Eye And Brain[JOURNAL]
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183 papers
AstroOphthalmology: Basic and Pathophysiological Concepts of Space-Induced Ocular Changes.
Cheraqpour K, Shahriari M, Ghazi M … +5 more , Heydari N, Moshfeghi S, Mousavi Ganji SM, Asgari S, Cheraqpour S
Eye Brain · 2026 · PMID 42205158 · Full text
Long-duration space missions pose a considerable risk to eye health, and visual dysfunction is recognized as a primary health concern for astronauts. Hence, we have developed a series of review reports to study the effec...
Long-duration space missions pose a considerable risk to eye health, and visual dysfunction is recognized as a primary health concern for astronauts. Hence, we have developed a series of review reports to study the effects of space on the eye, called AstroOphthalmology (including Basics, Ocular Anterior Segment, Ocular Posterior Segment). This report serves as the first report of our series, and integrates the current insights into the pathophysiological consequences of the space environment on the eye. The two key space-specific stressors include microgravity and cosmic radiation. Both stressors are the interconnected pathways of oxidative stress and mitochondrial dysfunction, which inflict damage on cellular components and disrupt the function of essential ocular tissues. Microgravity triggers a cephalad fluid shift, which leads to vascular congestion, changes in hemodynamics, and increased intracranial pressure. The aforementioned changes are considered to be culprits in the onset of spaceflight-associated neuro-ocular syndrome (SANS). Exposure to galactic cosmic radiation and solar particle events presents a substantial risk for the formation of cataracts, retinal cotton-wool spots, and optic neuropathy. This review indicates that ocular damage during spaceflight is influenced by multiple factors, resulting from the synergistic interaction of fluid shifts and radiation. In addition to pathophysiology, we summarize the current in-flight evaluations such as optical coherence tomography and fundoscopy. Future research should focus on assessing combined countermeasures and establishing predictive biomarkers to mitigate these risks, which is imperative for the success of future lunar and Martian missions.
Age-Related Differences in Perception of the Rotating Snakes Illusion Among Young and Older Adults with Normal Visual Acuity.
Fujita K, Suzuki E, Kitaoka A … +2 more , Ueda K, Watanabe E
Eye Brain · 2026 · PMID 41891116 · Full text
PURPOSE: Visual illusions are utilized to elucidate mechanism of visual information processing. For example, the Rotating Snakes illusion creates the illusory perception of motion when viewing a static image. This study...
PURPOSE: Visual illusions are utilized to elucidate mechanism of visual information processing. For example, the Rotating Snakes illusion creates the illusory perception of motion when viewing a static image. This study investigated the difference in perception of illusory rotation between younger and older adults with normal visual acuity. PARTICIPANTS AND METHODS: The participants included 105 younger adults (mean age: 23.7 years) and 100 older adults (mean age: 74.2 years). Each participant was presented with the Rotating Snakes illusion, then asked to respond whether they perceived the snakes to be "rotating" or "not rotating". The rate of perception of illusory rotation was compared between the two groups. To evaluate the effects of cataracts, a major age-related optical change, comparisons were also made between older participants with bilateral cataracts versus those with bilateral intraocular lens (IOL) implantation. RESULTS: Rotation was perceived by 100% (105/105) of participants in the younger group, but only by 16% (16/100) of participants in the older group, showing a significant difference (p < 0.001). Among the older adults, the IOL and cataract groups had no significant difference in the rate of those who perceived the illusion (6/54 vs 10/45, p = 0.12). CONCLUSION: Significantly more younger adults perceived illusory motion in the Rotating Snakes illusion versus older adults. Lens opacity due to aging likely does not contribute to this phenomenon.
Artificial Intelligence in Neuro-Ophthalmology for Optic Disc Pathologies and Neurodegenerative Disease.
Ahuja AS, Paredes Iii AA, Eisel MLS … +3 more , Miller C, Truong N, Falardeau J
Eye Brain · 2026 · PMID 41859471 · Full text
Artificial intelligence (AI) is rapidly reshaping neuro-ophthalmic care by extracting clinically significant information from imaging, biomarkers, and patient-level clinical data. We review recent advances across neurode...
Artificial intelligence (AI) is rapidly reshaping neuro-ophthalmic care by extracting clinically significant information from imaging, biomarkers, and patient-level clinical data. We review recent advances across neurodegenerative disease detection using retinal biomarkers, automated recognition of optic disc swelling and its mimics, glaucoma screening and quantification, and classification of hereditary optic neuropathies. Using fundus photography and optical coherence tomography (OCT), contemporary machine learning (ML) systems, including deep learning as well as other supervised learning models, report strong discrimination for papilledema versus pseudopapilledema, non-arteritic anterior ischemic optic neuropathy (NAION) against similar presenting entities, and glaucomatous damage including indirect estimation of retinal nerve fiber layer (RNFL) thickness. Early work also suggests that retinal features can aid detection of mild cognitive impairment (MCI) and major neurocognitive disease. However, despite promising results, most studies remain retrospective and single-center, while focusing on imaging-only, limiting generalizability and clinical interpretability. Therefore a variety of challenges related to dataset heterogeneity, overfitting, limited external validation, and the gap between high diagnostic accuracy and practical clinical utility remain unresolved. Future prospective, multicenter evaluations focusing on integrating multimodal clinical data through explainable AI systems are necessary to improve diagnostic consistency, shorten time to care, and expand access for underserved populations.
