RESUMO
Central serous chorioretinopathy (CSCR) is a retinal disease affecting the retinal pigment epithelium (RPE) and the choroid. This is a recognized side-effect of glucocorticoids (GCs), administered through nasal, articular, oral and dermal routes. However, CSCR does not occur after intraocular GCs administration, suggesting that a hypothalamic-pituitary-adrenal axis (HPA) brake could play a role in the mechanistic link between CSCR and GS. The aim of this study was to explore this hypothesis. To induce HPA brake, Lewis rats received a systemic injection of dexamethasone daily for five days. Control rats received saline injections. Baseline levels of corticosterone were measured by Elisa at baseline and at 5 days in the serum and the ocular media and dexamethasone levels were measured at 5 days in the serum and ocular media. The expression of genes encoding glucocorticoid receptor (GR), mineralocorticoid receptors (MR), and the 11 beta hydroxysteroid dehydrogenase (HSD) enzymes 1 and 2 were quantified in the neural retina and in RPE/ choroid. The expression of MR target genes was quantified in the retina (Scnn1A (encoding ENac-α, Kir4.1 and Aqp4) and in the RPE/choroid (Shroom 2, Ngal, Mmp9 and Omg, Ptx3, Plaur and Fosl-1). Only 10% of the corticosterone serum concentration was measured in the ocular media. Corticosterone levels in the serum and in the ocular media dropped after 5 days of dexamethasone systemic treatment, reflecting HPA axis brake. Whilst both GR and MR were downregulated in the retina without MR/GR imbalance, in the RPE/choroid, both MR/GR and 11ß-hsd2/11ß-hsd1 ratio increased, indicating MR pathway activation. MR-target genes were upregulated in the RPE/ choroid but not in the retina. The psychological stress induced by the repeated injection of saline also induced HPA axis brake with a trend towards MR pathway activation in RPE/ choroid. HPA axis brake causes an imbalance of corticoid receptors expression in the RPE/choroid towards overactivation of MR pathway, which could favor the occurrence of CSCR.
Assuntos
Glucocorticoides/metabolismo , Mineralocorticoides/metabolismo , Retina/metabolismo , Animais , Coriorretinopatia Serosa Central/tratamento farmacológico , Coriorretinopatia Serosa Central/fisiopatologia , Corioide/efeitos dos fármacos , Corioide/metabolismo , Corticosterona/sangue , Dexametasona/metabolismo , Dexametasona/farmacologia , Olho/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Ratos Endogâmicos Lew , Receptores de Glucocorticoides/metabolismo , Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologiaRESUMO
Purpose: To characterize the effects of timolol and latanoprost on calculated ocular perfusion pressure (OPP) in a multicenter, prospective, crossover-design study. Methods: Nonglaucomatous volunteers were evaluated at baseline, after 1 week of timolol 0.5% dosed twice daily, and after 1 week of latanoprost 0.005% dosed nightly (randomized treatment order; 6-week washout period). Pneumatonometric intraocular pressure (IOP) and brachial blood pressure (BP) were evaluated at each visit. Using 3 commonly used equations, OPP was calculated based on IOP and BP. The OPPs at each visit were compared by using linear mixed-effects models. Results: This analysis includes 121 participants (242 eyes; 75% female, 87% White, mean age 55 years). Mean OPP (standard deviation) calculated with mean arterial pressure was 46.8 (8.1) mmHg at baseline, 48.5 (7.9) mmHg with timolol (P = 0.005), and 49.6 mmHg (8.2) with latanoprost (P < 0.001). When compared with baseline, OPP calculated with diastolic BP was significantly increased with both timolol (1.3 mmHg) and latanoprost (3.1 mmHg). The OPP calculated with systolic BP was increased with latanoprost (2.8 mmHg) but decreased with timolol (-1.3 mmHg). Timolol reduced systolic BP by 3.2 mmHg. Compared with timolol, latanoprost conferred greater increases in OPP calculated with both systolic and diastolic BP compared with baseline; however, the difference in treatment effects on OPP calculated with mean arterial pressure was not significantly different (P = 0.068). Conclusion: In this crossover study of nonglaucomatous volunteers, latanoprost increased OPP. However, timolol's benefit to OPP may be limited in part because it reduced systolic BP. Clinical Trial Registration number: NCT01677507.
