Natamicina versus voriconazol para queratitis fúngica / Natamycin versus voriconazole for fungal keratitis

INTRODUCCIÓN: La queratitis infecciosa de origen fúngico afecta principalmente a personas de países tropicales y subtropicales, y constituye una importante causa de ceguera prevenible. Los antifúngicos tópicos, en particular la natamicina y el voriconazol, se consideran efectivos, pero no está claro cuál de ellos constituye la mejor alternativa de tratamiento. MÉTODOS: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos tres revisiones sistemáticas que en conjunto incluyeron tres estudios primarios, todos correspondientes a ensayos aleatorizados. Concluimos que natamicina probablemente se asocia a mejor agudeza visual tras la infección, y que previene la perforación corneal y/o la necesidad de realizar queratoplastia terapéutica en comparación a voriconazol en queratitis fúngica.

INTRODUCTION: Infectious keratitis of fungal origin mainly affects people in tropical and subtropical countries, and is an important cause of preventable blindness. Topical antifungals, particularly natamycin and voriconazole, are considered effective, but it is not clear which one is the best treatment alternative. METHODS: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified three systematic reviews including three studies overall,all of which were randomized trials. We concluded natamycin probably is associated with better visual acuity after infection, and it prevents corneal perforation and/or need to perform therapeutic keratoplasty compared to voriconazole in fungal keratitis.

Keratomycosis caused by Exserohilum rostratum.

We report a case of keratomycosis caused by Exserohilum rostratum. A 46-year-old farmer presented with history of pain, watery discharge and redness of the right eye for the past 2 weeks following trauma with vegetable matter. On ocular examination, a central corneal ulcer of about 8 mm with a greyish-white slough, feathery edges and diffuse corneal edema was seen in the right eye. KOH examination of corneal scrapings revealed thick, brown, branched, septate hyphae. Culture of corneal scrapings on Sabouraud dextrose agar showed velvety greenish-black colony with a black pigment on the reverse. The culture was identified as E. rostratum on the basis of microscopic morphology. The patient responded well to treatment with topical natamycin and oral itraconazole.

Natamycin in the treatment of keratomycosis: Correlation of treatment outcome and in vitro susceptibility of fungal isolates.

In this study, 60 fungal isolates from 60 patients with fungal keratitis were tested in vitro for their susceptibility to natamycin and the mean minimum inhibitory concentrations of natamycin (MICn) were correlated with clinical outcome. The mean MICn for various groups of fungi from patients with either early (<10 days) or late (≥10 days) presentation was correlated with the outcome. Aspergillus flavus showed resistance to natamycin with a high mean MICn (>16 μg/ml). While the clinical response in all patients with early A. flavus keratitis was good it was poor in late cases (5/8 patients, 62.5%). Fusarium species, Acremonium species and dematiaceous fungi were sensitive with low mean MICn (Fusarium: 5.7-7.2 μg/ml, Acremonium: 5.7-6.8 μg/ml, dematiaceous: (1.6-4 μg/ml). However, 46.6% (7/15) patients in Fusarium and 57.1% (4/7) in Acremonium group needed keratoplasty. We conclude that despite susceptibility of most fungal species causing keratitis to natamycin, the treatment outcome is poor in advanced fungal keratitis.

Colletotrichum graminicola keratitis: First case report from India.

Colletotrichum graminicola is a medically important fungus belonging to the order Melanconiales under the class Coelomycetes. The members of the genus Colletotrichum are primarily plant pathogens which cause anthracnoses (fungal infection in plants). In the past few decades, they are progressively being implicated as etiological agents of subcutaneous hyalohyphomycoses and keratomycoses. Of the five medically important members in the genus Colletotrichum, keratitis due to Colletotrichum graminicola is rare. We diagnosed Colletotrichum graminicola keratitis in a 44-year-old man who presented with a non-healing corneal ulcer since three weeks. Positive smears and cultures from the corneal scrapings established the causative organism as C. graminicola. The patient was treated with a combination of oral ketoconazole and topical fluconazole and natamycin. Infection resolved over 10 weeks and antimicrobials were stopped. We describe the clinical presentation and treatment outcome of Colletotrichum graminicola keratitis.

Effect of topical 0.5 percent povidone-iodine compared to 5 percent natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study / Efeito tópico de iodo-povidona 0, 5 por cento comparado com natamicina 5 por cento em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto

PURPOSE: To evaluate the efficacy of topical administration of 0.5 percent povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5 percent povidone-iodine; Group II (natamycin) - treated with topical 5 percent natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05). CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5 percent povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5 percent natamycin.

OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5 por cento em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de tratamento: Grupo I (iodo-povidona) - tratados com iodo-povidona 0,5 por cento; Grupo II (natamicina) - tratados com natamicina 5 por cento; Grupo III (controle) - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC). Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de coelhos nos quais não houve crescimento de colônias. Entretanto, não houve diferença estatística significante entre os 3 grupos quando se analizou o número de UFC (p>0,05). CONCLUSÃO: Este estudo demonstrou considerações metodológicas importantes na utilização de modelos animais para o teste de agentes antifúngicos. Usando a metodologia de contar UFC e com este tamanho amostral, administração tópica de iodo-povidona 0,5 por cento não demonstrou benefício do tratamento de ceratite fúngica experimental causada por Fusarium solani quando comparado com a administração tópica de natamicina 5 por cento.

Penicillium keratitis in vernal Keratoconjunctivitis.

We report a case of penicillium keratitis in vernal shield ulcer in the absence of corticosteroid use. This report illustrates super-added infection in vernal shield ulcer by an organism which is otherwise innocuous and forms a part of the normal ocular flora.

Simultaneous bilateral fungal keratitis caused by different fungi.

Fungal keratitis is an important cause of corneal disease in the tropical world. We report a rare presentation of simultaneous bilateral corneal ulceration caused by different fungi.