Search

The current study evaluates the epidemiological characteristics, risk factors, and microbiological diagnosis of fungal keratitis among patients living in the Egyptian Delta. This is a prospective hospital-based study that included patients who were clinically diagnosed and confirmed by culture test to have fungal keratitis. Patients were examined at baseline and risk factors were identified and collected. Patients were followed over 6 months and the outcomes were documented. A total of 171 (67%) of 252 microbial keratitis patients was proved fungal by microbial culture test. Rural residence and agricultural activity were reported in 139 (81.3%) and 85 (49.7%) patients, respectively. Patients presented within 1 week from the start of symptoms were 120 (70.2%). A total of 54 (31.6%) patients reported ocular trauma. Forty patients (23.4%) had prior ocular surgery and 43 (25.1%) patients had a history of previous ocular disorders. Aspergillus species was the most common organism found in 120 (70.17%) patients, followed by Dematiceous fungi that were found in 25 (14.6%) patients. The main outcome was corneal opacity in 132 (77.2%) patients following medical treatment. Filamentary fungal predominance in Mansoura is influenced by the rural residence of its population. Therefore, more efforts in spreading awareness about microbial keratitis among villagers are important to reduce blindness caused by corneal opacity in rural areas. [ABSTRACT FROM AUTHOR]

To evaluate the potential toxicity of operation microscopes with halogen and light emitting diode (LED) light source on the rabbit eyes. Thirty-two eyes of 16 male New Zealand pigmented rabbits were involved in the study. The rabbits were divided into two groups according to the type of light source applied. Only one eye of each rabbit was exposed to illumination light, unexposed fellow eyes served as the control group. Experimental groups included group 1 exposed to halogen light for 2 h and evaluated 1 day and 1 week after the illumination, group 2 exposed to LED light for two hours and evaluated 1 day and 1 week after the illumination. On the first and seventh days after exposing the light, we evaluated the rabbit corneas using in vivo confocal microscopy (IVCM). At the end of the seventh day, the Hematoxylin-eosin staining and TUNEL staining were performed to investigate the presence of apoptosis in the retina and retina pigment epithelium. Early IVCM findings revealed corneal epithelial cell ovalization and indistinct intercellular borders in the halogen light group. We also observed more increase in the keratocyte density index (23.7% vs 14.1%, p = 0.001, respectively) and the Bowman reflectivity index (12.4% vs 4.1%, p = 0.001, respectively) at first day of the light exposure in halogen light group compared to LED light group. However, late IVCM indicated that these findings disappeared one week later. No apoptosis was observed in the corneal and retinal layers in early and late examination groups. The present experimental study demonstrated that both halogen and LED lights, which were commonly used for microscopic eye surgery, had no sustained adverse effect on the cornea and retina of the rabbits; however, halogen light had a temporary adverse effect on corneal epithelium and stroma, which resolved within 1 week. [ABSTRACT FROM AUTHOR]

To manage glaucoma, timolol is currently delivered via eye drop solution in high doses due to poor ocular bioavailability. The silicone contact lenses can be used to control the release of timolol by conventional soaking technology without changing or altering the swelling and optical transmittance of the contact lens. However, the soaking method showed limitations of low timolol uptake and high-burst release. In this research work, we have investigated the influence of microemulsion on timolol loading from the soaking solution and its ability to control the drug release kinetics. The contact lenses were soaked in the timolol-microemulsion soaking solution (TB-ME-SM) and compared with the timolol-soaking solution (TB-SM) without microemulsion. The loading of timolol laden-microemulsion in the contact lenses did not alter the swelling and transmittance properties. The two fold improvement in the timolol loading was noted from the TB-ME-SM soaking solution in comparison to TB-SM solution. The flux report showed improvement in the release rate profiles of TB-ME-SM lenses (up to 48–96 h) in comparison to TB-SM lenses (up to 24–36 h). The rabbit tear fluid data of TB-ME-SM lenses showed improvement in the timolol retention time in comparison to TB-SM lenses and eye drop solution. The efficacy study in the rabbit model showed a peak and valley profile with eye drop therapy, while TB-ME-SM-2 contact lenses showed prolong reduction in intra ocular pressure for 96 h. The study demonstrates the potential of microemulsion to improve the uptake of timolol and control release kinetics without altering the swelling and transmittance of the contact lens. [ABSTRACT FROM AUTHOR]