Assuntos
Latanoprosta/farmacologia , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Soluções Oftálmicas/farmacologia , Timolol/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Feminino , Voluntários Saudáveis , Humanos , Pressão Intraocular/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
A previous study reported thermal effects resulting from millimeter wave exposures at 35 and 94 GHz on non-human primates, specifically rhesus monkeys' (Macaca mulatta) corneas, but the data exhibited large variations in the observed temperatures and uncertainties in the millimeter wave dosimetry. By incorporating improvements in models and dosimetry, a non-human primate experiment was conducted involving corneal exposures that agreed well with a three-layer, one-dimensional, thermodynamic model to predict the expected surface temperature rise. The new data indicated that the originally reported safety margins for eye exposures were underestimated by 41 ± 20% over the power densities explored. As a result, the expected minimal visible lesion thresholds should be raised to 10.6 ± 1.5 and 7.1 ± 1.0 J cm at 35 and 94 GHz, respectively, provided that the power density is less than 6 W cm for subjects that are unable to blink. If the blink reflex was active, a power density threshold of 20 W cm could be used to protect the eye, although the eyelid could be burned if the exposure was long enough.
Assuntos
Córnea/efeitos da radiação , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Algoritmos , Animais , Temperatura Corporal , Simulação por Computador , Relação Dose-Resposta à Radiação , Células Epiteliais/efeitos da radiação , Macaca mulatta , Micro-Ondas , Modelos Teóricos , Doses de Radiação , Exposição à Radiação , Ondas de Rádio , Radiometria , Pele/citologia , Fatores de TempoRESUMO
Serious cutaneous adverse drug reactions [i.e., SJS/TEN with severe ocular complications (SOC)] associated with cold medicine (CM) were reported in several studies. To assess the risks of CM-induced SJS/TEN with SOC, systematic review and meta-analysis were employed. Studies investigating associations between HLA genotypes and CM-induced SJS/TEN with SOC were systematically searched in PubMed, Scopus and the Cochrane Library. Overall odds ratios (ORs) with 95% CIs were calculated using a random-effects model to determine these associations. An initial search of the databases identified 24,011 articles, of which 6 studies met the inclusion criteria. In total from all studies, associations between 81 different HLA genotypes and CM-induced SJS/TEN with SOC (i.e., 22 different HLA-A genotypes, 40 different HLA-B genotypes and 19 different HLA-C genotypes) were investigated. Risk factors to develop SJS/TEN with SOC in patients who used CM were identified from our meta-analysis. HLA-A*0206 (OR = 3.90; 95% CI = 1.96-7.77), HLA-A*3303 (OR = 2.28; 95% CI = 1.31-3.97), HLA-B*4403 (OR = 3.27; 95% CI = 1.52-7.03) and HLA-C*0501 (OR = 2.55; 95% CI = 1.19-5.44) were associated with CM-induced SJS/TEN with SOC. With our results demonstrating a significant association between using of CMs and the severe ADR, a genetic testing can be helpful. However, the CMs are commonly used as an over-the-counter drug in practically almost of people in populations worldwide, the genetic screening prior to use of the CMs might not be cost-effective. Nonetheless, for people with a family history of developing the ADRs with a possible involvement of CMs, a genetic screening may be beneficial.
