Search Results (40)

Glaucoma is the leading cause of irreversible blindness worldwide and is characterized by progressive retinal ganglion cell (RGC) loss and optic nerve degeneration. While elevated intraocular pressure (IOP) remains the primary modifiable risk factor, a certain proportion of patients continue to deteriorate despite adequate IOP control, pointing to IOP-independent mechanisms of neurodegeneration. Oxidative stress—defined as an imbalance between the production of reactive oxygen species and the capacity of endogenous antioxidant defenses—has emerged as a central, multi-tiered contributor to glaucoma pathogenesis. In the anterior segment, chronic oxidative damage to the trabecular meshwork impairs aqueous humor outflow and drives IOP elevation. In addition, oxidative stress may impair ocular biomechanical integrity, including corneal hysteresis and lamina cribrosa, resulting in heightened susceptibility to IOP fluctuations. In the posterior segment, oxidative stress directly contributes to mitochondrial damage and vascular endothelial injury, leading to RGC apoptosis. The nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) pathway coordinates the principal endogenous antioxidant response, while nicotinamide adenine dinucleotide (NAD⁺) depletion links redox imbalance to metabolic vulnerability of RGCs. This narrative review synthesizes evidence published up to March 2026 on the molecular mechanisms of oxidative stress in glaucoma, the role of biomarkers in aqueous humor and systemic circulation, and the translational landscape of antioxidant-based neuroprotection—including nicotinamide, coenzyme Q10, alpha-lipoic acid, and Nrf2-activating compounds. We highlight gaps between preclinical promise and clinical evidence, and outline priorities for future randomized controlled trials. Full article

Continuous intraocular pressure (IOP) monitoring is crucial for glaucoma management. Currently, traditional static IOP measurements often fail to detect circadian fluctuations, leading to a clinical dilemma where “normal IOP” is observed despite persistent visual field deterioration. This study presents a wireless, passive localized surface plasmon resonance (LSPR) sensing platform integrated into flexible silicone hydrogel contact lenses. Gold nanoparticles (AuNPs), synthesized via the sodium citrate reduction method, were incorporated into the lens periphery using a “swelling-induced nano-doping” technique to transduce IOP-induced corneal strain into detectable spectral shifts. Ex vivo porcine eye investigations established a physical mapping model, confirming significant LSPR peak wavelength response trends in correlation with IOP variations (10–50 mmHg) and corneal curvature changes. Subsequent 21-day in vivo rabbit studies demonstrated excellent ocular surface biocompatibility; quantitative histopathological analysis (HE, PAS, and Ki67 staining) revealed no significant adverse alterations in corneal endothelial cell density or conjunctival goblet cell function compared to control groups (p > 0.05). Furthermore, the platform maintained high structural integrity and anterior segment tolerance under transient high-IOP conditions. While currently a proof-of-concept, these results indicate that the LSPR-active hybrid system effectively captures dynamic IOP fluctuation patterns as an optical response to acute interventions, providing a foundational engineering path for next-generation, battery-free wearable diagnostics in personalized glaucoma care without the need for built-in electronics. Full article

