Ocular ischemia is one of the leading causes of blindness. It is related to various ocular diseases and disorders, including age-related macular degeneration, diabetic retinopathy, glaucoma, and corneal injury. Ocular ischemia occurs due to an abnormal supply of oxygen and nutrients to the eye, resulting in ocular metabolic dysfunction. These changes can be linked with pathologic conditions in the eye, such as inflammation, neovascularization, and cell death, ultimately leading to vision loss. The current treatment care for ocular ischemia is limited. Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor protein functioning in regulating lipid metabolism, fatty acid oxidation, and glucose homeostasis. Recently, PPARα activation has been suggested as a useful therapeutic target in treating ocular ischemia. However, its applications have not been well summarized. In this review, we cover an overview of the therapeutic roles of PPARα activation in various ocular ischemic conditions with recent experimental evidence and further provide clinical implications of its therapeutic applications. Our review will enable more approaches to comprehensively understand the therapeutic roles of PPARα activation for preventing ocular ischemic diseases.

Heterozygous loss of function mutations in TWIST1 cause Saethre-Chotzen syndrome, which is characterized by craniosynostosis, facial asymmetry, ptosis, strabismus, and distinctive ear appearance. Individuals with syndromic craniosynostosis have high rates of strabismus and ptosis, but the underlying pathology is unknown. Some individuals with syndromic craniosynostosis have been noted to have absence of individual extraocular muscles or abnormal insertions of the extraocular muscles on the globe. Using conditional knock-out alleles for Twist1 in cranial mesenchyme, we test the hypothesis that Twist1 is required for extraocular muscle organization and position, attachment to the globe, and/or innervation by the cranial nerves. We examined the extraocular muscles in conditional Twist1 knock-out animals using Twist2-cre and Pdgfrb-cre drivers. Both are expressed in cranial mesoderm and neural crest. Conditional inactivation of Twist1 using these drivers leads to disorganized extraocular muscles that cannot be reliably identified as specific muscles. Tendons do not form normally at the insertion and origin of these dysplastic muscles. Knock-out of Twist1 expression in tendon precursors, using scleraxis-cre, however, does not alter EOM organization. Furthermore, developing motor neurons, which do not express Twist1, display abnormal axonal trajectories in the orbit in the presence of dysplastic extraocular muscles. Strabismus in individuals with TWIST1 mutations may therefore be caused by abnormalities in extraocular muscle development and secondary abnormalities in innervation and tendon formation.

IMPORTANCE: Literature and anecdotal evidence suggest a relationship between male sex and retinopathy of prematurity (ROP). It is not known whether a difference, if present, is sex-related pathophysiologic predisposition or sex difference in meeting ROP screening criteria. OBJECTIVE: To evaluate the association of sex with the development of treatment-warranted ROP. DATA SOURCES: PubMed, Embase, and Web of Science databases were searched from 2000 to 2022. The search strategy used keywords including retinopathy of prematurity or ROP or retrolental fibroplasia and treatment or anti-VEGF or bevacizumab or ranibizumab or aflibercept or conbercept or laser or cryotherapy and gender or sex or male or female and medical subject headings terms. STUDY SELECTION: All studies reporting on treatment with anti-vascular endothelial growth factor, laser photocoagulation, and/or cryotherapy for ROP were identified. Studies reporting sex distribution in the treatment group were included in the meta-analysis. Exclusion criteria included case reports, case series of fewer than 10 treated patients, systematic reviews, conference abstracts, letters to the editor, animal studies, and non-English records. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently screened and extracted the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The proportions of treated male and female infants were combined using random-effects meta-analysis. MAIN OUTCOMES AND MEASURES: Numbers and percentages of male and female infants treated for ROP. RESULTS: Of 11 368 identified studies, 316 met inclusion criteria, yielding a total of 31 026 treated patients. A higher percentage of male infants were treated for ROP (55% [95% CI, 0.54%-0.55%]), with low heterogeneity between studies (I2 = 34%; P < .001). Thirty-eight studies reported sex distribution in the screened population (170 053 patients; 92 612 [53%] male vs 77 441 [47%] female). There was no significant difference in the odds of receiving treatment between screened male and female infants (pooled odds ratio, 1.04 [95% CI, 0.91-1.18]; P = .67). CONCLUSIONS AND RELEVANCE: More male infants are treated for ROP than female infants. This could be due to a known relative pathophysiological fragility of preterm male infants in addition to a difference in ROP screening rates, with more male infants meeting the criteria than female infants. These findings have implications for future studies and may prompt more careful clinical monitoring of male neonates.