Assuntos
Antígenos HLA/genética , Medicamentos Compostos contra Resfriado, Influenza e Alergia/efeitos adversos , Síndrome de Stevens-Johnson/genética , Olho/efeitos dos fármacos , Feminino , Predisposição Genética para Doença , Genótipo , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Masculino , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Razão de Chances , Fatores de Risco , Síndrome de Stevens-Johnson/etiologia , Síndrome de Stevens-Johnson/imunologiaRESUMO
The ocular surface is naturally covered with a layer of mucus. Along with other functions, this mucus layer serves to trap and eliminate foreign substances, such as allergens, pathogens, and debris. In playing this pivotal role, mucus can also hinder topical delivery of therapeutics to the eye. Recent studies provide evidence that drugs formulated as traditional micro- or nanoparticles are susceptible to entrapment and rapid clearance by ocular mucus. Mucus-penetrating particles (MPPs) is a nanoparticle technology that emerged over the past decade. With a muco-inert surface and a particle size smaller than the mucus mesh size, MPPs can diffuse in ex vivo mucus essentially freely. Preclinical studies have shown that, compared with particles lacking the mucus-penetrating attributes, MPPs can improve the uniformity of drug particle distribution on mucosal surfaces and enhance drug delivery to ocular tissues.
Assuntos
Composição de Medicamentos/métodos , Muco/efeitos dos fármacos , Nanopartículas/administração & dosagem , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Administração Tópica , Animais , Composição de Medicamentos/estatística & dados numéricos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Camundongos , Modelos Animais , Muco/química , Muco/fisiologia , Nanopartículas/química , Nanopartículas/metabolismo , Propriedades de Superfície/efeitos dos fármacosRESUMO
Perfluorobutanesulfonate (PFBS), an aquatic pollutant of emerging concern, is found to disturb gut microbiota, retinoid metabolism and visual signaling in teleosts, while probiotic supplementation can shape gut microbial community to improve retinoid absorption. However, it remains unknown whether probiotic bacteria can modulate the toxicities of PFBS on retinoid metabolism and visual physiology. In the present study, adult zebrafish were exposed for 28 days to 0, 10 and 100 µg/L PFBS, with or without dietary administration of probiotic Lactobacillus rhamnosus. Interaction between PFBS and probiotic was examined regarding retinoid dynamics (intestine, liver and eye) and visual stimuli transmission. PFBS single exposures remarkably inhibited the absorption of retinyl ester in female intestines, which were, however, restored by probiotic to normal status. Although coexposure scenarios markedly increased the hepatic storage of retinyl ester in females, mobilization of retinol was reduced in livers by single or combined exposures regardless of sex. In the eyes, transport and catalytic conversion of retinol to retinal and retinoic acid were interrupted by PFBS alone, which were efficiently antagonized by probiotic presumably through an indirect action. In response to the availability of retinal chromophore, transcriptions of opsins and arrestin genes were altered adaptively to control visual perception and termination. Neurotransmission across retina circuitry was changed accordingly, centering on epinephrine and norepinephrine. In summary, the present study found the efficient modulation of probiotic on retinoid metabolic disorders of PFBS pollution, which subsequently impacted visual signaling. A future work is warranted to provide mechanistic clues in retinoid interaction.
Assuntos
Fluorocarbonos/toxicidade , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Probióticos/farmacologia , Retinoides/metabolismo , Ácidos Sulfônicos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Olho/efeitos dos fármacos , Olho/metabolismo , Feminino , Metabolismo dos Lipídeos/efeitos dos fármacos , Opsinas/genética , Transdução de Sinais , Transcrição Gênica/efeitos dos fármacosRESUMO
Dry eye disease (DED) is a complex multifactorial disease that affects an increasing number of patients worldwide. Close to 30% of the population has experienced dry eye (DE) symptoms and presented with some signs of the disease during their lifetime. The significant heterogeneity in the medical background of patients with DEs and in their sensitivity to symptoms renders a clear understanding of DED complicated. It has become evident over the past few years that DED results from an impairment of the ocular surface homeostasis. Hence, a holistic treatment approach that concomitantly addresses the different mechanisms that result in the destabilization of the tear film (TF) and the ocular surface would be appropriate. The goal of the present review is to compile the different types of scientific evidence (from in silico modeling to clinical trials) that help explain the mechanism of action of cationic emulsion (CE)-based eye drop technology for the treatment of both the signs and the symptoms of DED. These CE-based artificial tear (AT) eye drops designed to mimic, from a functional point of view, a healthy TF contribute to the restoration of a healthy ocular surface environment and TF that leads to a better management of DE patients. The CE-based AT eye drops help restore the ocular surface homeostasis in patients who have unstable TF or no tears.
