Age-dependent regional retinal nerve fibre changes in SIX1/SIX6 polymorphism.

SIX1/SIX6 polymorphism has been shown to be associated with glaucoma. Studies have also found that, in older adults, retinal nerve fibre layer (RNFL) thickness is significantly thinned with each copy of the risk allele in SIX1/SIX6. However, it is not known whether these genetic variants exert their effects in younger individuals.

Identification and activity of the functional complex between hnRNPL and the pseudoexfoliation syndrome-associated lncRNA, LOXL1-AS1.

Individuals with pseudoexfoliation (PEX) syndrome exhibit various connective tissue pathologies associated with dysregulated extracellular matrix homeostasis. PEX glaucoma is a common, aggressive form of open-angle glaucoma resulting from the deposition of fibrillary material in the conventional outflow pathway. However, the molecular mechanisms that drive pathogenesis and genetic risk remain poorly understood.

Gray Optic Disc Crescent: Evaluation of Anatomic Correlate by Spectral-Domain OCT.

Purpose: To test the hypothesis that the anatomic correlate of the gray optic disc crescent is pigmentation of externally oblique border tissue of Elschnig.

Design: Retrospective study.

Participants: African-American adult men with or without clinically apparent gray optic disc crescents.

Association between Chronic Obstructive Pulmonary Disease and Exfoliation Syndrome: The Utah Project on Exfoliation Syndrome.

Purpose: Exfoliation syndrome (XFS) is associated with genetic variants of lysyl oxidase-like 1 (LOXL1), a key enzyme in the stabilization of extracellular matrix (ECM) and elastin, and in connective tissue repair. Because patients with chronic obstructive pulmonary disease (COPD) have increased and altered elastin degradation, an association between XFS and COPD was hypothesized and analyzed. Impact of XFS on survival in patients with COPD was evaluated.

Association of Exfoliation Syndrome With Risk of Indirect Inguinal Hernia: The Utah Project on Exfoliation Syndrome.

Importance: Exfoliation syndrome (XFS) is a systemic connective tissue disease, and abnormal connective tissue metabolism is implicated in inguinal hernias (IH). Associating XFS with comorbid conditions may illuminate their underlying pathophysiology and affect clinical screening and treatment. Exfoliation syndrome involves altered systemic extracellular matrix (ECM) homeostasis involving elastin metabolism.

A Common Glaucoma-risk Variant of SIX6 Alters Retinal Nerve Fiber Layer and Optic Disc Measures in a European Population: The EPIC-Norfolk Eye Study.

Purpose: A common missense variant in the SIX6 gene (rs33912345) is strongly associated with primary open-angle glaucoma (POAG). We aimed to examine the association of rs33912345 with optic disc and retinal nerve fiber layer (RNFL) measures in a European population.

Methods: We examined participants of the population-based EPIC-Norfolk Eye Study.

Utah Project on Exfoliation Syndrome (UPEXS): Insight Into Systemic Diseases Associated With Exfoliation Syndrome.

The Utah Project on Exfoliation Syndrome (UPEXS) study was created to investigate the association between exfoliation syndrome (XFS) and systemic disorders or pathologies. The study utilizes the resources of the Utah Population Database, which is linked to the Utah genealogy, a compilation of large pedigrees extending back 3 to ≥11 generations, representing most families in the state. These family members medical and health records are linked to vital records and can be used effectively to identify familial clustering of disorders, like XFS, with comorbid diseases or health-related data.

Genome-wide association study identifies seven novel susceptibility loci for primary open-angle glaucoma.

Primary open-angle glaucoma (POAG) is the leading cause of irreversible blindness worldwide for which 15 disease-associated loci had been discovered. Among them, only 5 loci have been associated with POAG in Asians. We carried out a genome-wide association study and a replication study that included a total of 7378 POAG cases and 36 385 controls from a Japanese population.

Testosterone Pathway Genetic Polymorphisms in Relation to Primary Open-Angle Glaucoma: An Analysis in Two Large Datasets.

Purpose: Sex hormones may be associated with primary open-angle glaucoma (POAG), although the mechanisms are unclear. We previously observed that gene variants involved with estrogen metabolism were collectively associated with POAG in women but not men; here we assessed gene variants related to testosterone metabolism collectively and POAG risk.

Methods: We used two datasets: one from the United States (3853 cases and 33,480 controls) and another from Australia (1155 cases and 1992 controls).

Genomic locus modulating corneal thickness in the mouse identifies POU6F2 as a potential risk of developing glaucoma.

Central corneal thickness (CCT) is one of the most heritable ocular traits and it is also a phenotypic risk factor for primary open angle glaucoma (POAG). The present study uses the BXD Recombinant Inbred (RI) strains to identify novel quantitative trait loci (QTLs) modulating CCT in the mouse with the potential of identifying a molecular link between CCT and risk of developing POAG. The BXD RI strain set was used to define mammalian genomic loci modulating CCT, with a total of 818 corneas measured from 61 BXD RI strains (between 60-100 days of age).

