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1.
Int J Biol Macromol ; 273(Pt 1): 132838, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38838886

RESUMO

Management of infections at ocular injury often requires prolonged and high dose of antibiotic, which is associated with challenges of antibiotic resistance and bacterial biofilm formation. Tissue glues are commonly used for repairing ocular tissue defects and tissue regeneration, but they are ineffective in curing infection. There is a critical need for antibacterial ocular bio-adhesives capable of both curing infection and aiding wound closure. Herein, we present the development of an imine crosslinked N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride (HTCC)­silver chloride nanocomposites (QAm1-Agx) and poly-dextran aldehyde (PDA) based bactericidal sealant (BacSeal). BacSeal exhibited potent bactericidal activity against a broad spectrum of bacteria including their planktonic and stationary phase within a short duration of 4 h. BacSeal effectively reduced biofilm-embedded MRSA and Pseudomonas aeruginosa by ∼99.99 %. In ex-vivo human cornea infection model, BacSeal displayed ∼99 % reduction of ocular infection. Furthermore, the hydrogel exhibited excellent sealing properties by maintaining ocular pressure up to 75 mm-Hg when applied to human corneal trauma. Cytotoxicity assessment and hydrogel-treated human cornea with a retained tissue structure, indicate its non-toxic nature. Collectively, BacSeal represents a promising candidate for the development of an ocular sealant that can effectively mitigate infections and may assist in tissue regeneration by sealing ocular wounds.


Assuntos
Antibacterianos , Quitosana , Hidrogéis , Quitosana/química , Quitosana/farmacologia , Quitosana/análogos & derivados , Antibacterianos/farmacologia , Antibacterianos/química , Hidrogéis/química , Hidrogéis/farmacologia , Humanos , Adesivos Teciduais/química , Adesivos Teciduais/farmacologia , Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Traumatismos Oculares/tratamento farmacológico , Córnea/efeitos dos fármacos , Córnea/microbiologia , Testes de Sensibilidade Microbiana
2.
Int J Pharm ; 656: 124118, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38615806

RESUMO

Fungal infections of cornea are important causes of blindness especially in developing nations with tropical climate. However, the challenges associated with current treatments are responsible for poor outcome. Natamycin is the only FDA-approved antifungal drug to treat fungal keratitis, but unfortunately due to its poor water solubility, it is available as suspension. The marketed suspension (5% Natamycin) has rapid precorneal clearance, poor corneal permeability, a higher frequency of administration, and corneal irritation due to undissolved suspended drug particles. In our study, we developed clear and stable natamycin-loaded nanomicelles (1% Natcel) to overcome the above challenges. We demonstrated that 1% Natcel could permeate the cornea better than 5% suspension. The developed 1% Natcel was able to provide sustained release for up to 24 h. Further, it was found to be biocompatible and also improved the mean residence time (MRT) than 5% suspension in tears. Therefore, the developed 1% Natcel could be a potential alternative treatment for fungal keratitis.


Assuntos
Antifúngicos , Córnea , Liberação Controlada de Fármacos , Infecções Oculares Fúngicas , Ceratite , Micelas , Nanopartículas , Natamicina , Natamicina/administração & dosagem , Antifúngicos/administração & dosagem , Antifúngicos/química , Antifúngicos/farmacologia , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Animais , Córnea/microbiologia , Córnea/metabolismo , Córnea/efeitos dos fármacos , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Coelhos , Solubilidade , Preparações de Ação Retardada , Lágrimas/metabolismo
3.
Cornea ; 43(8): 1044-1048, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38537125