Assuntos
Síndromes do Olho Seco/tratamento farmacológico , Emulsões/química , Lubrificantes Oftálmicos/uso terapêutico , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Adulto , Emulsões/farmacologia , Voluntários Saudáveis/estatística & dados numéricos , Homeostase , Humanos , Lubrificantes Oftálmicos/administração & dosagem , Lubrificantes Oftálmicos/química , Propriedades de Superfície/efeitos dos fármacos , Lágrimas/fisiologiaRESUMO
PURPOSE: To evaluate high-dose intravenous glucocorticoid treatment on tear inflammatory cytokines and ocular surface parameters in patients with active TED. Correlations between tear inflammatory cytokines and clinical parameters were also investigated. METHODS: This prospective pilot study included 15 moderate-to-severe and active TED patients. Control group consist of 15 sex and age-matched healthy subjects. All TED patients were treated with high-dose intravenous methylprednisolone with cumulative dose of 4.5 g during the therapy subdivided into 12 weekly infusions. Tear concentrations of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-17A, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) were measured by multiplex bead analysis in TED patients at baseline and 12 weeks after treatment. Ocular surface disease index (OSDI), tear break-up time (TBUT), corneal fluorescent staining, and Schirmer's test were obtained from TED and controls. RESULTS: All baseline cytokine levels except for IL-17A were significantly elevated in active TED patients compared with controls. Concentrations of IL-1ß, IL-6, IL-8, TNF-α, and VEGF were significantly decreased at 12 weeks compared with baseline. OSDI and TBUT showed significant improvement at 6 and 12 weeks. There were significant positive correlations between IL-6, IL-8, and CAS, and negative correlation was found between IL-6 level and TED duration before methylprednisolone treatment. The reduction of IL-6, IL-8, and VEGF were positive correlated with the reduction in CAS at 12 weeks. CONCLUSIONS: High-dose glucocorticoids treatment improved ocular surface symptom, increased the tear film stability, and decreased tear inflammatory cytokines in active TED. The reduction of the inflammatory cytokines is consistent with the improvement of clinical parameters.
Assuntos
Citocinas/análise , Oftalmopatia de Graves/tratamento farmacológico , Metilprednisolona/administração & dosagem , Fenômenos Fisiológicos Oculares , Lágrimas/química , Administração Intravenosa , Adulto , Citocinas/metabolismo , Técnicas de Diagnóstico Oftalmológico , Relação Dose-Resposta a Droga , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacologia , Oftalmopatia de Graves/diagnóstico , Oftalmopatia de Graves/metabolismo , Oftalmopatia de Graves/patologia , Humanos , Mediadores da Inflamação/análise , Mediadores da Inflamação/metabolismo , Masculino , Análise por Pareamento , Metilprednisolona/farmacologia , Pessoa de Meia-Idade , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Projetos Piloto , Propriedades de Superfície/efeitos dos fármacos , Lágrimas/efeitos dos fármacos , Lágrimas/metabolismo , Resultado do TratamentoRESUMO
As one of the leading causes of central vision loss in elderly population, worldwide cases of age-related macular degeneration (AMD) have seen a dramatic increase over the past several years. Treatment regimens for AMD, especially with biological agents, are complicated due to anatomical and physiological barriers, as well as administration of high doses and frequent regimens. Some clinical examples include monthly intravitreal administration of anti-VEGF antibody ranibizumab (Lucentis®) from Genentech and aflibercept (Eylea®) from Regeneron Pharmaceuticals. Long-acting sustained intraocular drug delivery provides promising solutions, such as Vitrasert® from Bausch & Lomb, an intravitreal biodegradable polymeric implant made from poly(D,L-lactic co glycolic acid) (PLGA), and can be used as a guiding reference to formulate sustained delivery systems. In this review, we discuss the anatomy and physiology of the eye, barriers to delivery, pathology of AMD, opportunities for biological therapeutics, and future prospects of intraocular delivery strategies that are in development for treatment of AMD.