The Boston Keratoprosthesis (KPro) is the most used artificial cornea. It restores vision in patients with a poor prognosis with penetrating keratoplasty. Significant improvements have occurred recently in terms of implant design and postoperative care. Nonetheless, glaucoma remains the primary reason for vision loss after KPro implantation. Management of inflammation and intraocular pressure (IOP) is challenging in KPro eyes. Progressive optic nerve damage often persists in spite of medical and surgical interventions. Significant efforts are being invested to determine the best management, even when IOP is controlled. Glaucoma drainage devices (GDD) implanted during KPro surgery could offer beneficial visual outcomes. Cyclophotocoagulation (CPC) may be reserved for end-staged glaucoma. This review highlights glaucoma mechanisms in KPro eyes, the need to better monitor and treat glaucoma in KPro patients, and the latest innovation strategies. Recent data on current options and timing for GDD and CPC are discussed. Implantation of GDD before or during KPro surgery reduces the risk of glaucoma progression compared to CPC. Future developments could offer KPro implants integrated with drainage devices and IOP sensors. Targeted control of inflammation will be the next novel strategy to reduce optic nerve damage occurring despite appropriate IOP control. [ABSTRACT FROM AUTHOR]

Microbial biofilms are a natural adaptation of microorganisms, typically composed of multiple microbial species, exhibiting complex community organization and cooperation. Biofilm dynamics and their complex architecture are challenging for basic analyses, including the number of viable cells, biomass accumulation, biofilm morphology, among others. The methods used to study biofilms range from in vitro techniques to complex in vivo models. However, animal welfare has become a major concern, not only in society, but also in the academic and scientific field. Thus, the pursuit for alternatives to in vivo biofilm analyses presenting characteristics that mimic in vivo conditions has become essential. In this context, the present review proposes to provide an overview of strategies to study biofilms of medical interest, with emphasis on alternatives that approximate experimental conditions to host-associated environments, such as the use of medical devices as substrata for biofilm formation, microcosm and ex vivo models. [ABSTRACT FROM AUTHOR]

Assessment of intraocular pressure (IOP) is a core diagnostic tool in management of glaucoma. All established ways to measure IOP use indirect approaches through ocular tissues, mainly the cornea or the sclera. Telemetric IOP measurement with an implantable device could eliminate bias caused by indirect techniques and could allow continuous monitoring. A favorable safety profile, high efficacy and good tolerability are key requirements. The Eyemate-IO™ system (Implandata Ophthalmic Products GmbH, Hannover, Germany) is a novel CE-marked implantable medical device for direct measurement of IOP. It consists of an intraocular sensor ring and an external reading device. This review presents the mechanism of telemetric IOP measurement and summarizes the available clinical data. Twelve months follow-up data of two clinical trials provide support for the efficacy and safety of this device. The implantable Eyemate-IO™ in keratoprosthesis was well tolerated; recorded adverse events were known complications of standalone surgery. The system had a good agreement with other IOP measuring modalities, including intraoperative manometry. In glaucoma patients, the Eyemate-IO™ could be implanted safely and showed a favorable efficacy and safety profile in the first twelve months postoperatively. The potential to achieve IOP monitoring with the Eyemate-IO™ seems promising. [ABSTRACT FROM AUTHOR]

Corneal transplantation surgery faces several fundamental problems, including graft failure, especially in complicated cases, and a marked shortage of human donor corneas. The purpose of this review is to examine several developments in biosynthetic alternatives to donor corneal transplantation. In particular, we focus on the regulatory pathway and considerations needed to design an implant and take it to clinical application. We define biosynthetic implants as those that combine synthetic and natural components, as well as those that mimic materials found in nature. This is a non-comprehensive review of the topic that discusses examples of implants ranging from cell-free devices to those containing cells. We provide a guide to designing implants for clinical application as medical devices, highlighting aspects for consideration at the design and manufacturing stages. Biosynthetic implants developed as alternatives to conventional corneal transplantation afford customization, particularly for patients at high risk for graft failure. A range of these implants exist, but there appears to be a bottleneck to clinical entry. Implants should be designed with clinical application in mind from the outset to allow for an efficient bench to bedside translation. [ABSTRACT FROM AUTHOR]

