Allostatic Load and Glaucoma: Are We Missing the Big Picture?

Relationship Between Glaucoma and Chronic Stress Quantified by Allostatic Load Score in the All of Us Research Program

PURPOSE

To assess the relationship between glaucoma and allostatic load (AL), an established framework for quantifying the physiologic effects of chronic stress through measurements of systemic biomarkers.

DESIGN

Retrospective case-control study.

METHODS

Participants of the National Institutes of Health All of Us (AoU) Research Program with complete AL biomarker data between December 1984 and June 2022 and with (cases) or without (controls) primary glaucoma were identified. AL scores were calculated using the adapted Seeman AL scale consisting of 10 systemic biomarkers: body mass index, systolic blood pressure, diastolic blood pressure, glycated hemoglobin, total cholesterol, triglycerides, glomerular filtration rate, albumin, C-reactive protein, and homocysteine. AL score was defined as the number of biomarkers with measurements in the highest risk quartiles. Age was calculated as the median age at the time of biomarker measurements. Logistic regression analysis was performed to assess the association between the earliest possible AL score and glaucoma adjusted for race or ethnicity. Mediation analysis was performed to estimate the relationship between race or ethnicity and glaucoma mediated by AL score.

RESULTS

The study cohort consisted of 349 cases (16.1%) and 1819 controls (83.9%) with 52.7% females, 2.2% Asians, 10.7% Blacks, 10.0% Hispanics, and 72.5% non-Hispanic Whites. At the earliest time point (median [interquartile range (IQR)] = 6.4 [1.9-12.2] years prior to diagnosis), cases had higher AL score than controls (3 [1-4] vs 2 [1-3], respectively; P < .001). On multivariable analysis, a higher AL score (OR=1.09 per point), Black race (OR=2.58), and Hispanic ethnicity (OR=2.12) conferred higher risk of glaucoma (P ≤ .02). The AL score partially mediated higher glaucoma risk among Blacks (7.5%) and Hispanics (5.0%) compared with non-Hispanic Whites. On subgroup analysis, higher AL score was significantly associated with primary open angle glaucoma (OR=1.11; P = .01) but not primary angle closure glaucoma (P = .87).

CONCLUSION

AoU participants with glaucoma had greater AL 6.4 years before diagnosis, and the AL score partially mediated racial or ethnic differences in glaucoma risk. These findings suggest chronic stress may increase risk for glaucoma and contribute to racial disparities in glaucoma burden.

Reversing Aging and Improving Health Span in Glaucoma Patients: The Next Frontier?

How to cite this article: Dada T, Mahalingam K, Bhartiya S. Reversing Aging and Improving Health Span in Glaucoma Patients: The Next Frontier? J Curr Glaucoma Pract 2024;18(3):87-93.

Effect of "365 Breathing Technique" on Intraocular Pressure and Autonomic Functions in Patients With Glaucoma: A Randomized Controlled Trial

PRCIS

Patients with primary open angle glaucoma were advised to follow the "365 breathing technique" for 6 weeks in addition to their pharmacological glaucoma treatment. It helped to reduce intraocular pressure (IOP), stress biomarker-cortisol, and improve autonomic dysfunction.

OBJECTIVE

To study the effect of the "365 breathing technique" on IOP, autonomic functions, and stress biomarkers in patients with primary open angle glaucoma.

METHODS

In this randomized, controlled, interventional trial, after randomization, 40 patients in the intervention group followed "365 breathing" (three times a day, breathing rate: 6 cycles/min for 5 min) in addition to their pharmacological glaucoma treatment and 40 patients in the control group continued only with their pharmacological glaucoma treatment. IOP, serum cortisol, heart rate variability (HRV), and heart rate response to deep breathing test (DBT) were recorded at preintervention and 6 weeks postintervention.

RESULTS

The mean IOP, serum cortisol, parameters of the HRV test, and DBT were comparable between the two groups at baseline. At the 6-week follow-up, in the intervention group, mean IOP was significantly lower (16.09 ± 2.24 vs 18.38 ± 1.58 mm Hg, P = 0.03) and serum cortisol were significantly lower (13.20 ± 3.11 vs 14.95 ± 2.60 mcg/dL, P = 0.038) compared with the control group. In the HRV test, time domain analysis showed a significant difference in the root mean square of the successive difference between RR interval values between both groups at 6 weeks ( P = 0.015) pointing towards higher postintervention parasympathetic activation in the intervention group. In frequency domain analysis (HRV test), the ratio of the low-frequency component to the high-frequency component was significantly lower in the intervention group at 6 weeks (1.65 vs 1.79, P = 0.019) indicating a shift in sympathovagal balance towards greater vagal modulation.There was a significant increase in delta heart rate ( P = 0.019) and expiratory:inspiratory ratio ( P = 0.011) in the intervention group at 6 weeks when compared with baseline values, indicating improved parasympathetic reactivity to DBT.