Assuntos
Produtos Biológicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Degeneração Macular/tratamento farmacológico , Animais , Olho/anatomia & histologia , Olho/efeitos dos fármacos , Humanos , Injeções Intraoculares , Degeneração Macular/fisiopatologia , Fenômenos Fisiológicos Oculares/efeitos dos fármacosRESUMO
Polycyclic aromatic hydrocarbons (PAHs) present in crude oil have been shown to cause the dysregulation of genes important in eye development and function, as well as morphological abnormalities of the eye. However, it is not currently understood how these changes in gene expression are manifested as deficits in visual function. Embryonic red drum (Sciaenops ocellatus) and sheepshead minnow (Cyprinodon variegatus) were exposed to water accommodated fractions (WAFs) of weathered crude oil and assessed for visual function using an optomotor response assay in early life-stage larvae, with subsequent samples taken for histological analysis of the eyes. Larvae of both species exposed to increasing concentrations of oil exhibited a reduced optomotor response. The mean diameters of retinal layers, which play an important role in visual function and image processing, were significantly reduced in oil-exposed sheepshead larvae, though not in red drum larvae. The present study provides evidence that weathered crude oil has a significant effect on visual function in early life-stage fishes.
Assuntos
Olho/efeitos dos fármacos , Peixes Listrados/crescimento & desenvolvimento , Perciformes/crescimento & desenvolvimento , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Olho/anatomia & histologia , Olho/crescimento & desenvolvimento , Peixes Listrados/anatomia & histologia , Peixes Listrados/embriologia , Peixes Listrados/fisiologia , Larva/anatomia & histologia , Larva/efeitos dos fármacos , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Perciformes/anatomia & histologia , Perciformes/embriologia , Perciformes/fisiologiaRESUMO
INTRODUCTION: Thymosin beta 4 (Tß4) has important applications in ocular repair and Phase 3 clinical trials using Tß4 to treat dry eye and neurotrophic keratopathy are currently ongoing. These exciting clinical possibilities for Tß4 in the eye are the result of seminal basic scientific discoveries and contributions from so many talented investigators. Areas covered: My personal Tß4 journey began at the NIH in 1998 and propelled my career as a clinician scientist. As a tribute to the amazing individuals who have guided and supported me along with my brilliant colleagues and students who have contributed and collaborated with me over the years, this review will tell the cumulative story of how Tß4 became a major potential new therapy for corneal wound healing disorders. The journey has been marked by the thrilling exhilaration from fundamental breakthroughs in the laboratory and clinic, combined with the challenging and often harsh realities of submitting grants and obtaining funding. Expert opinion: The electrifying possibility of Tß4 as a revolutionary novel dry eye therapy is something that could have only been dreamed about just a few years ago. We believe that Tß4 eyedrops will help many patients suffering from several ocular surface related disorders.
