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Inflammation-driven scarring is a major contributor to surgical failure after subconjunctival bleb forming glaucoma surgery. The current gold standard anti-scarring adjuvant mitomycin C (MMC) has variable effectiveness and is associated with significant risks. Acetylsalicylic acid (ASA), when delivered locally, repurposes the typically pro-inflammatory cyclooxygenase (COX-2) signaling for the resolution of inflammation and mitigating inflammation-mediated fibrosis. The aim of this study is to compare the effects of ASA and MMC in an in vitro model of subconjunctival scarring. Glaucoma patient-derived Tenon's capsule fibroblasts (HTCFs) were treated with TGFß1 (2 ng/mL) plus or minus ASA (1600 µg/ml), or MMC (0.05, 0.1, 0.2 mg/mL). In vitro collagen contraction, MTT, LDH, immunofluorescence, and Western blot assays were performed. To elucidate the mechanistic effects of ASA in TGFß1-induced HTCFs, liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to identify and measure pro-inflammatory and pro-resolving lipid mediator secretion. ASA was at least as effective as MMC in reducing TGFß1-induced HTCF-mediated collagen contraction, metabolic activity, and pro-fibrotic protein expression, with less cytotoxicity. Within cytokine-activated HTCFs, ASA significantly impaired secretion of pro-inflammatory lipid mediators prostaglandin E2 and 6-keto-prostaglandin F1α and significantly increased secretion of the pro-resolving mediators 5-hydroxyeicosatetraenoic acid (HETE), 15-HETE and 18-hydroxyeicosapentaenoic acid (HEPE). ASA reduces cytokine-induced myofibroblast transdifferentiation in HTCFs, being non-inferior to MMC in vitro. ASA's effects are associated with a unique lipid mediator expression profile, suggesting that the ASA-induced resolution of inflammation may be a promising strategy to mitigate inflammation-mediated scarring and could offer a novel alternative as a surgical adjuvant.
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Glaucoma , Cápsula de Tenon , Humanos , Cápsula de Tenon/metabolismo , Mitomicina/farmacologia , Miofibroblastos/metabolismo , Transdiferenciação Celular , Aspirina/farmacologia , Aspirina/metabolismo , Citocinas/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Fibroblastos/metabolismo , Glaucoma/metabolismo , Cicatriz/metabolismo , Colágeno/metabolismo , Fibrose , Inflamação/metabolismo , Lipídeos , Células CultivadasRESUMO
Dysregulated wound healing and subsequent fibrosis represents the most common cause of failure in glaucoma filtration surgery. Primary means to prevent this outcome are the anti-metabolite surgical adjuvants, however, topical corticosteroids are commonly used postoperatively to permit further control of wound healing and development of the filtration bleb. Unfortunately, they carry important side effects such as raised intraocular pressure, cataract and increased infection risk. Non-steroidal anti-inflammatory drugs (NSAIDs) show promising results in clinical trials as an alternative wound modulatory drug. NSAIDs exhibit non-inferiority to steroids in terms of post-operative intraocular pressure control and secondary IOP lowering interventions, however there is little known about the differing effects these drugs exert on human Tenon's capsule fibroblast (HTCF) mediated wound healing. The purpose of this study was to assess the individual effects of dexamethasone and indomethacin on the extracellular matrix modifying actions of HTCFs in vitro. To this end, HTCFs were cultured in 3D collagen matrices as well as in 2D monolayers and exposed to clinically relevant concentrations of dexamethasone or indomethacin for up to seven days. HTCF-mediated wound healing functions were assayed through collagen matrix contraction, extracellular matrix morphology, estimation of HCTF proliferation and differentiation into myofibroblasts within the collagen matrices, as well as western blot. Both drugs significantly reduced HTCF-mediated collagen contraction relative to control however there was a significant trend towards greater inhibition with indomethacin exposure compared to dexamethasone. Indomethacin exposure significantly reduced HTCF-mediated collagen remodelling activity compared vehicle control, whereas dexamethasone was unable to reduce remodelling activity at any of the studied exposures. Both drugs reduced myofibroblast differentiation, however indomethacin alone demonstrated an inhibitory effect on final cell number relative to control whereas dexamethasone had no significant effect at any studied exposure. These findings demonstrate that both steroidal and NSAID treatment can mitigate HTCF-mediated collagen contraction and αSMA expression. However, NSAIDs may function to better impede HTCF proliferation and remodelling activity. Taken in the context of previous glaucoma surgical trials, NSAIDs appear to be a viable alternative to steroids for post-operative wound modulation.
