Stress, Allostatic Load, and Neuroinflammation: Implications for Racial and Socioeconomic Health Disparities in Glaucoma.

Glaucoma is the leading cause of irreversible blindness, and its pathophysiology includes neuroinflammatory changes. The present therapies for glaucoma target pressure-lowering mechanisms with limited success, making neuroinflammation a target for future interventions. This review summarizes the neuroinflammatory pathways seen in glaucoma and their interplay with stress. Glucocorticoids have been shown to activate proinflammatory glial cells, contributing to the neuroinflammation in glaucoma. Glucocorticoids have also been shown to increase the IOP directly. Stress-associated autonomic dysfunction can affect the vascular homeostasis in the retina and create oxidative stress. Diabetes, hyperglycemic-mediated endothelial damage, and vascular inflammation also play important roles in the neuroinflammation in glaucoma and diabetic retinopathy. Psychosocial stress has been implicated in an increased IOP and glaucoma outcomes. People who experience maladaptive chronic stress suffer from a condition known as allostatic load, which describes pathologic neuroendocrine dysregulation. The effects of allostatic load and chronic stress have been studied in patients affected by a lower socioeconomic status (SES) and marginalized racial identities. A lower SES is associated with higher rates of glaucoma and also affects the access to care and screening. Additionally, people of African ancestry are disproportionately affected by glaucoma for reasons that are multifactorial. In conclusion, this review explores neuroinflammation in glaucoma, highlighting opportunities for future investigation.

Learning from Black/African American Participants: Applying the Integrated Behavioral Model to Assess Recruitment Strategies for a Glaucoma Genetic Study.

The underrepresentation of African American (AA) participants in medical research perpetuates racial health disparities in the United States. Open-ended phone interviews were conducted with 50 AA adults from Philadelphia who had previously participated in a genetic study of glaucoma that included complimentary ophthalmic screenings. Recruitment for the genetic study was done in partnership with a Black-owned radio station. Thematic analysis of interview transcripts, guided by the integrated behavior model (IBM), identified self-reported motivations for participating in this care-focused and community-promoted research program. Findings revealed that decisions to enroll were influenced by strong instrumental attitudes regarding learning more about personal health and contributing to future care options for others. Notable normative influences that factored into participants' decisions to enroll in the study included hearing about the study from a respected community media outlet, friends, and family. About one-third of respondents discussed past and current racial discrimination in medical research as an important sociocultural frame within which they thought about participation, suggesting that experiential attitudes play a continuing role in AA's decisions to enroll in medical research studies. Medical researchers seeking to recruit AA participants should collaborate with community partners, combine enrollment opportunities with access to health services, and emphasize the potential for new research to mitigate racial inequalities.

The Bidirectional Relationship between Vision and Cognition: A Systematic Review and Meta-analysis.

TOPIC: Visual impairment (VI) and cognitive impairment (CIM) are prevalent age-related conditions that impose substantial burden on the society. Findings on the hypothesized bidirectional association of VI and CIM remains equivocal. Hence, we conducted a systematic review and meta-analysis to examine this bidirectional relationship. CLINICAL RELEVANCE: Sixty percent risk of CIM has not been well elucidated in the literature. A bidirectional relationship between VI and CIM may support the development of strategies for early detection and management of risk factors for both conditions in older people. METHODS: PubMed, Embase, and Cochrane Central registers were searched systematically for observational studies, published from inception until April 6, 2020, in adults 40 years of age or older reporting objectively measured VI and CIM assessment using clinically validated cognitive screening tests or diagnostic evaluation. Meta-analyses on cross-sectional and longitudinal associations between VI and CIM outcomes (any CIM assessed using screening tests and clinically diagnosed dementia) were examined. Random effect models were used to generate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We also examined study quality, publication bias, and heterogeneity. RESULTS: Forty studies were included (n = 47 913 570). Meta-analyses confirmed that persons with VI were more likely to have CIM, with significantly higher odds of: (1) any CIM (cross-sectional: OR, 2.38 [95% CI, 1.84-3.07]; longitudinal: OR, 1.66 [95% CI, 1.46-1.89]) and (2) clinically diagnosed dementia (cross-sectional: OR, 2.43 [95% CI, 1.48-4.01]; longitudinal: OR, 2.09 [95% CI, 1.37-3.21]) compared with persons without VI. Significant heterogeneity was explained partially by differences in age, sex, and follow-up duration. Also, some evidence suggested that individuals with CIM, relative to cognitively intact persons, were more likely to have VI, with most articles (8/9 [89%]) reporting significantly positive associations; however, meta-analyses on this association could not be conducted because of insufficient data. DISCUSSION: Overall, our work suggests that VI is a risk factor of CIM, although further work is needed to confirm the association of CIM as a risk factor for VI. Strategies for early detection and management of both conditions in older people may minimize individual clinical and public health consequences.