Elevated temperatures are frequently encountered in numerous occupational settings such as iron and steel foundries, non-ferrous metal foundries, brick and ceramic manufacturing plants, glass production facilities, rubber factories, electrical power plants, bakeries, laundries, chemical processing sites, mining operations, smelting plants, and steam tunnels. Employees working in these environments are at risk of developing various health issues and injuries, including ocular complications, due to prolonged exposure to heat and the physical demands of handling heavy materials. This study focuses on examining the pressure within the eye’s anterior chamber, referred to as Intraocular Pressure (IOP), and its association with the cornea’s biomechanical characteristics, with particular attention to corneal temperature. Our methodology is grounded in the principles of the first law of thermodynamics. The findings reveal a link between the temperature of the eye’s anterior chamber and the biomechanical behaviour of the cornea. Specifically, IOP serves as an indicator of the cornea’s elasticity and its optical properties as influenced by temperature variations. We investigated how the cornea’s elastic energy, or the work it performs, varies with temperature changes. The results show that an increase in temperature corresponds to a reduction in the work exerted by the cornea. The corneal temperature is affected by both the ambient environment and the temperature of the aqueous humour within the anterior chamber. This indicates a relationship between the mechanical work done by the cornea and the pressure exerted by the fluid in the eye’s front segment. Furthermore, our study identified a correlation between corneal thickness and IOP, which our modelling approach successfully quantifies. Utilizing the first law of thermodynamics, we calculated the work performed by the anterior chamber against the cornea’s internal surface. Temperature fluctuations influence the secretion, drainage, and flow characteristics of the aqueous humour, thereby impacting IOP and associated ocular conditions. These insights are valuable for devising strategies aimed at preventing eye injuries among workers exposed to high-temperature environments. Full article

Background/Objectives: This study aimed to evaluate the autoregulatory capacity of optic nerve head (ONH) tissue blood flow in response to intraocular pressure (IOP) fluctuations during vitrectomy in patients with proliferative diabetic retinopathy (PDR). We hypothesized that impaired autoregulation of ONH tissue blood flow in response to intraoperative IOP fluctuations could contribute to subsequent ONH atrophy and the development of visual field defects in PDR patients following vitrectomy. Methods: We included five eyes from five patients with PDR (mean age 70.6 ± 9.0 years) undergoing 25-gauge pars plana vitrectomy. ONH tissue blood flow was quantitatively assessed using intraoperative laser speckle flowgraphy. Mean blur rate in the tissue area (MT), an indicator of ONH tissue blood flow, was measured at baseline (infusion pressure 0 mmHg), during sustained elevation to 25 mmHg (at 5 and 10 min), and 1 min after return to baseline (11 min). IOP was modulated using the IOP Control system of the Constellation platform. Results: Elevation of IOP to 25 mmHg significantly reduced ONH tissue blood flow, with MT decreasing by 29% at 10 min compared with baseline (p < 0.05, Dunn’s multiple comparisons test). After IOP returned to baseline, MT significantly recovered compared with the 10 min measurement (p < 0.05) and returned to levels not significantly different from baseline (p > 0.05). Conclusions: MT decreases during intraoperative IOP elevation in PDR undergoing vitrectomy, but recovers after the return to baseline pressure, suggesting preserved short-term autoregulatory capacity. Careful IOP management during vitrectomy remains important in eyes with PDR. Full article

Objective: Evaluate the efficacy and safety following intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy in patients with diabetic macular oedema (DME). Methods: To evaluate retinal microvascular remodelling and photoreceptor metrics using adaptive optics (AO) alongside systemic vascular status assessed by brachial/aortic hemodynamic and carotid ultrasound. We conducted a single-centre longitudinal study including twenty-one patients with DME. The following four diagnostic visits were performed: baseline (V1, no anti-VEGF treatment), 2–3 months (V2), 6–8 months (V3), and 12–14 months (V4). Adaptive optics (rtx1) measured foveal cone number (N) and regularity (Reg) within a standardised 80 × 80 µm window, and superior temporal retinal arteriole morphology after the first bifurcation (vessel diameter [VD], lumen diameter [LD], wall thickness [WT], wall-to-lumen ratio [WLR], and wall cross-sectional area [WCSA]). SphygmoCor provided peripheral (brachial) and central (aortic) pressures, augmentation pressure (AP), augmentation index (AIx), and carotid–femoral pulse wave velocity (PWV and PWVHR heart rate adjusted). Carotid ultrasound assessed intima–media thickness (IMT), carotid lumen diameter (CLD), and IMT/CLD ratio (IMTLR) 2 mm proximal to the bifurcation in diastole. Visual acuity (Visus), intraocular pressure (IOP), and central retinal thickness (CRT) were obtained at each visit. Results: In the treated eye (TE), WLR showed a significant overall change (Friedman p = 0.007), with a modest V4 vs. V1 increase (Wilcoxon p = 0.045); LD also varied across visits (Friedman p = 0.034). Cone metrics improved as follows: Reg increased over time (Friedman p = 0.019), with a significant rise at V4 vs. V1 (p = 0.018), and cone number increased at V3 vs. V1 (p = 0.012). Functional/structural outcomes improved as follows: visual acuity increased at V3 (p = 0.009) and V4 (p = 0.028), while CRT decreased at V3 (p = 0.002) and V4 (p = 0.030); IOP remained stable compared to V1. Systemic hemodynamics was largely unchanged; small fluctuations in DBP and cDBP across V1–V4 were observed (Friedman p = 0.034 and p = 0.022, respectively), whereas AIx, AP, PWV, and PWVHR showed no significant trends. Carotid IMT, CLD, and IMTLR did not change significantly across visits, supporting systemic vascular safety. Conclusions: Intravitreal anti-VEGF therapy in DME was associated with improvements in photoreceptor organisation and macular structure/function, with AO-derived arteriolar remodelling detectable over time, and no adverse changes in large-artery structure. These findings support ocular efficacy and systemic vascular safety; confirmation in larger cohorts is warranted. Full article