Assuntos
Fenômenos Fisiológicos Oculares , Timosina/fisiologia , Animais , Doenças da Córnea/tratamento farmacológico , Doenças da Córnea/patologia , Ceratócitos da Córnea/patologia , Síndromes do Olho Seco/tratamento farmacológico , Síndromes do Olho Seco/patologia , Olho/efeitos dos fármacos , Olho/patologia , Humanos , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Timosina/uso terapêutico , Pesquisa Translacional Biomédica , Cicatrização/efeitos dos fármacosRESUMO
Cadmium (Cd) and lead (Pb) are ubiquitous environmental pollutants. There is a dearth of information on the mutual interaction between the antemortem metal intoxication and the postmortem changes of the eye. Thus, this study aimed to follow the morphological, biochemical, histopathological ocular perturbations and the retinal DNA damage up to 8 h postmortem (PM) in Cd and/or Pb intoxicated rabbits. The animals orally received 5 mg Cd Cl2/kg bw and/or 12.5 mg lead acetate/kg bw for 30 consecutive days. At time of death, eye pupil of different groups had a normal diameter except Pb-intoxicated group had marked myosis. After 8 h of death, different rabbit's eye corneas appeared wrinkled and covered with thin white cloud while the pupils were in the mydriatic stage. Up to 8 h PM, the individual exposure to Cd or Pb resulted in a significant elevation in GGT, urea, K, DNA damage and obvious retinal lesions. However, their co-exposure evoked an antagonistic outcome. The eye of Cd and/or Pb intoxicated rabbit showed mildly degenerated tissue of cornea and sclera and the presence of irregular eosinophilic droplets of variably size in the lens with a gradual degeneration and vacuolization in the different cell layers of retina especially ganglion up to 8 h PM. Also, by increasing post mortem interval (PMI), retinal DNA damage in Cd and/or Pb intoxicated group significantly decreased. It is concluded that Cd and/or Pb intoxication induced ocular alterations which retain the same trend in correlation with PMI as natural deaths except for the retinal DNA damage. Also, the simultaneous exposure to Cd and Pb evoked an antagonistic outcome in the eye. The findings of the current study should be taken into consideration when estimating PMI in areas with high Cd and/or Pb contamination.
Assuntos
Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Olho/efeitos dos fármacos , Chumbo/toxicidade , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Animais , Masculino , CoelhosRESUMO
PURPOSE: To determine the systemic impact of intravitreal injection of bevacizumab (IVB), an anti-vascular endothelium growth factor antibody, in newborn rabbits. MATERIALS AND METHODS: We used four groups of rabbits. Group 1 rabbits received a single injection of IVB starting from the age of 6 weeks. Group 2 rabbits received a single injection of balanced salt solution (BSS, 0.025 ml) and served as controls for group 1. Group 3 rabbits received two consecutive injections of IVB at the ages of 6 and 10 weeks. Group 4 rabbits received two consecutive injections of BSS at the ages of 6 and 10 weeks and served as controls for group 3. During the experiment, a complete blood count (CBC), clinical biochemistry, weight gain, food intake, body temperature, blood pressure, pulse, and mortality were measured in the animals. Two months after IVB injection, the animals were sacrificed, and histology of the major organs was checked. Immunohistochemistry was assessed to explore the neurons in the central nervous system (CNS). RESULTS: We found there were no morphological or functional changes in the eyes following IVB injection. Furthermore, there were no differences in CBC, biochemistry, or other measured parameters among the four groups of animals. We checked the histology of the major organs and neurons in the CNS and they did not reveal significant differences among the four groups of animals. CONCLUSIONS: Conclusively, IVB of either one or two injections (0.625 mg) in newborn rabbit eyes is well tolerated and does not cause noticeable systemic organ pathology.
Assuntos
Inibidores da Angiogênese/administração & dosagem , Bevacizumab/administração & dosagem , Animais , Animais Recém-Nascidos , Olho/anatomia & histologia , Olho/efeitos dos fármacos , Injeções Intravítreas , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , CoelhosRESUMO
Current ophthalmological drug discovery and testing methods have limitations and concerns regarding reliability, ethicality, and applicability. These drawbacks can be mitigated by developing biomimetic eye models through mathematical and experimental methods which are often referred to as "eye-on-a-chip" or "eye chip". These eye chip technologies emulate ocular physiology, anatomy, and microenvironmental conditions. Such models enable understanding of the fundamental biology, pharmacology, and toxicology mechanisms by investigating the pharmacokinetics and pharmacodynamics of various candidate drugs under ocular anatomical and physiological conditions without animal models. This review provides a comprehensive overview of the latest advances in theoretical and in vitro experimental models of the anterior segment of the eye and its microenvironment, including eye motions and tear film dynamics. The current state of ocular modeling and simulation from predictive models to experimental models is discussed in detail with their advantages and limitations. The potential for future eye chip models to expedite new ophthalmic drug discoveries is also discussed.