The association of mitochondrial DNA haplogroups with POAG in African Americans.

Mitochondrial dysfunction has been implicated in the pathogenesis of primary open-angle glaucoma (POAG). However, the potential significance of mitochondrial DNA (mtDNA) haplogroups to POAG has not been evaluated in the overaffected African American population. To investigate the association of mtDNA haplogroups with POAG and its phenotypic characteristics, genotyping data from 4081 African American subjects (1919 cases and 2162 controls) was analyzed using 1293 positions on mtDNA. The overall frequency of mtDNA haplogroups in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study cohort was 37% L3, 29% L2, 21% L1, 4% L0, and 10% non-African haplogroups (non-L). When all haplogroups (L0, L1, L2, and non-L) were compared against theL3 reference group, after adjusting by age and principal component of ancestry, the non-L3 haplogroups showed higher risk of POAG (OR-1.19, p = 0.02), with a particularly strong association among males (OR = 1.41, p = 0.003). More specifically the non-L group was associated with higher POAG risk than the L3 haplogroup (OR = 1.77, p = 0.007, Bonferroni adjusted p = 0.027) and to the L3e (n = 256, OR = 1.92, p = 0.007, Bonferroni adjusted p = 0.029). No significant association was found when genders were analyzed together or in female only analysis. There were no significant differences in various POAG endophenotypes across mtDNA haplogroups. This study expands our knowledge of mitochondrial genetics and mtDNA haplogroup associations in African American POAG. Further work is needed to better understand the functional role of mtDNA polymorphisms and their interactions with nuclear genes that affect POAG.

Association of primary open-angle glaucoma with mitochondrial variants and haplogroups common in African Americans.

PURPOSE: To estimate the population frequencies of all common mitochondrial variants and ancestral haplogroups among 1,999 subjects recruited for the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study, including 1,217 primary open-angle glaucoma (POAG) cases and 782 controls, and to identify ancestral subpopulations and mitochondrial mutations as potential risk factors for POAG susceptibility. METHODS: Subject classification by characteristic glaucomatous optic nerve findings and corresponding visual field defects, as defined by enrolling glaucoma specialists, stereo disc photography, phlebotomy, extraction of total DNA from peripheral blood or saliva, DNA quantification and normalization, PCR amplification of whole mitochondrial genomes, Ion Torrent deep semiconductor DNA sequencing on DNA pools ("Pool-seq"), Sanger sequencing of 3,479 individual mitochondrial DNAs, and bioinformatic analysis. RESULTS: The distribution of common African haplogroups within the POAAGG study population was broadly similar to prior surveys of African Americans. However, the POAG case population was found to be enriched in L1c2 haplogroups, which are defined in part by missense mutations m.6150G>A (Val83Ile, odds ratio [OR] 1.8, p=0.01), m.6253C>T (Met117Thr, rs200165736, OR 1.6, p=0.04), and m.6480G>A (Val193Ile, rs199476128, OR 4.6, p=0.04) in the cytochrome c oxidase subunit 1 (MT-CO1) gene and by a variant, m.2220A>G (OR 2.0, p=0.01), in MT-RNR2, which encodes the mitochondrial ribosomal 16s RNA gene. L2 haplogroups were predicted to be overrepresented in the POAG case population by Pool-seq, and the difference was confirmed to be significant with Sanger sequencing, that targeted the L2-associated variants m.2416T>C (rs28358580, OR 1.2, p=0.02) and m.2332C>T (OR 1.2, p=.02) in MT-RNR2. Another variant within MT-RNR2, m.3010G>A (rs3928306), previously implicated in sensitivity to the optic neuropathy-associated antibiotic linezolid, and arising on D4 and J1 lineages, associated with Leber hereditary optic neuropathy (LHON) severity, was confirmed to be common (>5%) but was not significantly enriched in the POAG cases. Two variants linked to the composition of the gut microbiome, m.15784T>C (rs527236194, haplogroup L2a1) and m.16390G>A (rs41378955, L2 haplogroups), were also enriched in the case DNA pools. CONCLUSIONS: These results implicate African mtDNA haplogroups L1c2, L1c2b, and L2 as risk factors for POAG. Approximately one in four African Americans have these mitochondrial ancestries, which may contribute to their elevated glaucoma risk. These haplogroups are defined in part by ancestral variants in the MT-RNR2 and/or MT-CO1 genes, several of which have prior disease associations, such as MT-CO1 missense variants that have been implicated in prostate cancer.

