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

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.

Ocular Perfusion Pressure in 7- and 12-Year-Old Chinese Children: The Anyang Childhood Eye Study

Purpose

The purpose of this study was to report the distribution of mean ocular perfusion pressure (MOPP) and its associated factors in Chinese children.

Methods

We enrolled 3048 grade 1 students and 2258 grade 7 students of the Anyang Childhood Eye Study in central China. Systolic and diastolic blood pressure (SBP and DBP) were recorded with a digital automatic sphygmomanometer. Intraocular pressure (IOP) was assessed by a non-contact tonometer. MOPP was calculated as 2/3 × (DBP + 1/3[SBP – DBP]) - IOP. Risk factors for myopia were obtained through a questionnaire survey.

Results

The MOPP was 33.83 ± 6.37 mm Hg (mean ± SD) in grade 1, which was lower than 36.99 ± 6.80 mm Hg in grade 7 (P < 0.001). Compared with myopic eyes, non-myopic eyes had higher MOPP in grade 7 (37.72 ± 6.72 mm Hg versus 36.58 ± 6.57 mm Hg, P < 0.001) and in grade 1 (33.88 ± 6.29 mm Hg versus 33.12 ± 7.03 mm Hg, P = 0.12). Multivariable analysis showed that higher MOPP was associated with less myopia (P < 0.001), higher body mass index (BMI; P < 0.001), thinner central corneal thickness (P < 0.001), less time on near work (P < 0.001), and more time on sleeping (P = 0.04).

Conclusions

MOPP was higher in children of older age, with higher BMI, less time on near work, and more time on sleeping, and was higher in eyes with less myopia.

Translational Relevance

We found that MOPP might be an indicator for the detection of myopia development.

Prevalence of pre-perimetric primary open angle glaucoma in hypertensives of North India

Background

Systemic hypertension is alleged to increase the risk of glaucoma. As clinically Primary Open angle Glaucoma (POAG) is diagnosed only after approximately 40% of ganglion cell loss has occurred, therefore this study was commenced with an aim to determine the prevalence of pre-perimetric glaucomatous damage and its association with systemic hypertension using optical coherence tomography (OCT).

Materials and Methods

A total of 680 study participants were enrolled in this cross-sectional study. Among them 340 patients were of systemic hypertension (Group 1) and 340 patients without hypertension (Group 2). All patients underwent detailed history, ocular and systemic examination including slit lamp examination, fundus examination by +90 D lens, Humphrey field analyser for field charting and OCT for nerve fiber analysis. For glaucomatous nerve damage.

Results

Group 1 and Group 2 had Male: Female ratio of 1:8 and 1:9, respectively (P = 0.809). Maximum participants 48.8% and 54.4% in Group 1 and Group 2, respectively, were in age group 50-59 years. Statistically significant difference was seen in the percentage of pre-perimetric glaucomatous patients between the two groups (P < 0.001). On OCT analysis between pre-perimetric glaucomatous eyes and healthy eyes significant difference in thickness was seen in temporal inner macula, inferior outer macula, temporal outer macula, superior outer macula and nasal outer macula. Significant difference in volume was seen for inferior temporal and nasal outer macula (P < 0.001).

Conclusion

In hypertensives, glaucomatous optic nerve damage starts much earlier before the obvious clinical signs of POAG appear, as compared to normotensive individuals.

The acute effect of systemic blood pressure reduction on intraocular pressure in hypertensive patients

OBJECTIVES:

Previous studies have shown an association between systemic hypertension and intraocular pressure (IOP). We analyzed the relationship between the decreases of the blood pressure (BP) and IOP in hypertensive patients.

METHODS:

The study includes a total of 214 patients: 158 hypertensive and 56 normotensive patients as study and control groups, respectively. The IOP of each eye in both the groups was measured once with a noncontact tonometer at presentation and an hour after BP reduction to normal in the study group. We analyzed the reduction in IOP with decreasing BP.

RESULTS:

In the study group, the mean IOP was 15.29 ± 4.05 mmHg in the right and 15.11 ± 3.78 mmHg in the left eyes. The mean IOP measured an hour after the patients became normotensive was 13.78 ± 4.06 mmHg in the right and 13.51 ± 3.82 in the left eyes. There was a statistically significant decrease in the IOPs (P < 0.001). The mean IOP in the control group was 13.54 ± 3.51 mmHg in the right and 13.20 ± 3.33 mmHg in the left eyes. The mean IOP at presentation in the study and control groups was found to be significantly different (P < 0.001).