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Anti-Inflamatórios/farmacologia , Dexametasona/farmacologia , Fibroblastos/efeitos dos fármacos , Glaucoma/cirurgia , Indometacina/farmacologia , Cápsula de Tenon/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Colágeno/metabolismo , Fibroblastos/metabolismo , Humanos , Cápsula de Tenon/metabolismoRESUMO
BACKGROUND: Matrix metalloproteinases (MMPs) are reported to contribute to the mechanism of argon laser trabeculoplasty, but it is unknown whether they are also secreted after selective laser trabeculoplasty (SLT). The aim of this study was to investigate whether human primary trabecular meshwork (HTM) cells secrete MMP-3 after stimulation by SLT. The relationship between SLT and the two principal forms of cell death, apoptosis and necrosis, was also examined. METHODS: Non-pigmented primary HTM cells were challenged with melanin granules to artificially introduce pigmentation. Isolated non-pigmented HTM cells and 1:1 co-cultures of pigmented and non-pigmented cells were treated with 0.5-1.5 mJ SLT. Cellular metabolic activity (CMA) was quantified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis and necrosis were measured using a cell death ELISA and a lactate dehydrogenase assay, respectively. MMP-3 secretion was measured by ELISA. RESULTS: Co-cultures exhibited a dose-dependent decline in CMA and a dose-dependent increase in necrosis 4 and 24 h after SLT. Non-pigmented cells did not undergo necrosis and displayed a trend towards increased CMA. Apoptosis was reduced in non-pigmented cells but elevated in co-cultures. Increased MMP-3 secretion was observed from co-cultures but not isolated non-pigmented cells. CONCLUSIONS: Pigmentation is necessary for both post-SLT cell death and MMP-3 secretion. SLT appears to have a hormetic effect on non-pigmented HTM cells.
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Terapia a Laser , Metaloproteinase 3 da Matriz/metabolismo , Malha Trabecular/enzimologia , Malha Trabecular/cirurgia , Trabeculectomia , Apoptose , Células Cultivadas , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Humanos , L-Lactato Desidrogenase/metabolismo , Lasers de Estado Sólido/uso terapêutico , Melaninas/farmacologia , Necrose , Sais de Tetrazólio , Tiazóis , Malha Trabecular/patologiaRESUMO
BACKGROUND: Benzalkonium chloride (BAK) is a controversial ophthalmic preservative because of its prominent side-effect profile. In this study, we examined the mechanism of BAK toxicity in human trabecular meshwork cells (HTMC) and compared the effects of BAK with tafluprost free acid, which is an active form of tafluprost commercially available in a preservative-free formulation. METHODS: Primary HTMC were treated with different BAK concentrations over various exposure times. Cell viability was quantified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenol tetrazolium bromide assay, and apoptosis was measured by enzyme-linked immunosorbent assay. The cell viability of primary HTMC exposed to various concentrations and times of tafluprost free acid was also determined. Cells were treated with BAK and tafluprost free acid for 30 min at 37°C, and cell viability was again assessed. The effect of BAK on the gap junction protein Connexin-43 (Cx43) expression was subsequently examined. RESULTS: BAK treatment resulted in a dose- and time-dependent decline in cell viability. Apoptosis increased following BAK treatment. Tafluprost-free acid treatment did not significantly affect cell viability. Tafluprost co-treatment with BAK resulted in an increase in cell viability as compared with BAK treatment alone. BAK treatment upregulated Cx43 expression in HTMC. CONCLUSIONS: These results demonstrate that BAK is harmful to the health of cultured HTMC. Tafluprost is both safe and cytoprotective against BAK for these HTMC. The effect of tafluprost on the gap junctions of the HTM should be further investigated.