RESUMO

PURPOSE: Antimicrobial resistance is a global health threat, compounded by the reduction in the discovery of new antibiotics. A repurposed drugs-based approach could provide a viable alternative for the treatment of multidrug-resistant (MDR) bacterial infections. In this study, we sought to evaluate the in vitro efficacy of a novel drug combination, polymyxin B/trimethoprim (PT) + rifampin on MDR isolates from patients with bacterial keratitis in India. METHODS: Forty-three isolates, which included 20 Staphylococcus aureus , 19 Pseudomonas aeruginosa , 3 Pseudomonas stutzeri , and 1 Acinetobacter baumannii , were evaluated for their antibiotic resistance by minimum inhibitory concentration (MIC). Fractional Inhibitory Concentration Index (FICI) testing was performed to measure the antimicrobial impact of PT + rifampin in combination. RESULTS: Among S. aureus isolates, 100% were resistant to at least 1 antibiotic class, 12 (60%) were MDR, and 14 (70%) were classified as methicillin-resistant. Among the gram-negative isolates, >90% were classified as MDR. Fractional Inhibitory Concentration (FIC) testing revealed that PT + rifampin was effective in completely inhibiting growth of all isolates while also displaying additive or synergistic activity in approximately 70% of the strains. Mean FICI values were 0.753 ± 0.311 and 0.791 ± 0.369 for S. aureus and gram-negative isolates, respectively, and a >2-fold reduction in MIC was measured for both PT and rifampin when tested in combination versus alone. CONCLUSIONS: Our data demonstrate the ability of PT + rifampin to eliminate all isolates tested, even those conferring MDR, highlighting the promise of this drug combination for the treatment of bacterial keratitis.


Assuntos
Antibacterianos , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla , Infecções Oculares Bacterianas , Testes de Sensibilidade Microbiana , Polimixina B , Rifampina , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Bacterianas/tratamento farmacológico , Rifampina/farmacologia , Rifampina/uso terapêutico , Polimixina B/farmacologia , Trimetoprima/farmacologia , Trimetoprima/uso terapêutico , Quimioterapia Combinada
4.
Int Ophthalmol ; 43(11): 4151-4162, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37526782

RESUMO

PURPOSE: To determine current institutional practice patterns for the use of perioperative antibiotics and other measures to prevent infection after cataract surgery in Asia. METHODS: An online survey-based study of leading eye institutions in China, Hong Kong, India, Indonesia, Japan, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam was conducted. The survey was administered to 26 representative key opinion leaders from prominent tertiary eye institutions that are also national academic teaching institutions in Asia. Survey responses were collated and anonymized during analysis. RESULTS: All surveyed institutions used povidone iodine for the preoperative antiseptic preparation of the eye, with notable variations in the concentration of povidone iodine used for conjunctival sac instillation. Preoperative topical antibiotics were prescribed by 61.5% and 69.2% of institutions in low-risk and high-risk cases, respectively. Regarding the use of intra-operative antibiotics, 60.0% and 66.7% of institutions administered intracameral antibiotics in low-risk and high-risk patients, respectively. Postoperative topical antibiotics use patterns were generally very similar in low-risk and high-risk patients. Over half of the institutions (52.2% and 68.0% in low-risk and high-risk patients, respectively) also indicated prolonged postoperative use of topical antibiotics (> 2 weeks). Not all surveyed institutions had established policies/protocols for perioperative antibiotic use in cataract surgery, endophthalmitis surveillance, and/or a monitoring program for emerging antimicrobial resistance. CONCLUSION: There are variations in antimicrobial prophylaxis approaches to preoperative, intra-operative and postoperative regimens in cataract surgery in Asia. More evidence-based research is needed to support the development of detailed guidelines for perioperative antibiotic prophylaxis to reduce postoperative infections.


Assuntos
Extração de Catarata , Catarata , Endoftalmite , Infecções Oculares Bacterianas , Humanos , Antibioticoprofilaxia/métodos , Povidona-Iodo/uso terapêutico , Antibacterianos/uso terapêutico , Extração de Catarata/efeitos adversos , Endoftalmite/etiologia , Complicações Pós-Operatórias/etiologia , Catarata/etiologia , Infecções Oculares Bacterianas/tratamento farmacológico
5.
Ocul Surf ; 32: 211-218, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37406881

RESUMO

Pseudomonas aeruginosa is a leading cause of corneal infection both within India and globally, often causing a loss of vision. Increasing antimicrobial resistance among the bacteria is making its treatment more difficult. Preventing initial bacterial adherence to the host membrane has been explored here to reduce infection of the cornea. Synthetic peptides derived from human tetraspanin CD9 have been shown to reduce infection in corneal cells both in vitro, ex vivo and in vivo. We found constitutive expression of CD9 in immortalized human corneal epithelial cells by flow cytometry and immunocytochemistry. The synthetic peptides derived from CD9 significantly reduced bacterial adherence to cultured corneal epithelial cells and ex vivo human cadaveric corneas as determined by colony forming units. The peptides also significantly reduced bacterial burden in a murine model of Pseudomonas keratitis and lowered the cellular infiltration in the corneal stroma. Additionally, the peptides aided corneal wound healing in uninfected C57BL/6 mice compared to control mice. These potential therapeutics had no effect on cell viability or proliferation of corneal epithelial cells and have the potential to be developed as an alternative therapeutic intervention.