Background/Objectives: To investigate the non-inferiority of preservative-free (PF) tafluprost eye drops (Taflotan sine^®) compared to latanoprost eye drops (Xalatan^®) in reducing mean 24 h intraocular pressure (IOP) on the second day of a diurnal IOP measurement. Methods: In this retrospective monocentric cohort study, patients suffering from primary open-angle glaucoma, ocular hypertension, normal tension glaucoma, pigment dispersion glaucoma, or pseudoexfoliation glaucoma who had undergone inpatient diurnal IOP measurement were included. Patients of cohort 1 used latanoprost eye drops as monotherapy; patients of cohort 2 used preservative-free tafluprost eye drops. Data from 7 January 2005 to 9 July 2019, inclusive, were analyzed. Results: Ninety-three eyes were included (n = 59 latanoprost group, n = 34 PF tafluprost group). Mean 24 h IOP on day 2 was 14.1 mmHg (SD 2.3) in the latanoprost group and 14.5 mmHg (SD 3.4) in the PF tafluprost group. The non-inferiority of PF tafluprost eye drops to latanoprost eye drops in efficacy on mean 24 h IOP could not be confirmed (95% CI −1.5, ∞, p = 0.235). The average difference in mean IOP at the individual measurement times between both cohorts was 0.24 mmHg (SD 0.17) on day 1 and 0.44 mmHg (SD 0.6) on day 2. The non-inferiority of PF tafluprost compared to latanoprost regarding fluctuation range could not be demonstrated for both days. Conclusions: The data suggests slight inferiority of PF tafluprost to latanoprost eye drops. There were similar mean 24 h IOP values in both cohorts. PF tafluprost eye drops remain a useful treatment option as long as the patient’s individual target pressure is achieved. Furthermore, according to the literature, it is also a treatment option for patients with symptoms of ocular surface disease and other side effects affecting the ocular surface while receiving preservative-containing topical therapy. Full article

