Blueberry eye: acquired total anterior staphyloma. BMJ Case Rep 2018;2018.
Effect of brimonidine, an α2 adrenergic agonist, on human meibomian gland epithelial cells. Exp Eye Res 2018;170:20-28.Abstract.
We recently discovered that the anti-glaucoma pharmaceuticals timolol, a β adrenergic antagonist, and pilocarpine, a cholinergic compound, negatively influence the morphology, proliferative capacity and survival of human meibomian gland epithelial cells (HMGECs). We hypothesize that another class of anti-glaucoma drugs, the α2 adrenergic agonists, also acts directly on HMGECs to affect their structure and function. We tested this hypothesis. Immortalized (i) HMGECs were cultured with brimonidine, as well as clonidine (α2 agonist), phenylephrine (α1 agonist), RX821002 (inverse α2 agonist) and MK912 (neutral α2 agonist) for up to 7 days. Cells were counted with a hemocytometer, and evaluated for morphology, signaling pathway activity, protein biomarker expression, and the accumulation of neutral lipids, phospholipids and lysosomes. Our findings demonstrate that brimondine treatment induces a dose-dependent decrease in Akt signaling and proliferation of iHMGECs. In contrast, brimonidine also promotes a dose-dependent differentiation of iHMGECs, including an increase in neutral lipid, phospholipid and lysosome levels. These effects were paralleled by an inhibition of p38 signaling, and duplicated by cellular exposure to clonidine, but not phenylephrine. Brimonidine also enhanced the cellular content of sterol regulatory binding protein-1, a master regulator of lipid synthesis. Of particular interest, the putative α2 antagonists, RX821002 and MK912, did not interfere with brimonidine action, but rather stimulated IHMGEC differentiation. Our results support our hypothesis and demonstrate that α2 adrenergic agonists act directly on iHMGECs. However, these compounds do not elicit an overall negative effect. Rather, the α2 agonists promote the differentiation of iHMGECs.
Association of Low Vitamin D Levels with Noninfectious Uveitis and Scleritis. Ocul Immunol Inflamm 2018;:1-8.Abstract.
PURPOSE: To determine whether an association between Vitamin D and noninfectious ocular inflammation exists. METHODS: Retrospective case-control study with 765 patients (333 uveitis cases, 103 scleritis cases, 329 controls). Logistic regression models examined the relationship between hypovitaminosis D and ocular inflammation. RESULTS: The odds of having uveitis were 1.92 times higher for patients with hypovitaminosis D compared to patients with normal Vitamin D levels in the multivariate analysis [odds ratio (OR) = 1.92, 95% Confidence Interval (CI) = 1.36-2.72, p = 2.32 × 10]. A secondary analysis demonstrated that the odds of developing uveitis or scleritis were 5% lower and 4% lower, respectively, for every unit increase in Vitamin D level (uveitis: OR = 0.95, 95% CI = 0.94-0.97, p = 9.87 × 10; scleritis: OR = 0.96, 95% CI = 0.93-0.99, p = 0.009). CONCLUSION: Hypovitaminosis D was associated with increased risk of ocular inflammation in this retrospective study.
Toxicity of cosmetic preservatives on human ocular surface and adnexal cells. Exp Eye Res 2018;Abstract.
Cosmetic products, such as mascara, eye shadow, eyeliner and eye makeup remover are used extensively to highlight the eyes or clean the eyelids, and typically contain preservatives to prevent microbial growth. These preservatives include benzalkonium chloride (BAK) and formaldehyde (FA)-releasing preservatives. We hypothesize that these preservatives, at concentrations (BAK = 1 mg/ml; FA = 0.74 mg/ml) approved for consumer use, are toxic to human ocular surface and adnexal cells. Accordingly, we tested the influence of BAK and FA on the morphology, survival, and proliferation and signaling ability of immortalized human meibomian gland (iHMGECs), corneal (iHCECs) and conjunctival (iHConjECs) epithelial cells. iHMGECs, iHCECs and iHConjECs were cultured with different concentrations of BAK (5 μg/ml to 0.005 μg/ml) or FA (1 mg/ml to 1 μg/ml) under basal, proliferating or differentiating conditions up to 7 days. We used low BAK levels, because we found that 0.5 mg/ml and 50 μg/ml BAK killed iHMGECs within 1 day after a 15 min exposure. Experimental procedures included analyses of cell appearance, cell number, and neutral lipid content (LipidTox), lysosome accumulation (LysoTracker) and AKT signaling in all 3 cell types. Our results demonstrate that BAK and FA cause dose-dependent changes in the morphology, survival, proliferation and AKT signaling of iHMGECs, iHCECs and iHConjECs. Many of the concentrations tested induced cell atrophy, poor adherence, decreased proliferation and death, after 5 days of exposure. Cellular signaling, as indicated by AKT phosphorylation after 15 (FA) or 30 (BAK) minutes of treatment, was also reduced in a dose-dependent fashion in all 3 cell types, irrespective of whether cells had been cultured under proliferating or differentiating conditions. Our results support our hypothesis and demonstrate that the cosmetic preservatives, BAK and FA, exert many toxic effects on cells of the ocular surface and adnexa.
