Aerobic exercise and intraocular pressure in normotensive and glaucoma patients

The Effect of Exercise on Intraocular Pressure and Glaucoma

PRCIS

A review of the literature found that certain types of exercise and physical activity result in transient reductions in intraocular pressure and may have a beneficial effect on glaucoma severity and progression.

INTRODUCTION

Glaucoma is the most common cause of irreversible vision loss worldwide. Raised intraocular pressure (IOP) is the most important risk factor for the disease. Exercise is known to result in changes in IOP. The purpose of this review was to investigate the effect of exercise on IOP and glaucoma.

METHODS

A comprehensive search of multiple literature databases was performed. Medline, EMBASE, and Cochrane libraries were used to search for the relevant terms. 16 original studies were selected for the review.

RESULTS

Exercise of varying intensity and type has differing effects on IOP. Moderate-intensity aerobic exercise results in transient reductions in IOP, while high-intensity resistance exercise and weight-lifting lead to transient elevations in IOP. There is evidence to suggest that exercise and higher levels of fitness may be protective against the development of glaucoma. In addition, increased daily physical activity may be associated with less visual field progression in patients with glaucoma. While secondary causes of glaucoma are included in some of the studies discussed in this review, the findings are largely applicable to primary open angle glaucoma.

CONCLUSION

Exercise may be a beneficial lifestyle modification in the management of glaucoma; however, further longitudinal studies are required to validate this.

Addressing neurodegeneration in glaucoma: Mechanisms, challenges, and treatments

Glaucoma is the leading cause of irreversible blindness globally. The disease causes vision loss due to neurodegeneration of the retinal ganglion cell (RGC) projection to the brain through the optic nerve. Glaucoma is associated with sensitivity to intraocular pressure (IOP). Thus, mainstay treatments seek to manage IOP, though many patients continue to lose vision. To address neurodegeneration directly, numerous preclinical studies seek to develop protective or reparative therapies that act independently of IOP. These include growth factors, compounds targeting metabolism, anti-inflammatory and antioxidant agents, and neuromodulators. Despite success in experimental models, many of these approaches fail to translate into clinical benefits. Several factors contribute to this challenge. Firstly, the anatomic structure of the optic nerve head differs between rodents, nonhuman primates, and humans. Additionally, animal models do not replicate the complex glaucoma pathophysiology in humans. Therefore, to enhance the success of translating these findings, we propose two approaches. First, thorough evaluation of experimental targets in multiple animal models, including nonhuman primates, should precede clinical trials. Second, we advocate for combination therapy, which involves using multiple agents simultaneously, especially in the early and potentially reversible stages of the disease. These strategies aim to increase the chances of successful neuroprotective treatment for glaucoma.

Migraine headache and other risk factors associated with glaucoma among the adult population living in Armenia: a case-control study

PURPOSE

This study aimed to assess the association between migraine headache and glaucoma among the adult population living in Armenia.

METHODS

This case-control study recruited 145 cases with glaucoma and 250 controls without glaucoma and other ocular disorders except refractive error from Optomed Canada Diagnostic Eye Center in Armenia. A structured questionnaire contained questions on socio-demographics, family history of glaucoma and stroke, ocular health, smoking, migraine, and obstructive sleep apnea. The Migraine Screening Questionnaire assessed possible migraine and the Berlin Questionnaire measured obstructive sleep apnea.

RESULTS

The mean ages of cases and controls were 63.3 (SD = 12.3) and 39.5 (SD = 13.5), respectively. Females comprised 62.8% of cases and 69.1% of controls. A total of 17.8% of cases and 19.0% of controls had possible migraine. In the adjusted analysis older age (OR 1.17; 95% CI 1.12; 1.23), average/lower than average socio-economic status (OR 5.27; 95% CI 1.30; 21.3), and family history of glaucoma (OR 4.25; 95% CI 1.51; 11.9) were associated with high-tension glaucoma.

CONCLUSION

Timely case detection of glaucoma among those with average/low socio-economic status and those with family history of glaucoma could prevent further progression of the disease. Further studies to explore the relationship between migraine headache and specific types of glaucoma may be worthwhile.

The intraocular pressure lowering-effect of low-intensity aerobic exercise is greater in fitter individuals: a cluster analysis

This study aimed to determine the influence of physical fitness level and sex on intraocular pressure (IOP) during the low-intensity aerobic exercise. Forty-four participants (twenty-two men) cycled 30 minutes at low intensity (10% of the maximal power). Maximal power was determined by asking participants to perform maximal sprints of 6 seconds against 3-4 different resistances separated by 3 minutes of rest. The IOP was measured on 9 occasions (1) prior to the warm-up, (2) after the warm-up, (3-7) every 6 minutes during the low-intensity cycling task, and (8-9) 5 and 10 minutes after the cycling task. Low-intensity aerobic exercise had a lowering effect on IOP, being the beneficial effect more accentuated and prolonged in the High-fit group (IOP reduction compared to baseline lasted 30 minutes) than in the Low-fit group (IOP was only reduced at 6 minutes of exercise compared to baseline). Participants´ sex had no effect on the IOP behaviour at any time point (p = 0.453). These findings indicate that individuals who need to reduce IOP levels (i.e., glaucoma patients or those at risk) should increase or maintain a high fitness level to benefit more from the IOP lowering effect during low-intensity aerobic exercises.