Purpose: This study investigates the association between obstructive sleep apnea (OSA), dry eye disease (DED), and glaucoma, focusing on the impact of positive airway pressure (PAP) usage and air leakage. Methods: This retrospective cross-sectional study included 57 adults with polysomnography-confirmed OSA between 2010 and 2023. Participants were grouped into PAP users (PAP+, n = 40) and non-users (PAP−, n = 17). Ocular assessments included tear film break-up time, Schirmer’s test, Oxford staining, meibomian gland evaluation, intraocular pressure, cup-to-disc (C/D) ratio, and retinal nerve fiber layer thickness. PAP device data (usage duration and air leak rate) and OSA severity metrics were recorded. Group comparisons used chi-square and Student’s t-test, and regression analyses identified associations between PAP leakage and ocular parameters. Results: Among the 57 OSA patients, PAP users showed a trend toward a higher risk of glaucoma (OR = 0.83) and DED (OR = 0.69) compared to non-users, but neither trend was statistically significant. PAP users had significantly more severe OSA, including longer N1 sleep stage (p = 0.0005), higher apnea-hypopnea index (AHI, p = 0.0001), and poorer oxygenation. PAP leakage: 95% (mean = 25.84 L/min) exceeded the 24 L/min threshold specified in ResMed’s clinical guidelines, suggesting suboptimal therapy. Higher PAP leak was significantly associated with a lower Schirmer’s test value (p = 0.031) and a higher C/D ratio (p = 0.040) on regression analysis. However, no significant differences were found in ophthalmic parameters between PAP+ and PAP− groups. Conclusions: Suboptimal PAP therapy as mask leakage or nocturnal hemodynamic changes may worsen evaporative dry eye and affect intraocular pressure. Our findings highlight the association between PAP mask leakage and reduced tear production, and suggest that OSA-related optic nerve stress may persist unless both hypoxia and nocturnal IOP fluctuations are properly managed. However, due to the relatively small sample size and retrospective cross-sectional design, future prospective studies with larger cohorts are needed to confirm these associations. Full article

Background/Objectives: Glaucoma affects over 70 million people worldwide and is a major cause of irreversible blindness, with elevated intraocular pressure (IOP) as the only modifiable risk factor. Conventional techniques like Goldmann applanation tonometry (GAT) are widely used but cannot provide continuous or nocturnal monitoring, limiting the detection of pressure peaks relevant to disease progression. Emerging technologies, including home-based devices, wearable sensors, such as contact lens-based sensors (CLBS), and implantable biomedical microelectromechanical systems (bioMEMS), offer more comprehensive and continuous assessment of IOP patterns. Thus, this scoping review aimed to map the available evidence on technologies for continuous IOP monitoring, summarizing their performance and agreement with traditional tonometry. Methods: A systematic search of electronic databases was conducted to identify studies published in the last 10 years evaluating self-tonometry devices, CLBS, or implantable systems designed for continuous IOP monitoring. Two reviewers independently screened articles, applied eligibility criteria, charted relevant data, including device characteristics and agreement with GAT, and reported clinical applications. Results: Self-tonometry devices demonstrated generally good agreement with GAT while enabling patients to monitor IOP outside clinical settings. These devices provided valuable information on diurnal and nocturnal IOP fluctuations, especially in individuals with rapid progression or those undergoing postoperative follow-up. BioMEMS-based wearable and implantable sensors showed promise for continuous long-term monitoring and revealed previously unrecognized fluctuation patterns, including activity-related changes. Conclusions: Emerging IOP-monitoring technologies appear to complement standard clinical methods by offering more detailed IOP profiles. Their integration into clinical practice may support individualized risk assessment and improved management of glaucoma progression. Full article

Objectives: To evaluate changes in intraocular pressure (IOP) before versus after a visual field test in glaucoma patients. Methods: A total of 132 patients with glaucoma and 103 control subjects who visited Konyang University Hospital between August 2024 and May 2025 were included in the study. the right eye of each patient was selected for analysis. Visual field tests were conducted using the Humphrey Visual Field (HVF) analyzer (Zeiss Humphrey, San Leandro, CA, USA) with the SITA standard program (Central 24-2). Intraocular pressure was measured by two ophthalmologists at five time points: before the test and immediately, 10 min, 30 min, and 60 min after the test. Results: The average intraocular pressure decreased from 15.09 mmHg before the test to 14.29 mmHg immediately afterward; it declined further to 13.59 mmHg at 10 min in glaucoma patients. It then gradually increased to 15.01 mmHg at 60 min, returning to pre-test levels. Participants were divided into three age groups (40s, 50s, and 60s) for analysis. Across all groups, the IOP followed a similar pattern: a significant decrease for up to 10 min, followed by recovery at 60 min. Although a reduction in IOP was also observed in the control group after visual field testing, the magnitude of the decrease was smaller compared to the glaucoma patients. Conclusions: IOP declined immediately after the visual field test and remained lower for up to 10 min. It subsequently returned to baseline by 60 min. Therefore, when measuring the IOP after a visual field test, there is no need to adjust for temporary fluctuations if the measurement is performed 60 min after the test. Full article