Brain-Computer Interfaces for Vision Recovery in Precortical Vision Loss.
Yang CD, Guo A, Lin KY
Eye Brain · 2026 · PMID 41846866 · Full text
INTRODUCTION: Precortical vision loss remains a major global health challenge. Advances in brain-computer interfaces (BCIs) offer a new pathway towards restoring functional vision by bypassing damaged structures in the v...
INTRODUCTION: Precortical vision loss remains a major global health challenge. Advances in brain-computer interfaces (BCIs) offer a new pathway towards restoring functional vision by bypassing damaged structures in the visual pathway. METHODS: This narrative review aims to synthesize the current evidence on BCIs for precortical vision recovery, including non-invasive and invasive techniques. Device design, testing, and outcomes are discussed, with an emphasis on developments in technology and engineering. RESULTS: Non-invasive BCIs induce neuroplasticity and may restore vision in conditions of precortical vision loss such as glaucoma and optic neuropathy. Cortical visual prostheses demonstrate the ability to evoke visual precepts and recover functional vision. Integration of artificial intelligence and high-density electrode arrays has improved image encoding and device adaptability to enhance user experience and rehabilitation potential. Patient selection, safety, and long-term outcomes remain active areas of investigation. DISCUSSION: BCIs present a paradigm shift in treating precortical blindness that offers hope for patients with no alternative options. Yet, challenges persist, including surgical risks, durability, and variability in response. Personalization of stimulation protocols and further technical refinement are needed to optimize efficacy and accessibility. CONCLUSION: BCIs are a promising experimental modality for precortical vision restoration. Continued research and interdisciplinary collaboration are essential to address current limitations.
Routine Blood and Cerebrospinal Fluid Markers in Newly Diagnosed Idiopathic Intracranial Hypertension: An Exploratory Case-Control Study.
Hansen NS, Schmidt IF, Steenfos TW … +6 more , Korsbæk JJ, Jørgensen NR, Westgate CSJ, Hamann S, Beier D, Jensen RH
Eye Brain · 2026 · PMID 41783413 · Full text
BACKGROUND: Idiopathic intracranial hypertension (IIH) is an enigmatic syndrome of raised intracranial pressure and papilledema with metabolic underpinnings, although the exact etiology remains obscure. We aimed to evalu...
BACKGROUND: Idiopathic intracranial hypertension (IIH) is an enigmatic syndrome of raised intracranial pressure and papilledema with metabolic underpinnings, although the exact etiology remains obscure. We aimed to evaluate routine blood and cerebrospinal fluid (CSF) markers covering several organ systems in newly diagnosed IIH and compared to controls. METHODS: We registered the results of routine blood and CSF analyses in patients consecutively included in a prospective cohort by clinically suspected IIH. We compared females with confirmed IIH (2013 criteria) to "IIH mimics" in whom IIH was refuted (controls). We excluded patients with secondary pseudotumor cerebri syndrome, pregnancy, IIH relapse, age >50 years, male sex, other significant disease, or use of medications associated with multiorgan biochemical abnormalities with a prevalence of >1%. RESULTS: We compared 139 females with IIH to 78 controls of similar sex, age, and body mass index (BMI). In IIH, we found relatively higher plasma levels of leukocytes (p=0.02), neutrophils (p=0.04), and alkaline phosphatase (p=0.03), and lower levels of plasma urea (p=0.04) and CSF protein (p=0.02). Leukocytes and neutrophils correlated with lumbar opening pressure and were significantly higher in severe papilledema. Findings were not explained by BMI, smoking, or statistically influential covariates. CONCLUSION: In a well-defined prospective cohort of newly diagnosed IIH restricted by careful censoring of secondary cases and confounding factors, we found relatively increased systemic inflammation in plasma which correlated with markers of more severe IIH disease activity. IIH is likely a heterogeneous and complex disease in which inflammation seems to be involved.
Exosome-Based Approaches in Regenerative Medicine and Targeted Therapy for Eye Malignancies: A Comprehensive Review.