PURPOSE: To identify prognostic factors for poor visual outcomes in patients with isolated retinal vasculitis and to elucidate the outcome of immunosuppressive treatment without the use of antituberculosis drugs for patients with retinal vasculitis associated with a positive QuantiFERON-TB Gold In-Tube (QFT) test. METHODS: A retrospective chart review was performed of patients presenting with retinal vasculitis. After the diagnosis of active retinal vasculitis had been confirmed by fluorescein angiography and other possible causes of retinal vasculitis had been excluded, patients were categorized into two groups by their QFT result. Potential associated factors between the poor and good visual outcome groups were statistically analyzed by the chi-square test and logistic regression model with generalized estimating equations. RESULTS: Seventy-three eyes (48 patients) were enrolled in this study. After univariate analysis, multivariate logistic regression analysis was performed and revealed that logMAR visual acuity at the initial visit ( P = 0.01) and outer retinal disruption ( P = 0.03) were the two factors significantly associated with poor visual outcomes. Systemic corticosteroids were administered without the use of antituberculosis drugs to all 16 cases of presumed tuberculous retinal vasculitis associated with positive QFT (26 eyes), 10 (63%) of whom were given nonsteroidal immunosuppressive drugs and achieved inflammatory control and treatment success. CONCLUSION: Risk factors leading to poor visual outcome in patients with isolated retinal vasculitis have been identified. Immunosuppressive treatment without antituberculosis drugs seems to be a promising regimen for selected patients with presumed tuberculous retinal vasculitis under vigilant care.

Purpose: To examine ophthalmologist use of an electronic health record (EHR)-based clinical decision support system (CDSS) to facilitate low vision rehabilitation (LVR) care referral. Methods: The CDSS alert was designed to appear when best documented visual acuity was <20/40 or hemianopia or quadrantanopia diagnosis was identified during an ophthalmology encounter from November 6, 2017, to April 5, 2019. Fifteen ophthalmologists representing eight subspecialties from an academic medical center were required to respond to the referral recommendation (order, don't order). LVR referral rates and ophthalmologist user experience were assessed. Encounter characteristics associated with LVR referrals were explored using multilevel logistic regression analysis. Results: The alert appeared for 3625 (8.9%) of 40,931 eligible encounters. The referral rate was 14.8% (535/3625). Of the 3413 encounters that met the visual acuity criterion only, patients who were worse than 20/60 were more likely to be referred, and 32.4% of referred patients were between 20/40 and 20/60. Primary reasons for deferring referrals included active medical or surgical treatment, refractive-related issues, and previous connection to LVR services. Eleven of the 13 ophthalmologists agreed that the alert was useful in identifying candidates for LVR services. Conclusions: A CDSS for patient identification and referral offers an acceptable mechanism to apply practice guidelines and prompt ophthalmologists to facilitate LVR care. Further study is warranted to optimize ophthalmologist user experience while refining alert criteria beyond visual acuity. Translational Relevance: The CDSS provides the framework for multi-center research to assess the development of pragmatic algorithms and standards for facilitating LVR care.

