The relationship between intraocular pressure and glaucoma: An evolving concept

Advances in the application of smart materials in the treatment of ophthalmic diseases

Smart materials dynamically sense and respond to physiological signals like reactive oxygen species (ROS), pH, and light, surpassing traditional materials such as poly(lactic-co-glycolic acid), which have high drug loss rates and limited spatiotemporal control. These innovative materials offer new strategies for ophthalmic treatments, with core advantages including targeted delivery via ROS-sensitive nanocarriers, precise regulation through microvalves, and multifunctional integration, such as glucose-responsive contact lenses that create a "sensing-treatment" loop. However, challenges remain, like pathological microenvironment interference with material response specificity, and the need to address long-term biocompatibility and energy dependence issues. This article systematically examines three key treatment barriers: the blood-ocular barrier, immune rejection, and physiological fluctuations, while reviewing innovative smart material design strategies. Future research should focus on biomimetic interface engineering, for example, cornea mimicking nanostructures, AI-driven dynamic optimization like causal network-regulated drug release, and multidisciplinary approaches combining gene editing with smart materials. These efforts aim to shift from structural replacement to physiological function simulation, enabling precise treatment of ophthalmic diseases. Clinical translation must balance innovation with safety, prioritizing clinical value to ensure reliable, widespread application of smart materials in ophthalmology.

Presence of Anxiety and Depression in Patients with Open-Angle Glaucoma of Different Degrees of Damage

Background: Glaucoma is a group of eye conditions that damage the optic nerve, and it can be interconnected with psychoneurotic disorders due to the psychological and emotional stress that comes with such a chronic condition. The aim of this study was to examine the characteristics of the occurrence of anxiety, depression and open-angle glaucoma (OAG) in glaucoma patients from December 2023 to December 2024. Methods: This cross-sectional study was conducted on 200 patients with three different stages of OAG. Multiple questionnaires were used to determine the influence of different OAG stages on the severity of anxiety and depression. Results: While predicting the anxiety expression, in a multivariate logistic regression (stepwise method), there was a significant model in predicting the expression of anxiety: female gender (Odds ratio (OR) = 3.03), age of 66 and over (OR = 3.4) and the feeling of being under stress (OR = 7.07). In the prediction of a higher severity of depression, predictors are age 66 and older (OR = 2.03) and feeling stressed (OR = 9.47). Conclusions: While glaucoma and psychoneurotic disorders affect different systems in the body, the psychological toll of living with glaucoma can lead to exacerbation of glaucoma.

Pericytes in the Optic Nerve Head

Pericytes are a unique population of contractile mural cells and an essential part of the microvasculature. In the retina and brain, pericytes play crucial roles in regulating blood flow, maintaining the blood-brain barrier, signaling with neighboring cells, and depositing extracellular matrix. Pericyte dysfunction is an early process in a variety of neurodegenerative conditions. However, remarkably little is known about pericytes at an early site of neurodegeneration in glaucoma, the optic nerve head (ONH). This work summarizes the current understanding of pericyte contributions to ONH physiology, identifies potential roles in glaucomatous pathophysiology, and uncovers open questions at the intersection of these areas. We surveyed the literature to identify the roles of ONH pericytes in the context of health and glaucoma. Additionally, we probed for the presence of pericytes along microvasculature in mouse, nonhuman primate, and human donor ONH tissues. We identified an association between factors influencing ONH dysfunction in glaucoma and factors influencing pericyte dysfunction in other neurodegenerative conditions. Pericytes exist in the mouse, nonhuman primate, and human ONH, implicating their capacity for local function. ONH pericytes represent a promising but underexplored target for treating microvascular impairment in glaucoma. Investigating the contribution of pericytes in both healthy and disease states can help inform mechanisms of dysfunction in glaucomatous pathology, paving the way for the development of novel therapeutic strategies.