Towards modifying the genetic predisposition for glaucoma: An overview of the contribution and interaction of genetic and environmental factors

Glaucoma, the leading cause of irreversible blindness worldwide, is a complex human disease, with both genetic and environmental determinants. The availability of large-scale, population-based cohorts and biobanks, combining genotyping and detailed phenotyping, has greatly accelerated research into the aetiology of glaucoma in recent years. Hypothesis-free genome-wide association studies have furthered our understanding of the complex genetic architecture underpinning the disease, while epidemiological studies have provided advances in the identification and characterisation of environmental risk factors. It is increasingly recognised that the combined effects of genetic and environmental factors may confer a disease risk that reflects a departure from the simple additive effect of the two. These gene-environment interactions have been implicated in a host of complex human diseases, including glaucoma, and have several important diagnostic and therapeutic implications for future clinical practice. Importantly, the ability to modify the risk associated with a particular genetic makeup promises to lead to personalised recommendations for glaucoma prevention, as well as novel treatment approaches in years to come. Here we provide an overview of genetic and environmental risk factors for glaucoma, as well as reviewing the evidence and discussing the implications of gene-environment interactions for the disease.

The Association of Physical Activity with Glaucoma and Related Traits in the UK Biobank

PURPOSE

To examine the association of physical activity (PA) with glaucoma and related traits, to assess whether genetic predisposition to glaucoma modified these associations, and to probe causal relationships using Mendelian randomization (MR).

DESIGN

Cross-sectional observational and gene-environment interaction analyses in the UK Biobank. Two-sample MR experiments using summary statistics from large genetic consortia.

PARTICIPANTS

UK Biobank participants with data on self-reported or accelerometer-derived PA and intraocular pressure (IOP; n = 94 206 and n = 27 777, respectively), macular inner retinal OCT measurements (n = 36 274 and n = 9991, respectively), and glaucoma status (n = 86 803 and n = 23 556, respectively).

METHODS

We evaluated multivariable-adjusted associations of self-reported (International Physical Activity Questionnaire) and accelerometer-derived PA with IOP and macular inner retinal OCT parameters using linear regression and with glaucoma status using logistic regression. For all outcomes, we examined gene-PA interactions using a polygenic risk score (PRS) that combined the effects of 2673 genetic variants associated with glaucoma.

MAIN OUTCOME MEASURES

Intraocular pressure, macular retinal nerve fiber layer (mRNFL) thickness, macular ganglion cell-inner plexiform layer (mGCIPL) thickness, and glaucoma status.

RESULTS

In multivariable-adjusted regression models, we found no association of PA level or time spent in PA with glaucoma status. Higher overall levels and greater time spent in higher levels of both self-reported and accelerometer-derived PA were associated positively with thicker mGCIPL (P < 0.001 for trend for each). Compared with the lowest quartile of PA, participants in the highest quartiles of accelerometer-derived moderate- and vigorous-intensity PA showed a thicker mGCIPL by +0.57 μm (P < 0.001) and +0.42 μm (P = 0.005). No association was found with mRNFL thickness. High overall level of self-reported PA was associated with a modestly higher IOP of +0.08 mmHg (P = 0.01), but this was not replicated in the accelerometry data. No associations were modified by a glaucoma PRS, and MR analyses did not support a causal relationship between PA and any glaucoma-related outcome.

CONCLUSIONS

Higher overall PA level and greater time spent in moderate and vigorous PA were not associated with glaucoma status but were associated with thicker mGCIPL. Associations with IOP were modest and inconsistent. Despite the well-documented acute reduction in IOP after PA, we found no evidence that high levels of habitual PA are associated with glaucoma status or IOP in the general population.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Availability of Physical Activity Tracking Data from Wearable Devices for Glaucoma Patients

Physical activity has been found to potentially modulate glaucoma risk, but the evidence remains inconclusive. The increasing use of wearable physical activity trackers may provide longitudinal and granular data suitable to address this issue, but little is known regarding the characteristics and availability of these data sources. We performed a scoping review and query of data sources on the availability of wearable physical activity data for glaucoma patients. Literature databases (PubMed and MEDLINE) were reviewed with search terms consisting of those related to physical activity trackers and those related to glaucoma, and we evaluated results at the intersection of these two groups. Biomedical databases were also reviewed, for which we completed database queries. We identified eight data sources containing physical activity tracking data for glaucoma, with two being large national databases (UK BioBank and All of Us) and six from individual journal articles providing participant-level information. The number of glaucoma patients with physical activity tracking data available, types of glaucoma-related data, fitness devices utilized, and diversity of participants varied across all sources. Overall, there were limited analyses of these data, suggesting the need for additional research to further investigate how physical activity may alter glaucoma risk.

Analysis of aerobic exercise influence on intraocular pressure and ocular perfusion pressure in patients with primary open-angle glaucoma: A randomized clinical trial

Purpose

To investigate the change pattern of ocular perfusion pressure (OPP) and intra-ocular pressure (IOP) after short-term and long-term aerobic exercise.

Methods

In this prospective, single-masked, randomized clinical trial, 123 patients with a primary open angle glaucoma that locally used prostaglandin analog alone were randomly divided into the exercise and control groups. In the short-term study, all individuals underwent a cycling exercise at moderate intensity (20% Wmax for 10 minutes) and high intensity (60% Wmax for 5 minutes). During the long-term study, the exercise group is characterized by regular jogging exercise lasting for 30 minutes during 6: 00-10: 00 in the morning for 3 months, with the exercise frequency of at least 20 times per month, and with the intensity reflected by the target heart rate. The control group is designed as a group with irregular exercise.

Results

After short-term aerobic exercise, IOP significantly decreased, whereas the ocular perfusion pressure (OPP) significantly increased. The decreasing amplitude of IOP is related to the baseline of IOP, the intensity of exercise, gender, and so on. After 3 months of long-term exercise, the changes in the IOP level of the exercise group indicated a decreasing trend.

Conclusion

The significant decrement of IOP and the increment of OPP suggest that aerobic exercise is beneficial for patients with primary open-angle glaucoma and appropriate aerobic exercise is appropriate in treating glaucoma patients.

Trial registration

ChiCTR, ChiCTR-TRC-10001055. Registered one October 2010-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj = 8483.

Effect of Aerobic Exercise at Different Intensities on Intraocular Pressure in Young Males

PRCIS

High intensity aerobic exercise significantly reduced intraocular pressure in healthy young male adults.