Importance: Presence of predominantly peripheral diabetic retinopathy (DR) lesions on ultra-widefield fluorescein angiography (UWF-FA) was associated with greater risk of DR worsening or treatment over 4 years. Whether baseline retinal nonperfusion assessment is additionally predictive of DR disease worsening is unclear. Objective: To assess whether the extent and location of retinal nonperfusion identified on UWF-FA are associated with worsening in Diabetic Retinopathy Severity Scale (DRSS) score or DR treatment over time. Design, Setting, and Participants: This cohort study was a prospective, multicenter, longitudinal observational study with data for 508 eyes with nonproliferative DR and gradable nonperfusion on UWF-FA at baseline. All images were graded at a centralized reading center; 200° ultra-widefield (UWF) color images were graded for DR at baseline and annually for 4 years. Baseline 200° UWF-FA images were graded for nonperfused area, nonperfusion index (NPI), and presence of predominantly peripheral lesions on UWF-FA (FA PPL). Interventions: Treatment of DR or diabetic macular edema was at investigator discretion. Main Outcomes and Measures: Association of baseline UWF-FA nonperfusion extent with disease worsening, defined as either 2 or more steps of DRSS worsening within Early Treatment Diabetic Retinopathy Study fields on UWF-color images or receipt of DR treatment. Results: After adjusting for baseline DRSS, the risk of disease worsening over 4 years was higher in eyes with greater overall NPI (hazard ratio [HR] for 0.1-unit increase, 1.11; 95% CI, 1.02-1.21; P = .02) and NPI within the posterior pole (HR for 0.1-unit increase, 1.35; 95% CI, 1.17-1.56; P < .001) and midperiphery (HR for 0.1-unit increase, 1.08; 95% CI, 1.00-1.16; P = .04). In a multivariable analysis adjusting for baseline DRSS score and baseline systemic risk factors, greater NPI (HR, 1.11; 95% CI, 1.02-1.22; P = .02) and presence of FA PPL (HR, 1.89; 95% CI, 1.35-2.65; P < .001) remained associated with disease worsening. Conclusions and Relevance: This 4-year longitudinal study has demonstrated that both greater baseline retinal nonperfusion and FA PPL on UWF-FA are associated with higher risk of disease worsening, even after adjusting for baseline DRSS score and known systemic risk. These associations between disease worsening and retinal nonperfusion and FA PPL support the increased use of UWF-FA to complement color fundus photography in future efforts for DR prognosis, clinical care, and research.

Objective: To assess the effect of diabetic retinopathy (DR) on vision-related quality of life (VRQoL) in patients with type 2 diabetes. Methods: In this cross-sectional study, patients with type 2 diabetes residing in 15 residency communities in Fushun, Liaoning province were enrolled from July 2012 to May 2013. We measured the VRQoL by the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Patients were grouped according to their age, gender, presence of visual impairment, and affected eyes. NEI-VFQ-25 scores were compared between/among groups using the Wilcoxon rank-sum test or Kruskal-Wallis H test. The severity of DR in the eyes was graded into no DR, mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR, and proliferative diabetic retinopathy (PDR). Severity scores from both eyes were then summarized to create a single per-person grade ranging from 1 (no DR in either eye) to 7 (bilateral PDR). Generalized linear models were used to assess the linear relationship between NEI-VFQ-25 scores and DR severity. Locally weighted scatterplot smoothing plots were generated to evaluate the possible nonlinear associations between concatenated severity of DR and VRQoL. Results: A total of 1 537 patients were recruited, including 836 (54.4%) with no DR, 479 (31.2%) with mild NPDR, 90 (5.9%) with moderate NPDR, 72 (4.7%) with severe NPDR and 60 (3.9%) with PDR. Compared with patients with unilateral DR, bilaterally involved subjects were statistically significantly compromised in general vision [70.2 (66.5, 72.5) vs. 68.9 (63.9, 71.6), Z=90.222, P=0.038], near activities [90.5 (85.8, 94.0) vs. 88.8 (84.5, 92.5), Z=114.942, P=0.005], dependency [91.1 (85.6, 96.5) vs. 89.3 (83.8, 94.5), Z=91.934, P=0.033], mental health [80.0 (73.4, 84.9) vs. 77.5 (70.8, 82.0), Z=118.388, P=0.003], role difficulties [76.8 (70.1, 82.4) vs. 74.5 (67.6, 80.6), Z =90.791, P=0.036] and NEI-VFQ-25 composite [88.3 (84.2, 91.0) vs. 86.9 (82.8, 90.1), Z=96.207, P=0.024]. Scores on general vision (χ2=85.665), near activities (χ2=78.462), distance activities (χ2=145.489), social function (χ2=53.629), dependency (χ2=86.710), mental health (χ2=68.281), role difficulties (χ2=45.357), color vision (χ2=68.176), peripheral vision (χ2=116.179) and NEI-VFQ-25 composite (χ2=133.291) decreased gradually as DR severity increased (all P<0.001). On role difficulties, locally weighted scatterplot smoothing plots showed significant"turning points"from bilateral mild NPDR to mild NPDR/>mild NPDR (slope m=-4.7) and from moderate NPDR/≥moderate NPDR to severe NPDR/≥severe NPDR (slope m=-12.6). Conclusion: Both greater severity and bilaterality of DR were associated with lower vision-specific VRQoL, particularly role difficulties and mental health.