The primary open-angle african american glaucoma genetics study: baseline demographics.

PURPOSE: To describe the baseline characteristics of the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study cohort, the largest African American population with primary open-angle glaucoma (POAG) recruited at a single institution (University of Pennsylvania [UPenn], Department of Ophthalmology, Scheie Eye Institute) to date. DESIGN: Population-based, cross-sectional, case-control study. PARTICIPANTS: A total of 2520 African American subjects aged 35 years or more who were recruited from the greater Philadelphia, Pennsylvania area. METHODS: Each subject underwent a detailed interview and eye examination. The interview assessed demographic, behavioral, medical, and ocular risk factors. Current ZIP codes surrounding UPenn were recorded and US census data were queried to infer socioeconomic status. The eye examination included measurement of visual acuity (VA) and intraocular pressure, and a detailed anterior and posterior segment examination, including gonioscopy, dilated fundus and optic disc examination, visual fields, stereo disc photography, optical coherence tomography, and measurement of central corneal thickness. MAIN OUTCOME MEASURES: The baseline characteristics of gender, age, and glaucoma diagnosis were collected. Body mass index (BMI), hypertension, diabetes, alcohol and tobacco use, ocular conditions (including blindness, cataract, nonproliferative diabetic retinopathy, and age-related macular degeneration), and use of ocular medication and surgery were examined. Median population density, income, education level, and other socioeconomic measures were determined for the study cohort. RESULTS: Of the 2520 African Americans recruited to the POAAGG study to date, 2067 (82.0%), including 807 controls and 1260 POAG cases, met all inclusion criteria and completed the detailed clinical ocular examination. Cases were more likely to have a lower BMI (P < 0.01) and report a history of blindness (VA of ≤20/200; P < 0.001), whereas controls were more likely to have diabetes (P < 0.001), have nonproliferative diabetic retinopathy (P = 0.02), and be female (P < 0.001). Study participants were drawn largely from predominantly African American neighborhoods of low income, high unemployment, and lower education surrounding UPenn. CONCLUSIONS: The POAAGG study has currently recruited more than 2000 African Americans eligible for a POAG genetics study. Blindness and low BMI were significantly associated with POAG. This population was predominantly recruited from neighborhoods whose population income exists at or near the federal poverty level.

Frequent somatic mutations of GNAQ in uveal melanoma and blue naevi.

BRAF and NRAS are common targets for somatic mutations in benign and malignant neoplasms that arise from melanocytes situated in epithelial structures, and lead to constitutive activation of the mitogen-activated protein (MAP) kinase pathway. However, BRAF and NRAS mutations are absent in a number of other melanocytic neoplasms in which the equivalent oncogenic events are currently unknown. Here we report frequent somatic mutations in the heterotrimeric G protein alpha-subunit, GNAQ, in blue naevi (83%) and ocular melanoma of the uvea (46%). The mutations occur exclusively in codon 209 in the Ras-like domain and result in constitutive activation, turning GNAQ into a dominant acting oncogene. Our results demonstrate an alternative route to MAP kinase activation in melanocytic neoplasia, providing new opportunities for therapeutic intervention.