7.
Future Microbiol ; 18: 249-253, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37140251

RESUMO

The authors report the clinical and microbiological findings of a unique case of stromal keratitis caused by a rare microsporidium, Trachipleistophora hominis. This case of stromal keratitis was in a 49-year-old male with a history of COVID-19 infection and diabetes mellitus. Corneal scraping specimens revealed numerous microsporidia spores upon microscopic examination. PCR of the corneal button revealed the presence of T. hominis infection, which could be controlled by penetrating keratoplasty surgery. The graft was clear with no recurrence of infection until the last follow-up 6 weeks postsurgery. This is the first case of human stromal keratitis caused by this organism in a post-COVID infection, confirmed by molecular diagnosis.


Assuntos
COVID-19 , Ceratite , Microsporídios , Microsporidiose , Masculino , Humanos , Pessoa de Meia-Idade , Substância Própria/microbiologia , Microsporidiose/diagnóstico , Microsporidiose/microbiologia , Microsporidiose/cirurgia , Ceratite/diagnóstico , Ceratite/microbiologia , Ceratite/cirurgia , Microsporídios/genética
8.
Cornea ; 42(7): 837-846, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35942533

RESUMO

PURPOSE: The aims of this study were to assess the trends in microorganisms from patients with infectious keratitis and to assess their antibiogram patterns at a tertiary eye care center in India. METHODS: In this retrospective observational case series, microbiological records of all corneal ulcers were reviewed from 1991 to 2020 and assessed for trends in keratitis and antibiotic susceptibility using the χ 2 test. RESULTS: Of the total of 51,747 patients, 51.13% were culture positive. A decrease in bacteria was noted from 56% to 38%, with a parallel increase in fungal isolates from 24% to 51%. Gram-positive bacteria accounted for 70.8% of the total bacteria, a trend in rise of Streptococcus pneumoniae (31%) and a decreasing trend in prevalence of Staphylococcus epidermidis was observed over 30 years . Pseudomonas aeruginosa (55.5%) was the most prevalent gram-negative pathogen, whereas Fusarium spp . (33.1%) and Aspergillus spp. (32.4%) were the most common fungal isolates. The susceptibility of gram-positive organisms to cefazolin decreased from 95.5% to 66% ( P = 0.0001), amikacin from 88% to 55% ( P = 0.0001), and vancomycin from 98.9% to 90.7% ( P < 0.05). A similar decrease in susceptibility was also significant for gram-negative organisms with piperacillin/tazobactam and chloramphenicol ( P < 0.05). A significant trend toward increasing resistance against fluoroquinolones was also observed for ciprofloxacin (gram-positive organisms: 16% to 50%; gram-negative organisms: 11.5% to 18.7%), gatifloxacin (38% to 47%), and moxifloxacin (9.4% to 29%). CONCLUSIONS: The spectrum of keratitis has changed, and fungus is now the predominant etiology. An increasing trend in resistance to all antibiotics studied would affect the empiric treatment, also suggesting regular surveillance.


Assuntos
Infecções Oculares Bacterianas , Ceratite , Humanos , Estudos Retrospectivos , Atenção Terciária à Saúde , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/epidemiologia , Infecções Oculares Bacterianas/microbiologia , Ceratite/tratamento farmacológico , Ceratite/epidemiologia , Ceratite/microbiologia , Bactérias , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana , Centros de Atenção Terciária
9.
Pathogens ; 11(11)2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36422638