Falahi Tabar MM, Yavari A, Bagheri M … +4 more , Yavari P, Mansouri K, Rostaminasab G, Rahmati S
Eye Brain · 2026 · PMID 41737198 · Full text
Diagnosing and treating ocular malignancies-such as uveal melanoma, retinoblastoma, intraocular lymphoma, and conjunctival tumors-can be very difficult given their rarity, complicated pathophysiology, and a high potentia...
Diagnosing and treating ocular malignancies-such as uveal melanoma, retinoblastoma, intraocular lymphoma, and conjunctival tumors-can be very difficult given their rarity, complicated pathophysiology, and a high potential for complications that threaten vision or life. Traditional treatments such as chemotherapy, radiation, and surgery result in limited clinical value because of systemic toxicity, versatile drug resistance, and insufficient local control. Exosomes (EXOs)-naturally occurring nanoscale vesicles held in biocompatible structures-represent a uniquely advantageous platform for targeting and delivering miRNAs, proteins and/or gene editing molecules across ocular barriers to create corrective, sustained, and targeted diagnostics, drug delivery, and immune modulation. Mesenchymal stem cell-derived exosomes (MSC-EXOs) also possess regenerative potential in both animal and human models of retinal and ocular injury, engaging biological pathways involved in modulating inflammation and neuroprotection such as HMGB1 and PI3K/AKT pathways. While the use of EXOs presents a promising option for ocular treatment application, several factors complicate actual clinical translation, including standardization of isolation, scalable manufacture, and regulatory issues. In general, EXO-based nanomedicine may be a promising new direction for precision therapy and regenerative ophthalmology with the increasing introduction of synthetic and bioengineered EXOs introducing precursor paving new avenues for clinically scalable and biologically customizable EXO therapeutics.
Assessing Retinal Thickness and Associations with Cognitive Function in Women with History of Preeclampsia.
Ibarra AJ, Phan BN, Silverstein SM … +5 more , Chhablani J, Snyder V, Rossi EA, Butters MA, Catov JM
Eye Brain · 2026 · PMID 41551403 · Full text
PURPOSE: Women with preeclampsia are at risk of developing cognitive changes and dementia later in life. The retina - an extension of the brain - may provide insight about structural changes associated with preeclampsia...
PURPOSE: Women with preeclampsia are at risk of developing cognitive changes and dementia later in life. The retina - an extension of the brain - may provide insight about structural changes associated with preeclampsia and serve as a biomarker of long-term neural and vascular consequences. Our goal was to compare retinal thickness measurements between women with and without history of preeclampsia, and to determine associations with cognitive performance. PATIENTS AND METHODS: This prospective cohort study recruited preeclampsia (N=17) and normotensive (N=18) women 10-15 years after delivery. We assessed retinal thickness using spectral-domain optical coherence tomography (SD-OCT). Principal component analysis was used to detect retinal regional patterns. Cognitive performance was evaluated to assess memory (Wechsler Memory immediate and delayed), working memory-Letter-Number Sequencing, information processing speed (Digit Symbol, Stroop Word and Color) and executive (WAIS similarities, matrix reasoning, and Stroop interference) domains. Regression models estimated associations between retina measurements, preeclampsia history and cognitive performance. RESULTS: Using the standard early treatment diabetic retinopathy study grid, compared to normotensive, preeclampsia women had thinner outer retina subfields. Similarly, two out of three principal components suggested different patterns of retinal changes at the outer vs central region. The thinner inner nasal and superior quadrants were associated with lower scores on the executive function domain - Stroop Color test (β=12.2, 0.032; β=12.9, 0.037, respectively). In the memory domain, Letter-Number sequencing test, preE history significantly altered the relationship with the maximum fovea central subfield (β=-17.3, 0.013). CONCLUSION: Our study provides a novel, integrated assessment of preeclampsia by simultaneously evaluating retina and cognitive markers. Retinal imaging 10-15 years after delivery in women with a history of preeclampsia showed a decreased thickness in the outer region of the retina. Selective vulnerability of peripheral retinal regions to persistent microvascular changes after preeclampsia may reflect broader central nervous system changes associated with impairments in information processing speed, executive functioning and working memory.
Macular Pigment Carotenoid Supplementation for the Preservation of Visual Structure and Function Following a Collegiate Rugby Season.
Kelly J, Papa L, Stringham JM … +2 more , Griffith O, Slobounov S
Eye Brain · 2025 · PMID 41466853 · Full text
INTRODUCTION: Repetitive head impacts (RHIs) and visual system dysfunction are often associated. Interventions to prevent or limit visual deficits following RHIs are not well understood. This study examined visual struct...