Introduction: If intraocular pressure (IOP) is the sole modifiable risk factor for glaucoma progression, glaucoma management should not rely on a vague estimation of its value measured over seconds, out of the 31,536,000 seconds in a year. A technology that would allow continuous and accurate IOP measurement in any situation could drastically enhance the diagnosis, treatment, follow-up and advice we give glaucoma patients. Areas covered: This review covers the development history of IOP telemetry devices, from Green and Gilman's first 24-hour telemetry concept in 1974 to the two devices commercially available today: Sensimed's TriggerFish contact lens sensor and Implandata's implantable monitoring device. Through a systematic review of the articles indexed by the US National Library of Medicine National Institute of Health between November 1969 and July 2019 with the keywords 'telemetry', 'continuous iop' and '24 hour iop', it details the ongoing contribution of telemetry to glaucoma knowledge. Expert opinion: The usage and purpose of the currently available telemetry devices remain specific and targeted. However, we foresee that this is likely to change in the upcoming years, with the advent of new, more versatile devices and ergonomic modules. The future of telemetry may lie in miniaturization, connectivity and new organic measures. [ABSTRACT FROM AUTHOR]

Purpose: Boston keratoprosthesis (KPro) patients are prone to glaucoma even with well-controlled intraocular pressure (IOP). Recent experimental data have shown that soluble tumor necrosis factor alpha (TNF-α) after ocular injury may contribute to progressive retinal damage and subsequent glaucoma. This study evaluates the blood plasma levels of soluble TNF-α, TNF receptors 1 (TNFR1) and 2 (TNFR2), and leptin in patients with Boston type I KPro. Methods: Venous blood samples were collected from KPro patients with glaucoma (KPro G, n = 19), KPro patients without glaucoma (KPro NoG, n = 12), primary angle closure glaucoma without KPro (PACG, n = 13), and narrow angles without glaucoma or KPro (NA, n = 21). TNF-α, TNFR1, TNFR2, and leptin levels were quantified using the enzyme-linked immunosorbent assay. Erythrocyte sedimentation rate (ESR) was assessed using the Westergren test. Patients with underlying autoimmune conditions or diabetes were excluded from the study. Results: All groups had similar age, body mass index (BMI), IOP, and ESR (p ≥ 0.11). The mean time from KPro surgery to blood draw was 5.3 ± 3.7 years. Compared to NA patients (0.72 ± 0.3 pg/ml), KPro G and KPro NoG patients had higher blood plasma levels of TNF-α (1.18 ± 0.58 pg/ml, p = 0.006; 1.16 ± 0.50 pg/ml, p = 0.04, respectively). Similarly, KPro G patients had higher blood plasma levels of TNFR2 (2768 ± 1368 pg/ml) than NA patients (2020 ± 435 pg/ml, p = 0.048). In multivariate analysis, KPro status remained positively associated with TNF-α levels (β = 0.36; 95% confidence intervals [CI]: 0.14–0.58; p = 0.002) and TNFR2 levels (β = 458.3; 95% CI: 32.8–883.7; p = 0.035) after adjusting for age, gender, BMI, glaucoma status, and ESR. TNFR1 and leptin levels were not significantly different in the study groups. Conclusions: We detected elevated serum levels of TNF-α and TNFR2 in KPro patients. Longitudinal studies are needed to establish TNF-α and TNFR2 as serum biomarkers related to KPro surgery. Abbreviations: BCVA: best corrected visual acuity; BMI: body mass index; CDR: cup-to-disc ratio; EDTA: ethylenediaminetetraacetic acid; ELISA: enzyme-linked immunosorbent assay; ESR: erythrocyte sedimentation rate; HVF: Humphrey visual field; IOP: intraocular pressure; KPro G: keratoprosthesis with glaucoma; KPro NoG: keratoprosthesis without glaucoma; KPro: keratoprosthesis; MD: mean deviation; NA: narrow angle; non-KPro: without keratoprosthesis; PACG: primary angle closure glaucoma; RNFL: retinal nerve fiber layer; TNF-α: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2 [ABSTRACT FROM AUTHOR]