OBJECTIVE

This study sought to determine how aerobic exercise at various intensities affects intraocular pressure (IOP) in young adults.

DESIGN

A repeated measures design was adopted.

PARTICIPANTS

A group of 20 volunteers (mean age: 21.24±1.73 y) took part in this study.

METHODS

IOP was measured with a tonometer (iCare TA01i, Icare Finland, Finland). Subjects completed 4 cycle ergometer sessions. During the first session, power was increased by 60 W every 3 minutes until exhaustion, corresponding to peak power. For the 3 following tests, each lasting 25 minutes, subjects exercised at intensities of 50%, 70%, and 85% of peak power, respectively, and measurements were taken every 5 minutes.

MAIN OUTCOME MEASURES

IOP, as determined using a tonometer, was the primary measure.

RESULTS

There was a significant reduction ( P <0.05) in IOP of both eyes during the 25 minutes high-intensity (85%) exercise test. There were also significant interactions between exercise durations and intensities. During high-intensity exercise, IOP, blood pressure, blood lactate, and the rating of perceived exertion were significantly related ( P <0.01).

CONCLUSIONS

These data show a significant reduction in IOP at high-intensity aerobic exercise, which may have implications for the management of ocular health.

Intraocular Pressure Fluctuation during Aerobic Exercise at Different Exercise Intensities

Few studies have examined the effects of different aerobic-exercise intensities on intraocular-pressure (IOP) changes. This may be important for eye diseases that are impacted by IOP or its fluctuation, including glaucoma, and diabetes that is complicated by diabetic retinopathy. We investigated the effects of low-, moderate-, and high-intensity exercise on IOP in healthy subjects. A submaximal cardiopulmonary exercise test was performed in 18 healthy male subjects, and the maximal oxygen uptake was calculated. The subjects then exercised for 20 min at 30%, 50%, and 70% ·VO₂ of maximal oxygen uptake, and their IOP was measured at rest and every 5 min during exercise. Oxygen uptake was monitored using an expiratory gas analyzer during exercise to maintain accurate exercise intensity and adjust exercise load. Oxygen uptake during exercise was significantly higher at all intensities from 5 to 20 min than at rest. IOP was significantly lower at 70% exercise intensity from 5 to 20 min than at rest. A negative correlation existed between IOP and ·VO₂. IOP remained unchanged during low- and moderate-intensity exercise but significantly declined during high-intensity exercise compared with that at rest. Although various factors, such as β-blockers, are involved in IOP decline at rest, a different mechanism is involved in IOP decline during exercise.

Therapeutic and preventive eff ect of physical exercises in primary open-angle glaucoma

The review assesses physical exercises as an additional non-pharmacological mean of combating the progression of primary open-angle glaucoma. The ophthalmic hypotensive effect is determined by the type of exercise, its duration and intensity. Moderate aerobic activity is preferred. Among dynamic exercises, jogging has the greatest hypotensive effect. Upper body isometric resistance training provides a more lasting decrease in ophthalmotonus. The decrease in intraocular pressure (IOP) in patients with glaucoma is several times more pronounced in comparison with healthy people and occurs regardless of the nature of the local drug antihypertensive therapy. After the termination of classes IOP returns to the previous level on average within a month. An increase in ocular perfusion pressure associated with physical activity dictates the appropriateness of physical exercise for patients with pseudo-normal pressure glaucoma. The combination of hypotensive, vascular, neuroprotective effects of physical activity with a high level of physical fi tness does not exclude a decrease in the risk of development and progression of primary open-angle glaucoma. The development of indications for the use of physical activity by patients with advanced glaucoma, including those who have undergone hypotensive surgery, remains relevant. The type, intensity, dosage and mode of performing the recommended physical exercises require an individual choice.

A Review of Potential Novel Glaucoma Therapeutic Options Independent of Intraocular Pressure

Glaucoma, a progressive optic neuropathy characterized by retinal ganglion cell degeneration and visual field loss, is the leading cause of irreversible blindness worldwide. Intraocular pressure (IOP) is presently the only modifiable risk factor demonstrated to slow or halt disease progression; however, glaucomatous damage persists in almost 50% of patients despite significant IOP reduction. Many studies have investigated the non-IOP-related risk factors that contribute to glaucoma progression as well as interventions that can prevent or delay glaucomatous neurodegeneration and preserve vision throughout life, independently of IOP. A vast number of experimental studies have reported effective neuroprotection in glaucoma, and clinical studies are ongoing attempting to provide strong evidence of effectiveness of these interventions. In this review, we look into the current understanding of the pathophysiology of glaucoma and explore the recent advances in non-IOP related strategies for neuroprotection and neuroregeneration in glaucoma.

Effects of regular exercise on intraocular pressure

BACKGROUND

Exercise may potentially provide an adjunctive measure to help control intraocular pressure in glaucoma patients. However, currently, there is still no substantial evidence that regular exercise can produce a prolonged effect of intraocular pressure reduction. We aim to determine the effects of regular exercise on intraocular pressure in healthy individuals.

METHODS

We conducted a prospective, interventional study at the University of Malaya Medical Centre. Our subjects consist of 45 healthy participants in the intervention arm, and 38 healthy control participants who were age- and gender-matched. The intervention arm was enrolled into a supervised exercise programme for a 6-week period, where controls were asked to continue their usual daily lifestyle. The intervention consists of three sessions every week, which focused on aerobic exercise and strength training.

RESULTS

Baseline intraocular pressure was measured, and then remeasured again at the end of 6 weeks of exercise conditioning. In the intervention group, there was a reduction of baseline intraocular pressure from pre-intervention mean intraocular pressure of 15.55 ± 2.63 mmHg, down to 13.36 ± 3.16 mmHg at 6 weeks, a statistically significant reduction of -2.18 ± 2.25 mmHg (p < 0.001) post-intervention. On the other hand, the control group recorded a non-statistically significant mean increase of 0.63 ± 2.47 mmHg (p = 0.123) at 6 weeks.