RESUMO

BACKGROUND: To examine the relationship between single-nucleotide polymorphisms (SNPs) in interleukin (IL) genes and keratitis and its clinical manifestations. METHODS: SNPs in IL1B, IL6, CXCL8, IL10, and IL12B were analysed. Differences in frequencies of alleles, genotypes and haplotypes between cases and controls as well as associations between SNPs and clinical variables were calculated by χ2 tests with odds ratios. RESULTS: The minor homologous genotype in IL1B rs16944 (p = 0.036; odds ratio (OR) = 2.063, 95% confidence interval (CI): 1.048-4.061) and CXCL8 rs4073 (p = 0.041; OR = 0.463, 95% CI: 0.224-0.956) and the heterologous genotypes in IL6 rs1800795 (p = 0.046; OR = 0.563, 95% CI: 0.326-0.972) and IL12B rs2569254 (p = 0.0446; OR = 0.557, 95% CI: 0.314-0.989) or rs730691 (p = 0.0051; OR = 0.451, 95% CI: 0.260-0.784) were associated with keratitis. The minor genotype of rs16944 was associated with severe infection (p = 0.046). The heterologous genotype in rs2569254 was associated with hospital admission, photophobia, and mode of contact lens wear (p ≤ 0.041). The heterologous genotype in rs730691 was associated with blurred vision, discharge, anterior chamber reaction, and mode of wear (p ≤ 0.047). CONCLUSIONS: This study demonstrates that SNPs in IL1B and CXCL8 are associated with risk of developing keratitis. The study also found relationships between SNPs and clinical measures of keratitis. The potential for ethnic differences in frequency of SNPs and their association with keratitis should be followed up using different populations.

10.
Indian J Ophthalmol ; 70(11): 4079-4081, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36308167

RESUMO

While ophthalmology as a surgical branch itself has evolved technologically with newer instruments, techniques and procedures; ophthalmic surgical training appears to have stagnated in terms of how it is delivered and how trainees' learning and performance are assessed. This collaborative editorial attempts to identify the lacunae in ophthalmic residency training and highlight how technological tools such as surgical simulators can be incorporated into ophthalmic training even in limited-resource settings with good results.


Assuntos
Extração de Catarata , Catarata , Internato e Residência , Oftalmologia , Humanos , Oftalmologia/educação , Educação de Pós-Graduação em Medicina/métodos , Competência Clínica , Tecnologia , Extração de Catarata/educação
11.
Artigo em Inglês | MEDLINE | ID: mdl-36092742

RESUMO

Background: In low-and-middle income countries, corneal abrasions and ulcers are common and not always well managed. Previous studies showed better clinical outcomes with early presentation and treatment of minor abrasions, however, there have been no formal studies estimating the financial impact of early treatment of abrasions and ulcers compared to delayed treatment. Methods: We used the LV Prasad Eye Institute's (LVPEI's) electronic health record system (eyeSmart) to estimate the impact of early presentation on clinical outcomes associated with abrasions and ulcers. 861 patients with corneal abrasion and 1821 patients with corneal ulcers were studied retrospectively, and 134 patients with corneal abrasion prospectively. A health economic model was constructed based on LVPEI cost data for a range of patient scenarios (from early presentation with abrasion to late presentation with ulcer). Findings: Our findings suggest that delayed presentation of corneal abrasion results in poor clinical and economic outcomes due to increased risk of ulceration requiring more extensive surgical management, increasing associated costs to patients and the healthcare system. However, excellent results at low cost can be achieved by treatment of patients with early presentation of abrasions at village level health care centres. Interpretation: Treatment of early minor corneal abrasions, particularly using local delivery of treatment, is effective clinically and economically. Future investment in making patients aware of the need to react promptly to corneal abrasions by accessing local healthcare resources (coupled with a campaign to prevent ulcerations occurring) will continue to improve clinical outcomes for patients at low cost and avoid complex and more expensive treatment to preserve sight. Funding: This research was funded by the Medical Research Council, grant MR/S004688/1.