INTRODUCTION: Repetitive head impacts (RHIs) and visual system dysfunction are often associated. Interventions to prevent or limit visual deficits following RHIs are not well understood. This study examined visual structure and function following exposure to RHIs and the effectiveness of a supplemental intervention of macular pigment carotenoids (MPCs) and omega-3 fatty acids in attenuating visual changes from pre- to post-season in collegiate rugby players. Additionally, blood biomarkers associated with neurodegeneration were examined. METHODS: Optical coherence tomography measured visual structure through ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) thickness. Bioavailability of the supplement was assessed through skin carotenoid concentration (SC). Contrast sensitivity (CS) and critical flicker-fusion frequency (CFF) were used to measure visual function. NF-L, GFAP, Tau, and UCH-L1 concentrations in blood samples were analyzed. RESULTS: Thirty-one rugby players (15M/16F; 19±1.4 years) were randomly assigned to supplement (n = 15) or placebo (n = 16) groups. Left eye GCC inferior region was thinner at post-season in supplement (102.1±4.4 vs 102.9±4.7 μm; = 0.002) and placebo groups (101.4±5.3 vs 102.6±5.0 μm, < 0.001). The supplement group had a higher SC score at post-season versus the placebo group (409.2±76.3 vs 323.4±61.3; = 0.04). With regards to visual function, CFF approached a significant increase in the supplemental group versus placebo (27.6±1.8 vs 25.7±2.2 Hz, = 0.08), but there were no differences found between groups in MPOD or CS. NF-L was different at post-season in the placebo (10.05 vs 7.21 pg/mL; = 0.003) but not the supplement group (7.07 vs 7.78 pg/mL; = 0.40). Tau was different between groups at pre- (1.2 vs 0.87 pg/mL; = 0.04) and post-season (1.33 vs 1.01 pg/mL; = 0.02) with greater concentrations in the supplement group. GFAP and UCH-L1 were not different. One season of collegiate rugby resulted in retinal thinning and increased concentrations of NF-L and Tau. Supplementation with MPCs and omega-3s may be useful in limiting retinal thinning and preventing increases in biomarkers of neurodegeneration.
A Narrative Review of the Association Between Cataracts and Dementia.
Yu HN, Ying GS
Eye Brain · 2025 · PMID 41399395 · Full text
Dementia and cataract are two of the most prevalent conditions in older adults, together representing a substantial global health burden. Increasing evidence suggests a potential link between cataract and dementia, and t...
Dementia and cataract are two of the most prevalent conditions in older adults, together representing a substantial global health burden. Increasing evidence suggests a potential link between cataract and dementia, and this narrative review synthesizes current epidemiological and mechanistic evidence on their association. Recent cohort and case-control studies report a modestly increased risk of dementia in individuals with cataracts, though inconsistencies persist across populations. Mechanistic insights highlight roles for visual impairment and protein aggregation in this association. Importantly, cataract surgery shows a robust, protective effect against incident dementia, potentially via restoration of sensory input and enhanced cognitive engagement. Future studies may examine longitudinal, multi-ethnic cohorts that integrate genetic, imaging, and molecular data to investigate causality and the underlying biological mechanisms. In summary, our narrative review shows that cataract and dementia may be linked through multifactorial pathways, and maintaining visual health, particularly through timely cataract surgery, represents a potentially modifiable factor in dementia prevention strategies.
Intraocular Pressure and Retinal Nerve Fiber Layer Changes in a Microgravity Mouse Model and Relevance to Spaceflight-Associated Neuro-Ocular Syndrome.
Zarrinbakhsh A, Gupta N, Sinha J … +7 more , Zhou X, Chen S, Khan HM, Navajas EV, Beg MF, Liang Y, Yucel Y
Eye Brain · 2025 · PMID 41221163 · Full text
PURPOSE: Microgravity-induced headward fluid shifts are one of the mechanisms implicated in spaceflight-associated eye conditions, including intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) thickness chang...
PURPOSE: Microgravity-induced headward fluid shifts are one of the mechanisms implicated in spaceflight-associated eye conditions, including intraocular pressure (IOP) and retinal nerve fiber layer (RNFL) thickness changes. In this longitudinal study, we investigated IOP and RNFL thickness changes over time in a mouse model of microgravity-induced headward fluid shifts. METHODS: The study involved 20 adult male B6(Cg)- /J mice, randomly assigned to two groups: the hindlimb unloading (HU) mice, unloaded for 21 days followed by 14 days of release, and control mice kept under the same conditions except HU for 35 days. IOP and RNFL thickness in peripapillary and peripheral rings of right and left eyes were measured before and once a week after HU. Our analysis utilized mixed linear models to compare the estimated marginal means of IOP and RNFL thickness on each day with baseline values for each eye. Post hoc splined mixed linear models with a knot at day 14 were employed to assess the rate of IOP change in each segment. RESULTS: IOP was significantly elevated in both eyes of the HU mice on day 14 compared to baseline. The splined analysis revealed a bilateral positive rate of IOP change up to day 14, followed by a negative rate of change thereafter. In contrast, control mice displayed no significant differences in IOP at any timepoint. RNFL thicknesses of right eye peripapillary and peripheral rings were reduced after 1 week and 2 weeks, respectively. In contrast, left eye RNFL thickness measurements did not show any significant change compared to baseline. CONCLUSION: The HU mouse model displays a distinct ocular phenotype that may be useful for understanding IOP and RNFL changes in microgravity and their relevance to Spaceflight-Associated Neuro-ocular Syndrome.