CONCLUSION

"365 breathing" technique can reduce IOP and serum cortisol, and improve autonomic dysfunction in patients with glaucoma.

Stress and Allostatic Load in Patients With Primary Open Angle Glaucoma

PRCIS

This study evaluated the allostatic load (AL) in primary open angle glaucoma (POAG) patients and reported that the AL score was significantly higher in glaucoma patients compared with age-matched controls.

PURPOSE

To evaluate the AL in patients with POAG.

METHODS

This case-control study comprised 50 POAG (glaucoma patients) and 50 age-matched controls without glaucoma (controls). AL was estimated based on 13 variables: systolic blood pressure (BP), diastolic BP, homocysteine, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, body mass index, serum cortisol, glycosylated hemoglobin, albumin, creatinine clearance, and C-reactive protein. High-risk thresholds were determined based on biological cutoffs of each biomarker. One point was assigned for each biomarker reading above cutoff and were summated to obtain AL score; score ≥4 was considered high.

RESULTS

Mean age of glaucoma patients was 60.82±6.26 and 60.14±6.72 years in controls ( P =0.602). All components of AL score (except C-reactive protein) had higher values in glaucoma patients. There was a statistically significant difference in homocysteine ( P =0.001), total cholesterol ( P =0.037), high-density lipoprotein ( P =0.005), and glycosylated hemoglobin ( P =0.003). Mean AL score was 4.68±2.09 in glaucoma patients and 3.32±1.34 in controls ( P <0.001). There was significant association of high AL score with older age ( P =0.006), low socioeconomic status ( P =0.020), and glaucoma severity ( P =0.001). Negative correlation was seen between AL and retinal nerve fiber layer thickness (Right Eye: r =-0.37, P <0.001; Left Eye: r =-0.298, P <0.001) and visual field mean deviation (Right Eye: r =-0.469, P <0.001; Left Eye: r =-0.520, P <0.001).

CONCLUSIONS

Glaucoma patients exhibited allostatic overload indicating physiological dysregulation to chronic stress although additional research is required to establish causality. A holistic approach with lifestyle modifications to reduce chronic stress should be an integral part of managing glaucoma patients as it would serve both to possibly reduce or prevent disease progression and improve overall health outcomes.

Stress, Allostatic Load, and Neuroinflammation: Implications for Racial and Socioeconomic Health Disparities in Glaucoma

Glaucoma is the leading cause of irreversible blindness, and its pathophysiology includes neuroinflammatory changes. The present therapies for glaucoma target pressure-lowering mechanisms with limited success, making neuroinflammation a target for future interventions. This review summarizes the neuroinflammatory pathways seen in glaucoma and their interplay with stress. Glucocorticoids have been shown to activate proinflammatory glial cells, contributing to the neuroinflammation in glaucoma. Glucocorticoids have also been shown to increase the IOP directly. Stress-associated autonomic dysfunction can affect the vascular homeostasis in the retina and create oxidative stress. Diabetes, hyperglycemic-mediated endothelial damage, and vascular inflammation also play important roles in the neuroinflammation in glaucoma and diabetic retinopathy. Psychosocial stress has been implicated in an increased IOP and glaucoma outcomes. People who experience maladaptive chronic stress suffer from a condition known as allostatic load, which describes pathologic neuroendocrine dysregulation. The effects of allostatic load and chronic stress have been studied in patients affected by a lower socioeconomic status (SES) and marginalized racial identities. A lower SES is associated with higher rates of glaucoma and also affects the access to care and screening. Additionally, people of African ancestry are disproportionately affected by glaucoma for reasons that are multifactorial. In conclusion, this review explores neuroinflammation in glaucoma, highlighting opportunities for future investigation.