12.
MethodsX ; 9: 101684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35540105

RESUMO

This paper outlined our method for developing polymer-linked contact lens type materials for rapid detection and differentiation of Gram-positive, Gram-negative bacteria and fungi in infected corneas. It can be applied to both model synthetic or ex-vivo corneal models and has been successfully trialed in an initial efficacy tested animal study. First a hydrogel substrate for the swab material is selected, we have demonstrated selective swabs using a glycerol monomethacrylate hydrogel. Alternatively any commercial material with carboxylic acid functional groups is suitable but risks nonspecific adhesion. This is then functionalised via use of N-hydroxysuccinimide reaction with amine groups on the specified highly branched polymer ligand (either individually gram negative, gram positive or fungal binding polymers or a combination of all three can be employed for desired sensing application). The hydrogel is then cut into swabs suitable for sampling, used, and then the presence of gram positive, game negative and fungi are disclosed by the sequential addition of dyes (fluorescent vancomycin, fluorescein isothiocyanate and calcofluor white). In summary this method presents: Method to produce glycerol monomethacrylate hydrogels to minimize nonspecific binding Methods of attaching pathogen binding highly branched polymers to produce selective hydrogel swabs Method for disclosing bound pathogens to this swab using sequential dye addition.

13.
Indian J Ophthalmol ; 70(4): 1107-1120, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35325996

RESUMO

Pythium insidiosum is an oomycete and is also called "parafungus" as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis.


Assuntos
Úlcera da Córnea , Ceratite , Pitiose , Pythium , Ágar/uso terapêutico , Animais , Úlcera da Córnea/diagnóstico , Humanos , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Ceratite/epidemiologia , Pitiose/diagnóstico , Pitiose/epidemiologia , Pitiose/terapia
14.
Eye Contact Lens ; 48(3): 119-126, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35192566

RESUMO

ABSTRACT: The field of ophthalmic drug delivery is undergoing rapid changes not only in the evolution of pharmacologic agents but also in the novel drug delivery vehicles. The ocular surface has limitations to drug penetration because of the presence of tight junctions between basal epithelial cells, which limits the amount of drug that can be absorbed after topical instillation. In addition, nasolacrimal drainage reduces the precorneal residence time significantly. Contact lenses (CLs) have been considered as possible carriers for topical medications because they reside on the ocular surface for a sufficient length of time, and pharmacologic agents may be copolymerized with hydrogels allowing controlled drug diffusion. This strategy reduces the frequency of dosage while improving compliance. Modification of drug delivery vehicles is essential to allow sustained release of the drug from a polymeric complex, facilitate stability and residence time of the drug on the precorneal tear film, and improve penetration into biologic membranes. This review focuses on updates in CL-based and non-CL-based strategies in ophthalmic drug delivery.


Assuntos
Lentes de Contato , Sistemas de Liberação de Medicamentos , Córnea , Hidrogéis , Soluções Oftálmicas , Lágrimas
15.
Cornea ; 41(2): 238-242, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852410

RESUMO

PURPOSE: The purpose of this study was to evaluate the prevalence of SARS-CoV-2 in human postmortem ocular tissues of asymptomatic donors and its implications on our eye banking protocols. METHODS: The expression of SARS-CoV-2 RNA was assessed by reverse transcription-polymerase chain reaction in corneal rims and conjunctival tissues from 100 donors who were found suitable for transplantation as per the donor screening guidelines of the Global Alliance of Eye Bank Associations. The donor's clinical history and cause of death were assessed for secondary analysis. RESULTS: Of 200 ocular tissues (100 corneal and 100 conjunctival) from the same 1 eye of 100 surgical-intended donors, between September 2020 and April 2021, the overall positivity rate for SARS-CoV-2 was ∼1% (2/200). Both the ocular samples that tested positive were conjunctival biopsies (2/100, 2%), whereas corneal samples were negative (0/100, 0%) in both donors. The causes of donor death were trauma in 51 donors, suicide in 33, cardiac arrest in 7, electric shock in 5, metabolic cause in 2, malignancy in 1, and snake bite in 1. None of the donors had a medical history suggestive of COVID infection or possible contact. None of the recipients from the donors were reported to have any systemic adverse event after keratoplasty until the follow-up of 6 weeks. CONCLUSIONS: The overall prevalence of SARS-CoV-2 was 1% (2% for conjunctival and 0% for corneal samples, P value = 0.5) in the donors who were found suitable for cornea recovery and transplantation. The findings of exceptionally low positive rates in our samples validate the criticality of history-based donor screening and do not support the necessity of postmortem PCR testing as a criterion for procurement and subsequent use for corneal transplantation.