Aim: To investigate the role of interleukin-17 in ocular surface and corneal disease. Ocular surface and corneal disease is a leading cause of blindness and is an ongoing challenge for the public health sector to implement effective therapies. The majority of cells in corneal lesions are derived primarily from neutrophils that induce inflammatory events that lead to tissue damage. One of the key pro-inflammatory cytokines is IL-17, and it has been investigated in order to facilitate the understanding of the pathogenesis of ocular surface lesion development. Method: A review of the literature was performed through a systematic approach. Results: IL-17 has been shown to exacerbate dry eye disease, viral and bacterial keratitis lesion severity, although it was found to be protective for Acanthamoeba. Antibodies developed to neutralize IL-17 have shown some promise in reducing the severity of some diseases. Conclusion: IL-17 plays a role in the pathogenesis of ocular surface and corneal disease and targeting this cytokine may provide a useful treatment option in the future. [ABSTRACT FROM AUTHOR]

Corneal blindness can occur due to improper healing of the corneal tissues after induced injury or abrasion which can be accidental, pathogenic, or after corneal surgery. Abnormal regulation of the healing mechanisms can lead to corneal opacity. Reducing inflammation and promoting epithelial wound healing are crucial for scar-free corneal recovery without eyesight complications. Current approaches for corneal wound healing involve amniotic membrane (AM) bandages, bandage contact lenses (BCL), and collagen shields in conjunction with frequent administration of therapeutic eye drops. The problem with eye drops is poor bioavailability and patient incompliance that might lead to corneal wound healing complications and poor clinical outcomes. Various methods have been proposed for loading drugs into medicated bandage lenses. There are advantages and limitations associated with each technique regarding the ease of manufacture, drug loading, release kinetics, and suitability with various therapeutics and hydrogel types. There is still, however, no drug-eluting corneal bandage on the market despite the need for such a convenient and cost-efficient strategy for corneal wound healing. This review will highlight materials and therapeutics that can be used in medicated ocular bandages and various ways of incorporating drugs, while discussing the limitations and challenges associated with bringing medicated ocular bandages in the market. [ABSTRACT FROM PUBLISHER]

Salmonella entericaserovar Typhimurium (S. Typhimurium) is a Gram-negative pathogen that causes various host-specific diseases. During their life cycle, Salmonellaesurvive frequent exposures to a variety of environmental stresses, e.g. carbon-source starvation. The virulence of this pathogen relies on its ability to establish a replicative niche, named Salmonella-containing vacuole, inside host cells. However, the microenvironment of the SCV and the bacterial metabolic pathways required during infection are largely undefined. In this work we developed different biological probes whose expression is modulated by the environment and the physiological state of the bacterium. We constructed transcriptional reporters by fusing promoter regions to the gfpmut3a gene to monitor the expression profile of genes involved in glucose utilization and lipid catabolism. The induction of these probes by a specific metabolic change was first tested in vitro, and then during different conditions of infection in macrophages. We were able to determine that Entner-Doudoroff is the main metabolic pathway utilized bySalmonelladuring infection in mouse macrophages. Furthermore, we found sub-populations of bacteria expressing genes involved in pathways for the utilization of different sources of carbon. These populations are modified in presence of different metabolizable substrates, suggesting the coexistence of Salmonellawith diverse metabolic states during the infection. [ABSTRACT FROM AUTHOR]

Purpose: To review antibiotic resistance associated with S. aureus endophthalmitis and the virulence of S. aureus.Methods: Review of the current and prospective approaches for treating S. aureus endophthalmitis.Results: Bacterial endophthalmitis remains to be a major threat for vision. S. aureus endophthalmitis specifically, carries a poor visual prognosis making early diagnosis and treatment crucial. Methicillin resistant Staphylococcus aureus (MRSA) endophthalmitis represents a significant number of S. aureus endophthalmitis cases. MRSA with reduced susceptibility to glycopeptide antibiotics such as vancomycin (vancomycin intermediate S. aureus, VISA) have also emerged in the ocular infections, and there has been a rise in S. aureus resistance to new and old generation fluoroquinolones that are commonly used for prophylaxis after intravitreal injections and intraocular surgeries.Conclusions: With the rise in the number of penetrating procedures in the ophthalmology practice and the parallel rise in antibiotic resistance, prophylaxis and awareness of the antimicrobial resistance profiles remain crucial and the identification of novel antimicrobials is essential. [ABSTRACT FROM AUTHOR]