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Apoptose/efeitos dos fármacos , Compostos de Benzalcônio/toxicidade , Citoproteção/efeitos dos fármacos , Conservantes Farmacêuticos/toxicidade , Prostaglandinas F/farmacologia , Malha Trabecular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Conexina 43/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Humanos , Microscopia Confocal , Sais de Tetrazólio/metabolismo , Tiazóis/metabolismo , Fatores de Tempo , Malha Trabecular/metabolismo , Malha Trabecular/patologiaRESUMO
BACKGROUND: To assess the effects of amniotic membrane extract (AMX) on cellular activity of primary human corneal epithelial (HCE) cells under mechanical and oxidative stress, and on human limbal cells under oxidative stress. METHODS: Corneal mechanical stress was simulated with a linear scratch in confluent HCE cell plates, then incubated with 0.1% AMX for 48 and 72 h. Subjecting HCE cultures to 0.5 mmol/L tertiary-butylhydroperoxide for 1 h simulated an oxidative stress. 0.1% AMX-treated cultures were compared with controls at 24 and 48 h using cellular viability assay, along with 12-h AMX pretreatment and human limbal cell comparisons. RESULTS: Mechanical stress on HCE cultures revealed a statistically significant distance ratio at 48 and 72 h in favour of 0.1% AMX-treated cultures (P = 0.021 and 0.035, respectively). Oxidative stress did not reveal any significant difference in cellular viability of AMX-treated versus control cultures. Twelve hour AMX pre-treatment prior to oxidative stress revealed a significant difference after 24 h from oxidative injury (73.3% AMXâ vs. 66.0% control, P = 0.035), but not after 48 h. Human limbal cells demonstrated significantly improved oxidative viability compared with HCE cells, with (91.0% vs. 82.0% control, P = 0.017) and without 0.1% AMX pre-treatment (91.2% vs. 83.7% control, P = 0.019). CONCLUSIONS: HCE cells treated with AMX healed faster after mechanical insult, suggesting a potential benefit in acute corneal injuries. Under oxidative stress, human limbal cells, a more proliferative cell type, showed superior viability compared with HCE cells.
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Âmnio/química , Epitélio Corneano/efeitos dos fármacos , Limbo da Córnea/efeitos dos fármacos , Extratos de Tecidos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Epitélio Corneano/citologia , Humanos , Limbo da Córnea/citologia , Estresse Oxidativo , Estresse Mecânico , Cicatrização/fisiologia , terc-Butil Hidroperóxido/toxicidadeRESUMO
Homeostasis is essential for cell survival. However, homeostatic regulation of surface epithelia is poorly understood. The eye surface, lacking the cornified barrier of skin, provides an excellent model. Tears cover the surface of the eye and are deficient in dry eye, the most common eye disease affecting at least 5% of the world's population. Only a tiny fraction of the tear proteome appears to be affected, including lacritin, an epithelium-selective mitogen that promotes basal tearing when topically applied to rabbit eyes. Here we show that homeostasis of cultured corneal epithelia is entirely lacritin-dependent and elucidate the mechanism as a rapid autophagic flux to promptly restore cellular metabolism and mitochondrial fusion in keeping with the short residence time of lacritin on the eye. Accelerated flux appears to be derived from lacritin-stimulated acetylation of FOXO3 as a novel ligand for ATG101 and coupling of stress-acetylated FOXO1 with ATG7 (which remains uncoupled without lacritin) and be sufficient to selectively divert huntingtin mutant Htt103Q aggregates largely without affecting non-aggregated Htt25Q. This is in keeping with stress as a prerequisite for lacritin-stimulated autophagy. Lacritin targets the cell surface proteoglycan syndecan-1 via its C-terminal amino acids Leu(108)-Leu(109)-Phe(112) and is also available in saliva, plasma, and lung lavage. Thus, lacritin may promote epithelial homeostasis widely.
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Autofagia/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Fatores de Transcrição Forkhead/metabolismo , Glicoproteínas/farmacologia , Metaboloma/efeitos dos fármacos , Sequência de Aminoácidos , Proteína 7 Relacionada à Autofagia , Proteínas Relacionadas à Autofagia , Células Cultivadas , Células Epiteliais/metabolismo , Proteína Forkhead Box O3 , Fatores de Transcrição Forkhead/genética , Glicoproteínas/química , Glicoproteínas/genética , Homeostase/efeitos dos fármacos , Humanos , Proteína Huntingtina , Interferon gama/farmacologia , Espectrometria de Massas , Dados de Sequência Molecular , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/farmacologia , Interferência de RNA , Proteínas Recombinantes/farmacologia , Sindecana-1/genética , Sindecana-1/metabolismo , Lágrimas/química , Lágrimas/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Enzimas Ativadoras de Ubiquitina/genética , Enzimas Ativadoras de Ubiquitina/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMO
Selective laser trabeculoplasty is a safe and effective treatment for glaucoma, with greater cost effectiveness than its pharmacological and surgical alternatives. Nevertheless, although the basic science literature on selective laser trabeculoplasty continues to grow, there remains uncertainty over the mechanism by which laser trabeculoplasty reduces intraocular pressure. To address this uncertainty, the evidence behind several potential biological and mechanical mechanisms of selective laser trabeculoplasty were reviewed. In particular, cytokine secretion, matrix metalloproteinase induction, increased cell division, repopulation of burn sites and macrophage recruitment were discussed. Refining our understanding of these mechanisms is essential both to understanding the pathophysiology of ocular hypertension and developing improved therapies to treat the condition.