CONCLUSIONS

Our study concluded that regular exercise results in a significant intraocular pressure reduction in healthy individuals.

Physical Activity and Cardiovascular Fitness During Childhood and Adolescence: Association With Retinal Nerve Fibre Layer Thickness in Young Adulthood

PRECIS

Higher physical working capacity (PWC) at age 17 was associated with thicker peripapillary retinal nerve fiber layer (pRNFL) at age 20, suggesting a mechanistic link between cardiovascular fitness and neuroretinal integrity.

PURPOSE

Physical activity and cardiovascular fitness have been linked with lower odds of developing glaucoma. We tested the hypothesis that early beneficial effects of physical activity and cardiovascular fitness can be observed by measuring the pRNFL thickness in young healthy adults.

METHODS

The Raine Study is a longitudinal study that has followed a cohort since before their births in 1989-1992. Parent-reported physical activity was collected between 8 and 17 years, and latent class analysis was used to identify the participants' physical activity trajectories. At the 20-year follow-up (participants' mean age=20.1±0.4 y), participants' metabolic equivalent of task-minutes/week was determined using self-reported physical activity data. Participants' PWC was assessed at the 14- and 17-year follow-ups to estimate their level of cardiovascular fitness. An eye examination, which included spectral-domain optical coherence tomography imaging, was conducted at the 20-year follow-up for 1344 participants.

RESULTS

Parent-reported or participant-reported physical activity was not associated with pRNFL thickness. However, higher PWC at 17 years was associated with thicker pRNFL globally [by 0.3 µm; 95% confidence interval (CI)=0.2-0.6; P<0.001], superotemporally (by 0.4 µm; 95% CI=0.1-0.7; P=0.013), inferonasally (by 0.7 µm; 95% CI=0.1-0.9; P=0.002), and nasally (by 0.4 µm; 95% CI=0.1-0.7; P=0.006) per 10 Watt increase in PWC.

CONCLUSIONS

The association between estimated cardiovascular fitness and pRNFL thickness suggests there may be overlapping mechanisms for cardiovascular health and retinal ganglion cell integrity. While the effect sizes were small, it is possible that larger effects and clinically significant associations may arise as we follow this cohort of participants through their later adulthood.

Effects of Wearing the Elevation Training Mask During Low-intensity Cycling Exercise on Intraocular Pressure

PRCIS

Low-intensity aerobic exercise is recommended to reduce intraocular pressure (IOP) levels. However, this effect depends on several factors. We found that using an elevation training mask (ETM) during low-intensity aerobic exercise causes an IOP rise.

PURPOSE

The aim was to assess the influence of wearing an ETM on IOP during low-intensity endurance training.

METHODS

Sixteen physically active young adults (age=23.9±2.9 y) cycled during 30 minutes at 10% of maximal power production with and without an ETM in 2 different days and randomized order. A rebound tonometer was used to measure IOP at baseline, after a warm-up of 5 minutes, during cycling (6, 12, 18, 24, and 30 min), and recovery (5 and 10 min) by rebound tonometry.

RESULTS

The use of an ETM significantly affects the IOP behaviour during exercise (P<0.001, ηp²=0.66). In the ETM condition, there was an IOP increment during exercise (P<0.001, ηp²=0.28) whereas an IOP-lowering effect was observed in the control condition (P<0.001, ηp²=0.41). Post hoc comparisons showed that there were greater IOP values during exercise in the ETM condition in comparison to the control condition (average IOP difference=3.7±2.2 mm Hg; corrected P<0.01, and the Cohen d's >1.10, in all cases).

CONCLUSION

Low-intensity endurance exercise causes an increment in IOP when it is performed wearing an ETM and a decrease in IOP when the air flow is not restricted (control condition). Therefore, the ETM should be discouraged during low-intensity endurance exercise for individuals who need to reduce IOP levels (eg, glaucoma patients or those at risk). However, the external validity of these results needs to be addressed in future studies with the inclusion of glaucoma patients.

Determinant Factors of Intraocular Pressure Responses to a Maximal Isometric Handgrip Test: Hand Dominance, Handgrip Strength and Sex

PURPOSE

To assess the mediating role of strength levels, hand dominance and participants´ sex on the intraocular pressure (IOP) behaviour during the execution of a maximal isometric handgrip test.

METHODS

One hundred and seventy-six sport science students (102 men and 74 women) performed a maximal isometric handgrip test with the dominant and non-dominant hands. A rebound tonometer was used to measure IOP before effort, during effort, and immediately after performing the handgrip test. Men and women were divided based on their handgrip strength in low- and high-strength groups using a median split analysis.

RESULTS

There was an acute IOP rise during effort, returning to baseline levels immediately after exercise cessation (P < .001, η_p ² = 0.79). A greater increase in IOP during the execution of the handgrip test was observed for the dominant-hand compared to the non-dominant hand (P = .004, d = 0.30) and for men compared to women (P = .001, d = 0.90). The main effect of strength level did not reach statistical significance (P = .266).

CONCLUSIONS

The IOP rise associated with a maximal isometric handgrip effort is affected by the participants´ sex (men > women) and hand dominance (dominant hand > non-dominant hand), but not on strength levels. These findings need to be corroborated in glaucoma patients.

Evening exercise is associated with lower odds of visual field progression in Chinese patients with primary open angle glaucoma

Background

Exercise is widely known to lower intraocular pressure and increase ocular blood flow, which may be beneficial for glaucoma management. However, there are few studies that have reported on the relationship between exercise and glaucoma progression. The aim of our study was to investigate the exercise habits of those with primary open angle glaucoma (POAG) and its association with the progression of visual field (VF) loss.

Methods

Daily physical activity (PA) was monitored by an accelerometer (ActiGraph wGT3x-BT) which patients wore for more than 10 h of being awake on their right wrists for 1 week.