Ocular and Systemic Factors Associated with Glaucoma

Glaucoma is one of the leading causes of irreversible blindness in the world. Although numerous factors have been implicated in the pathogenesis of glaucoma, the main focus of management still remains lowering the intraocular pressure (IOP) by medical or surgical therapy. However, a major challenge is that many glaucoma patients continue to progress despite good control of IOP. In this regard, the importance of other coexisting factors that may contribute to disease progression needs to be explored. Ophthalmologists need to be aware of ocular risk factors and the impact of systemic diseases and their medications, along with lifestyle modifications on the course of glaucomatous optic neuropathy and adopt a holistic approach in treating the eye as well as the patient to alleviate the suffering from glaucoma in a comprehensive manner.

How to cite this article

Dada T, Verma S, Gagrani M, et al. Ocular and Systemic Factors associated with Glaucoma. J Curr Glaucoma Pract 2022;16(3):179-191.

Effect of Mindfulness-Based Stress Reduction on Intraocular Pressure in Patients With Ocular Hypertension: A Randomized Control Trial

PURPOSE

To evaluate the effect of mindfulness-based stress reduction (MBSR) on intraocular pressure (IOP) in patients with ocular hypertension (OHT).

DESIGN

Parallel arm, single masked, randomized controlled trial.

METHODS

Sixty patients with ocular hypertension and IOP > 21 and < 30 mmHg were recruited at a tertiary eye care centre in India. Thirty patients (group 1) underwent six weeks of one hour daily MBSR sessions, while the other 30 patients (group 2) were waitlisted and kept on follow-up. The primary outcome was change in IOP (ΔIOP) after six weeks of MBSR. Secondary outcomes were effect on serum cortisol level, diurnal variation of IOP, vessel perfusion and vessel density on optical coherence tomography angiography (OCTA), and quality of life (QOL).

RESULTS

At six weeks, a significant decrease in IOP was noted in group 1 (23.05 ± 1.17 to 19.15 ± 1.45 mmHg; P = .001) compared with group 2 (22.55 ± 0.98 mmHg to 22.37 ± 1.07 mmHg; P = .107). The ΔIOP was significantly greater in group 1 (3.93 ± 1.47) than group 2 (0.17 ± 0.58; P = .001). The diurnal fluctuation of IOP decreased in group 1 (4.87 ± 1.13 mmHg to 2.73 ± 0.98 mmHg; P = .001) as compared with group 2 (4.50 ± 0.86 mmHg to 4.30 ± 0.83 mmHg; P = .227). Significant improvement in vessel perfusion, vessel density, and flux index was noted on OCTA in group 1 compared with group 2. Group 1 showed a significant decrease (P ≤ .001) in serum cortisol level and an improved QOL (P = .001).

CONCLUSION

Mindfulness-based stress reduction was associated with a significant decrease in IOP and serum cortisol, along with an improvement in optic nerve head perfusion and QOL. Mindfulness-based stress reduction can be considered as a potential treatment option in the management of OHT.

Beneficial effect of mindfulness based stress reduction on optic disc perfusion in primary open angle glaucoma: A randomized controlled trial

Background and aim

Glaucoma is one of the leading causes of visual impairment worldwide. Next to intraocular pressure (IOP), vascular factors play a major role in glaucoma. Mindfulness-based stress reduction (MBSR) has been shown to reduce the IOP, normalize the stress biomarkers, modulate gene expression, and also improve the quality of life. This study was aimed to assess the effect of MBSR in optic disc perfusion of patients with primary open angle glaucoma (POAG).

Experimental procedure

POAG patients with controlled IOP (<21 mmHg) were randomised in to intervention group (n = 30) and control group (n = 30). Both the groups continued their routine glaucoma medications while the intervention group practiced 45 min of MBSR every day in addition. IOP and optic disc perfusion using OCT-Angiography were recorded at baseline and at 6 weeks for both the groups.

Results

The mean age of the participants were 53.23 ± 8.4yr in intervention and 50.23 ± 7.3yr in the control group (p = 0.06). All the baseline parameters were comparable in both groups. After MBSR, in the intervention group there was a significant reduction of IOP (p=0.001), increase in circum-papillary vessel density in superior quadrant (15.8%-17.4%, p=0.02) and nasal quadrant (14.2%-16.5%, p=0.01), increase in circum papillary vascular perfusion, in superior quadrant (38.9%-41.1%, p<0.001), in temporal quadrant (42.2%-44.5%, p<0.001), in inferior quadrant (40.1%-43.8%, p<0.001), and in nasal quadrant (40.6%-42.8%, p<0.001). There was also a significant increase in Flux Index after 6weeks (0.38-0.40, p<0.001).

Conclusion

MBSR can reduce barotrauma and improve optic disc perfusion in POAG patients and serve as a useful adjunct to the standard medical therapy.