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Coagulação com Plasma de Argônio , Glaucoma/cirurgia , Malha Trabecular/cirurgia , Trabeculectomia/métodos , Humanos , Pressão IntraocularRESUMO
OBJECTIVE: Because of increased evidence for safety and increased demands, there appears to be a recent adoption and endorsement of immediate sequential bilateral cataract surgery (ISBCS). This study aims to determine whether a paradigm shift has occurred in the delivery of cataract surgery in the province of Ontario and its the extent, if any, and to analyze the current role of ISBCS. DESIGN: Retrospective health records analysis. METHODS: We analyzed aggregate Ontario Health Insurance Plan claim counts for cataract surgeries between 2016 and 2022, categorizing cases into unilateral, ISBCS, and delayed sequential bilateral cataract surgery (DSBCS) cases. We examined trends, compared wait times for second surgeries in the DSBCS cohort with wait times for first surgeries, and used previously published cost estimates for ISBCS to estimate annual savings in Ontario. RESULTS: There were 1,122 ISBCS cases in 2016, which increased sixfold during the pandemic (2020-2021) and further increased to 11,876 cases in 2022. Unilateral and DSBCS cases decreased during the pandemic but rebounded in 2022 to 102% and 153% of baseline, respectively. ISBCS increased from 1% to 10%, unilateral cases decreased from 41% to 29% of total cases, and DSBCS increased from 58% to 61%. Median wait for patients' first and second surgeries increased from 65 to 87 days and 28 to 33 days, respectively. Using estimates, ISBCS saved approximately $19 million in 2022. CONCLUSION: Our study demonstrates a paradigm shift in Ontario in favour of ISBCS. ISBCS also may be a strategy to reduce increasing wait times while saving health care system dollars.
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OBJECTIVE: This study aimed to assess whether the research output of medical students who matched into a Canadian ophthalmology residency program influences their subsequent research productivity during residency, decision to pursue a fellowship, or engagement in academic practice. DESIGN: Retrospective database review. PARTICIPANTS: A total of 369 trainees commencing ophthalmology residency from 2004 to 2015 at 15 residency programs. METHODS: Each trainee's publication record was queried in Scopus before and after the date they started residency. Multiple public sources were searched to identify fellowship placement and the type of subsequent practice (i.e., academic or community). Predictors of research productivity during residency, fellowship, and practice setting were assessed using multivariable regression analyses. RESULTS: Trainees with pre-residency publications (nâ¯=â¯187) demonstrated significantly higher research productivity during residency than those without pre-residency publications (nâ¯=â¯182), with a mean of 5.17 ± 5.97 versus 1.60 ± 2.38 publications on any topic (p < 0.001). Pre-residency research output was a predictor of research productivity during residency (relative riskâ¯=â¯1.17; 95% CI, 1.09-1.27; p < 0.001), pursuing fellowship (odds ratio, 2.9; 95% CI, 1.74-4.83), and an academic career (odds ratioâ¯=â¯1.85; 95% CI, 1.07-3.2). CONCLUSION: Pre-residency research output is a significant predictor of research productivity during residency and subsequent career choices, suggesting that pre-residency publishing reflects a propensity toward an academic trajectory. Residency publication count moderates this association, underscoring the role of the residency program environment in fostering research productivity. Addressing barriers such as mentorship, funding, and curriculum may be key to incentivizing trainees to pursue academic medicine.
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BACKGROUND: To investigate the effect of perioperative intraocular pressure (IOP) lowering medications on controlling postoperative IOP following uncomplicated phacoemulsification. METHODS: Ovid MEDLINE, EMBASE, and Cochrane CENTRAL databases were searched up until November 2022. Randomised controlled trials (RCTs) that assessed IOP change via applanation tonometry in medicated and control arms following uncomplicated cataract surgery in healthy eyes were included. The primary outcome was the weighted mean difference (WMD) of IOP at 2-8 h, 12-24 h, and 1-7 days postoperatively within each medication class or common fixed-combination formulations. Risk of bias was assessed using the revised risk of bias in randomised trials (RoB-2). Level of evidence was rated using the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) RESULTS: From 702 screened articles, 30 RCTs involving 2986 eyes were included. There was a statistically significant reduction in IOP favouring treatment arms at 2-8 h (WMD = -3.87 mmHg; 95% CI [-4.75, -3.00]; p < 0.001) and 12-24 h (WMD = -2.69 mmHg; 95% CI [-3.36, -2.02]; p < 0.001), with the effect wearing off beyond 1 day (p = 0.18). Between medication classes, the largest effect at both 2-8 h and 12-24 h was observed with intracameral cholinergics or fixed-combination carbonic anhydrase inhibitor-beta-blocker (FCCB) formulations. Conversely, the smallest effect was observed with prostaglandin analogues, alpha-agonists, and topical carbonic anhydrase inhibitors (CAIs). CONCLUSION: Prophylaxis against acute IOP elevations following uncomplicated cataract surgery is effective. FCCB and intracameral cholinergics are the most effective ocular antihypertensive agents, while alpha-agonists, prostaglandin analogues, and topical CAIs were found to be the least effective. These findings may inform future surgical guidelines.