Zinc chelation and Klf9 knockdown cooperatively promote axon regeneration after optic nerve injury. Exp Neurol 2018;300:22-29.Abstract.
The inability of axons to regenerate over long-distances in the central nervous system (CNS) limits the recovery of sensory, motor, and cognitive functions after various CNS injuries and diseases. Although pre-clinical studies have identified a number of manipulations that stimulate some degree of axon growth after CNS damage, the extent of recovery remains quite limited, emphasizing the need for improved therapies. Here, we used traumatic injury to the mouse optic nerve as a model system to test the effects of combining several treatments that have recently been found to promote axon regeneration without the risks associated with manipulating known tumor suppressors or oncogenes. The treatments tested here include TPEN, a chelator of mobile (free) zinc (Zn); shRNA against the axon growth-suppressing transcription factor Klf9; and the atypical growth factor oncomodulin combined with a cAMP analog. Whereas some combinatorial treatments produced only marginally stronger effects than the individual treatments alone, co-treatment with TPEN and Klf9 knockdown had a substantially stronger effect on axon regeneration than either one alone. This combination also promoted a high level of cell survival at longer time points. Thus, Znchelation in combination with Klf9 suppression holds therapeutic potential for promoting axon regeneration after optic nerve injury, and may also be effective for treating other CNS injuries and diseases.
Testosterone Pathway Genetic Polymorphisms in Relation to Primary Open-Angle Glaucoma: An Analysis in Two Large Datasets. Invest Ophthalmol Vis Sci 2018;59(2):629-636.Abstract.
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). Both datasets contained densely called genotypes imputed to the 1000 Genomes reference panel. We used pathway- and gene-based approaches with Pathway Analysis by Randomization Incorporating Structure (PARIS) software to assess the overall association between a panel of single nucleotide polymorphisms (SNPs) in testosterone metabolism genes and POAG. In sex-stratified analyses, we evaluated POAG overall and POAG subtypes defined by maximum IOP (high-tension [HTG] or normal tension glaucoma [NTG]). Results: In the US dataset, the SNP panel was not associated with POAG (permuted P = 0.77), although there was an association in the Australian sample (permuted P = 0.018). In both datasets, the SNP panel was associated with POAG in men (permuted P ≤ 0.033) and not women (permuted P ≥ 0.42), but in gene-based analyses, there was no consistency on the main genes responsible for these findings. In both datasets, the testosterone pathway association with HTG was significant (permuted P ≤ 0.011), but again, gene-based analyses showed no consistent driver gene associations. Conclusions: Collectively, testosterone metabolism pathway SNPs were consistently associated with the high-tension subtype of POAG in two datasets.
Tacrolimus Optic Neuropathy. J Neuroophthalmol 2018;38(2):160-166.Abstract.
BACKGROUND: Tacrolimus (FK506, Prograf) is a potent immunosuppressant, which inhibits cytokine synthesis and blocks T-cell development. Optic neuropathy from tacrolimus toxicity is very uncommon but, when present, can result in severe vision loss. METHODS: Case series and review of the literature. RESULTS: We present 3 patients with tacrolimus optic neuropathy after bone marrow transplantation complicated by graft-vs-host disease and demonstrate the differing clinical and radiologic presentation of this presumed toxic optic neuropathy. CONCLUSIONS: Tacrolimus optic neuropathy can manifest in a multitude of clinical presentations and can have devastating visual consequences.
Analysis combining correlated glaucoma traits identifies five new risk loci for open-angle glaucoma. Sci Rep 2018;8(1):3124.Abstract.