Acetazolamide for Idiopathic Intracranial Hypertension: An Up-to-Date Review in 2025.
Naqvi J, Wall M, Chung SM … +4 more , Thurtell M, Linton E, Rodriguez-Barrath A, Kardon R
Eye Brain · 2025 · PMID 41054617 · Full text
Idiopathic Intracranial Hypertension (IIH) is characterized by elevated intracranial pressure in the absence of secondary causes. The treatment of IIH entails a combination of lifestyle modifications, medical therapy, an...
Idiopathic Intracranial Hypertension (IIH) is characterized by elevated intracranial pressure in the absence of secondary causes. The treatment of IIH entails a combination of lifestyle modifications, medical therapy, and surgical intervention. This article aims to evaluate the role of acetazolamide in the treatment of IIH and identify its mechanism of action, efficacy, and side effect profile. This article also aims to discuss acetazolamide's role in conjunction with other treatment modalities.
Müller-Lyer Illusion in Adults Increases with Age but Is Not Affected by Mild Visual Acuity Loss.
Chen B, Lin N, Tian L … +5 more , Mao J, Yang M, Sun X, Lu F, Deng R
Eye Brain · 2025 · PMID 40922733 · Full text
PURPOSE: To investigate the impact of mild visual acuity loss on the Müller-Lyer illusion in adults and evaluate its potential as a clinical indicator for visual-cognitive integration mechanisms. METHODS: Three experimen...
PURPOSE: To investigate the impact of mild visual acuity loss on the Müller-Lyer illusion in adults and evaluate its potential as a clinical indicator for visual-cognitive integration mechanisms. METHODS: Three experiments were conducted. Experiment 1 measured illusion intensity in 49 young adults (25.08 ± 3.38 years) before and after inducing transient visual acuity loss (0.40 logMAR) via Bangerter occlusion foils. Experiment 2 compared 26 cataract patients (65.19 ± 3.87 years) with 59 age-matched controls (63.98 ± 5.57 years). Experiment 3 tracked 14 cataract patients (69.50 ± 6.14 years) pre- and post-surgery. Illusion intensity was quantified using a two-alternative forced-choice task. RESULTS: Illusion intensity remained stable across conditions: no differences were observed before /after wearing occlusion glasses (4.33% vs 3.75%, = 0.141), between cataract patients and controls (8.79% vs 8.20%, = 0.301), or pre-/post-surgery (9.46% vs 9.87%, = 0.357). However, normally-sighted elderly participants exhibited stronger illusions than young adults (8.20% vs 4.33%, < 0.001). Multivariate regression confirmed age as the sole predictor of illusion intensity ( = 0.088, = 0.001), independent of visual acuity. CONCLUSION: The intensity of Müller-Lyer illusion in adults is modulated by age but resistant to mild visual acuity loss, implicating its utility in studying visual-cognitive integration.
Visual Prostheses in the Era of Artificial Intelligence Technology.
Sarbout I, Gungor A, Ounissi M … +5 more , Zaher S, Ptito M, Kupers R, Racoceanu D, Milea D
Eye Brain · 2025 · PMID 40909105 · Full text
BACKGROUND: Over the past few decades, technological advancements have transformed invasive visual prostheses from theoretical concepts into real-world applications. However, functional outcomes remain limited, especiall...
BACKGROUND: Over the past few decades, technological advancements have transformed invasive visual prostheses from theoretical concepts into real-world applications. However, functional outcomes remain limited, especially in visual acuity. This review aims to summarize current developments in retinal and cortical prostheses (RCPs) and critically assess the role of artificial intelligence (AI) in advancing these systems. PURPOSE: To describe current RCPs and provide a systematic review on image and signal processing algorithms designed for improved clinical outcomes. PATIENTS AND METHODS: We performed a systematic review of the literature related to AI subserving prosthetic vision, using mainly PubMed, but also, Elicit, a dedicated AI-based reference research assistant. A total of 455 studies were screened on PubMed, of which 23 were retained for inclusion. An additional 5 studies were identified and included through Elicit. RESULTS: The analysis of current RCPs highlights various limitations affecting the quality of the visual flow provided by current artificial vision. Indeed, the 28 reviewed studies on AI covered two applications for RCPs including extraction of saliency in camera captured images, and consistency between electrical stimulation and perceived phosphenes. A total of 14 out of 28 studies involved the use of artificial neural networks, of which 12 included model training. Evaluation with data from a visual prosthesis was conducted in 7 studies, including 1 that was prospectively assessed with a human RCP. Validation with empirical data from human or animal data was performed in 22 out of 28 studies. Out of these, 15 were validated using simulated prosthetic vision. Finally, out of 22 studies leveraging a mathematical model for phosphenes perception, 14 used a symmetrical oversimplified modeling. CONCLUSION: AI algorithms show promise in optimizing prosthetic vision, particularly through enhanced image saliency extraction and stimulation strategies. However, most current studies are based on simulations. Further development and validation in real-world settings, especially through clinical testing with blind patients, are essential to assess their true effectiveness.