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Anti-Hipertensivos , Pressão Intraocular , Facoemulsificação , Humanos , Pressão Intraocular/efeitos dos fármacos , Pressão Intraocular/fisiologia , Anti-Hipertensivos/uso terapêutico , Complicações Pós-Operatórias/prevenção & controle , Tonometria Ocular , Hipertensão Ocular/prevenção & controleRESUMO
Purpose: The gold standard for managing postoperative ocular fibrosis in glaucoma surgery is the chemotherapeutic mitomycin C (MMC) despite its association with significant adverse effects. This study compares in vitro the antifibrotic efficacy and cytotoxicity of the small-molecule TGFß1 inhibitor SB-431542 (SB) to MMC. Methods: To measure collagen contraction, human Tenon's capsule fibroblasts (HTCFs) embedded in a three-dimensional collagen lattice were exposed to 0.2 mg/mL MMC or 20 µM SB followed by incubation with 2 ng/mL TGFß1. Total protein extracted from experimentally treated HTCFs underwent immunoblotting for α-smooth muscle actin (α-SMA), matrix metallopeptidase 9 (MMP-9), and EDA splice-variant fibronectin (EDA-FN) expression. Cytotoxicity and cell metabolism were assessed using LIVE/DEAD staining, lactate dehydrogenase (LDH) assay, and methylthiazole tetrazolium (MTT) assay. Results: Collagen lattice contraction in TGFß1-induced HTCFs was significantly lowered by SB and MMC. Pretreatment with SB and MMC significantly lowered protein expression of α-SMA, MMP-9, and EDA-FN in HTCFs relative to TGFß1 alone. HTCF viability in collagen lattices was significantly reduced with MMC pretreatment but not SB pretreatment. MMC-pretreated HTCFs had a significant increase in LDH release after 3 hours and a decrease in MTT activity after 20 minutes, while SB-pretreated HTCFs showed no significant changes via MTT or LDH assay during the same treatment period. Conclusions: SB shows comparable efficacy to MMC in reducing expression of fibrosis-promoting proteins in HTCFs and in vitro scarring activity. SB distinguishes itself from MMC by exhibiting less cytotoxicity in both two-dimensional and three-dimensional in vitro assays. Translational Relevance: This study demonstrates in vitro the potential of SB as a safer alternative ocular antifibrotic agent.