Results

Seventy-one non-progressive and 27 progressive patients were enrolled in the study. 24-h moderate to vigorous physical activity (MVPA) exercise showed that POAG patients had similar variation trends consisting of 3 wave peaks and 2 wave hollows. Minutes spent in MVPA was 19.89 ± 15.81 and 21.62 ± 15.10 during 07:00–09:00 h (p = 0.204), 15.40 ± 14.49 and 15.67 ± 12.43 during 15:00–17:00 h (p = 0.822) and 17.26 ± 21.11 and 11.42 ± 11.58 during 18:00–20:00 h (p = 0.001) in the non-progressive and progressive group, respectively. Univariate analysis indicated that 10 min of MVPA (18:00–20:00 h) [odds ratio, OR (95% CI) = 0.82 (0.73, 0.92)], average mean arterial pressure [OR (95% CI) = 0.96 (0.94, 0.98)], age [OR (95% CI) = 1.06 (1.03, 1.08)], male [OR (95% CI) = 0.67 (0.48, 0.96)], spherical equivalent [OR (95% CI) = 1.14 (1.07, 1.22)] and IOP-lowering medications [OR (95% CI) = 1.54 (1.16, 2.05)] were significantly correlated with having progressive VF damage. Multivariable analysis showed that 10 min of MVPA (18:00–20:00 h) [OR (95% CI) = 0.85 (0.75, 0.97)] was associated with progressive VF loss even after adjusting for other risk factors.

Conclusions

Evening exercise may lower the odds of VF progression, suggesting that exercise habits possibly play an important role in glaucoma progression.

Association of Exercise and Swimming Goggles With Modulation of Cerebro-ocular Hemodynamics and Pressures in a Model of Spaceflight-Associated Neuro-ocular Syndrome

Importance

Astronauts on International Space Station missions demonstrate adverse neuro-ocular changes. Reversing a negative translaminar pressure gradient (TLPG) by modulating cerebral blood flow, decreasing intracranial pressure, or increasing intraocular pressure (IOP) has been proposed as potential intervention for spaceflight-associated neuro-ocular syndrome (SANS).

Objective

To examine whether exercise (resistance, moderate-intensity aerobic, and high-intensity aerobic) or artificially increasing IOP is associated with modulated cerebro-ocular hemodynamic and pressure changes during head-down tilt (HDT), an analogue of spaceflight, in healthy adults.

Design, Setting, and Participants

A single-center investigation was conducted at Johnson Space Center, Houston, Texas, from January 1, 2014, to December 31, 2016, in 20 healthy men.

Exposure

On 3 separate days, participants rested supine, were tilted to -15° HDT, and then completed 1 of 3 experimental exercise conditions (moderate-intensity aerobic, resistance, or high-intensity interval aerobic). A subset of 10 participants wore swimming goggles on all days.

Main Outcomes and Measures

Applanation rebound tonometry was used to noninvasively assess IOP, and compression sonography was used to assess internal jugular venous pressure (IJVP). Estimated TLPG was calculated as the difference between IOP and IJVP. Cerebral inflow and outflow were measured in extracranial arteries using color-coded duplex ultrasonography.

Results

Twenty men participated in the study (mean [SD] age, 36 [9] years). Compared with supine IOP (mean [SD], 19.3 [3.7] mm Hg), IJVP (mean [SD], 21.4 [6.0] mm Hg), and estimated TLPG (mean [SD], -2.1 [7.0] mm Hg), -15° HDT was associated with increased IOP (mean difference, 2.3 mm Hg; 95% CI, 1.4-3.3 mm Hg; P < .001) and IJVP (mean difference, 10.5 mm Hg; 95% CI, 8.9-12.2 mm Hg; P < .001) and with decreased TLPG (mean difference, -8.2 mm Hg; 95% CI, -10.1 to -6.3 mm Hg; P < .001). Exercise (regardless of modality) at -15° HDT was associated with decreased IOP (mean difference, -1.6 mm Hg; 95% CI, -2.6 to -0.6 mm Hg; P = .002) and TLPG (mean difference, -3.5 mm Hg; 95% CI, -6.2 to -0.7 mm Hg; P = .01) compared with rest. Both IOP (mean difference, 2.9 mm Hg; 95% CI, 0.7-5.1 mm Hg; P = .01) and TLPG (mean difference, 5.1 mm Hg; 95% CI, 0.8-9.4 mm Hg; P = .02) were higher in participants who wore swimming goggles compared with those not wearing goggles.

Conclusions and Relevance

In this study, exercise was associated with decreased IOP and estimated translaminar pressure gradient in a spaceflight analogue of HDT. The addition of swimming goggles was associated with increased IOP and TLPG in HDT. Further evaluation in spaceflight may be warranted to determine whether modestly increasing IOP is an effective SANS countermeasure.

Quantitative assessment of the effect of acute anaerobic exercise on macular perfusion via swept-source optical coherence tomography angiography in young football players

AIM

To evaluate the effect of acute anaerobic exercise on macular perfusion measured by swept-source optical coherence tomography angiography (SS-OCTA) in young football players.

MATERIALS AND METHODS

Football players with ages between 18 and 20 years were included into the study. After a detailed ophthalmological examination, physiological parameters including height (cm), body weight (kg), body fat percentage (%), systemic blood pressure (BP) (mmHg), hematocrit values (%), oxygen saturation pO₂ (%) and heart rate (bpm) were recorded. Intraocular pressure (IOP) (mmHg) and SS-OCTA using DRI OCT Triton (Topcon, Tokyo, Japan) were measured immediately before and after Wingate test.