Objectives: Elevated intraocular pressure (IOP) is a well-known risk factor for glaucoma. This study investigated the impact of two distinct types of physical activity—endurance (marathon running) and strength (weightlifting)—on IOP variations. Methods: Forty healthy male athletes (20 marathon runners, 20 weightlifters) aged 18–35 years were recruited and monitored over three months. IOP was measured using Goldmann and Icare IC200 tonometers before and after 1 h training sessions. Results: The results showed a significant increase in IOP after training among weightlifters (mean post-training IOP: 19.3 mmHg), in contrast to stable or slightly reduced values in marathon runners (mean post-training IOP: 15.1 mmHg). Conclusions: These findings suggest the need for regular ophthalmologic monitoring in strength athletes. Future studies should examine the long-term impact of sport-specific IOP fluctuations on ocular health and glaucoma risk. Full article

Background/objectives: The aim of the study was to create a nanofiber insert incorporating Timolol (TIM) and Dorzolamide (DOR), targeting the management of glaucoma. This condition encompasses a variety of chronic, advancing ocular disorders typically associated with elevated intraocular pressure (IOP). Methods: The insert was made of Eudragite RL100 (EUD) polymer, a biocompatible material with high bioavailability, using the electrospinning method. The inserts were studied for morphology, drug–polymer interaction, physicochemical properties, and in vitro drug-release study. The pharmacokinetic properties of fibers were examined alongside consideration for irritation using a rabbit model and cell compatibility. Results: The results of the in vitro drug-release test showed retention and controlled release of both DOR/TIM over 80 h. Morphological examination demonstrated uniform nanofibers with mean diameters < 465 nm. The cell compatibility test showed a high percentage of cell survival, and none of the formulations irritated the rabbit’s eye. The Area Under the Curve (AUC0-72) for DOR and TIM in EDT formulations was approximately 3216.63 ± 63.25 µg·h/mL and 2598.89 ± 46.65 µg·h/mL, respectively, with Mean Residence Times (MRTs) of approximately 21.6 ± 0.19 h and 16.29 ± 6.44 h. Conclusions: Based on the results, the dual drug-loaded nanofiber preservative-free system can potentially be a suitable alternative to eye drops and can be used to reduce fluctuation and dose frequency. Full article

Glaucoma treatment involves reducing the intraocular pressure (IOP), which can damage the optic nerve, to a normal range. Aqueous drainage devices may be used for treatment, and a variety of devices have been proposed. However, they have a non-variable and uniform inner diameter, which makes it difficult to accommodate the IOP fluctuations that occur after glaucoma surgery. To ensure effective treatment in the early post-operative period with low IOP and the late post-operative period with high IOP, the inner diameter should be expandable over time to allow for smooth aqueous drainage. Here, we applied 3D printing technology with a tri-axial nozzle to develop an aqueous drainage tube that can expand its inner diameter. The distinct bilayer structure of the device allows it to expand its inner diameter through biodegradation, which can accommodate the IOP fluctuations that often occur after glaucoma surgery. The fabricated structure was evaluated in a series of tests, including leakage, cytotoxicity, and degradation experiments. The device did not show any leakage, was not toxic to cells, and demonstrated the expansion of the inner diameter through biodegradation. The device may provide a more effective post-operative solution for glaucoma patients by alleviating the effects of low IOP in the early post-operative period and high IOP in the late post-operative period. Full article