Open-angle glaucoma (OAG) is a major cause of blindness worldwide. To identify new risk loci for OAG, we performed a genome-wide association study in 3,071 OAG cases and 6,750 unscreened controls, and meta-analysed the results with GWAS data for intraocular pressure (IOP) and optic disc parameters (the overall meta-analysis sample size varying between 32,000 to 48,000 participants), which are glaucoma-related traits. We identified and independently validated four novel genome-wide significant associations within or near MYOF and CYP26A1, LINC02052 and CRYGS, LMX1B, and LMO7 using single variant tests, one additional locus (C9) using gene-based tests, and two genetic pathways - "response to fluid shear stress" and "abnormal retina morphology" - in pathway-based tests. Interestingly, some of the new risk loci contribute to risk of other genetically-correlated eye diseases including myopia and age-related macular degeneration. To our knowledge, this study is the first integrative study to combine genetic data from OAG and its correlated traits to identify new risk variants and genetic pathways, highlighting the future potential of combining genetic data from genetically-correlated eye traits for the purpose of gene discovery and mapping.
Clinical Age-Specific Seasonal Conjunctivitis Patterns and Their Online Detection in Twitter, Blog, Forum, and Comment Social Media Posts. Invest Ophthalmol Vis Sci 2018;59(2):910-920.Abstract.
Purpose: We sought to determine whether big data from social media might reveal seasonal trends of conjunctivitis, most forms of which are nonreportable. Methods: Social media posts (from Twitter, and from online forums and blogs) were classified by age and by conjunctivitis type (allergic or infectious) using Boolean and machine learning methods. Based on spline smoothing, we estimated the circular mean occurrence time (a measure of central tendency for occurrence) and the circular variance (a measure of uniformity of occurrence throughout the year, providing an index of seasonality). Clinical records from a large tertiary care provider were analyzed in a similar way for comparison. Results: Social media posts machine-coded as being related to infectious conjunctivitis showed similar times of occurrence and degree of seasonality to clinical infectious cases, and likewise for machine-coded allergic conjunctivitis posts compared to clinical allergic cases. Allergic conjunctivitis showed a distinctively different seasonal pattern than infectious conjunctivitis, with a mean occurrence time later in the spring. Infectious conjunctivitis for children showed markedly greater seasonality than for adults, though the occurrence times were similar; no such difference for allergic conjunctivitis was seen. Conclusions: Social media posts broadly track the seasonal occurrence of allergic and infectious conjunctivitis, and may be a useful supplement for epidemiologic monitoring.
Transferable vancomycin resistance in clade B commensal-type Enterococcus faecium. J Antimicrob Chemother 2018;73(6):1479-1486.Abstract.
Objectives: Vancomycin-resistant Enterococcus faecium is a leading cause of MDR hospital infection. Two genetically definable populations of E. faecium have been identified: hospital-adapted MDR isolates (clade A) and vancomycin-susceptible commensal strains (clade B). VanN-type vancomycin resistance was identified in two isolates of E. faecium recovered from blood and faeces of an immunocompromised patient. To understand the genomic context in which VanN occurred in the hospitalized patient, the risk it posed for transmission in the hospital and its origins, it was of interest to determine where these strains placed within the E. faecium population structure. Methods: We obtained the genome sequence of the VanN isolates and performed comparative and functional genomics of the chromosome and plasmid content. Results: We show that, in these strains, VanN occurs in a genetic background that clusters with clade B E. faecium, which is highly unusual. We characterized the chromosome and the conjugative plasmid that carries VanN resistance in these strains, pUV24. This plasmid exhibits signatures of in-host selection on the vanN operon regulatory system, which are associated with a constitutive expression of vancomycin resistance. VanN resistance in clade B strains may go undetected by current methods. Conclusions: We report a case of vancomycin resistance in a commensal lineage of E. faecium responsible for an atypical bacteraemia in an immunocompromised patient. A reservoir of transferable glycopeptide resistance in the community could pose a concern for public health.
Laser Peripheral Iridotomy in Primary Angle Closure: A Report by the American Academy of Ophthalmology. Ophthalmology 2018;125(7):1110-1120.Abstract.