RESULTS

Out of 20, 16 participants completed the study. All participants were males with a mean age of 18.12 ± .34 years. Systolic BP, hematocrit and heart rate increased, while pO₂ and IOP decreased remarkably after Wingate test (p < .01). After anaerobic exercise, there was an increase in mean FAZ area in superficial capillary plexus (FAZs) which was not significant (p = .13), while decrease in FAZ area in deep capillary plexus (FAZd) (mm²) was remarkable (p = .04). No changes were observed in mean vessel density (VD) (%) in superficial capillary plexus (VDs), deep capillary plexus (VDd), choriocapillaris (VDcc), central macular thickness (CMT) (μm) and subfoveal choroidal thickness (SFCT) (μm) after Wingate test (p > .05). FAZd and some of the VD parameters showed a significant correlation with BP (p < .05).

CONCLUSION

Acute anaerobic exercise seems not to alter either mean VD in retina and choroid or CMT and SFCT. Among OCTA parameters, only FAZd decreased remarkably.

Exercise-Induced Changes in Ocular Blood Flow Parameters in Primary Open-Angle Glaucoma Patients

PURPOSE

To evaluate exercise-induced changes in ocular blood flow (OBF) parameters in primary open-angle glaucoma (POAG) patients.

METHODS

A prospective observational study was carried out, in which medically treated patients with POAG were enrolled. Following inclusion, all patients performed a 40-min cycloergometry in a standardized fashion. The following parameters were measured and compared immediately before and 1 and 30 min after the exercise: intraocular pressure (IOP; Goldman applanation tonometry), mean arterial pressure (MAP), ocular pulse amplitude (OPA; assessed by dynamic contour tonometry), and ocular perfusion pressure (OPP; 2/3 MAP - IOP). In addition, we investigated possible factors associated with OBF parameter changes immediately after exercise.

RESULTS

A total of 30 eyes (30 patients; mean age was 62.9 ± 1.7 years) were included. Most patients were women (53%), and median visual field mean deviation index was -3.5 dB. Both MAP (mean change, 21%) and IOP (mean change, 17.3%) increased significantly immediately after the workout (p < 0.01), persisting higher than baseline following 30 min (p < 0.01%). Regarding OBF parameters, both OPA (mean change, 58.8%) and OPP (mean change, 21.7%) increased significantly immediately after the workout and persisted higher than baseline 30 min after the workout (p < 0.01). Regression analysis revealed that only age was significantly associated with OPA variation (R2 0.14; p < 0.05). No significant associations were found for OPP (p ≥ 0.19).

CONCLUSION

Aerobic exercise leads to a significant short-time increase in OBF parameters in patients with POAG. Even though IOP seems to present a modest elevation, it is accompanied by a significant increase in MAP, leading to higher OBF measurements. Exercise-induced short-term changes and its possible implications for glaucoma prognosis deserve further investigation.

The evaluation of intraocular pressure fluctuation in glaucoma subjects during submaximal exercise using an ocular telemetry sensor

Purpose:

To evaluate the effect of acute submaximal exercise on intraocular pressure (IOP) fluctuations in open-angle glaucoma (OAG) subjects using an ocular telemetry sensor (OTS, Sensimed TriggerFish^®).

Methods:

Twelve OAG subjects aged 45–65 years with no medical limitation for exercise were included in this prospective study. A submaximal exercise test was performed using a cycle ergometer for 20 min during which OTS voltages and metabolic parameters were recorded continuously. IOP voltages taken before, during, and after exercise were compared using the Friedman test and correlations with the metabolic parameters were evaluated using the Spearman analysis.

Results:

In two subjects, the OTS stopped functioning after a few hours. Median OTS measurements were 37.60 mVeq 10 min before exercise [interquartile range (IQR) 137.27], 51.75 (IQR 121.2), 62.35 (IQR 123.72), 54.6 (IQR 141.3), and 59.7 mVeq (IQR 196.7) during exercise (4 time points, 5 min apart), and 50.7 (IQR 147.35) and 64.2 mVeq (IQR 103.25) 10 and 30 min after exercise and the change was statistically non-significant (P = 0.66). No correlations were found between OTS and metabolic parameters measured at the same time points (P > 0.05). Nocturnal acrophase pattern was detected in five subjects (50%), diurnal acrophase in two patients, and double-hump in two patients. Median IOP voltages in the morning, afternoon/evening, and night were 335.84, 149.15, and 341.38 mVeq, respectively (P < 0.001).

Conclusion:

Continuous IOP monitoring did not reveal a remarkable voltage change in OAG patients during or immediately after exercise, but nocturnal IOP peaks in half of the patients.

Exogenous influences on intraocular pressure

Intraocular pressure (IOP), the pressure within the eyeball, is a function mainly of the production and elimination of aqueous humour. Balanced IOP helps to maintain the eyeball contour, allowing proper refraction of light in the anterior segment of the eye. Increases in IOP can cause injury to the ocular structure, typically the optic nerve head and retinal ganglion cells. IOP increase, additionally, is a risk factor for glaucoma progression. However, it is not unusual that glaucoma worsens despite well-managed IOP; indeed, glaucoma can develop and progress even within the normal IOP range. IOP measured once during daytime office hours might not provide sufficient information for effective glaucoma management. In fact, IOP is not a fixed value but rather changes over time: it fluctuates with the intrinsic circadian rhythm and can also change in various lifestyle-related situations (eg, with body posture, during exercise, while holding breath and according to dietary habits). It is therefore worth exploring the various factors that can affect IOP and glaucoma risk. In this review, the various exogenous influences on IOP in the literature are investigated.

Relationship of lifestyle, exercise, and nutrition with glaucoma

PURPOSE OF REVIEW

Although reducing the intraocular pressure (IOP) through medications, laser or surgery remains the primary means of glaucoma treatment, there is increasing evidence during the last decade that environmentally modifiable factors may help to prevent glaucoma or its progression through different mechanisms that may or may not involve lowering IOP. Additionally, patients are increasingly interested in maintaining a healthy lifestyle and taking an active role in the management of their disease. Therefore, the aim of this review is to summarize the current evidence regarding environmentally modifiable factors such as lifestyle, exercise, and nutrition in the pathogenesis of glaucoma.