Assuntos
Descoberta de Drogas , Olho/efeitos dos fármacos , Dispositivos Lab-On-A-Chip , Modelos Biológicos , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Soluções Oftálmicas , Animais , Biomimética , Desenho de Equipamento , Humanos , CamundongosAssuntos
Fenômenos Fisiológicos Oculares , Receptores Purinérgicos/fisiologia , Aniversários e Eventos Especiais , Olho/efeitos dos fármacos , História do Século XX , História do Século XXI , Humanos , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Agonistas Purinérgicos/farmacologia , Antagonistas Purinérgicos/farmacologiaRESUMO
N-butylscopolammonium bromide (NBB), an anticholinergic muscarinic antagonist, was assessed as a mydriatic agent for field examination of equine eyes. Six adult horses were randomly assigned to four treatments with 2 weeks washout between treatments: (1) topical saline/IV saline (negative control); (2) topical tropicamide/IV saline (positive control); (3) topical NBB/IV saline; or (4) topical saline/IV NBB. Horizontal and vertical pupil diameters, temperature, pulse, respiration, pupillary light reflexes (PLRs) and mydriasis sufficient to perform complete fundic examination were recorded. Tropicamide induced mydriasis in all horses. Topical NBB induced mydriasis in one horse, and IV NBB enabled thorough fundic examination in two horses, delayed PLRs without allowing thorough examination in two horses and had no effect in two horses.
Assuntos
Brometo de Butilescopolamônio/farmacologia , Cavalos/fisiologia , Midriáticos/farmacologia , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Animais , Feminino , Masculino , Antagonistas Muscarínicos/farmacologiaRESUMO
Visual impairment due to glaucoma currently impacts 70 million people worldwide. While disease progression can be slowed or stopped with effective lowering of intraocular pressure, current medical treatments are often inadequate. Fortunately, three new classes of therapeutics that target the diseased conventional outflow tissue responsible for ocular hypertension are in the final stages of human testing. The rho kinase inhibitors have proven particularly efficacious and additive to current therapies. Unfortunately, non-contact technology that monitors the health of outflow tissue and its response to conventional outflow therapy is not available clinically. Using optical coherence tomographic (OCT) imaging and novel segmentation software, we present the first demonstration of drug effects on conventional outflow tissues in living eyes. Topical netarsudil (formerly AR-13324), a rho kinase/ norepinephrine transporter inhibitor, affected both proximal (trabecular meshwork and Schlemm's Canal) and distal portions (intrascleral vessels) of the mouse conventional outflow tract. Hence, increased perfusion of outflow tissues was reliably resolved by OCT as widening of the trabecular meshwork and significant increases in cross-sectional area of Schlemm's canal following netarsudil treatment. These changes occurred in conjunction with increased outflow facility, increased speckle variance intensity of outflow vessels, increased tracer deposition in conventional outflow tissues and decreased intraocular pressure. This is the first report using live imaging to show real-time drug effects on conventional outflow tissues and specifically the mechanism of action of netarsudil in mouse eyes. Advancements here pave the way for development of a clinic-friendly OCT platform for monitoring glaucoma therapy.