Transpalpebral measurement of intraocular pressure with the Tono-Pen XL, in a young, healthy, adult population

Identification of increased intraocular pressure has been conventionally limited by direct, corneal applanation, and indentation measurement procedures, conducted by highly trained eye-care specialists e.g. optometrists and ophthalmologists. This practice greatly limits the numbers of individuals which can and need to be screened, for increased intraocular pressures. Increased intraocular pressure is the second leading cause of preventable, irreversible blindness throughout the world and a major modifiable risk factor for the development and progression of glaucoma. Current screening practices are inadequate, leaving many undetected, resulting in high base-rates of unnecessary and preventable blindness worldwide. Three primary research questions are investigated: Can intraocular pressures be measured through the eyelid, using the Tono-Pen XL tonometer? If yes, can the transpalpebral values be transformed to approximate corneal values? If yes, are the transformed values sufficiently precise, accurate, and reliable to substitute for intraocular pressure values measured directly from the cornea, for screening purposes?. Ninety (n = 90), healthy, young, adults completed measurement of intraocular pressures, from each eye (n = 180 eyes), using the Tono-Pen XL tonometer. Intraocular pressures were measured directly from the cornea and then directly from the closed eyelid. Transpalpebral measurements were transformed by simple linear regression to estimate direct corneal measurements. Transformed values were assessed for accuracy, precision, reliability, and agreement with direct corneal measurements. Findings revealed high accuracy, precision, reliability, and agreement between direct corneal and transpalpebral measurements. Transformed transpalpebral measurements correctly classified 95% and 93% of subjects, within 4 mm Hg or less of direct corneal measurements, when intraocular pressures were measured from the right and left eyes, respectively. Intraocular pressures measured directly from the closed eyelid, using the Tono-Pen XL, can be linearly transformed, using simple linear regression, to estimate intraocular pressure values measured directly from the cornea with high agreement, precision, and reliability, in a healthy, young, adult population. Findings have implications for non-eye-care specialists e.g. primary care physicians, choosing to quickly, accurately, and reliably screen individuals for normal intraocular pressures, without the need to anesthetize the eyes or use expensive, office-bound. equipment.

High Glucose-induced transcriptomic changes in human trabecular meshwork cells

Glaucoma is a leading cause of irreversible blindness, often associated with elevated intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction. Diabetes mellitus (DM) is recognized as a significant risk factor for glaucoma; however, the molecular mechanisms through which hyperglycemia affects TM function remain unclear. This study investigated the impact of high glucose on gene expression in human TM (HTM) cells to uncover pathways that contribute to TM dysfunction and glaucoma pathogenesis under diabetic conditions. Primary HTM cells were cultured under normoglycemic (5.5 mM) and hyperglycemic (30 mM) conditions for seven days, followed by mRNA sequencing (mRNA-seq) to identify differentially expressed genes, with quantitative PCR (qPCR) used for confirmatory analysis. STRING network analysis was performed to predict potential interactions among upregulated and downregulated genes. mRNA-seq analysis revealed 25 significantly differentially expressed genes in high glucose conditions, including upregulated genes associated with oxidative stress, apoptosis, autophagy, immune response, and fibrosis. Notably, TXNIP gene was significantly upregulated, indicating increased oxidative stress and apoptosis in TM cells, while downregulation of autophagy-related genes, such as HSPA6 and LAMP3, suggests compromised protein quality control. Immune response genes, including CCL7 and CHI3L1, were upregulated, suggesting an inflammatory response to oxidative stress. Increased expression of fibrosis-related genes, such as SNAI1, FGF7, and KRT19, and an increase in ECM proteins like Collagen 1 and FN accumulation and fibril formation suggest increased fibrosis of TM in diabetic conditions, potentially elevating IOP. Metabolic changes in diabetic patients could therefore lead to TM dysfunction, impair aqueous humor outflow, and elevate IOP, thereby increasing glaucoma risk. Targeting oxidative stress and fibrosis pathways offers therapeutic strategies to mitigate glaucoma progression in diabetic populations.