RECENT FINDINGS

In the last decade, large population-based studies have helped to identify possible environmentally modifiable protective and risk factors with regard to glaucomatous disease. Smoking cessation; moderate aerobic exercise; recommended weight; and a balanced diet including green leafy vegetables, omega fatty-acids, and moderate intake of hot tea and coffee have been reported to be possibly protective against developing glaucoma or its progression.

SUMMARY

Modifiable environmental factors such as lifestyle, exercise, and nutrition may play a role in glaucoma pathogenesis. Large prospective studies with long-term follow-up should be encouraged to corroborate these findings, which may guide future treatments for our patients, some of which may not be limited to IOP reduction.

Physical exercise and glaucoma: a review on the roles of physical exercise on intraocular pressure control, ocular blood flow regulation, neuroprotection and glaucoma-related mental health

The benefits of physical exercise on health and well-being have been studied in a wide range of systemic and ocular diseases, including glaucoma, a progressive optic neuropathy characterized by accelerated apoptosis of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and insufficient ocular perfusion have been postulated to be the two main theories in glaucoma development and progression. The effects of exercise in these two aspects have been demonstrated by numerous researches. A review in 2009 focusing on these two theories concluded that exercise results in transient IOP reduction but an inconsistent elevation in ocular perfusion. However, the majority of the studies had been conducted in healthy subjects. Over the past decade, technological advancement has brought forth new and more detailed evidence regarding the effects of exercise. Moreover, the neuroprotective effect of exercise by upregulation of neurotrophin and enhancement of mitochondrial function has been a focus of interest. Apart from visual impairment, the mental health issues in patients with glaucoma, which include anxiety and depression, should also be addressed. In this review, we mainly focus on publications from the recent years, so as to provide a comprehensive review on the impact of physical exercise on IOP, ocular perfusion, neuroprotection and mental health in patients with glaucoma.

Muscular Strength Is Associated with Higher Intraocular Pressure in Physically Active Males

SIGNIFICANCE

The positive association between intraocular pressure (IOP) and relative maximum force may have relevance for exercise recommendations when IOP is a concern.

PURPOSE

The relationship between exercise and IOP has been approached in several studies. However, the influence of muscle function on IOP remains underexplored. This study aimed to determine the relationship between the maximal mechanical capabilities of muscles to generate force, velocity, and power with IOP.

METHODS

Sixty-five physically active males participated in this cross-sectional study. Baseline IOP measures were obtained by rebound tonometry, and participants performed an incremental loading test in the ballistic bench press.

RESULTS

Baseline IOP showed a strong positive correlation with relative maximum force (r65 = 0.85, P < .001) relative maximum power (r65 = 0.85, P < .001), and relative one-repetition maximum (r65 = 0.91, P < .001). Also, a moderate positive association was obtained between baseline IOP and maximum force (r65 = 0.74, P < .001), maximum power (r65 = 0.72, P < .001), and maximum dynamic strength (r65 = 0.80, P < .001). No significant correlations between IOP and maximal velocity were obtained (all P > .05).

CONCLUSIONS

There is a positive association between greater upper-body power and strength with higher baseline IOP, which might have important implications in the management of ocular health and especially in individuals constantly involved in resistance training programs (e.g., military personnel, weightlifters). The possible protective effect of high fitness level on the acute IOP response to strength exercise needs to be addressed in future studies.

Non-pharmacological therapies for primary open angle glaucoma: A quasi-experimental pilot study

Purpose: One of the major causes of blindness is Primary open angle glaucoma (POAG) and it has only surgical treatment and lifelong use of medication. Hence many side effects arise. To overcome this, the drugless approach is in practice but the importance of Muscle Energy Technique (MET) and Myofacial (MFR) Release is not explored. Hence, our objective was to determine the effectiveness of MET and MFR on POAG. Methods: A total of 12 patients with POAG were recruited from the tertiary care teaching hospital through criteria based convenience sampling for the study. But nine patients with POAG completed the study. The age of the patient with POAG ranges from 15 to 30 years. MET and MFR were given to the patient for 30 min/day, six days/week for three weeks. Intraocular pressure (IOP) was assessed with Tonometer as dependent variable by Ophthalmologist. Pre and post treatment IOP change was established. Result: Pre IOP and Post are 23.1 ± 1.9 mmHg and Post IOP is 20 ± 1.4 mmHg respectively. The mean pre-post difference is 3.1 ± 1.9 mmHg with significance difference of p = 0.002. Conclusion: MET and MFR reduce IOP. This proves to be one of the feasible and cost effective treatments in the management of POAG. Clinical Trial Registry: CTRI/2014/09/4986.

Changes in intraocular pressure after exercise test

BACKGROUND

The decrease in intraocular pressure (IOP) within exercise has been recently suggested; however, this change remained ambiguous following exercise test. The present study aimed to assess changes in IOP induced by exercise test in patients who suspected to coronary artery disease (CAD) and indicated for exercise test evaluation.

METHODS

In a cross-sectional study at the cardiovascular research center of Amin Heart Hospital in Isfahan, 101 eyes from 51 consecutive patients suspected to CAD aged 30-70 years referred for exercise testing were evaluated. IOP was measured at the three time points of before exercise test as well as 5 and 20 min after completing exercise test using Schiotz tonometer. All exercise tests were programmed by the treadmill.

RESULTS

The mean IOP in all assessed eyes was 16.12 ± 2.61 mmHg initially that was gradually decreased to 13.79 ± 2.40 mmHg 5 min after the exercise test, but elevated to 15.67 ± 2.26 mmHg 20 min after the test. Assessing IOP following exercise testing showed a significant decrease in IOP in 75 eyes (74.3%), remained unchanged in 19.8% of eyes, and even elevated in 5.9% of eyes. There was a significant direct association between patients' age and IOP changes assessed by the Pearson's correlation test (r = 0.350,P = 0.009). No significant difference was revealed in the trend of the changes in IOP after exercise test between men and women, between left-sided and right-sided eyes as well as between different body mass index subgroups.