Assuntos
Benzoatos/farmacologia , Olho/efeitos dos fármacos , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , beta-Alanina/análogos & derivados , Animais , Humor Aquoso/efeitos dos fármacos , Humor Aquoso/metabolismo , Humor Aquoso/fisiologia , Benzoatos/administração & dosagem , Olho/metabolismo , Corantes Fluorescentes/metabolismo , Processamento de Imagem Assistida por Computador , Pressão Intraocular/efeitos dos fármacos , Camundongos , Tomografia de Coerência Óptica , Malha Trabecular/efeitos dos fármacos , Malha Trabecular/metabolismo , Malha Trabecular/fisiologia , beta-Alanina/administração & dosagem , beta-Alanina/farmacologiaRESUMO
PURPOSE: To evaluate the retinal toxicity of intravitreal minocycline in rabbit eyes. METHODS: Intravitreal injection of minocycline with concentrations of 1000, 500, 250, 125 and 62.5 µg in 0.1 ml was performed in 10 New Zealand albino rabbits. Each concentration was injected into two rabbit eyes. For each dose, normal saline was injected in one contralateral eye and the other fellow eye remained non-injected. Electrophysiologic testing was performed before and 4 weeks after injections. The eyes were enucleated 4 weeks after injections and examined using light microscopy. RESULTS: The clinical examination was unremarkable after injections. Electroretinography recordings were significantly affected at all doses in at least one of the a- or b-waves of photopic or scotopic responses. Histopathologic examination revealed marked atrophy and loss of integrity in all retinal layers in all minocycline injected eyes. Contralateral eyes were normal. CONCLUSION: In our study, intravitreal minocycline was toxic to the retina in albino rabbits even at a concentration of 62.5 µg/0.1 ml.
Assuntos
Antibacterianos/efeitos adversos , Minociclina/efeitos adversos , Animais , Eletrorretinografia , Injeções Intravítreas , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Coelhos , Retina/efeitos dos fármacos , Retina/patologia , Retina/fisiologiaRESUMO
Over the past 10 years, a literature has emerged concerning the sex steroid hormone oestrogen and its role in human vision. Herein, we review evidence that oestrogen (oestradiol) levels may significantly affect ocular function and low-level vision, particularly in older females. In doing so, we have examined a number of vision-related disorders including dry eye, cataract, increased intraocular pressure, glaucoma, age-related macular degeneration and Leber's hereditary optic neuropathy. In each case, we have found oestrogen, or lack thereof, to have a role. We have also included discussion of how oestrogen-related pharmacological treatments for menopause and breast cancer can impact the pathology of the eye and a number of psychophysical aspects of vision. Finally, we have reviewed oestrogen's pharmacology and suggest potential mechanisms underlying its beneficial effects, with particular emphasis on anti-apoptotic and vascular effects.
Assuntos
Estrogênios/farmacologia , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Baixa Visão/induzido quimicamente , Idoso , Antineoplásicos Hormonais/efeitos adversos , Comportamento/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Estrogênios/uso terapêutico , Olho/efeitos dos fármacos , Oftalmopatias/induzido quimicamente , Oftalmopatias/epidemiologia , Feminino , Humanos , Baixa Visão/epidemiologia , Percepção Visual/efeitos dos fármacosRESUMO
The effects of dopamine receptor blockade by sulpiride (D2-class antagonist) and sulpiride plus SCH 23390 (D1-class antagonist) on the V - log I function of the electroretinographic (ERG) b- and d-waves were investigated in light-adapted frog eyes. Sulpiride significantly decreased the absolute sensitivity of the b- and d-waves. The amplitude of the both waves was diminished over the whole intensity range studied. A similar effect on the b-, but not d-wave amplitude was seen during the perfusion with sulpiride plus SCH 23390. The effect on the d-wave amplitude depended on stimulus intensity. The threshold of the d-wave was not significantly altered. The suprathreshold d-wave amplitude was enhanced at the lower stimulus intensities and remained unchanged at the higher ones. The results obtained indicate that the action of endogenous dopamine on the photopic ERG shows clear ON-OFF asymmetry. Participation of different classes of dopamine receptors is probably responsible for this difference.