Retinal Vessel Oxygen Saturation in Patients with Unilateral Edema of the Optic Nerve Head: A Pilot Study.
Březík M, Matušková V, Vysloužilová D … +5 more , Šín M, Chovancová V, Sičová K, Jankaničová N, Chrapek O
Eye Brain · 2025 · PMID 40657237 · Full text
PURPOSE: Evaluate whether optic disc edema results in changes in retinal microcirculation. PATIENTS AND METHODS: The study group consisted of 11 patients with unilateral optic disc edema (papilledema). The control group...
PURPOSE: Evaluate whether optic disc edema results in changes in retinal microcirculation. PATIENTS AND METHODS: The study group consisted of 11 patients with unilateral optic disc edema (papilledema). The control group consisted of the healthy eyes of the same 11 patients. Patients underwent non-invasive photo-spectrometric retinal oximetry using Oxymap T1 retinal oximeter (Oxymap, Reykjavik, Iceland). In the eyes of these 11 patients, we examined the diameter of the retinal arteries and veins, arterial and venous blood oxygen saturation, and the difference in oxygen saturation between arterioles and venules (A-V difference). RESULTS: In the papilledema group, the decrease in the retinal arterial diameter was statistically significant (p=0.001). The median diameter of the retinal artery was 11.70 px (IQR 1.47) or after conversion 109.00 µm (IQR 14.00) in the papilledema group and 13.75 px (IQR 1.61) or 128.00 µm (IQR 15.00) in the control group. The increase in the diameter of the retinal veins in the papilledema group was statistically significant (p=0.012), where the median diameter in the papilledema group was 20.88 px (IQR 3.72) or 194.00 µm (IQR 35.00), and in the control group was 18.18 px (IQR 3.60) or 169 µm (IQR 33.00). There was a statistically significant decrease (p<0.001) in the venous saturation in the papilledema group with a median value of 53.16% (IQR 17.38) and 60.02% (IQR 11.98) in the control group. The median of the A-V difference was 51.92 (IQR 15.96) in the papilledema group, resp. 38.49 (IQR 9.75) in the control group and a significant increase in the papilledema group (p<0.001) was reported. CONCLUSION: Automatic retinal oximetry demonstrated changes in the retinal microcirculation in patients with optic disc edema.
A Novel Retinal Nerve Fiber Layer Biomarker of Amyotrophic Lateral Sclerosis (ALS) Identified Using Longitudinal in vivo Ocular Imaging.
Khorrami F, Gupta N, Zhou X … +2 more , Liang Y, Yucel YH
Eye Brain · 2025 · PMID 40625857 · Full text
PURPOSE: Like motor neurons, retinal ganglion cells (RGCs) have long axons and high metabolic demands, making them vulnerable to disruption of axonal transport. Unlike motor neurons, the RGC axons are accessible to high-...
PURPOSE: Like motor neurons, retinal ganglion cells (RGCs) have long axons and high metabolic demands, making them vulnerable to disruption of axonal transport. Unlike motor neurons, the RGC axons are accessible to high-resolution non-invasive optical imaging in their intraocular portion. A non-invasive in vivo retinal imaging biomarker can be valuable for amyotrophic lateral sclerosis (ALS) diagnosis and monitoring. We aim to assess the presence of inner retinal pathology in a mouse model of ALS and its possible progression with age. METHODS: Transgenic SOD1G93A mice (n=8, 4M/4F) and age-matched controls (n=8, 4M/4F) underwent in vivo retinal imaging with confocal scanning laser ophthalmoscopy (cSLO) coupled with optical coherence tomography (OCT) at 20 weeks of age. Another group of SOD1G93A mice (n=20, 6M/14F) and age-matched controls (n=20, 6M/14F) underwent longitudinal in vivo retinal imaging with the same device. Each retinal imaging session included infrared reflectance (IR) and blue reflectance (BR) cSLO coupled with OCT. Hyperreflective puncta located in the retinal nerve fiber layer (RNFL) were counted in a blinded fashion in ALS and control mice. The number of puncta at 20 weeks of age in ALS mice was compared with controls using Wilcoxon test. The rates of increase of puncta number were analyzed using a Generalized Linear Mixed-Effect Model (GLMM) for genotype, time, and sex. RESULTS: IR-cSLO coupled with OCT revealed hyperreflective puncta located in the RNFL of ALS mice. IR-cSLO fundus imaging at the age of 20 weeks showed ALS mice had significantly higher number of puncta compared to controls (2.1±2.3 vs 0.5±0.8; (mean±SD), respectively, p=0.036). GLMM analysis showed both ALS mutation and age were significantly associated with the rate of increase of puncta number (p=0.000232 and p=0.000366, respectively). In addition, female ALS mice had a steeper increase of puncta compared to male ALS mice (0.21±0.04 log number puncta/week vs 0.16±0.04, respectively; p=0.037). CONCLUSION: Our findings demonstrate distinct inner retinal nerve fiber layer pathology, detected using cSLO coupled with OCT, which worsens over time. These findings support the potential of retinal imaging as a translationally relevant, non-invasive biomarker for ALS diagnosis or disease monitoring in humans.
