Microsporidial Keratitis Research Articles

Coexistence of herpes simplex virus infection in microsporidial stromal keratitis associated with granulomatous inflammation.

Background:Microsporidial stromal keratitis poses several diagnostic challenges. Patients may present with corneal ulceration, marked stromal thinning, or even as a quite corneal scar. The presentation of microsporidial stromal keratitis commonly mimics viral keratitis. Microbiology scrapings are usually helpful; however, scraping and culture-negative cases pose a significant diagnostic dilemma. Histopathological examination is diagnostic but shows varying degree of inflammation, predominantly composed of polymorphonuclear leukocytes. Granulomatous inflammation, in microsporidial stromal keratitis, is never well described, and the authors in this article aim to describe the presence of granulomatous inflammation in microsporidial stromal keratitis, in patients with associated herpes simplex virus (HSV) keratitis.Methods:This was a retrospective and observational study conducted at a tertiary eye care center.Results:Of 263 patients who underwent therapeutic penetrating keratoplasty for infectious keratitis, during 2011–2013, seven patients were diagnosed as microsporidial stromal keratitis. Microsporidial spores could be demonstrated on microbiological scrapings in 5/7 (71%) of cases, but identified on histopathological examination and also confirmed on polymerase chain reaction (PCR) for microsporidium in 100% of cases. There was evidence of diffuse stromal necrosis with markedly severe degree of polymorphonuclear leukocytic infiltrates, with granulomatous inflammation in 42% of cases. Interestingly, these were positive for HSV-1 DNA on PCR. Review of medical records revealed much severe clinical presentations in patients with granulomatous inflammation, in comparison to cases without granulomatous inflammation.Conclusions:The authors hereby recommend that severe clinical presentation in patients with microsporidial stromal keratitis, markedly dense polymorphonuclear leukocytic infiltrates or the presence of granulomatous inflammation on the histopathological examination, should be investigated further for the presence of HSV-1 DNA for better patient management and good visual outcome.

Microsporidial Stromal Keratitis: Clinical Features, Unique Diagnostic Criteria, and Treatment Outcomes in a Large Case Series.

To describe the history, clinical features, and outcomes of a large case series of microsporidial stromal keratitis with emphasis on probable predictors of the etiology in this rare and unspecified form of keratitis. Retrospective analysis of cases seen between January, 2002, and December, 2013, diagnosed at LV Prasad Eye Institute as having microsporidial stromal keratitis based on clinical, microbiology, and histopathology examination. Outcomes of medical and surgical management with visual recovery were documented. There were 34 cases of microsporidial stromal keratitis with a mean age of 43.3 years (range 2-77 years) and male preponderance. The duration of symptoms was chronic in most cases (mean duration of 288 days). Nearly half of the cases had a history of trauma, in the age group of 20 to 50 years. The most common clinical misdiagnosis was herpes simplex virus keratitis (26.5%) followed by fungal keratitis (17.6%). This could be attributed to the nonspecific clinical picture of diffuse multifocal stromal lesions in 82.4% of cases. The organisms were detected in microbiological evaluation of corneal scrapings in 47% cases, and histopathological detection of the organisms showed a positivity rate of 92.3%. Surgical management was necessary in the majority of the cases (73.5% of patients). The typical history of trauma with a smoldering, diffuse form of keratitis refractory to conventional medical therapy, responding to surgical removal for recovery is clearly demonstrated as a recurring feature in the majority of the cases. Patients presenting with this characteristic clinical picture should be suspected to harbor this rare pathogen, and early surgical interventions should be considered.