Background: Thickening of the inner nuclear layer (INL) or microcystic macular changes has been reported to be implicated in glaucoma patients, but their potential impact on disease progression remains unclear. We investigated the relationship between baseline microcystic macular edema in the INL or INL thickness and subsequent visual field (VF) progression in glaucoma patients. Methods: This retrospective observational study included primary open-angle glaucoma with follow-up exceeding 3 years. We identified macular cystic changes through Spectralis optical coherence tomography and measured the INL thickness using automated segmentation. Glaucoma progression was determined using the Guided Progression Analysis program of the Humphrey filed analyzer, calculating the mean deviation (MD) changes (dB/year). Results: Microcystic macular changes were observed in 12 (7.5%) of 162 patients. Patients with microcystic macular change had thicker INL thickness than those without it (p = 0.010). Progressors had a higher probability of having microcystic macular changes and a thicker average INL thickness than nonprogressors (p = 0.003, p = 0.019). Thicker INL thickness was associated with faster VF progression based on MD slope (dB/year) in the multivariate regression analysis (p = 0.045). Additionally, greater intraocular pressure (IOP) fluctuation was found to be associated with both a thicker INL and the presence of microcystic changes in the multivariate regression analysis (p = 0.003, 0.028). Conclusions: Increased macular INL thickness indicative of INL changes was linked to subsequent VF progression in glaucoma patients. These findings suggest that retinal inner nuclear change could serve as an indicator of progressive glaucoma. Full article

Performing physical exercise affects intraocular pressure, and its elevation and fluctuations are the main risk factors for glaucoma development or progression. The aim of this study was to examine the acute alterations in intraocular pressure (IOP) during four unweighted isometric exercises and to determine whether the different head and body positions taken during exercise additionally affect IOP. Twelve healthy volunteers between the ages of 25 and 33 performed four isometric exercises: wall sit in neutral head and body position, elbow plank in prone head and body position, reverse plank in supine head and body position for 1 min, and right-side plank in lateral head and body position for 30 s. Intraocular pressure was measured by applanation portable tonometry, before performing the exercise, immediately after exercise completion, and after five minutes of rest. A significant acute increase in intraocular pressure was found as a response to the performance of the elbow plank (p < 0.01), the reverse plank (p < 0.001), and the right-side plank (p < 0.001). The wall sit exercise did not reveal a statistically significant IOP elevation (p = 0.232). Different head and body positions had no significant additional influence on IOP (F (3,33) = 0.611; p = 0.613), even though the alteration in IOP was found to be greater in exercises with a lower head and body position. Our data revealed that IOP elevation seems to be affected by the performance of the elbow plank, the reverse plank, and the right-side plank; and not by the wall sit exercise. More different isometric exercises should be examined to find ones that are safe to perform for glaucoma patients. Full article

Increased intraocular pressure (IOP) is the most important risk factor for glaucoma. The role of IOP fluctuation, independently from elevated IOP, has not yet been confirmed in glaucoma. We investigated the effects of IOP fluctuation itself on retinal neurodegeneration. Male rats were treated with IOP-lowering eyedrops (brinzolamide and latanoprost) on Mondays and Thursdays (in the irregular instillation group) or daily (in the regular instillation group), and saline was administered daily in the normal control group for 8 weeks. The IOP standard deviation was higher in the irregular instillation group than the regular instillation group or the control group. The degree of oxidative stress, which was analyzed by labeling superoxide, oxidative DNA damage, and nitrotyrosine, was increased in the irregular instillation group. Macroglial activation, expressed by glial fibrillary acidic protein in the optic nerve head and retina, was observed with the irregular instillation of IOP-lowering eyedrops. Microglial activation, as indicated by Iba-1, and the expression of TNF-α did not show a significant difference between the irregular instillation and control groups. Expression of cleaved caspase-3 was upregulated and the number of retinal ganglion cells (RGCs) was decreased in the irregular instillation group. Our findings indicate that IOP fluctuations could be induced by irregular instillation of IOP-lowering eyedrops and this could lead to the degeneration of RGCs, probably through increased oxidative stress and macrogliosis. Full article