Advancing Glaucoma Care: Integrating Artificial Intelligence in Diagnosis, Management, and Progression Detection.

Glaucoma, the leading cause of irreversible blindness worldwide, comprises a group of progressive optic neuropathies requiring early detection and lifelong treatment to preserve vision. Artificial intelligence (AI) technologies are now demonstrating transformative potential across the spectrum of clinical glaucoma care. This review summarizes current capabilities, future outlooks, and practical translation considerations. For enhanced screening, algorithms analyzing retinal photographs and machine learning models synthesizing risk factors can identify high-risk patients needing diagnostic workup and close follow-up. To augment definitive diagnosis, deep learning techniques detect characteristic glaucomatous patterns by interpreting results from optical coherence tomography, visual field testing, fundus photography, and other ocular imaging. AI-powered platforms also enable continuous monitoring, with algorithms that analyze longitudinal data alerting physicians about rapid disease progression. By integrating predictive analytics with patient-specific parameters, AI can also guide precision medicine for individualized glaucoma treatment selections. Advances in robotic surgery and computer-based guidance demonstrate AI's potential to improve surgical outcomes and surgical training. Beyond the clinic, AI chatbots and reminder systems could provide patient education and counseling to promote medication adherence. However, thoughtful approaches to clinical integration, usability, diversity, and ethical implications remain critical to successfully implementing these emerging technologies. This review highlights AI's vast capabilities to transform glaucoma care while summarizing key achievements, future prospects, and practical considerations to progress from bench to bedside.

Primary Open-Angle Glaucoma Is Associated with Short-Term Memory Decline and Dementia in Individuals of African Ancestry.

Background: Over the last decade, studies have suggested that primary open-angle glaucoma (POAG) may be associated with cognitive impairment and dementia, as both pathologies are age-related neurodegenerative processes. It remains unclear to what extent neurodegeneration in POAG extends to other neurological functions beyond vision, such as cognition. This follow-up study examined the potential association between POAG and cognitive decline in an African ancestry population. Methods: The Telephone-Montreal Cognitive Assessment (T-MoCA) was administered to POAG cases and controls previously enrolled in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. Cases were assessed for retinal nerve fiber layer (RNFL) thickness and for the presence of dementia via chart review. Comparisons between POAG cases and controls were performed using two-sample t-tests for the T-MoCA total score and five subsection scores, and using chi-squared tests for incidence of dementia. Current scores were compared to scores from this same cohort from 7 years prior. Results: The T-MoCA was administered to 13 cases and 20 controls. The mean ± standard deviation (SD) T-MoCA total score was 15.5 ± 4.0 in cases and 16.7 ± 3.5 in controls (p = 0.36). However, there was a borderline significant difference in the delayed recall sub-score (2.3 ± 1.6 for cases vs. 3.4 ± 1.5 for controls, p = 0.052) and a significant difference in its sub-domain, the memory index score (MIS, 9.1 ± 4.3 for cases vs. 12.1 ± 3.0 for controls, p = 0.02). There were no significant differences between cases and controls for the remaining subsections. During 7 years of follow-up, a higher incidence of dementia was noted in POAG cases (7.1% for cases vs. 0% for controls, p = 0.058). Over 7 years, there was no significant deterioration in the cognitive performance of cases versus controls, and no association was seen between RNFL thinning and cognitive impairment. Conclusions: In this small-sample follow-up study of African ancestry individuals, POAG cases demonstrated worse short-term memory and higher incidence of dementia compared to controls. Future larger studies are needed to further investigate the presence and impact of neurodegeneration in POAG.

Features Associated with Visible Lamina Cribrosa Pores in Individuals of African Ancestry with Glaucoma: Primary Open-Angle African Ancestry Glaucoma Genetics (POAAGG) Study.