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Glaucoma , Mitomicina , Humanos , Mitomicina/metabolismo , Mitomicina/farmacologia , Cápsula de Tenon/metabolismo , Cápsula de Tenon/patologia , Cicatriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/farmacologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Colágeno , Glaucoma/cirurgiaRESUMO
TOPIC: The purpose of the current study was to systematically identify and evaluate existing patient-reported outcome measures (PROMs) for clinical glaucoma practice. CLINICAL RELEVANCE: Understanding and incorporating patient preferences into decision-making is now recognized as critical for optimal resource allocation, especially in technologically advancing areas, such as minimally invasive surgeries. Patient-reported outcome measures are instruments designed to evaluate the health outcomes that are most important to patients. Despite their recognized importance, especially in the era of patient-centered care, their routine use in clinical settings remains low. METHODS: A systematic literature search was conducted in 6 databases (EMBASE, MEDLINE, PsycINFO, Scopus, BIOSIS, and Web of Science) from the date of inception. Studies were included in the qualitative review if they reported measurement properties of PROMs in adult patients with glaucoma. COnsensus-based Standards for the selection of health Measurement INstruments guidelines were used to assess the included PROMs. The study protocol is registered with PROSPERO (registration number: CRD42020176064). RESULTS: The literature search yielded 2661 records. After deduplication, 1259 studies entered level 1 screening, and based on title and abstract review, 164 records proceeded to full-text screening. In 48 included studies, 70 instrument reports discuss 43 distinct instruments in 3 major categories: glaucoma-specific, vision-specific, and general health-related quality of life. Most used measures were glaucoma-specific (Glaucoma Quality of Life [GQL] and Glaucoma Symptom Scale [GSS]) and vision-specific (National Eye Institute Visual Function Questionnaire [NEI VFQ-25]). All 3 have sufficient validity (especially construct), with GQL and GSS having sufficient internal consistency, cross-cultural validity, and reliability, with reports suggesting high methodological quality. CONCLUSION: The GQL, GSS, and NEI VFQ-25 are the 3 most used questionnaires in a research setting, having considerable validation in a patient population with glaucoma. Limited reports on interpretability, responsiveness, and feasibility in all 43 identified instruments make identifying a single optimal questionnaire for clinical use challenging and highlight the need for further studies. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Glaucoma , Qualidade de Vida , Adulto , Humanos , Reprodutibilidade dos Testes , Medidas de Resultados Relatados pelo Paciente , Glaucoma/diagnóstico , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Connexins (Cx) are the basic units of gap junctions and contribute to cellular integrity by promoting intercellular communication. Disruption of the retinal pigment epithelial monolayer may be an early event in the pathogenesis of age-related macular degeneration, a condition in which vascular endothelial growth factor (VEGF) is known to be of importance. This study was designed to assess the effect of connexin43 (Cx43) expression and gap junctional intercellular communication (GJIC) on the expression and secretion of VEGF from the retinal pigment epithelium under normal cell culture and oxidative stress conditions. METHODS: Stable cell lines of ARPE-19 were produced in which wild-type Cx43 was either over-expressed, down-regulated by targeted shRNA, or functionally inhibited by co-expression of a disease-linked dominant-negative mutant (G21R). Pharmacologic blockade of GJIC was accomplished with flufenamic acid. Oxidant challenge was performed with tert-butyl hydroperoxide (tBH). VEGF gene expression and secretion were assessed by real-time PCR and ELISA respectively. RESULTS: Over-expression of Cx43 in ARPE-19 cells reduced both gene expression and secretion of VEGF. Down-regulation of Cx43 increased gene expression and secretion of VEGF. Increased secretion of VEGF was also observed in ARPE-19 cells expressing a dominant-negative mutant of Cx43, and when GJIC was blocked. Over-expression of Cx43 reduced tBH-induced secretion of VEGF from ARPE-19 cells. CONCLUSIONS: These studies show that Cx43 protects against oxidative stress-induced VEGF secretion in ARPE-19 cells, and thus has important implications in understanding the pathogenesis of age-related macular degeneration.
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Conexina 43/farmacologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Western Blotting , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Ácido Flufenâmico/farmacologia , Junções Comunicantes/efeitos dos fármacos , Humanos , Estresse Oxidativo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Epitélio Pigmentado da Retina/metabolismo , terc-Butil Hidroperóxido/farmacologiaRESUMO
The current diagnostic aids for red eye are static flowcharts that do not provide dynamic, stepwise workups. The diagnostic accuracy of a novel dynamic Bayesian algorithm for red eye was tested. Fifty-seven patients with red eye were evaluated by an emergency medicine physician who completed a questionnaire about symptoms/findings (without requiring extensive slit lamp findings). An ophthalmologist then attributed an independent "gold-standard diagnosis". The algorithm used questionnaire data to suggest a differential diagnosis. The referrer's diagnostic accuracy was 70.2%, while the algorithm's accuracy was 68.4%, increasing to 75.4% with the algorithm's top two diagnoses included and 80.7% with the top three included. In urgent cases of red eye (n = 26), the referrer diagnostic accuracy was 76.9%, while the algorithm's top diagnosis was 73.1% accurate, increasing to 84.6% (top two included) and 88.5% (top three included). The algorithm's sensitivity for urgent cases was 76.9% (95% CI: 56-91%) using its top diagnosis, with a specificity of 93.6% (95% CI: 79-99%). This novel algorithm provides dynamic workups using clinical symptoms, and may be used as an adjunct to clinical judgement for triaging the urgency of ocular causes of red eye.
