti-HTN agents had an average IOP decrease of 6.38±0.56 mmHg. Comparatively, patients on anti-HTN agents had an average IOP decrease of 6.66±0.48 mmHg (P=0.61). In addition, there was no statistical difference between IOP decrease between patients on single vs multiple systemic anti-HTN agents (P=0.85). There were eight nonresponders to PGs on no anti-HTN medications and 12 nonresponders on anti-HTN medication (P=0.55).

Conclusion

Systemic anti-HTN medication use did not significantly impact IOP reduction after topical PG initiation for POAG. Additionally, nonresponse to PG therapy was not correlated to systemic anti-HTN use.

Is primary open-angle glaucoma an ocular manifestation of systemic disease?

Primary open-angle glaucoma is currently characterized by a pattern of progressive retinal ganglion cell loss that stems from a complex underlying pathophysiology that remains poorly elucidated. The roles of blood flow and intraocular pressure (IOP) in glaucoma pathogenesis have been extensively studied. Further, it has been established that lowering IOP can slow the progression of glaucoma. In addition, a number of influential factors have emerged and gained momentum over the years. Increasing evidence implicates the contributions of low cerebrospinal fluid pressure, autoimmunity, neurodegeneration, and impaired autoregulation towards glaucoma pathophysiology. We aggregate and explore these different camps of thought that have garnered attention over the last few decades, and, in doing so, aim to challenge the long-standing view of glaucoma as a primary disease of the eye. A shift in our perspective towards understanding glaucoma as an ocular manifestation of systemic dysregulation may lead ultimately to better clinical management of the disease.

Research progress on human genes involved in the pathogenesis of glaucoma (Review)

Glaucoma is the leading cause of irreversible blindness globally. It is known that the incidence of glaucoma is closely associated with inheritance. A large number of studies have suggested that genetic factors are involved in the occurrence and development of glaucoma, and even affect the drug sensitivity and prognosis of glaucoma. In the present review, 22 loci of glaucoma are presented, including the relevant genes (myocilin, interleukin 20 receptor subunit B, optineurin, ankyrin repeat- and SOCS box-containing protein 10, WD repeat-containing protein 36, EGF-containing fibulin-like extracellular matrix protein 1, neurotrophin 4, TANK-binding kinase 1, cytochrome P450 subfamily I polypeptide 1, latent transforming growth factor β binding protein 2 and TEK tyrosine kinase endothelial) and 74 other genes (including toll-like receptor 4, sine oculis homeobox Drosophila homolog of 1, doublecortin-like kinase 1, RE repeats-encoding gene, retinitis pigmentosa GTPase regulator-interacting protein, lysyl oxidase-like protein 1, heat-shock 70-kDa protein 1A, baculoviral IAP repeat-containing protein 6, 5,10-methylenetetrahydrofolate reductase and nitric oxide synthase 3 and nanophthalmos 1) that are more closely associated with glaucoma. The pathogenesis of these glaucoma-associated genes, glaucomatous genetics and genetic approaches, as well as glaucomatous risk factors, including increasing age, glaucoma family history, high myopia, diabetes, ocular trauma, smoking, intraocular pressure increase and/or fluctuation were also discussed.

Systemic hypertension is not protective against chronic intraocular pressure elevation in a rodent model

High intraocular pressure is the most well documented glaucoma risk factor; however many patients develop and/or show progression of glaucoma in its absence. It is now thought that in some instances, ocular perfusion pressure (blood pressure – intraocular pressure) may be as important as intraocular pressure alone. Thus, systemic hypertension would be protective against glaucoma. Epidemiological studies, however, are inconclusive. One theory of why hypertension may not protect against elevated intraocular pressure in spite of increasing ocular perfusion pressure is that with time, morphological changes to the vasculature and autoregulatory failure outweigh the benefits of improved perfusion pressure, ultimately leading to poor retinal and optic nerve head blood supply. In this study we showed the presence of increased wall:lumen ratio and wall area of the ophthalmic artery in rats with chronic hypertension in addition to failure of retinal autoregulation in response to acute modification of ocular perfusion pressure. Subsequently we found that in spite of dramatically increasing ocular perfusion pressure, chronic systemic hypertension failed to protect retinal structure and function from a rodent model of glaucoma.

Systemic and Ocular Determinants of Peripapillary Retinal Nerve Fiber Layer Thickness Measurements in the European Eye Epidemiology (E3) Population

PURPOSE

To investigate systemic and ocular determinants of peripapillary retinal nerve fiber layer thickness (pRNFLT) in the European population.

DESIGN

Cross-sectional meta-analysis.

PARTICIPANTS

A total of 16 084 European adults from 8 cohort studies (mean age range, 56.9±12.3-82.1±4.2 years) of the European Eye Epidemiology (E3) consortium.

METHODS

We examined associations with pRNFLT measured by spectral-domain OCT in each study using multivariable linear regression and pooled results using random effects meta-analysis.