Infectious keratitis is a serious cause of vision loss. Proper treatment of infectious keratitis requires antimicrobials that target the organism responsible for a patient’s ulcer. The frequency of infection by a given organism varies by location. We examined the literature to determine geographic disparities in the etiology of bacterial and fungal keratitis in the United States of America. Bacterial keratitis makes up a greater proportion of cases in northern locations, and fungal keratitis increases in prevalence in southern locations. Gram-negative organisms make up a greater proportion of bacterial keratitis in southern locations when compared to northern locations. [ABSTRACT FROM PUBLISHER]

Purpose: To investigate the efficacy of a topical hydrogel ring for drug delivery to the posterior segment of the rabbit eye. Materials and methods: Novel hydrogel corneal lenses (CL), scleral/corneal lenses (S/CL), and rings were prepared using poly(hydroxyethyl methacrylate). The devices were immersed in 0.3% ofloxacin ophthalmic solution (OOS) to homogeneously distribute the drug throughout the hydrogel. The medicated CL, S/CL, Ring 1 (standard ring), or Ring 2 (shape-optimized ring) was applied to the surface of the cornea, cornea/bulbar conjunctiva, or bulbar conjunctiva of albino rabbits, respectively. Medicated rings did not touch the corneal surface. In another group, one OOS drop was administered to the eye. After 0.25–8 hours, the hydrogel devices were removed and ocular tissues were harvested. High-performance liquid chromatography (HPLC) was used to measure the ofloxacin concentration in the devices and tissues. The drug concentrations in the posterior segment tissues were compared among ofloxacin delivery methods. Results: One hour after placement, eyes treated with Ring 1 or S/CL had markedly higher ofloxacin levels in the posterior segment tissues (conjunctiva, sclera, and retina/choroid) than eyes treated with topical OOS or a CL. Lower levels of ofloxacin were found in anterior segment tissues (cornea and aqueous humor) in eyes treated with Ring 1 compared to those treated with S/CL. Ring 2 most effectively delivered ofloxacin to the retina/choroid. The tissue ofloxacin concentration in the fellow eye was markedly lower than the eye treated with Ring 2. Conclusions: Our results suggest that hydrogel rings are effective in delivering topical ophthalmic drugs to the posterior segment. The drugs are most likely delivered via the transconjunctival/scleral route by lateral diffusion across the bulbar conjunctiva and through the sclera. Systemic drug delivery to the posterior segment is minimal. [ABSTRACT FROM AUTHOR]

The Boston Keratoprosthesis (B-KPro) is a widely accepted modality of corneal restoration in eyes where traditional penetrating keratoplasty has little chance of success. It is the most commonly used keratoprosthesis worldwide. While the introduction of broad-spectrum antibiotic prophylaxis has virtually eliminated cases of bacterial endophthalmitis, fungal colonization and infections are a growing concern. This review of the literature summarizes risk factors for fungal infections in KPro eyes, rates of fungal infection and colonization, clinical presentation, causative organisms, management, and outcomes. We also focus on current recommendations for antifungal prophylaxis, and highlight the role of translational research at the Massachusetts Eye and Ear Infirmary (MEEI, Boston, USA) with its aim of developing novel strategies for reducing rates of fungal infections in KPro patients. [ABSTRACT FROM AUTHOR]

Measurements of intraocular pressure (IOP) are crucial to the diagnosis and management of glaucoma, the leading cause of irreversible blindness worldwide. Goldmann applanation tonometry remains the gold standard in obtaining IOP measurements, but is limited by its inability to obtain measurements outside of the clinical setting or account for diurnal variations in pressures. This review focuses on existing technologies available for measuring diurnal shifts in IOP at home, including portable tonometers and other temporary and permanent devices for continuous IOP monitoring using telemetry. We discuss the deficiencies of home tonometry technologies and present recent advances in telemetry technology that could revolutionize the ability to monitor IOP response to glaucoma therapy. [ABSTRACT FROM PUBLISHER]

Boston Keratoprosthesis type I (KPro) surgery is a relatively novel treatment for severe corneal blindness in the context of recurrent graft failure and high-risk conditions such as cicatrizing disease, aniridia, herpetic keratitis or chemical burns. Recently, modifications in design, surgical techniques and postoperative management have increased the success rate and popularity of the Boston KPro. Complication rates have decreased substantially in the last decade making the Boston KPro a safe therapeutic alternative to certain corneal pathologies. However, certain comorbidities such as glaucoma and late-onset fungal infections remain a problem. This article will review recent evidence about management and outcomes of the Boston KPro type I. [ABSTRACT FROM AUTHOR]