CONCLUSIONS:

Patients in the study group showed a significantly higher IOP compared to patients in the normotensive group. Furthermore, patients in the study group showed a significant reduction in IOP after BP reduction. This may indicate that uncontrolled hypertension poses a risk for prolonged higher IOP. Prolonged higher IOP can be considered a risk factor for the glaucoma.

Role of hypertension as a risk factor for open-angle glaucoma: a systematic review and meta-analysis

Glaucoma is the leading cause of irreversible blindness. It is estimated that as many as 3.2 million people worldwide experience blindness due to glaucoma, including open-angle glaucoma (OAG). Until now, there is no definite mechanism related to the incidence of OAG. However, increased intraocular pressure (IOP) is considered to be the most important risk factor. Several current studies show that there is a significant relationship between hypertension (HTN) and IOP. In particular, several epidemiological studies have shown that an increase in systemic blood pressure (BP) is associated with an increase in IOP. However, several studies report that high BP provides a protective effect at a young age against the incidence of OAG. Therefore, this literature aims to explore the effect of HTN on the incidence of OAG. In this review, search for the literature using keywords that match the topic, then a gradual screening was carried out with the predetermined eligibility criteria. From 3711 studies, 16 studies matched the criteria having a total sample size of 72 212 and then a quantitative meta-analysis was conducted. The results showed a risk ratio of 1.69 (95% CI 1.50 to 1.90) in the HTN group. However, from our qualitative synthesis, we found that people who have an unstable diastolic blood pressure (DBP), either high or low, are both able to increase the risk of OAG events. In conclusion, we found that HTN was able to increase the risk of OAG and DBP instability, whether high or low, can also increase the risk of OAG incidence.

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.

Common systemic medications that every optometrist should know

Healthcare in the twenty-first century has witnessed an increased use of prescription drugs. As a member of a patient's health care team, optometrists should be aware of the pharmaceuticals taken by patients and their potential ocular complications. This paper will discuss the most prescribed medications in Australia today and their effects on the visual system. The paper will review the agents used to treat six common systemic conditions, their frequency of use, mechanism of action, clinical indications, and potential ocular manifestations. Literature has documented both positive and negative associations of systemic medications on the eye's health. Many associations documented here have shown conflicting evidence, thus warranting further investigation. Based on the frequency and severity of the ocular manifestations in the literature, recommendations for clinical care are given. Being familiar with the most common ocular side effects associated with common systemic medications aids in the correct and timely diagnosis of ocular complications to prevent permanent sequelae.

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.

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.

Effect of physical activity on severity of primary angle closure glaucoma

Objective:

To determine the association between physical activity and severity of primary angle closure glaucoma in Malay patients.

Methods:

A cross-sectional study was conducted involving 150 primary angle closure glaucoma patients between April 2014 and August 2016. Using the International Physical Activity Questionnaire, the physical activity status was assessed and divided into three categories: mild, moderate and heavy physical activity. The duration of physical activity and corresponding minimum energy requirements were calculated. Ocular examination was performed including Humphrey visual field 24-2 analysis assessment. Based on two consecutive reliable Humphrey visual fields, the severity of glaucoma was scored according to modified Advanced Glaucoma Intervention Study and classified as mild (0–5), moderate (6–11) and severe (12–20). Association between physical activity and Advanced Glaucoma Intervention Study score was determined with multiple linear regression analysis.

Results:

A total of 150 Malay patients with primary angle closure glaucoma were included (50 patients with mild, 50 with moderate and 50 with severe glaucoma). Physical activity showed inverse association with the severity of primary angle closure glaucoma. After calculating adjustments for age, sex, duration of glaucoma, body mass index, systemic co-morbidities, family history of glaucoma, myopia and educational status [adjusted b –3.41, 95% confidence interval (–5.23, –1.59), p < 0.001], there was also an inverse relationship with Advanced Glaucoma Intervention Study score. Every increase in physical activity level reduces the Advanced Glaucoma Intervention Study score by 3.4 point.

Conclusion:

Physical activity is the potential modifiable risk factor in reducing the severity of glaucoma among primary angle closure glaucoma patients. However, there is possibility of the severity of glaucoma restricted the physical activity of primary angle closure glaucoma patients.

Heterogeneity in arterial hypertension and ocular perfusion pressure definitions: Towards a consensus on blood pressure-related parameters for glaucoma studies

PURPOSE

Glaucoma studies have long taken into account the blood pressure (BP) status of patients. This study summarizes and evaluates the impact of the different criteria that have been used for BP-related variables in glaucoma research.

METHODS

Studies included in two meta-analyses that reviewed the role of BP in glaucoma were analyzed. Additional studies published after the search periods of the meta-analyses were also included. Criteria for the definition of arterial hypertension and other BP-related variables, such as mean arterial pressure (MAP) and mean ocular perfusion pressure (MOPP), were retrieved.