PURPOSE: To examine the efficacy and complications of laser peripheral iridotomy (LPI) in subjects with primary angle closure (PAC). METHODS: Literature searches in the PubMed and Cochrane databases were last conducted in August 2017 and yielded 300 unique citations. Of these, 36 met the inclusion criteria and were rated according to the strength of evidence; 6 articles were rated level I, 11 articles were rated level II, and 19 articles were rated level III. RESULTS: Reported outcomes were change in angle width, effect on intraocular pressure (IOP) control, disease progression, and complications. Most of the studies (29/36, 81%) included only Asian subjects. Angle width (measured by gonioscopy, ultrasound biomicroscopy, and anterior segment OCT) increased after LPI in all stages of angle closure. Gonioscopically defined persistent angle closure after LPI was reported in 2% to 57% of eyes across the disease spectrum. Baseline factors associated with persistent angle closure included narrower angle and parameters representing nonpupillary block mechanisms of angle closure, such as a thick iris, an anteriorly positioned ciliary body, or a greater lens vault. After LPI, further treatment to control IOP was reported in 0%-8% of PAC suspect (PACS), 42% to 67% of PAC, 21% to 47% of acute PAC (APAC), and 83%-100% of PAC glaucoma (PACG) eyes. Progression to PACG ranged from 0% to 0.3% per year in PACS and 0% to 4% per year in PAC. Complications after LPI included IOP spike (8-17 mmHg increase from baseline in 6%-10%), dysphotopsia (2%-11%), anterior chamber bleeding (30%-41%), and cataract progression (23%-39%). CONCLUSIONS: Laser peripheral iridotomy increases angle width in all stages of primary angle closure and has a good safety profile. Most PACS eyes do not receive further intervention, whereas many PAC and APAC eyes, and most PACG eyes, receive further treatment. Progression to PACG is uncommon in PACS and PAC. There are limited data on the comparative efficacy of LPI versus other treatments for the various stages of angle closure; 1 randomized controlled trial each demonstrated superiority of cataract surgery over LPI in APAC and of clear lens extraction over LPI in PACG or PAC with IOP above 30 mmHg.
Efficacy and Safety of Low-Dose Iodine Plaque Brachytherapy for Juxtapapillary Choroidal Melanoma. Am J Ophthalmol 2018;186:32-40.Abstract.
PURPOSE: To evaluate low- vs high-dose plaque brachytherapy for juxtapapillary choroidal melanoma. DESIGN: Retrospective interventional case series. METHODS: Setting: Single institution. STUDY POPULATION: Forty-seven patients with juxtapapillary choroidal melanoma. INTERVENTION: Iodine-125 plaque brachytherapy. Eyes were divided into apex low-dose (LD) and high-dose (HD) groups (≤ or > median apex dose 84.35 Gy). Main outcome measures were time to distant failure, local failure, death, enucleation, radiation retinopathy, optic neuropathy, and best-corrected visual acuity (BCVA). RESULTS: Freedom from distant failure rates were 96% and 95% in apex LD and HD groups at 5 years and 77% and 95% at 10 years, respectively (P = .84). Freedom from local failure rates were 90% in the apex LD group vs 89% in the HD group at 5 and 10 years (P = .96). Apex LD and HD groups did not differ for time to death or enucleation. Five- and 10-year freedom from radiation retinopathy and optic neuropathy rates were higher in the apex LD than HD group. Loss of ≥3 BCVA lines, final BCVA 20/40 or better, and final BCVA 20/200 or worse were more favorable in the 5 mm LD compared to HD group. Visual acuity outcomes did not differ between apex LD and HD groups. CONCLUSIONS: Low-dose iodine-125 plaque brachytherapy (67.5-81 Gy at tumor apex) provides safe and effective tumor control for juxtapapillary choroidal melanoma and may be associated with reduced radiation toxicity. Larger trials are needed to determine the optimal therapeutic dose for juxtapapillary choroidal melanoma.
NQO1 downregulation potentiates menadione-induced endothelial-mesenchymal transition during rosette formation in Fuchs endothelial corneal dystrophy. Free Radic Biol Med 2018;116:19-30.Abstract.