MAIN OUTCOME MEASURES

Determinants of pRNFLT.

RESULTS

Mean pRNFLT ranged from 86.8±21.4 μm in the Rotterdam Study I to 104.7±12.5 μm in the Rotterdam Study III. We found the following factors to be associated with reduced pRNFLT: Older age (β = -0.38 μm/year; 95% confidence interval [CI], -0.57 to -0.18), higher intraocular pressure (IOP) (β = -0.36 μm/mmHg; 95% CI, -0.56 to -0.15), visual impairment (β = -5.50 μm; 95% CI, -9.37 to -1.64), and history of systemic hypertension (β = -0.54 μm; 95% CI, -1.01 to -0.07) and stroke (β = -1.94 μm; 95% CI, -3.17 to -0.72). A suggestive, albeit nonsignificant, association was observed for dementia (β = -3.11 μm; 95% CI, -6.22 to 0.01). Higher pRNFLT was associated with more hyperopic spherical equivalent (β = 1.39 μm/diopter; 95% CI, 1.19-1.59) and smoking (β = 1.53 μm; 95% CI, 1.00-2.06 for current smokers compared with never-smokers).

CONCLUSIONS

In addition to previously described determinants such as age and refraction, we found that systemic vascular and neurovascular diseases were associated with reduced pRNFLT. These may be of clinical relevance, especially in glaucoma monitoring of patients with newly occurring vascular comorbidities.

The effects of antioxidants on ocular blood flow in patients with glaucoma

PURPOSE

To investigate the effects of an antioxidant dietary supplement that includes Ginkgo biloba, on retinal and retrobulbar blood flow in patients with open-angle glaucoma (OAG).

METHODS

Forty-five patients with confirmed OAG were enroled in a randomized, double blinded, placebo-controlled cross-over study. Baseline and postadministration measurements of intraocular pressure (IOP), ocular perfusion pressure (OPP), retrobulbar blood flow, and retinal capillary blood flow were non-invasively measured (ultrasound and laser Doppler modalities, respectively) before and one month after antioxidant nutraceuticals and placebo administration. Changes in measurements between the active supplement and placebo arms were evaluated using paired t-tests, with p < 0.05 considered statistically significant.

RESULTS

Antioxidant supplementation produced a statistically significant increase in peak systolic and/or end diastolic blood flow velocities in all retrobulbar blood vessels compared to placebo. Vascular resistance was also reduced in central retinal and nasal short posterior ciliary arteries following antioxidant administration. Additionally, antioxidant supplementation increased superior and inferior temporal retinal capillary mean blood flow and the ratio of active to non-active retina capillaries compared to placebo.

CONCLUSION

One-month oral administration of antioxidants produced increases in biomarkers of ocular blood flow within retinal and retrobulbar vascular beds in patients with OAG.

Systemic Medication Associations with Presumed Advanced or Uncontrolled Primary Open-Angle Glaucoma

PURPOSE

To identify associations between systemic medications and primary open-angle glaucoma (POAG) requiring a procedure using United States insurance claims data in a hypothesis-generating study.

DESIGN

Database study.

PARTICIPANTS

In total, 6130 POAG cases (defined as patients with POAG undergoing a glaucoma procedure) were matched to 30 650 controls (defined as patients undergoing cataract surgery but without a coded glaucoma diagnosis, procedure, or medication) by age, gender, and region of residence.

METHODS

Participant prescription drug use was calculated for the 5-year period before the glaucoma procedure or cataract surgery. Separately for individual generic drugs and drug classes, logistic regression was used to assess the association with POAG status. This was done across all generic drugs and drug classes that were prescribed in at least 1% of cases and controls. Analyses were adjusted for age, sex, region of residence, employment status, insurance plan type, and the total number of drugs prescribed.

MAIN OUTCOME MEASURES

Odds ratio (OR) and 95% confidence intervals (CIs) for the association between each drug or drug class and POAG.

RESULTS

The median age of participants was 72 years, and 52% were women. We tested for associations of POAG with 423 drug classes and 1763 generic drugs, resulting in a total of 2186 statistical tests and a Bonferroni-adjusted significance threshold of P < 2.3 × 10^-5. Selective serotonin reuptake inhibitors (SSRIs) were strongly associated with a reduced risk of POAG (OR, 0.70; 95% CI, 0.64-0.76; P = 1.0 × 10^-15); the most significant drug in this class was citalopram (OR, 0.66; 95% CI, 0.57-0.77; P = 1.2 × 10^-7). Calcium channel blockers were strongly associated with an increased risk of POAG (OR, 1.26; 95% CI, 1.18-1.35; P = 1.8 × 10^-11); the most significant drug in this class was amlodipine (OR, 1.27; 95% CI, 1.18-1.37; P = 5.9 × 10^-10).