RESULTS

Sixty-four studies were evaluated. One-third used 140 mmHg as a systolic BP cut-off to define hypertension, 20% used 160 mmHg and the remaining half used various other criteria. Less than 20% of studies reported MAP and/or MOPP. While eight of the ten studies reporting MAP used a correct formula that only happened for five of the eleven studies reporting MOPP. Using as an example average blood pressure values, incorrectly used formulas could have led to an overestimation of more than 100% of the expected values.

CONCLUSION

Considerable heterogeneity exists in BP-related variables in glaucoma research and different definitions can lead to large disparities. Glaucoma research would benefit from a consensus regarding blood pressure parameters.

Characterization of the ocular surface temperature dynamics in glaucoma subjects using long-wave infrared thermal imaging

We evaluated the dynamics of ocular surface temperature using thermal imaging in 21 glaucoma subjects and 19 healthy subjects. On opening of the eye, subjects with glaucoma showed significantly cooler temperatures in the central cornea compared to the control group. The upper eyelid was also significantly cooler just before the eye opened. Immediately after opening the eye, the dynamic of temperature change was different in the two groups. In subjects with glaucoma, the eyes cooled significantly faster, with an average decrease of 0.49°C during the first second compared to 0.24°C in the control group. Our results support the hypothesis that both the stability of the tear film and changes in the ocular blood supply in subjects with glaucoma play an important role in thermal dynamics of the ocular surface.

Evaluation of the 24-hour intraocular pressure and systemic blood pressure at the same time

PURPOSE

To obtain simultaneous 24-hour contact lens voltage and systemic arterial blood pressure values with the Sensimed Triggerfish system and Holter monitoring device.

METHODS

Ten primary open-angle glaucoma (POAG) and 8 pseudoexfoliation glaucoma (PXG) patients were included in the study. The Sensimed Triggerfish contact lens device was used to calculate the 24-hour IOP, and a Holter sphygmomanometer device was used for simultaneous 24-hour blood pressure measurements. We define the 8:00 am-11:00 pm period measurements as diurnal values and the other measurements as nocturnal values.

RESULTS

The mean nocturnal systolic values (nocturnal SBP 120.5±3.4 for POAG and 122.8±5.3mmHg for PXG) and diastolic BP (nocturnal DBP 70.2±1.9 for POAG and 68.1±1.2mmHg for PXG) were lower than the diurnal (diurnal SBP 134.6±5.3 for POAG, 145.9±41.7mmHg for PXG, diurnal DBP 79.4±5.8 for POAG and 78.6±5.1mmHg for PXG) values, and these differences were statistically significant in both groups (P=0.001 in DBP in PXG and P<0.001 for other values). In addition, nocturnal CL voltage values (228.8±41.1 for POAG and 214.3±47.0mVEq for PXG) were higher than the diurnal values (55.8±77.2 for POAG and 145.9±41.7mVEq for PXG) in the POAG and PXG groups, and these were statistically significant as well (P<0.001 for all). In the POAG and PXG groups, CL voltage had a statistically significant negative correlation with systolic (respectively, r: -0.248, P=0.001 and r: -0.272, P˂0.001) and diastolic (respectively, r: -0.115, P=0.036 and r: -0.160, P=0.028) BP values.

CONCLUSION

We observed that CL voltage values rose during the nocturnal period, with a concomitant decrease in systolic and diastolic BP.

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.

Antihypertensive Medication Postpones the Onset of Glaucoma: Evidence From a Nationwide Study

The aim was to investigate the impact of antihypertensive medication on the onset of glaucoma. Data from the complete Danish population between 40 and 95 years of age were used in the period from 1996 to 2012, covering >2.6 million individuals. The National Danish Registry of Medicinal Products Statistics was used to identify all claimed prescriptions for glaucoma medication and antihypertensive drugs. We first investigated basic correlations in the data and found that patients treated with antihypertensive medication, at any time during the study period, had a significantly higher overall relative risk (RR) of glaucoma, even when controlling for age and sex (with a RR of 1.31 and P<0.0001). Furthermore, our data confirm the well-known positive association between age and glaucoma. To investigate the causal effect of antihypertensive treatment on the onset of treatment for glaucoma, we used a regression discontinuity study design. This analysis provides our main finding, namely that prescription of antihypertensive medication leads to a significant reduction in the risk of developing glaucoma. Therefore, although hypertension-as indicated by the use of antihypertensive medication-is positively correlated with glaucoma, our study indicates that antihypertensive medication itself may have a preventive effect on the development of glaucoma.