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Purpose: Vision impairment affects 2.2 billion people worldwide, half of which is preventable with early detection and treatment. Currently, automatic screening of ocular pathologies using convolutional neural networks (CNNs) on retinal fundus photographs is limited to a few pathologies. Simultaneous detection of multiple ophthalmic pathologies would increase clinical usability and uptake. Methods: Two thousand five hundred sixty images were used from the Retinal Fundus Multi-Disease Image Dataset (RFMiD). Models were trained (n = 1920) and validated (n = 640). Five selected CNN architectures were trained to predict the presence of any pathology and categorize the 28 pathologies. All models were trained to minimize asymmetric loss, a modified form of binary cross-entropy. Individual model predictions were averaged to obtain a final ensembled model and assessed for mean area under the receiver-operator characteristic curve (AUROC) for disease screening (healthy versus pathologic image) and classification (AUROC for each class). Results: The ensemble network achieved a disease screening (healthy versus pathologic) AUROC score of 0.9613. The highest single network score was 0.9586 using the SE-ResNeXt architecture. For individual disease classification, the average AUROC score for each class was 0.9295. Conclusions: Retinal fundus images analyzed by an ensemble of CNNs trained to minimize asymmetric loss were effective in detection and classification of ocular pathologies than individual models. External validation is needed to translate machine learning models to diverse clinical contexts. Translational Relevance: This study demonstrates the potential benefit of ensemble-based deep learning methods on improving automatic screening and diagnosis of multiple ocular pathologies from fundoscopy imaging.
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Algoritmos , Doenças Retinianas , Humanos , Fundo de Olho , Redes Neurais de Computação , Aprendizado de Máquina , Área Sob a Curva , Doenças Retinianas/diagnóstico por imagemRESUMO
OBJECTIVE: To assess the impact of ophthalmology resident research and its relationship to subsequent practice. DESIGN: Cross-sectional study. PARTICIPANTS: Three hundred and twenty residents of Canadian ophthalmology programs graduating between 2009 and 2020. METHODS: Bibliometric data were obtained for each resident from Scopus. Indices of scholarly productivity included number of publications, h-index, m-quotient, and total citations. Demographic and career data were obtained from faculty listings and professional and regulatory web sites. Career outcomes included location and subspecialty of fellowship training and type of ultimate practice (academic vs community). RESULTS: In total, 208 of 320 graduates (65%) published at least 1 peer-reviewed article during residency. Bibliometric indices, including numbers of papers, h-index, and total citations, were significantly higher for male residents and residents who pursued academic and subspecialized practices. No significant trends were seen regarding scholarly productivity and fellowship match outcomes (e.g., location and subspecialty of fellowship). The bulk of resident research projects was of lower tiers of evidence, including retrospective studies (nâ¯=â¯111) and case reports (nâ¯=â¯108). Five-year scholarly impact of resident research decreased over time (h-index, mâ¯=â¯-0.14; p < 0.01) despite stable publication volumes. CONCLUSIONS: Greater scholarly activity in residency corresponds to more academic and subspecialized practices but is not associated with type of fellowship. The impact of resident research declined between 2009 and 2020. Sex-based disparities exist.
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Purpose: Starting in 2019, the Global Initiative for Asthma recommended the use of inhaled corticosteroids (ICS) as part of reliever combination therapy in patients 12 years of age and older, thus dramatically increasing the population exposure to ICS. ICS and intranasal corticosteroids (INS) are commonly used for a variety of respiratory diseases. Chronic steroid use is a well-known risk factor for elevated intraocular pressure (IOP) and glaucoma regardless of route of administration. This study aimed to determine the reported risk of glaucoma, ocular hypertension (OHT) and IOP elevation associated with ICS and INS use. Materials and Methods: Systematic literature search in MEDLINE, EMBASE, Cochrane, CINAHL, BIOSIS, and Web of Science databases from the date of inception identified studies that assess ocular outcomes related to glaucoma in ICS and INS users. Study selection, risk of bias assessment and data extraction were done independently in duplicate. Meta-analysis assessed glaucoma incidence, OHT incidence and IOP changes in patients using ICS and INS. Study adhered to PRISMA guidelines. Study protocol was registered with PROSPERO: CRD42020190241. Results: Qualitative and quantitative analyses included 65 and 41 studies, respectively. Incidence of glaucoma was not significantly different in either ICS or INS users compared to control over 45,457 person-years of follow-up. Similarly, no significant difference in OHT incidence over 4431 person-years was detected. In studies reporting IOP, a significantly higher IOP was observed (0.69 mmHg) in 857 ICS or INS users compared to 615 controls. However, no significant increase in IOP was observed within ICS or INS users when compared to pre-treatment baseline. Conclusion: Overall, use of ICS or INS does not significantly increase the incidence of glaucoma or OHT. However, ICS and INS patients had significantly higher IOPs compared to untreated patients. Awareness of these findings is significant in care of patients with additional risk factors for glaucoma.