Ocular hypertension is a risk factor for developing glaucoma, which consists of a group of optic neuropathies characterized by progressive degeneration of retinal ganglion cells and subsequent irreversible vision loss. Our understanding of how intraocular pressure damages the optic nerve is based on clinical measures of intraocular pressure that only gives a partial view of the dynamic pressure load inside the eye. Intraocular pressure varies over the course of the day and the oscillator regulating these daily changes has not yet been conclusively identified. The purpose of this study was to compare and contrast the circadian rhythms of intraocular pressure and body temperature in Brown Norway rats when these animals are housed in standard light-dark and continuous dim light (40-90 lux) conditions. The results from this study show that the temperature rhythm measured in continuous dim light drifted forward relative to external time, indicating that the rhythm was free running and being regulated by an internal biological clock. Also, the results show that there is a persistent, but dampened, circadian rhythm of intraocular pressure in continuous dim light and that the circadian rhythms of temperature and intraocular pressure are not synchronized by the same central oscillator. We conclude that once- or twice-daily clinical measures of intraocular pressure are insufficient to describe intraocular pressure dynamics. Similarly, our results indicate that, in experimental animal models of glaucoma, the common practice of housing animals in constant light does not necessarily eliminate the potential influence of intraocular pressure rhythms on the progression of nerve damage. Future studies should aim to determine whether an oscillator within the eye regulates the rhythm of intraocular pressure and to better characterize the impact of glaucoma on this rhythm. [ABSTRACT FROM AUTHOR]

The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug-loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate-based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. pHEMA-UV revealed some superficial porosity and a lower short-range order than pHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant inin vivoconditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered. [ABSTRACT FROM PUBLISHER]

The Boston Keratoprosthesis has allowed for visual restoration in patients with corneal blindness; however, vitreoretinal complications remain a significant cause of ocular morbidity. Retroprosthetic membranes, infectious endophthalmitis, sterile vitritis, vitreous hemorrhage, vitreous opacities, retinal detachment, cystoid macular edema, choroidal detachments, retinal vascular occlusion, and epiretinal membrane have all been described, may require the intervention of a vitreoretinal specialist, and are reviewed herein. A strong familiarity with associated posterior segment complications is important to maximizing patient outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Acinetobacter (A.) baumannii is an opportunistic pathogen and has been reported as a causative agent of ocular infections. The aim of this study is to identify virulence properties (biofilm formation, adhesion, invasion and cytotoxicity) and antibiotic resistance among A. baumannii isolates recovered from the eye. Materials and Methods: The Microscan Walk-Away®, an automated bacterial identification and susceptibility testing system was used to determine antibiotic resistance. Clonal relatedness was assessed by Pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. Conjugation experiments were carried out to determine the transfer of antibiotic resistance genes and PCR was used to confirm gene transfer. Virulence properties of the isolates were determined by biofilm formation using crystal violet and immunofluorescence staining, adherence and internalization using cultured corneal epithelial cells, and cytotoxicity by TUNEL-staining and LDH release assays. Results: All ocular isolates ( n = 12) exhibited multidrug resistant (MDR) phenotype and one of the isolate (AB12) was resistant to 18 antibiotics (β-lactam, aminoglycosides, tetracycline, chloramphenicol and quinolones). The plasmid profile analysis showed the presence of multiple plasmids in each isolate and a total of 10 different profiles were observed. However, PFGE analysis was more discriminatory which revealed 12 distinct genotypes. Antibiotic resistance (tetracycline and quinolone) was transferable from the isolate AB12 to a recipient Escherichia coli J53. Ten isolates were strong biofilm producers and the remaining two (AB5 and AB7) were moderate producers. All isolates demonstrated adherence and invasive properties towards HCECs. A similar trend was observed in their ability to cause cell death and toxicity. Conclusions: Our results indicate that ocular isolates of A. baumannii are biofilm producers and adherent and invasive to corneal epithelium, a first step in the pathogenesis of ocular infection. In addition, they demonstrated plasmid-mediated transfer of MDR traits making them a reservoir of resistance genes at ocular surface. [ABSTRACT FROM AUTHOR]