There are scarce data regarding the rate of the occurrence of primary open-angle glaucoma (POAG) and visible lamina cribrosa pores (LCPs) in the eyes of individuals with African ancestry; the potential impact of these features on disease burden remains unknown. We recruited subjects with POAG to the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. Through regression models, we evaluated the association between the presence of LCPs and various phenotypic features. In a multivariable analysis of 1187 glaucomatous eyes, LCPs were found to be more likely to be present in eyes with cup-to-disc ratios (CDR) of ≥0.9 (adjusted risk ratio (aRR) 1.11, 95%CI: 1.04-1.19, p = 0.005), eyes with cylindrical-shaped (aRR 1.22, 95%CI: 1.11-1.33) and bean pot (aRR 1.24, 95%CI: 1.13-1.36) cups versus conical cups (p < 0.0001), moderate cup depth (aRR 1.24, 95%CI: 1.06-1.46) and deep cups (aRR 1.27, 95%CI: 1.07-1.50) compared to shallow cups (p = 0.01), and the nasalization of central retinal vessels (aRR 1.33, 95%CI: 1.23-1.44), p < 0.0001). Eyes with LCPs were more likely to have a higher degree of African ancestry (q0), determined by means of SNP analysis (aRR 0.96, 95%CI: 0.93-0.99, p = 0.005 for per 0.1 increase in q0). Our large cohort of POAG cases of people with African ancestry showed that LCPs may be an important risk factor in identifying severe disease, potentially warranting closer monitoring by physicians.

Piezo1 and Piezo2 channels in retinal ganglion cells and the impact of Piezo1 stimulation on light-dependent neural activity.

Piezo channels are associated with neuropathology in diseases like traumatic brain injury and glaucoma, but pathways linking tissue stretch to aberrant neural signaling remain unclear. The present study demonstrates that Piezo1 activation increases action potential frequency in response to light and the spontaneous dark signal from mouse retinal explants. Piezo1 stimulation was sufficient to increase cytoplasmic Ca 2+ in soma and neurites, while stretch increased spiking activity in current clamp recordings from of isolated retinal ganglion cells (RGCs). Axon-marker beta-tubulin III colocalized with both Piezo1 and Piezo2 protein in the mouse optic nerve head, while RGC nuclear marker BRN3A colocalized with Piezo channels in the soma. Piezo1 was also present on GFAP-positive regions in the optic nerve head and colocalized with glutamine synthetase in the nerve fiber layer, suggesting expression in optic nerve head astrocytes and Müller glia end feet, respectively. Human RGCs from induced pluripotent stem cells also expressed Piezo1 and Piezo2 in soma and axons, while staining patterns in rats resembled those in mice. mRNA message for Piezo1 was greatest in the RPE/choroid tissue, while Piezo2 levels were highest in the optic nerve, with both channels also expressed in the retina. Increased expression of Piezo1 and Piezo2 occurred both 1 and 10 days after a single stretch in vivo; this increase suggests a potential role in rising sensitivity to repeated nerve stretch. In summary, Piezo1 and Piezo2 were detected in the soma and axons of RGCs, and stimulation affected the light-dependent output of RGCs. The rise in RGCs excitability induced by Piezo stimulation may have parallels to the early disease progression in models of glaucoma and other retinal degenerations. Highlights: Activation of Piezo1 excites retinal ganglion cells, paralleling the early neurodegenerative progression in glaucoma mouse models and retinal degeneration.Piezo1 and Piezo2 were expressed in axons and soma of retinal ganglion cells in mice, rats, and human iPSC-RGCs.Functional assays confirmed Piezo1 in soma and neurites of neurons. Sustained elevation of Piezo1 and Piezo2 occurred after a single transient stretch may enhance damage from repeated traumatic nerve injury.

Eye-brain connections revealed by multimodal retinal and brain imaging genetics.

