Effect of 24-h blood pressure dysregulations and reduced ocular perfusion pressure in open-angle glaucoma progression

Color Doppler Imaging Assessment of Ocular Blood Flow Following Ab Externo Canaloplasty in Primary Open-Angle Glaucoma

Background/Objectives: Glaucomatous neuropathy, a progressive deterioration of retinal ganglion cells, is the leading cause of irreversible blindness worldwide. While elevated intraocular pressure (IOP) is a well-established modifiable risk factor, increasing attention is being directed towards IOP-independent factors, such as vascular alterations. Color Doppler imaging (CDI) is a prominent technique for investigating blood flow parameters in extraocular vessels. This prospective, nonrandomized clinical trial aimed to assess the impact of ab externo canaloplasty on ocular blood flow parameters in patients with primary open-angle glaucoma (POAG) at a three-month follow-up. Methods: Twenty-five eyes of twenty-five patients with early or moderate POAG underwent canaloplasty with simultaneous cataract removal. CDI was used to measure peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs) before and after surgery. Results: The results showed a significant reduction in IOP and improvement in mean deviation at three months post-surgery. Best corrected visual acuity and retinal nerve fiber layer thickness significantly increased at each postoperative control visit. However, no significant changes were observed in PSV, EDV, and RI in the studied vessels. Conclusions: In conclusion, while canaloplasty effectively reduced IOP and medication burden, it did not significantly improve blood flow parameters in vessels supplying the optic nerve at three months post-surgery. Careful patient selection considering glaucoma severity and vascular risk factors is crucial when choosing between canaloplasty and more invasive procedures like trabeculectomy. Further larger studies are needed to comprehensively analyze this issue.

Association between glaucoma and the risk of Alzheimer's disease: A meta-analysis

BACKGROUND

The role of glaucoma in predicting Alzheimer's disease (AD) factors is unknown. This current meta-analysis was aimed at evaluating the risk of AD events in individuals suffering from glaucoma based on a meta-analysis.

MATERIALS AND METHODS

Databases which included Cochrane Library, PubMed, and EMBASE were searched to detect the relevant articles, with language being restricted to English. The risk of AD events in patients with glaucoma was analyzed using the combined hazard ratios.

RESULTS

This study included 8 articles with 131,987 subjects published after 2012. We identified glaucoma as the risk factor for disease-free survival (hazard ratio = 1.29; 95% confidence interval = 1.05-1.59; P = .000; I2 = 95.1%) in AD patients. According to subgroup analyses, normal tension glaucoma group was the major risk factor for disease-free survival of AD patients.

CONCLUSIONS

Although diverse approaches have been used for AD cases of various events, the current meta-analysis indicates that that glaucoma patients have a higher AD risk.

Differences and Similarities Between Primary Open Angle Glaucoma and Primary Angle-Closure Glaucoma

Glaucoma is the leading cause of irreversible blindness worldwide. It is an ocular disease characterized by an increase in intraocular pressure or, in some cases, normal intraocular pressure, which leads to optic nerve damage and progressive constriction of the visual field (VF). Primary Open-Angle Glaucoma (POAG) and Primary Angle-Closure Glaucoma (PACG) represent the predominant forms of glaucoma. Numerous hypotheses have been posited to elucidate the pathogenic mechanisms underlying these conditions. There is an emerging understanding of the distinct pathological processes that differentiate the various types of glaucoma. While some similarities in the mechanisms between PACG and POAG have been suggested, evidence indicates that there are also significant differences between the two. This review synthesizes the similarities and differences in the etiology of optic neuropathy caused by POAG and PACG, considering their respective pathophysiological mechanisms, the morphology of the optic disc and surrounding tissues, genetic characteristics, optical coherence tomography angiography, optical coherence tomography, and structural and functional features from VF examinations. These characteristics may contribute to a deeper comprehension of the underlying pathogenesis of glaucoma and enhance the management of different types of this ocular condition.

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial

Background

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care.

Aims

The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Methods

The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6 months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6 months.

Anticipated results

We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Discussion

HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression.

Clinical Trial Registration Number

The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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