PURPOSE: The purpose of this systematic review is to identify techniques used for quantification of choriocapillaris (CC) flow in eyes with uveitis using optical coherence tomography angiography (OCTA), report reliability and level of correlation with techniques such as indocyanine green angiography (ICGA). METHODS: A systematic search of several databases was done. The studies were analyzed for techniques of measurement, reliability, and correlation with other modalities. Risk of bias assessment was performed. RESULTS: Thirteen studies were included. CC vessel density (7 studies) and flow deficit area (4 studies) were the most used indices. There was significant heterogeneity in the studies due to differences in the scan protocol, thresholding strategy, and analysis. Comparison with ICGA was performed by only one study, and reliability indices were reported by only two studies. CONCLUSION: OCTA is a useful tool to measure the CC vascularity in eyes with uveitis. However, standardized acquisition and analysis protocols are needed.

The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here, we found that in two mouse glaucoma models, microglia transitioned to a neurodegenerative phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3), which were also upregulated in human glaucomatous retinas. Mice with targeted deletion of Apoe in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss, despite elevated intraocular pressure (IOP). Similarly to Apoe-/- retinal microglia, APOE4-expressing microglia did not upregulate neurodegeneration-associated genes, including Lgals3, following IOP elevation. Genetic and pharmacologic targeting of Galectin-3 ameliorated RGC degeneration, and Galectin-3 expression was attenuated in human APOE4 glaucoma samples. These results demonstrate that impaired activation of APOE4 microglia is protective in glaucoma and that the APOE-Galectin-3 signaling can be targeted to treat this blinding disease.

In response to brain insults, astrocytes become reactive, promoting protection and tissue repair. However, astroglial reactivity is typical of brain pathologies, including Alzheimer's disease (AD). Considering the heterogeneity of the reactive response, the role of astrocytes in the course of different forms of AD has been underestimated. Colombia has the largest human group known to have familial AD (FAD). This group carries the autosomal dominant and fully penetrant mutation E280A in PSEN1, which causes early-onset AD. Recently, our group identified an E280A carrier who did not develop FAD. The individual was homozygous for the Christchurch mutation R136S in APOE3 (APOEch). Remarkably, APOE is the main genetic risk factor for developing sporadic AD (SAD) and most of cerebral ApoE is produced by astroglia. Here, we characterized astrocyte properties related to reactivity, glutamate homeostasis, and structural integrity of the gliovascular unit (GVU), as factors that could underlie the pathogenesis or protection of AD. Specifically, through histological and 3D microscopy analyses of postmortem samples, we briefly describe the histopathology and cytoarchitecture of the frontal cortex of SAD, FAD, and APOEch, and demonstrate that, while astrodegeneration and vascular deterioration are prominent in SAD, FAD is characterized by hyperreactive-like glia, and APOEch displays the mildest astrocytic and vascular alterations despite having the highest burden of Aβ. Notably, astroglial, gliovascular, and vascular disturbances, as well as brain cell death, correlate with the specific astrocytic phenotypes identified in each condition. This study provides new insights into the potential relevance of the gliovasculature in the development and protection of AD. To our knowledge, this is the first study assessing the components of the GVU in human samples of SAD, FAD, and APOEch.