Fuchs endothelial corneal dystrophy (FECD) is a genetic and oxidative stress disorder of post-mitotic human corneal endothelial cells (HCEnCs), which normally exhibit hexagonal shape and form a compact monolayer compatible with normal corneal functioning and clear vision. FECD is associated with increased DNA damage, which in turn leads to HCEnC loss, resulting in the formation rosettes and aberrant extracellular matrix (ECM) deposition in the form of pro-fibrotic guttae. Since the mechanism of ECM deposition in FECD is currently unknown, we aimed to investigate the role of endothelial-mesenchymal transition (EMT) in FECD using a previously established cellular in vitro model that recapitulates the characteristic rosette formation, by employing menadione (MN)-induced oxidative stress. We demonstrate that MN treatment alone, or a combination of MN and TGF-β1 induces reactive oxygen species (ROS), cell death, and EMT in HCEnCs during rosette formation, resulting in upregulation of EMT- and FECD-associated markers such as Snail1, N-cadherin, ZEB1, and transforming growth factor-beta-induced (TGFβI), respectively. Additionally, FECD ex vivo specimens displayed a loss of organized junctional staining of plasma membrane-bound N-cadherin, with corresponding increase in fibronectin and Snail1 compared to ex vivo controls. Addition of N-acetylcysteine (NAC) downregulated all EMT markers and abolished rosette formation. Loss of NQO1, a metabolizing enzyme of MN, led to greater increase in intracellular ROS levels as well as a significant upregulation of Snail1, fibronectin, and N-cadherin compared to normal cells, indicating that NQO1 regulates Snail1-mediated EMT. This study provides first line evidence that MN-induced oxidative stress leads to EMT in corneal endothelial cells, and the effect of which is further potentiated when redox cycling activity of MN is enhanced by the absence of NQO1. Given that NAC inhibits Snail-mediated EMT, this may be a potential therapeutic intervention for FECD.
Genomic analysis of a large set of currently-and historically-important human adenovirus pathogens. Emerg Microbes Infect 2018;7(1):10.Abstract.
Human adenoviruses (HAdVs) are uniquely important "model organisms" as they have been used to elucidate fundamental biological processes, are recognized as complex pathogens, and are used as remedies for human health. As pathogens, HAdVs may effect asymptomatic or mild and severe symptomatic disease upon their infection of respiratory, ocular, gastrointestinal, and genitourinary systems. High-resolution genomic data have enhanced the understanding of HAdV epidemiology, with recombination recognized as an important and major pathway in the molecular evolution and genesis of emergent HAdV pathogens. To support this view and to actualize an algorithm for identifying, characterizing, and typing novel HAdVs, we determined the DNA sequence of 95 isolates from archives containing historically important pathogens and collections housing currently circulating strains to be sequenced. Of the 85 samples that were completely sequenced, 18 novel recombinants within species HAdV-B and D were identified. Two HAdV-D genomes were found to contain novel penton base and fiber genes with significant divergence from known molecular types. In this data set, we found additional isolates of HAdV-D53 and HAdV-D58, two novel genotypes recognized recently using genomics. This supports the thesis that novel HAdV genotypes are not limited to "one-time" appearances of the prototype but are of importance in HAdV epidemiology. These data underscore the significance of lateral genomic transfer in HAdV evolution and reinforce the potential public health impact of novel genotypes of HAdVs emerging in the population.
Long-chain polyunsaturated fatty acids decline rapidly in milk from mothers delivering extremely preterm indicating the need for supplementation. Acta Paediatr 2018;107(6):1020-1027.Abstract.
AIM: Our aim was to perform an in-depth analysis of the composition of fatty acids in milk from mothers delivering extremely preterm babies. We investigated longitudinal changes in milk fatty acid profiles and the relationship between several types of fatty acids, including omega-3 and omega-6. METHODS: Milk samples were collected at three stages of lactation from 78 mothers who delivered at less than 28 weeks of pregnancy at the Sahlgrenska University Hospital, Gothenburg, Sweden, from April 2013 to September 2015. Fatty acid composition was analysed by gas chromatography-mass spectrometry. RESULTS: A reduction in long-chain polyunsaturated fatty acids (LCPUFAs) was observed during the lactation period. The concentrations of arachidonic acid and docosahexaenoic acid declined from medians of 0.34 to 0.22 mol% and 0.29 to 0.15 mol%, respectively, between postnatal day 7 and a postmenstrual age of 40 weeks. Strong correlations were found between the intermediates of several classes of fatty acids, including omega-3, omega-6 and omega-9. CONCLUSION: A rapid reduction in LCPUFA content in the mother's milk during the lactation period emphasises the importance of fatty acid supplementation to infants born extremely preterm, at least during the period corresponding to the third trimester, when rapid development of the brain and adipose tissue requires high levels of LCPUFAs.