Purpose: Acinetobacter (A.) baumannii is an opportunistic pathogen and has been reported as a causative agent of ocular infections. The aim of this study is to identify virulence properties (biofilm formation, adhesion, invasion and cytotoxicity) and antibiotic resistance among A. baumannii isolates recovered from the eye. Materials and Methods: The Microscan Walk-Away®, an automated bacterial identification and susceptibility testing system was used to determine antibiotic resistance. Clonal relatedness was assessed by Pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis. Conjugation experiments were carried out to determine the transfer of antibiotic resistance genes and PCR was used to confirm gene transfer. Virulence properties of the isolates were determined by biofilm formation using crystal violet and immunofluorescence staining, adherence and internalization using cultured corneal epithelial cells, and cytotoxicity by TUNEL-staining and LDH release assays.Results: All ocular isolates (n = 12) exhibited multidrug resistant (MDR) phenotype and one of the isolate (AB12) was resistant to 18 antibiotics (β-lactam, aminoglycosides, tetracycline, chloramphenicol and quinolones). The plasmid profile analysis showed the presence of multiple plasmids in each isolate and a total of 10 different profiles were observed. However, PFGE analysis was more discriminatory which revealed 12 distinct genotypes. Antibiotic resistance (tetracycline and quinolone) was transferable from the isolate AB12 to a recipient Escherichia coli J53. Ten isolates were strong biofilm producers and the remaining two (AB5 and AB7) were moderate producers. All isolates demonstrated adherence and invasive properties towards HCECs. A similar trend was observed in their ability to cause cell death and toxicity. Conclusions: Our results indicate that ocular isolates of A. baumannii are biofilm producers and adherent and invasive to corneal epithelium, a first step in the pathogenesis of ocular infection. In addition, they demonstrated plasmid-mediated transfer of MDR traits making them a reservoir of resistance genes at ocular surface. [ABSTRACT FROM AUTHOR]

Although intraocular pressure (IOP) is the only treatable risk factor for glaucoma, its 24-hour behavior is poorly understood. Conflicting information is available in the literature with regard to the importance and predictive value of IOP peaks and fluctuations on the risk of glaucoma development and progression. This may be secondary to lack of prospective studies designed to address this issue. This article critically reviews the current evidence for the importance of 24-h IOP measurements in glaucoma and discusses shortcomings of current methods to assess 24-h IOP data, drawing attention to new developments in this field. [ABSTRACT FROM AUTHOR]

Microbial infections of the cornea frequently cause painful, blinding and debilitating disease that is often difficult to treat and may require corneal transplantation. In addition, sterile corneal infiltrates that are associated with contact lens wear cause pain, visual impairment and photophobia. In this article, we review the role of Toll-Like Receptors (TLR) in bacterial keratitis and sterile corneal infiltrates, and describe the role of MD-2 regulation in LPS responsiveness by corneal epithelial cells. We conclude that both live bacteria and bacterial products activate Toll-Like Receptors in the cornea, which leads to chemokine production and neutrophil recruitment to the corneal stroma. While neutrophils are essential for bacterial killing, they also cause tissue damage that results in loss of corneal clarity. These disparate outcomes, therefore, represent a spectrum of disease severity based on this pathway, and further indicate that targeting the TLR pathway is a feasible approach to treating inflammation caused by live bacteria and microbial products. Further, as the P. aeruginosa type III secretion system (T3SS) also plays a critical role in disease pathogenesis by inducing neutrophil apoptosis and facilitating bacterial growth in the cornea, T3SS exotoxins are additional targets for therapy for P. aeruginosa keratitis. [ABSTRACT FROM AUTHOR]

Purpose: Microbiology, clinical perspective of ocular fungal infections, and the experimental models were overviewed. Methods: Review of published studies were evaluated and personal experience was mentioned. In this review, clinical features of keratitis and endogenous and exogenous endophthalmitis are also mentioned, but this article mainly focused on laboratory diagnosis and the experimental models of ophthalmic mycoses. Results: Fungal infections were discussed according to the anatomical part of the eye involved in the disease. Trauma is the most important predisposing cause; the species of Fusarium, Aspergillus, and Candida are the most frequently isolated organisms. Laboratory methods, such as culture, remains the cornerstone of diagnosis; direct microscopic detection of fungal structures in ocular samples permits a rapid presumptive diagnosis. New approaches, such as serological and molecular methods, have been widely used in recent years. A variety of antifungals have been evaluated in the therapy of this condition. Experimental models would facilitate investigations exploring the pathophysiology, cell biology, genetics, immunology, and therapy of this disease. Conclusions: Fungal infections of the eye continue to be an important cause of ocular morbidity, particularly in the developing world. Understanding ocular infections will improve the outcome of this condition. [ABSTRACT FROM AUTHOR]