Assuntos
Teste de Ácido Nucleico para COVID-19/estatística & dados numéricos , COVID-19/epidemiologia , Túnica Conjuntiva/virologia , Córnea/virologia , Ceratoplastia Penetrante , SARS-CoV-2/isolamento & purificação , Doadores de Tecidos/estatística & dados numéricos , Adulto , Teste para COVID-19 , Causas de Morte , Seleção do Doador , Bancos de Olhos/estatística & dados numéricos , Feminino , Humanos , Índia/epidemiologia , Ceratoplastia Penetrante/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prevalência , RNA Viral/genética , SARS-CoV-2/genética
17.
Int J Pharm ; 612: 121305, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-34800618

RESUMO

The delivery of therapeutics to the posterior segment of the eye is achieved by invasive procedures, including intravitreal injections and implants. The topically applied formulations would not permeate through different tissue barriers of the eye to reach the posterior segment. Here, we demonstrate the effectiveness of microneedle scleral patch in delivering the model molecule, triamcinolone acetonide, to the posterior segment of the eye. Microneedle scleral patch (MSP) and microneedle corneal patch (MCP) were fabricated through the micromolding technique using rapidly dissolvable polyvinylpyrrolidone. The patches containing 25 microneedles were characterized for physical and mechanical properties, drug loading and release behavior in vitro and ex vivo porcine eye globe model. The distribution of TA administered using MSP and MCP in different ocular tissues was evaluated in the rabbit eye model. The results showed that microneedles with 545 ± 8 µm length and 279 ± 26 µm width at the base in MSP penetrate the scleral membrane with the application of 0.35 ± 0.06 N force. The needles dissolved within 60 s after insertion in the corneal and scleral tissue. The 5 min application of MSP showed a significantly (p < 0.05) greater TA disposition in the vitreous humor and choroid-retinal complex in excised porcine eye globe compared with MCP and TA nanosuspension eye drops. In rabbit model studies, the TA concentration was greatest in the choroid-retinal complex and sclera after administration through intravitreal injection and MSP, respectively. The TA disposition in the sclera was significantly (p < 0.05) greater after MSP application compared with intravitreal injection and MCP application for up to 24 h. MSP application provided a greater safety score compared with intravitreal injection. In conclusion, MSP can be developed as a minimally invasive drug delivery system to target the posterior segment of the eye.


Assuntos
Preparações Farmacêuticas , Esclera , Animais , Sistemas de Liberação de Medicamentos , Agulhas , Coelhos , Suínos , Triancinolona Acetonida
18.
Indian J Ophthalmol ; 70(1): 90-94, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34937215

RESUMO

PURPOSE: To evaluate the efficacy of voriconazole and amphotericin B in McCarey-Kaufman (MK) media. METHODS: MK media vials were supplemented with either voriconazole at 1, 2, 20, 50, 100 µg/mL or amphotericin B at 0.5, 1, 2, 10, 20 µg/mL. The standard inoculum of the American Type Culture Collection (ATCC) strain of Candida albicans, Aspergillus flavus, and Fusarium keratinoplasticum was added to the set of vials. The efficacy outcomes were calculated as 'viable fungal colony counts' determined from the samples taken on Days 0 and 4. MK media containing fungal inoculum but without antifungal supplements were used as control. RESULTS: In the voriconazole arm, on Day 4, a reduction in the colony count was observed for Candida albicans (1 µg/mL, 36%; 100 µg/mL, 100%), Aspergillus flavus (1 µg/mL, 53.8%; 100 µg/mL, 80.4%), and Fusarium keratinoplasticum (1 µg/mL, 39.0%; 100 µg/mL, 72.2%). Similarly, in the amphotericin B arm, on Day 4, a reduction in the colony count was observed for Candida albicans (0.5 µg/mL; 99.9%; 20 µg/mL, 100%), Aspergillus flavus (0.5 µg/mL, 65.2%; 20 µg/mL, 84.8%), and Fusarium keratinoplasticum (0.5 µg/mL, 90.1%; 20 µg/mL, 100%). CONCLUSION: Compared to voriconazole, the addition of amphotericin B significantly reduces fungal contamination in MK media.