The influence of oral statin medications on progression of glaucomatous visual field loss: A propensity score analysis.

Purpose: The purpose of this study was to examine the association between oral statin use and the progression of open angle glaucoma.

Methods: Medical records of 847 Veterans were reviewed to collect statin use history, record demographic and comorbid medical conditions, and review visual fields. Visual field progression was judged by an ophthalmologist masked to statin use history.

Modeling Glaucoma: Retinal Ganglion Cells Generated from Induced Pluripotent Stem Cells of Patients with SIX6 Risk Allele Show Developmental Abnormalities.

Glaucoma represents a group of multifactorial diseases with a unifying pathology of progressive retinal ganglion cell (RGC) degeneration, causing irreversible vision loss. To test the hypothesis that RGCs are intrinsically vulnerable in glaucoma, we have developed an in vitro model using the SIX6 risk allele carrying glaucoma patient-specific induced pluripotent stem cells (iPSCs) for generating functional RGCs. Here, we demonstrate that the efficiency of RGC generation by SIX6 risk allele iPSCs is significantly lower than iPSCs-derived from healthy, age- and sex-matched controls.

Major review: Molecular genetics of primary open-angle glaucoma.

Glaucoma is a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG), the most common type, is a complex inherited disorder that is characterized by progressive retinal ganglion cell death, optic nerve head excavation, and visual field loss. The discovery of a large, and growing, number of genetic and chromosomal loci has been shown to contribute to POAG risk, which carry implications for disease pathogenesis.

VEGF as a Paracrine Regulator of Conventional Outflow Facility.

Purpose: Vascular endothelial growth factor (VEGF) regulates microvascular endothelial permeability, and the permeability of Schlemm's canal (SC) endothelium influences conventional aqueous humor outflow. We hypothesize that VEGF signaling regulates outflow facility.

Methods: We measured outflow facility (C) in enucleated mouse eyes perfused with VEGF-A164a, VEGF-A165b, VEGF-D, or inhibitors to VEGF receptor 2 (VEGFR-2).

Intravitreal Anti-VEGF Injections Reduce Aqueous Outflow Facility in Patients With Neovascular Age-Related Macular Degeneration.

Purpose: We assess the effect of intravitreal anti-VEGF injections on tonographic outflow facility.

Methods: Patients with age-related macular degeneration who had received unilateral intravitreal anti-VEGF injections were recruited into two groups, those with ≤10 and those with ≥20 total anti-VEGF injections. Intraocular pressure and tonographic outflow facility of injected and uninjected fellow eyes were measured and compared between groups.

Retrospective analysis of translaminar, demographic, and physiologic parameters in relation to papilledema severity.

Objective: Some case reports suggest that the translaminar pressure difference is important in cases of papilledema. The purpose of this study was to determine ocular, physiologic, and demographic factors associated with papilledema severity.

Design: Retrospective, blinded study.

Spectrum and Clinical Course of Visual Field Abnormalities in Ethambutol Toxicity.

Visual toxicities from ethambutol are rare but represent one of the few causes of non-glaucomatous and non-compressive bitemporal hemianopsia. The authors present a six-patient case series illustrating variable clinical presentation and reversibility of visual loss in patients treated with ethambutol for complex, including four patients who presented with visual field defects suggestive of bitemporal hemianopsia. Two additional patients were being followed for glaucoma, developed visual field defects with ethambutol treatment, and subsequently recovered with cessation of drug.

Transcriptome analysis of adult and fetal trabecular meshwork, cornea, and ciliary body tissues by RNA sequencing.

Purpose: To characterize the transcriptional landscape of human adult and fetal trabecular meshwork (TM), cornea, and ciliary body (CB) tissues, and to evaluate the expression level of candidate genes selected from genetic association studies of primary-open angle glaucoma, central corneal thickness, intraocular pressure, vertical cup to disc ratio, and optic nerve parameters.

Methods: Deep RNA sequencing was performed on the selected human tissues. Transcriptome analyses were performed to 1) characterize the total number of expressed genes, 2) identify the most highly expressed genes, 3) estimate the number of novel transcripts, and 4) evaluate the expression of candidate genes in each tissue.

Major review: Exfoliation syndrome; advances in disease genetics, molecular biology, and epidemiology.

Exfoliation syndrome (XFS) is a common age-related disorder that leads to deposition of extracellular fibrillar material throughout the body. The most recognized disease manifestation is exfoliation glaucoma (XFG), which is a common cause of blindness worldwide. Recent developments in XFS genetics, cell biology and epidemiology have greatly improved our understanding of the etiology of this complex inherited disease.

Age at natural menopause genetic risk score in relation to age at natural menopause and primary open-angle glaucoma in a US-based sample.

Objective: Several attributes of female reproductive history, including age at natural menopause (ANM), have been related to primary open-angle glaucoma (POAG). We assembled 18 previously reported common genetic variants that predict ANM to determine their association with ANM or POAG.

Methods: Using data from the Nurses' Health Study (7,143 women), we validated the ANM weighted genetic risk score in relation to self-reported ANM.