CONCLUSIONS

We present data documenting potential associations of SSRIs and calcium channel blockers with POAG requiring a procedure. Further research may be indicated to better evaluate any associates of serotonin metabolism or calcium channels in glaucoma, or establish whether the associations are due to variations in the patterns for prescribing these drugs.

Glaucoma history and risk factors

Apart from the risk of developing glaucoma there is also the risk that it is not detected and irreversible loss of vision ensues. Some studies of methods of glaucoma diagnosis have examined the results of instrument-based examinations with great if not complete reliance on objective findings in arriving at a diagnosis. The very valuable advances in glaucoma detection instrument technologies, and apparent increasing dependence on them, may have led to reduced consideration of information available from a patient history in those studies. Dependence on objective evidence of glaucomatous pathology may reduce the possibility of detecting glaucoma suspects or patients at risk for becoming glaucoma suspects. A valid positive family history of glaucoma is very valuable information. However, negative family histories can often be unreliable due to large numbers of glaucoma cases being undiagnosed. No evidence of family history is appropriate rather than no family history. In addition the unreliability of a negative family history is increased when patients with glaucoma fail to inform their family members. A finding of no family history can only be stated as no known family history. In examining the potential diagnostic contribution from a patient history, this review considers, age, frailty, race, type and degree of refractive error, systemic hyper- and hypotension, vasospasm, migraine, pigmentary dispersion syndrome, pseudoexfoliation syndrome, obstructive sleep apnea syndrome, diabetes, medication interactions and side effects, the degree of exposure to intraocular and intracranial pressure elevations and fluctuations, smoking, and symptoms in addition to genetics and family history of the disease.

Diurnal blood pressure parameters in normal tension glaucoma, primary open angle glaucoma, and healthy subjects

OBJECTIVE

The pathophysiology of glaucoma is still undisclosed. Cardiovascular hemodynamic changes are hypothesized to contribute to glaucoma. This study aimed to determine the differences in the diurnal blood pressure (BP) of patients with normal tension glaucoma (NTG), primary open angle glaucoma (POAG), and controls without glaucoma.

METHODS

A total of 129 patients were included in this study. The day-night average systolic and diastolic BPs, the day-night average pulse pressures (PPs), the day-night average heart rates, and the percentage of BP decline at night were obtained from the Holter devices and compared.

STUDY DESIGN

Prospective, randomized, case-control study.

RESULTS

This study included 43 NTG patients (Group 1), 44 POAG patients (Group 2), and 42 healthy subjects without glaucoma (Group 3). The age (p=0.138) and sex (p=0.216) distributions between the groups were similar. The average day-night PP values of Group 1 were 49.17±9.90 and 46.07±10.84 mm Hg, respectively, while their total average PP was 48.48±9.60, their total average systolic BP was 120.02±12.65, and their night average systolic BP was 111.93±15.87 mm Hg. In Group 2, the average day and night PP values were 54.83±10.35 and 51.73±9.10 mm Hg, respectively, their total average PP was 54.00±9.87, their total average systolic BP was 126.75±11.50, and their night average systolic BP was 119.21±12.38 mm Hg. These differences were statistically significant and the corresponding p values were 0.040, 0.040, 0.037, 0.033, and 0.038.

CONCLUSION

NTG patients have low diurnal BP parameters, which may reduce their optic nerve perfusion and may be responsible for their glaucomatous visual field damage.

Relationship between systemic hypertension, perfusion pressure and glaucoma: a comparative study in an adult Indian population

AIMS

To study the relationship between blood pressure (BP), intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and primary open angle glaucoma (POAG) in patients with hypertension and compare it to a control group of normotensives.

DESIGN

Cross-sectional observational study.

MATERIALS AND METHODS

A total of 108 subjects with primary hypertension and 100 age-matched controls without hypertension were enrolled for the study. IOP measurement using Noncontact Tonometer and dilated fundus evaluation using + 90 D lens were done for all cases. Single recording of BP was taken. Gonioscopy, Humphrey's central visual fields, optical coherence tomography and pachymetry were done for all subjects with IOP > 21 mm Hg or C: D ratio ≥ 0.5 or asymmetry of > 0.2.

STATISTICAL ANALYSIS

Univariate and multivariate multinomial regression models were used to determine the association between covariates and risk of glaucoma or glaucoma suspect.

RESULTS

There was no difference in the glaucoma status between subjects with and without hypertension. Subjects on antihypertensive medications were 1΍ times more likely to have suspicious glaucoma (odds ratio [OR] =1.56] and nearly twice as likely to have POAG (OR = 1.85). In addition, we found a 31% and 12% reduction in risk of having POAG (95% confidence interval [CI] =13-45%, P = 0.001) and glaucoma suspect (95% CI = 2-21%, P = 0.03) respectively with every 1 mm Hg increment in MOPP.

CONCLUSION

Subjects on antihypertensive medications are more likely to have either glaucoma or glaucoma suspect, and higher ocular perfusion pressure offers relative protection from glaucomatous damage.