Assuntos
Anfotericina B , Antifúngicos , Candida albicans , Humanos , Testes de Sensibilidade Microbiana , Voriconazol
19.
Exp Eye Res ; 214: 108881, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34871569

RESUMO

Corneal ulcers, a leading cause of blindness in the developing world are treated inappropriately without prior microbiology assessment because of issues related to availability or cost of accessing these services. In this work we aimed to develop a device for identifying the presence of Gram-positive or Gram-negative bacteria or fungi that can be used by someone without the need for a microbiology laboratory. Working with branched poly (N-isopropyl acrylamide) (PNIPAM) tagged with Vancomycin, Polymyxin B, or Amphotericin B to bind Gram-positive bacteria, Gram-negative bacteria and fungi respectively, grafted onto a single hydrogel we demonstrated specific binding of the organisms. The limit of detection of the microbes by these polymers was between 10 and 4 organisms per high power field (100X) for bacteria and fungi binding polymers respectively. Using ex vivo and animal cornea infection models infected with bacteria, fungi or both we than demonstrated that the triple functionalised hydrogel could pick up all 3 organisms after being in place for 30 min. To confirm the presence of bacteria and fungi we used conventional microbiology techniques and fluorescently labelled ligands or dyes. While we need to develop an easy-to-use either a colorimetric or an imaging system to detect the fluorescent signals, this study presents for the first time a simple to use hydrogel system, which can be applied to infected eyes and specifically binds different classes of infecting agents within a short space of time. Ultimately this diagnostic system will not require trained microbiologists for its use and will be used at the point-of-care.


Assuntos
Resinas Acrílicas/metabolismo , Úlcera da Córnea/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Fúngicas/diagnóstico , Hidrogéis/metabolismo , Ligantes , Resinas Acrílicas/química , Anfotericina B/farmacologia , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Candidíase/diagnóstico , Candidíase/microbiologia , Úlcera da Córnea/microbiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Fúngicas/microbiologia , Fungos/efeitos dos fármacos , Fungos/metabolismo , Humanos , Hidrogéis/química , Testes de Sensibilidade Microbiana , Polimixina B/farmacologia , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/microbiologia , Coelhos , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Vancomicina/farmacologia
20.
Indian J Ophthalmol ; 69(12): 3643-3647, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34827013

RESUMO

Purpose: To study the changing trends in the morphology of cataracts at a tertiary eye care center in South India due to COVID-19 pandemic-related national lockdown. Methods: A retrospective study conducted at a tertiary eye care center in Andhra Pradesh state of South India, which included 1724 patients (1753 eyes) who underwent cataract surgery at our center during April 2019-July 2019 (1298 eyes of 1271 patients) and April 2020-July 2020 (455 eyes of 453 patients). Factors studied included preoperative lens status, associated phacodonesis or subluxation, pupil size, other eye lens status, associated retinal problems, glaucoma, and complications during surgery. Postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal clarity, intraocular pressure (IOP), and disc status at postoperative day 1, 1 week, and 1-month visits were compared. Results: A significantly lower proportion of nuclear sclerosis (decreased from 83.2% in last year before lockdown to 55.2% during lockdown) and significantly higher proportions of mature, brown, or black cataract and phacomorphic, phacolytic, or Morgagnian cataract (increased from 15.5% in last year before lockdown to 43.8% during lockdown) were observed. The proportion of small-incision cataract surgery decreased significantly (from 63.2% to 57.4%), whereas the proportion of phacoemulsification increased significantly (from 35.9% to 41.5%) during lockdown as compared to last year. A significantly higher proportion of eyes with small pupils and association with retinal pathology were also observed during the lockdown. Conclusion: During the national lockdown, there was a shift from nuclear sclerosis grade toward mature, brown, black grade of cataracts. In addition, the proportion of small-incision cataract surgery decreased significantly whereas the proportion of phacoemulsification increased significantly during the lockdown. More number of cataracts with small pupils and associated retinal pathology were observed during the lockdown.


Assuntos
COVID-19 , Extração de Catarata , Catarata , Facoemulsificação , Catarata/epidemiologia , Controle de Doenças Transmissíveis , Humanos , Implante de Lente Intraocular , Pandemias , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , SARS-CoV-2 , Resultado do Tratamento
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