The retina, an anatomical extension of the brain, forms physiological connections with the visual cortex of the brain. Although retinal structures offer a unique opportunity to assess brain disorders, their relationship to brain structure and function is not well understood. In this study, we conducted a systematic cross-organ genetic architecture analysis of eye-brain connections using retinal and brain imaging endophenotypes. We identified novel phenotypic and genetic links between retinal imaging biomarkers and brain structure and function measures from multimodal magnetic resonance imaging (MRI), with many associations involving the primary visual cortex and visual pathways. Retinal imaging biomarkers shared genetic influences with brain diseases and complex traits in 65 genomic regions, with 18 showing genetic overlap with brain MRI traits. Mendelian randomization suggests bidirectional genetic causal links between retinal structures and neurological and neuropsychiatric disorders, such as Alzheimer's disease. Overall, our findings reveal the genetic basis for eye-brain connections, suggesting that retinal images can help uncover genetic risk factors for brain disorders and disease-related changes in intracranial structure and function.

Shared and unique 3D genomic features of substance use disorders across multiple cell types.

Recent genome-wide association studies (GWAS) have revealed shared genetic components among alcohol, opioid, tobacco and cannabis use disorders. However, the extent of the underlying shared causal variants and effector genes, along with their cellular context, remain unclear. We leveraged our existing 3D genomic datasets comprising high-resolution promoter-focused Capture-C/Hi-C, ATAC-seq and RNA-seq across >50 diverse human cell types to focus on genomic regions that coincide with GWAS loci. Using stratified LD regression, we determined the proportion of genomewide SNP heritability attributable to the features assayed across our cell types by integrating recent GWAS summary statistics for the relevant traits: alcohol use disorder (AUD), tobacco use disorder (TUD), opioid use disorder (OUD) and cannabis use disorder (CanUD). Statistically significant enrichments (P<0.05) were observed in 14 specific cell types, with heritability reaching 9.2-fold for iPSC-derived cortical neurons and neural progenitors, confirming that they are crucial cell types for further functional exploration. Additionally, several pancreatic cell types, notably pancreatic beta cells, showed enrichment for TUD, with heritability enrichments up to 4.8-fold, suggesting genomic overlap with metabolic processes. Further investigation revealed significant positive genetic correlations between T2D with both TUD and CanUD (FDR<0.05) and a significant negative genetic correlation with AUD. Interestingly, after partitioning the heritability for each cell type's cis-regulatory elements, the correlation between T2D and TUD for pancreatic beta cells was greater (r=0.2) than the global genetic correlation value. Our study provides new genomic insights into substance use disorders and implicates cell types where functional follow-up studies could reveal causal variant-gene mechanisms underpinning these disorders.

3D genomic features across >50 diverse cell types reveal insights into the genomic architecture of childhood obesity.

The prevalence of childhood obesity is increasing worldwide, along with the associated common comorbidities of type 2 diabetes and cardiovascular disease in later life. Motivated by evidence for a strong genetic component, our prior genome-wide association study (GWAS) efforts for childhood obesity revealed 19 independent signals for the trait; however, the mechanism of action of these loci remains to be elucidated. To molecularly characterize these childhood obesity loci we sought to determine the underlying causal variants and the corresponding effector genes within diverse cellular contexts. Integrating childhood obesity GWAS summary statistics with our existing 3D genomic datasets for 57 human cell types, consisting of high-resolution promoter-focused Capture-C/Hi-C, ATAC-seq, and RNA-seq, we applied stratified LD score regression and calculated the proportion of genome-wide SNP heritability attributable to cell type-specific features, revealing pancreatic alpha cell enrichment as the most statistically significant. Subsequent chromatin contact-based fine-mapping was carried out for genome-wide significant childhood obesity loci and their linkage disequilibrium proxies to implicate effector genes, yielded the most abundant number of candidate variants and target genes at the BDNF, ADCY3, TMEM18 and FTO loci in skeletal muscle myotubes and the pancreatic beta-cell line, EndoC-BH1. One novel implicated effector gene, ALKAL2 - an inflammation-responsive gene in nerve nociceptors - was observed at the key TMEM18 locus across multiple immune cell types. Interestingly, this observation was also supported through colocalization analysis using expression quantitative trait loci (eQTL) derived from the Genotype-Tissue Expression (GTEx) dataset, supporting an inflammatory and neurologic component to the pathogenesis of childhood obesity. Our comprehensive appraisal of 3D genomic datasets generated in a myriad of different cell types provides genomic insights into pediatric obesity pathogenesis.