Enhanced in vivo performance of topical ocular acetazolamide nanocrystals: A novel approach for glaucoma treatment

High intraocular pressure (IOP) is the main risk factor for glaucoma progression. Acetazolamide (AZM) presents a potent IOP-lowering effect but is only administered orally due to its low aqueous solubility and ocular permeability. This study aimed to develop AZM nanocrystals (AZM-NC) as an alternative for its topical ocular delivery. AZM-NC were obtained by wet bead milling technique followed by spray-drying, and a mixture design study was conducted to evaluate the optimal drug-to-stabilizer ratio regarding colloidal properties and stability. AZM-NC exhibited an average particle size of 299.7 ± 8.8 nm, a polydispersity index of 0.13 ± 0.01, and a zeta potential of -29.0 ± 0.9 mV, which remained mostly unchanged for at least 60 days when the dried powder was stored at room temperature. Fourier-transformed spectroscopy and powder X-ray diffraction analyses revealed no chemical or crystallinity changes in AZM-NC compared with AZM, respectively. Additionally, AZM-NC demonstrated increased drug saturation concentration, globular shapes, and higher adhesive properties than normal-sized AZM powder. Topical ocular administration of AZM-NC in albino male rabbits showed no clinical signs of ocular damage. Further, in vivo studies revealed a significant IOP reduction of up to 32 % of the basal IOP (-4.8 ± 1.2 mmHg, p < 0.05) in normotensive rabbit eyes (n = 7), after 4 h of AZM-NC suspension topical application, compared to groups treated with AZM suspension, normal saline solution and, AZOPT® (-1.8 ± 1.4 mmHg). Thus, AZM-NC could present a promising approach for developing an eye drop formulation for the localized management of glaucoma.

Clinical implications of lowering episcleral venous pressure in the management of glaucoma and the use of Rho kinase inhibitors

There has been limited success in both measuring and modifying episcleral venous pressure (EVP) in clinical practice. Understanding the potential role of EVP in the management of glaucoma for different patients may allow for more individualized treatment approaches. To explore the clinical implications of lowering EVP, an international group of 9 glaucoma experts (the ENGAGE Global Expert Working Group) convened to bridge the gap between the current literature and evidence with clinical opinion and best practices. This review summarizes insights from the group on the effect of current medical therapies on EVP and its potential impact. It also discusses unmet investigational needs to enhance the understanding of EVP, as well as the challenges associated with the measurement and treatment of EVP. Regardless of the relatively modest EVP reductions achieved with current treatments, EVP lowering may have clinical significance in patients with glaucoma, particularly those with low intraocular pressure (IOP). Those who might benefit include patients with elevated EVP; normal-tension glaucoma; undergoing trabecular meshwork bypass surgery, goniotomy, or selective laser trabeculoplasty; or requiring additional IOP lowering to the low teens or with a lower-than-usual target IOP.

Improvement of Presbyopia, Dry Eye, Intraocular Pressure, and Near Vision Through Cassiae Tea Consumption

Background and Objectives: This study aimed to illustrate a novel method for improving presbyopia by drinking cassiae tea. Materials and Methods: A total of 425 eyes from 425 participants (aged 52.5 ± 9.5 years) were recruited and divided into several experimental groups over a 6-month period. Participants consumed cassiae tea daily (10 g of cassiae semen brewed in 500 cc of water). Meanwhile, control group participants consumed 500 cc of plain water along with 1000 mg of vitamin C each day. Experiments 1 and 2: Participants with severe dry eye and intraocular pressure (IOP) > 30 mmHg were enrolled, and outcomes were assessed for these conditions, respectively. Experiments 3, 4, and 7: These experiments evaluated pupil size, near vision, and serum superoxide dismutase (SOD) levels in two groups of volunteers. Experiment 5: Different quantities of cassiae tea were prescribed to various groups, and near vision was measured. Experiment 6: Three questionnaires assessed presbyopic symptoms after cassiae tea consumption. Experiment 8: The antioxidant activity of cassiae tea compared with other bioactive compounds and Chinese herbs was evaluated using the DPPH test. Results: By the fourth month of the study, participants experienced increased tear volume and reduced IOP. Pupil size constricted, near vision improved, and serum SOD levels increased. Furthermore, greater consumption of cassiae tea was correlated with better near vision. The antioxidant activity of cassiae tea was found to surpass that of anthocyanins, wolfberry, and vitamin C. Conclusions: Drinking cassiae tea improves dry eye symptoms, reduces IOP, regulates pupil size, and enhances near vision due to its excellent antioxidant and pharmacological properties. These benefits may particularly aid individuals with presbyopia and those engaged in near-distance activities, such as smartphone use.