Although effective drugs have become available, improvements in the treatment of contact lens-associated microbial keratitis are required. Over the last decade, the outcome of contact lens-associated bacterial keratitis has improved owing to fluoroquinolones, leading to a better control of infection, earlier institution of anti-inflammatory therapy and surgical intervention. The antimicrobial effectiveness of some antibiotics may be increased by preservatives. Antibiotic resistance according to serum standard limits has not been found to be relevant for the eye, with the exception of methicillin-resistant Staphylococcus aureus. Newer antifungals (voriconazole, itraconazole) are being evaluated, but the mainstay is liposomal amphotericin B and econzole or natamycin. Therapy for acanthamebic (biguanides and combinations) and microsporidial (fluoroquinolones) infections remains unchanged. New hydrophilic contact lens materials may slow down the formation of biofilm. Antibiofilm research has introduced substances that interfere with quorum sensing, and affect enzymatic and peptide-mediated matrix dispersal. Nanotechnology will be used to penetrate the biofilm matrix as well as nanoetching to prevent biofilm development on surfaces. Management of contact lens keratitis comprises of management of the biofilm. Early aggressive antimicrobial treatment, and surgery in certain cases, have resulted in better outcomes. The role of corticosteroids seems beneficial, but has to be further studied. Further improvements rely on biofilm-active agents added to antimicrobials. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to review the current literature on in vivo confocal microscopy of the cornea and to discuss the current clinical indications for its use in microbial keratitis. Methods: Review of select recent literature on in vivo confocal microscopy and atypical microbial keratitis. Results: Delayed diagnosis of Acanthamoeba and fungal keratitis is typical, resulting in significant vision loss. This is partially due to the low sensitivity and time delay of corneal cultures. In the hands of an experienced viewer, the confocal microscope has been found to have a sensitivity of up to 90% in the diagnosis of Acanthamoeba keratitis and close to 80% for fungal keratitis. Conclusion: In vivo confocal microscopy is emerging as a tool for rapid diagnoses in severe infectious keratitis with high sensitivity. In addition, it can be used to monitor treatment response, allowing guidance to clinicians for medical or surgical management. [ABSTRACT FROM AUTHOR]

Purpose: Infectious and inflammatory corneal diseases are a major cause of blindness. To date, assessment of corneal inflammation, has only been possible by slit-lamp biomicroscopy. The purpose of this study is to review the current state of imaging technologies enabling in vivo imaging of inflammation in the cornea. Methods: Literature review of peer-reviewed articles on in vivo imaging modalities. Results: Current means of diagnosis and treatment follow-up for immune and infectious keratitis are limited to slit-lamp biomicroscopy. Several modalities are currently emerging, allowing for in vivo imaging of corneal inflammation, including in vivo confocal microscopy, anterior segment optical coherence tomography, and intravital multiphoton microscopy. Conclusion: Several in vivo imaging technologies are currently evolving, allowing for objective assessment of corneal inflammation and treatment response. [ABSTRACT FROM AUTHOR]

This study demonstrates that the growth of S. typhimurium in Luria Bertani broth supplemented with acetate, propionate, butyrate, or a mixture of the three SCFA, affected cell‐association and the ability to invade cultured HEp‐2 cells. Cell‐association and invasion was determined after growth for 4 h of growth in the presence of the SCFA at pH 6 and 7. The results suggest that the growth rate of the culture may have affected cell‐association and invasion since accompanying the significant decrease in growth rate in the presence of SCFA at pH 6 was a decrease in cell‐association and invasion. However, the results also suggest that the individual SCFA may play a role in modulating cell‐association and the invasion phenotype and the regulation of cell‐association and invasion by the SCFA was dependent on the concentration and the pH of the medium. Although the growth rates were similar for S. typhimurium in the SCFA mixture, butyrate (100 mM) and propionate (50 mM) at pH 6, differences in cell‐association and invasion were observed among these cultures. Also, at pH 7, differences were observed among the SCFA treatments even though the growth rates were similar. [ABSTRACT FROM PUBLISHER]