Comparison of the diagnostic value of MR imaging and ophthalmoscopy for the staging of retinoblastoma.

PURPOSE: To compare the diagnostic value of magnetic resonance (MR) imaging and ophthalmoscopy for staging of retinoblastoma. METHODS: MR and ophthalmoscopic images of 36 patients who underwent enucleation were evaluated retrospectively following institutional review board approval. Histopathology being the standard of reference, the sensitivity and specificity of both diagnostic modalities were compared regarding growth pattern, iris neoangiogenesis, retinal detachment, vitreous seeds and optic nerve invasion. Data were analysed via McNemar's test. RESULTS: Both investigations showed no significant difference in accuracy for the detection of different tumour growth patterns (P = 0.80). Vitreous seeding detection was superior by ophthalmoscopy (P < 0.001). For prelaminar optic nerve invasion, MR imaging showed similar sensitivity as ophthalmoscopy but increased specificity of 40 % (CI 0.12-0.74) vs. 20 % (0.03-0.56). MR detected optic nerve involvement past the lamina cribrosa with a sensitivity of 80 % (0.28-0.99) and a specificity of 74 % (0.55-0.88). The absence of optic nerve enhancement excluded histopathological infiltration, but the presence of optic nerve enhancement included a high number of false positives (22-24 %). CONCLUSIONS: Ophthalmoscopy remains the method of choice for determining extent within the globe while MR imaging is useful for evaluating extraocular tumour extension. Thus, both have their own strengths and contribute uniquely to the staging of retinoblastoma. KEY POINTS: • Ophthalmoscopy: method of choice for determining extent of retinoblastoma within the globe. • MR imaging provides optimal evaluation of extrascleral and extraocular tumour extension. • Positive enhancement of the optic nerve on MRI does not necessarily indicate involvement.

Full-field electroretinography under general anesthesia in retinoblastoma.

PURPOSE: To investigate the electrical responses of the retina in retinoblastoma (RB), by recording full-field electroretinography (ERG) under general anesthesia. METHODS: The ERG was recorded using Ephios hand-held portable ERG system, according to International Standards for Clinical Electrophysiology of Vision. Forty-eight eyes of 43 cases and 33 eyes of 33 controls were enrolled. The cases were classified based on international intraocular retinoblastoma classification (IIRC). Forty-eight eyes of cases were divided into 30 cases with active RB and 18 cases with regressed RB. RESULTS: The amplitudes of a- and b-waves were decreased as compared to controls in all subgroups. The implicit times of all RB patients from group A to C differed statistically from controls (p value < 0.05) except for single-flash rod response. The ERG waveforms in group E eyes were non-recordable. The comparison of ERG parameters between active and regressed groups (IIRC groups A and B) was statistically insignificant. Single case follow-up of unilateral RB after systemic chemotherapy showed improvement in amplitudes compared to baseline parameters. CONCLUSIONS: Reduced amplitudes and delayed implicit times were noted in advanced disease. The ERG of RB cases did not follow any specific pattern of waveform. ERG appears to be a dynamic parameter to observe changes following treatment for RB. Although ERG is not a diagnostic test for RB, it can be used as a complementary test to assess the residual retinal function in RB eyes.

The potential for mitochondrial therapeutics in the treatment of primary open-angle glaucoma: a review.