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PURPOSE: To report a case of accelerated visual field progression secondary to a new orbital apex lesion in a patient with a longstanding history of fatigue and cough. OBSERVATIONS: A 73-year-old myopic female with known open angle glaucoma presented with accelerated unilateral visual field progression. Maximally tolerated medical therapy was instituted over a period of 1-2 years with imminent discussions of surgical intervention. Around this time the patient reported worsening cough and fatigue, which were initially attributed to glaucoma medication side effects. Consideration of the patient's remote history of melanoma and the current asymmetry of the visual field progression triggered a computerized tomography (CT) scan of the orbits as part of the management. An orbital apex lesion was discovered, raising suspicion for metastatic melanoma, and restaging CT imaging uncovered renal, hepatic, and mediastinal masses. Unexpectedly, biopsies revealed non-necrotizing granulomatous inflammatory processes consistent with a diagnosis of sarcoidosis. It is perhaps noteworthy that the patient had received interferon therapy for management of her melanoma; previous reports have associated interferon exposure with subsequent sarcoid disease, regardless of duration of therapy or elapsed time since exposure. CONCLUSIONS AND IMPORTANCE: Although rare, sarcoidosis can occur virtually anywhere in the body, including the orbital apex. Its common early symptoms, fatigue and cough, are insidious and seen frequently in this patient's age group and medication side effect profile. It is important to maintain an appropriate index of suspicion when monitoring atypical visual field progression in a patient with glaucoma. In this case, imaging, subsequent biopsy, and a multi-specialty team were integral to this patient's diagnosis and management.
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OBJECTIVE: To outline the current impact of Canadian ophthalmology and vision science research as measured by novel research metrics. DESIGN: Cross-sectional survey. PARTICIPANTS: All Canadian ophthalmologists (n = 687) and vision scientists (n = 119) with an online bibliometric profile and academic appointment at a major ophthalmology training centre were included. METHODS: Faculty lists of Canada's 15 major academic ophthalmology departments were obtained. Faculty names, appointments, sex, and educational background were recorded. Elsevier's Scopus database was used to calculate H-index, m-quotient, and total citations for each faculty member. Details around grant funding were obtained through the Canadian Institutes of Health Research (CIHR) Funding Decisions Database. RESULTS: Average H-indices were 7.42 ± 7.98 for ophthalmologists and 23.78 ± 15.25 for vision scientists. Higher academic appointment was correlated with higher h-indices and m-quotients (p <0.0001 for both). Most academic departments had significantly more males than females (avg. 71% male, 29% female); however, more equal ratios were seen in faculties in Quebec. No significant differences in research impact were identified between male and female ophthalmologists when controlled for academic appointment and career stage (p > 0.05). In clinical ophthalmology research, the top three departments with the highest average H-indices were Western University, the University of Toronto, and Dalhousie University. The University of British Columbia, Université de Montréal, and McGill University received the most funding from the CIHR in the last 10 years. CONCLUSION: This study highlights the current scope of ophthalmology and vision science research in Canada. Important trends were identified in research productivity across academic rank, sex, and clinical subspecialty.
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The key clinical attributes of preserved dorzolamide/timolol fixed combination (DTFC) and the emerging potential of preservative-free (PF) DTFC are reviewed with published evidence and clinical experience. The indications and role of DTFC in current glaucoma management are critically discussed. Preserved DTFC became the first intraocular pressure (IOP)-lowering fixed combination (FC) approved by the US Food and Drug Administration (FDA) and remains one of most commonly used medications worldwide. The pharmacological properties of DTFC reflect those of its two time-tested constituents, i.e., the carbonic anhydrase inhibitor dorzolamide and the non-selective beta-blocker timolol. In regulatory studies DTFC lowers IOP on average by 9 mmHg (32.7%) at peak and by 7.7 mmHg (27%) at trough. In trials DTFC shows equivalence to unfixed concomitant therapy, but in real-life practice it may prove superior owing to enhanced convenience, elimination of the washout effect from the second drop, improved tolerability, and better adherence. PF DTFC became the first PF FC approved, first in unit-dose pipettes, and more recently in a multidose format. Cumulative evidence has confirmed that PF DTFC is at least equivalent in efficacy to preserved DTFC and provides a tangible clinical benefit to patients with glaucoma suffering from ocular surface disease by improving tolerability and adherence. Finally, we identify areas that warrant further investigation with preserved and PF DTFC.