Recent Advances in Visual Dysfunction and Ocular Biomarkers in Neurological Disorders.
Cheng J, Paracha SS, Agrawal S … +2 more , Wu Z, Sung CH
Eye Brain · 2025 · PMID 40534708 · Full text
The visual system is an integral part of the central nervous system, and visual symptoms often serve as an early manifestation of underlying neurological pathologies. This review synthesizes recent findings on visual dys...
The visual system is an integral part of the central nervous system, and visual symptoms often serve as an early manifestation of underlying neurological pathologies. This review synthesizes recent findings on visual dysfunction in various neurodevelopmental and neurodegenerative diseases. These reports emphasize that ophthalmological symptoms are increasingly recognized as part of a broader spectrum of neurological conditions, enhancing their clinical relevance for differential diagnosis and symptom management. Non-invasive, high-resolution ocular imaging techniques can identify retinal pathologies at the subcellular level. Additionally, the non-invasive visual functional assay, electroretinography, can further corroborate findings of retinal pathology. Distinct retinal changes are detectable in the early stages of progressive neurodegenerative diseases, such as Parkinson's disease, and are strongly correlated with cognitive decline in conditions like Huntington's disease, Alzheimer's disease, and Joubert syndrome. These findings highlight the clinical potential of retinal imaging for risk assessment, diagnosis, and monitoring the progression of diseases with insidious onset. Furthermore, this review emphasizes the retina's accessibility as a key component in investigating the underlying pathophysiology of neurological conditions. Additional clinical and basic science research is needed to better understand the distinct and potentially interconnected contributions of the brain and retina to specific visual symptoms. Investigating suitable preclinical mouse models will be vital for developing and refining novel ocular diagnostic markers, which are important for symptom management and the advancement of therapeutic strategies.
Ocular Dominance Plasticity: A Mini-Review.
Min SH
Eye Brain · 2025 · PMID 40519698 · Full text
Ocular dominance plasticity, the ability of the brain to change sensory eye balance, has traditionally been believed to be extremely limited in adult visual cortex. However, recent studies on short-term monocular depriva...
Ocular dominance plasticity, the ability of the brain to change sensory eye balance, has traditionally been believed to be extremely limited in adult visual cortex. However, recent studies on short-term monocular deprivation (MD) demonstrate that its presence is prevalent in adult humans, as short-term MD is capable of significantly shifting ocular dominance in favor of the previously deprived eye. Thus, findings over the last 15 years highlight that short-term MD can be a promising alternative treatment for amblyopia, a neurodevelopmental disorder characterized by binocular imbalance. Conventionally, amblyopia has been treated with patching therapy, which shows limited effectiveness in restoring binocularity of adults and is associated with poor compliance rate and high psychosocial distress. Thus, it is an opportune time to explore how short-term MD can be utilized as an alternative treatment option for restoring amblyopic vision, especially individuals who do not respond robustly to standard treatment. This review provides an overview of foundational studies on ocular dominance plasticity in both visually intact and impaired observers. It also evaluates the potential of short-term MD as a treatment for amblyopia and suggests its future research directions, including the integration of multimodal therapeutic strategies that include short-term MD.
Optimal Diagnostic Strategies for Concussion-Related Vision Disorders: A Review.
Adhan IK, Gunton KB
Eye Brain · 2025 · PMID 40386378 · Full text
Concussions are a mild form of traumatic brain injury (TBI) that is typically self-limited and transient with a high prevalence within our communities. Due to the vast visual network interconnectivity, visual symptoms se...
Concussions are a mild form of traumatic brain injury (TBI) that is typically self-limited and transient with a high prevalence within our communities. Due to the vast visual network interconnectivity, visual symptoms secondary to a concussion occur about 90% of the time. A gold standard to confirm concussion acutely has not been well established. Visual function testing based on symptoms remains the standard of care in off-site evaluation for diagnosis of oculomotor dysfunction. This review covers the current diagnostic strategies for vision based disorders post-concussion for sideline testing, off-site testing, and research driven testing.