CONCLUSION

IOP temporarily reduced after exercise test, but return to baseline value shortly after test. This lowering is more evident in advanced aging.

Intraocular pressure and glaucoma: Is physical exercise beneficial or a risk?

Intraocular pressure may become elevated with muscle exertion, changes in body position and increased respiratory volumes, especially when Valsalva manoeuver mechanisms are involved. All of these factors may be present during physical exercise, especially if hydration levels are increased. This review examines the evidence for intraocular pressure changes during and after physical exercise. Intraocular pressure elevation may result in a reduction in ocular perfusion pressure with the associated possibility of mechanical and/or ischaemic damage to the optic nerve head. A key consideration is the possibility that, rather than being beneficial for patients who are susceptible to glaucomatous pathology, any intraocular pressure elevation could be detrimental. Lower intraocular pressure after exercise may result from its elevation causing accelerated aqueous outflow during exercise. Also examined is the possibility that people who have lower frailty are more likely to exercise as well as less likely to have or develop glaucoma. Consequently, lower prevalence of glaucoma would be expected among people who exercise. The evidence base for this topic is deficient and would be greatly improved by the availability of tonometry assessment during dynamic exercise, more studies which control for hydration levels, and methods for assessing the potential general health benefits of exercise against any possibility of exacerbated glaucomatous pathology for individual patients who are susceptible to such changes.

The period of the day affects the twenty-four hour blood pressure response to an acute combined exercise session in Brazilian jiu jitsu athletes

AbstractThe purpose of this study was to compare the effect of a combined exercise session performed at different periods of the day on the 24h blood pressure (BP) response. Anaerobic threshold (AT) and 12 repetition maximum (12RM) tests were evaluated in nine Brazilian jiu-jitsu athletes (male) (22±3.7 y; 176±5.0 cm; 73.4±9.7 kg; 6.8±2.1 % body fat). Four experimental sessions were performed: resistance exercise followed by aerobic exercise [Morning (MornS) and Afternoon (AfternS)] and Control (C) [Morning and Afternoon]. The morning sessions were conducted at 09:00 a.m. and the afternoon sessions were conducted at 3:00 p.m. The resistance exercise consisted of three sets at 90% of a 12RM for six resistance exercises. The aerobic exercise consisted of 15min at 90% of the AT. Blood pressure (BP) was measured before, during and 1h (Microlife(r) BP3A1C) after the performance of exercises in laboratory, and then during daily activities for the succeeding 23h by ambulatory BP monitoring (Dyna-MAPA(r)). Analysis of the area under the curve (AUC) indicated significant reductions in blood pressure parameters at various time points during the 24h monitoring period. For systolic BP (SBP), significantly lower values were shown following the morning session versus the control (MornS: 1756.2±100.8 vs. C: 1818.2±84.3 mmHg*15h; p < .05) and total-24h (MornS: 2695.8±143.3 vs. C: 2784.1±143.2 mmHg*24h; p < .05). The total-24h mean BP (MAP) was also significantly lower following the morning session versus the control (MornS: 2015.7±121.2 vs. C: 2087.3±153.8 mmHg*24h; p < .05). There were significant differences in the sleeping AUC of SBP (AfternS: 883.6±27.0 vs. C: 965.2±67.9 mmHg*9h; p< .05), diastolic BP (DBP) (AfternS: 481.4±30.9 vs. MornS: 552.9±34.2 and C: 562.1±52.3 mmHg*9h; p < .01) and MBP (AfternS: 651.9±22.4 vs. MornS: 708.7±43.1 and C: 726.9±64.7 mmHg*9h; p < .01). The combined exercise performed at different periods of the day contributed distinctly to the reduction of BP. The morning session was important in reducing SBP and MBP in the total-24h monitoring, while the afternoon session reduced SBP, DBP and MBP during sleeping in jiu-Jitsu athletes.

Intraocular pressure is not associated with acute mountain sickness

OBJECTIVE

Acute mountain sickness (AMS) is common at high altitude and may lead to high altitude cerebral edema (HACE) if not properly recognized. Previous studies have suggested that AMS is associated with increases in intracranial pressure (ICP). Increased ICP has been associated with increased intra-ocular pressure (IOP). This study was designed to determine the association between IOP and AMS.

METHODS

Subjects were recruited from a convenience sample of travelers in the Khumbu region of Nepal, elevation 14,410 ft (4392 m). Study participation involved completion of a questionnaire to assess for AMS by the Lake Louise Score (LLS), followed by three IOP measurements in each eye. Investigators were blinded to the LLS. Subjects with a history of ocular surgery were excluded. Three IOP measurements per eye were made using an applanation tonometer (Tono-Pen XL(®), Reichart Technologies) and averaged across both eyes. Multivariable logistic regression analysis was used to estimate the association between IOP and AMS while adjusting for age, ascent or descent, and use of acetazolamide. IOP and blood O2 saturation were compared using a Spearman correlation coefficient.

RESULTS

161 subjects were enrolled with a median age of 36 (IQR: 29-45) years; 60% were male, 75% were ascending, and 64% were taking acetazolamide; additionally, 38%, (95% CI: 31%-47%) were diagnosed with AMS (LLS ≥3). The median IOP was 21 (IQR 18-24) mmHg. The logistic regression model demonstrated no association between IOP and AMS as measured by LLS (odds ratio [OR] 1.0, 95% CI: 0.9-1.1),age (OR 1.0, 95% CI: 0.9-1.0) or with use of acetazolamide (OR 1.4, 95% CI: 0.6-2.6). Ascent (OR 0.4, 95% CI: 0.2-0.9) was negatively associated with IOP but not significantly so. IOP and O2 saturation were not correlated (p=0.93).

CONCLUSIONS

IOP measured at high altitude is not associated with the diagnosis of AMS. Other approaches to diagnose AMS easily and accurately are needed.