Glaucoma, an age-related neurodegenerative disease, is characterized by the death of retinal ganglion cells (RGCs) and the corresponding loss of visual fields. This disease is the leading cause of irreversible blindness worldwide, making early diagnosis and effective treatment paramount. The pathophysiology of primary open-angle glaucoma (POAG), the most common form of the disease, remains poorly understood. Current available treatments, which target elevated intraocular pressure (IOP), are not effective at slowing disease progression in approximately 30% of patients. There is a great need to identify and study treatment options that target other disease mechanisms and aid in neuroprotection for POAG. Increasingly, the role of mitochondrial injury in the development of POAG has become an emphasized area of research interest. Disruption in the function of mitochondria has been linked to problems with neurodevelopment and systemic diseases. Recent studies have shown an association between RGC death and damage to the cells' mitochondria. In particular, oxidative stress and disrupted oxidative phosphorylation dynamics have been linked to increased susceptibility of RGC mitochondria to secondary mechanical injury. Several mitochondria-targeted treatments for POAG have been suggested, including physical exercise, diet and nutrition, antioxidant supplementation, stem cell therapy, hypoxia exposure, gene therapy, mitochondrial transplantation, and light therapy. Studies have shown that mitochondrial therapeutics may have the potential to slow the progression of POAG by protecting against mitochondrial decline associated with age, genetic susceptibility, and other pathology. Further, these therapeutics may potentially target already present neuronal damage and symptom manifestations. In this review, the authors outline potential mitochondria-targeted treatment strategies and discuss their utility for use in POAG.

Factors Associated with Large Cup-to-Disc Ratio and Blindness in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) Study.

BACKGROUND/AIMS: Primary open-angle glaucoma (POAG) disproportionately affects individuals of African ancestry. In these patients' eyes, a large cup-to-disc ratio (LCDR > 0.90) suggests greater retinal ganglion cell loss, though these patients often display varied visual ability. This study investigated the prevalence and risk factors associated with LCDR in African ancestry individuals with POAG and explored the differences between blind (>20/200) and not blind (≤20/200) LCDR eyes. METHODS: A case-control methodology was used to investigate the demographic, optic disc, and genetic risk factors of subjects in the Primary Open-Angle African American Glaucoma Genetics Study. Risk factors were analyzed using univariable and multivariable logistic regression models with inter-eye correlation adjusted using generalized estimating equations. RESULTS: Out of 5605 eyes with POAG, 1440 eyes (25.7%) had LCDR. In the multivariable analysis, LCDR was associated with previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.04), decreased mean deviation (OR = 1.08), increased pattern standard deviation (OR = 1.06), thinner retinal nerve fiber layer (OR = 1.05), nasalization of vessels (OR = 2.67), bayonetting of vessels (OR = 1.98), visible pores in the lamina cribrosa (OR = 1.68), and a bean-shaped cup (OR = 2.11). Of LCDR eyes, 30.1% were classified as blind (≤20/200). In the multivariable analysis, the statistically significant risk factors of blindness in LCDR eyes were previous glaucoma surgery (OR = 1.72), increased intraocular pressure (OR = 1.05), decreased mean deviation (OR = 1.04), and decreased pattern standard deviation (OR = 0.90). CONCLUSIONS: These findings underscore the importance of close monitoring of intraocular pressure and visual function in African ancestry POAG patients, particularly those with LCDR, to preserve visual function.

Eye-brain connections revealed by multimodal retinal and brain imaging genetics in the UK Biobank.

As an anatomical extension of the brain, the retina of the eye is synaptically connected to the visual cortex, establishing physiological connections between the eye and the brain. Despite the unique opportunity retinal structures offer for assessing brain disorders, less is known about their relationship to brain structure and function. Here we present a systematic cross-organ genetic architecture analysis of eye-brain connections using retina and brain imaging endophenotypes. Novel phenotypic and genetic links were identified between retinal imaging biomarkers and brain structure and function measures derived from multimodal magnetic resonance imaging (MRI), many of which were involved in the visual pathways, including the primary visual cortex. In 65 genomic regions, retinal imaging biomarkers shared genetic influences with brain diseases and complex traits, 18 showing more genetic overlaps with brain MRI traits. Mendelian randomization suggests that retinal structures have bidirectional genetic causal links with neurological and neuropsychiatric disorders, such as Alzheimer's disease. Overall, cross-organ imaging genetics reveals a genetic basis for eye-brain connections, suggesting that the retinal images can elucidate genetic risk factors for brain disorders and disease-related changes in intracranial structure and function.