Structural-Functional Correlation in Non-Arteritic Acute Ischemic Optic Neuropathy.
Wei J, Zhang L, Wang H … +5 more , Wang Q, Jia W, Wang R, Wang R, Cui Z
Eye Brain · 2025 · PMID 40336777 · Full text
PURPOSE: This study investigated the relationships between structural and functional parameters in non-arteritic ischemic optic neuropathy (NAION). METHODS: This retrospective study enrolled 29 patients (58.2 ± 10.4 year...
PURPOSE: This study investigated the relationships between structural and functional parameters in non-arteritic ischemic optic neuropathy (NAION). METHODS: This retrospective study enrolled 29 patients (58.2 ± 10.4 years old) with unilateral NAION. During the acute phase, we performed comprehensive evaluations including best-corrected visual acuity (BCVA), optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), visual fields (VF), visual evoked potentials (VEP), electroretinography (ERG), and multifocal ERG (mf-ERG). At three months post-presentation, patients underwent follow-up assessments comprising visual acuity testing, perimetry, and advanced retinal imaging. RESULTS: During the acute phase, affected eyes demonstrated increased mean retinal nerve fiber layer (RNFL) thickness, while ganglion cell-inner plexiform layer (GCIPL) thickness decreased. Both visual fields mean deviation (MD) and VEP P100 amplitude were reduced, accompanied by prolonged peak latency. We also observed decreased P1 response density in mf-ERG. Analysis revealed significant direct correlations between GCIPL parameters and electrophysiological measurements, particularly VEP P100 amplitude and mf-ERG P1 response density. Mean GCIPL thickness, VF MD, and VEP P100 amplitude showed negative correlations with baseline logMAR VA. Baseline VF MD, VEP P100 amplitude, and minimum GCIPL thickness showed negative correlations with logMAR VA at 3-month follow-up. CONCLUSION: Retinal ganglion cell layer thickness serves as a valuable indicator to objective evaluate optic nerve function in acute NAION patients. Decreases in both VEP amplitude and mf-ERG response density showed significant correlations with retinal ganglion cell layer thickness. Baseline visual field performance, VEP measurements, and minimum GCIPL thickness exhibited negative correlations visual acuity at 3-month follow-up. TRIAL REGISTRATION: Clinical Research Ethics Committee of Xi'an People's Hospital (NO. 20220018). Registered 27 September 2022-Retrospectively registered, https://www.medicalresearch.org.cn/. Informed consent was obtained from each participant.
Diagnostic and Management Strategies of Visual Snow Syndrome: Current Perspectives.
Ayesha A, Riehle C, Leishangthem L
Eye Brain · 2025 · PMID 40129600 · Full text
INTRODUCTION: Visual Snow Syndrome (VSS) is characterized by the presence of dynamic, continuous, tiny dots in the entire visual field persisting for more than three months, with at least two associated symptoms- palinop...
INTRODUCTION: Visual Snow Syndrome (VSS) is characterized by the presence of dynamic, continuous, tiny dots in the entire visual field persisting for more than three months, with at least two associated symptoms- palinopsia, photopsia, photophobia, or nyctalopia. VSS was introduced as perpetual visual disturbance representing TV static, based on early case reports from 1995. Despite its recognition, VSS management remains vague as many cases are refractory to treatment. This literature review aims to provide a summary of all attempted treatments and efficacies to help physicians manage VSS. METHODS: The authors performed a search of articles, literature reviews, and case reports using PubMed and Google Scholar with the key words "visual snow" and "treatment". Forty-one publications were identified; however, 14 were excluded as they did not discuss treatment options or focused on medical conditions associated with visual snow, such as migraine with aura. 27 articles were found to be relevant (from 1999-2024) with treatments in patients officially diagnosed with VSS. Treatments included pharmacotherapy, tinted lenses, neuromodulation, and behavioral therapy. RESULTS: Based on this review of 27 publications, benzodiazepines and lamotrigine had the best effect (71.4% and 61.5% of patients had an improvement of VS symptoms on each medication, respectively). Antidepressants and AV nodal blocking agents were frequently prescribed but were less effective. VS symptoms improved with filtered lenses combined with cognitive behavioral therapy. Most treatments only partially alleviate VSS or manage associated symptoms like headache and palinopsia, rather than the visual snow itself. CONCLUSION: The subjective nature of VSS has posed challenges. Among pharmacological treatments, benzodiazepines and lamotrigine have the most favorable therapeutic ratio in managing VSS. FL-41 tinted lenses consistently provide symptom relief, with cognitive behavioral therapy showing promise as an emerging intervention. Due to the small sample size, further research is recommended to enhance the applicability of findings.
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