Utility of Polymerase chain reaction in diagnosis of Acanthamoeba and Microsporidial keratitis

Acanthamoeba and Microsporidia are two opportunistic parasitic organisms which are now increasingly recognized as significant emerging cause of microbial keratitis. The reason for this rise in numbers could possibly be because of increasing awareness of the condition, gradual rise in the use of contact lens and improvement in the diagnostic modalities. Early and accurate diagnosis is the most vital step in managing Acanthamoeba and Microsporidial keratitis as prognosis is directly related to timely diagnosis. Current methods of diagnosing these parasites depends mainly upon their morphologic demonstration in the clinical specimen by microscopy. Culture which is the gold standard in diagnosis of Acanthamoeba keratitis is time consuming and requires advanced laboratory set up because of the special growth requirements International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 5 Number 2(2016) pp. 854-860 Journal homepage: http://www.ijcmas.com

A study of microsporidiosis in corneal scrapings of keratitis patients referring to Farabi Eye Hospital, Tehran, Iran in 2013-14.

Background and Purpose:Microsporidiosis is one of the emerging and opportunistic infections, which causing various clinical symptoms in humans. The prevalence of this infection varies, depending on the infected organ, diagnostic methods, and geographical conditions. In the present study, we aimed to investigate microsporidial keratitis in patients referring to Farabi Eye Hospital Tehran, Iran in 2013-14.Materials and Methods:Two scraping samples were collected from 91 keratitis patients, five cases had prior history of receiving immune suppressive drugs. One of the two collected samples from each participant was used for Vero cell culture and the other was used for the preparation of Giemsa and Gram staining slides. After 30 days, the cells were scrapped and used for DNA extraction; afterwards, nested polymerase chain reaction (PCR) detection method was applied. Primer pairs of small-subunit ribosomal RNA gene were designed by CLC Genomics workbench software to amplify all major microsporidian pathogens, as well as E. bieneusi , which was used as the positive control in this study. Results:The nested PCR showed negative results regarding the presence of microsporidia in the samples. Similarly, Giemsa and Gram staining slides did not detect any spores.Conclusion:The prevalence of human microsporidiosis ranges between 0% and 50%, worldwide. Based on all the negative samples in the present study, we can conclude that the prevalence of this infection among Iranian patients falls in the lower quartile. By gathering further evidence, researchers can take a step forward in this area and open new doors for the assessment of AIDS patients and users of immunosuppressive drugs.

Clinical Features, Risk Factors, and Treatments of Microsporidial Epithelial Keratitis

Objective: To report the clinical manifestations, risk factors, and treatments of microsporidial epithelial keratitis in Thailand. Methods: Twenty eyes of 19 patients were diagnosed and the clinical presentations, risk factors, and management were analyzed. Results: Of 19 patients, six patients (32%) had no apparent risk factors. Predisposing factors included soil exposure (6/19, 32%), water contamination (6/19, 32%), and eye liner (1/19, 4%). Twelve cases (63%) were detected in the rainy season. All cases presented with disseminated, punctated, elevated, epithelial keratitis. Corneal scrapings with Gram-chromotrope staining were positive in all patients. Moxifloxacin 0.5% eye drops were given and all 16 patients experienced complete resolution. Three recurrent cases were resolved with only topical moxifloxacin without corneal scraping or swabbing. Conclusions: Predisposing factors were not found in some patients; thus, corneal scraping with staining should be considered in cases having a high index of suspicion. The incidence is increased during the rainy season; therefore, clinicians should have more awareness during these times. Debridement with topical moxifloxacin eye drops, without any systemic medication, may be an effective treatment. Corneal scraping or swabbing may not be required in recurrences.

In vivo confocal microscopy of cystic lesions in corneal disorders

AbstractPurpose The purpose of this study was to assess the correlation between slit‐lamp biomicroscopy and in vivo confocal microscopy and to describe the morphology of corneal intraepithelial cystic lesions by in vivo confocal microscopy in several corneal disorders.Methods 15 patients with clinically diagnosed Cogan Dystrophy (9), Meesmann’s Dystrophy (2), Acanthamoeba Keratitis (2), Microsporidial Keratitis (1) and Incontinentia Pigmenti (1) were examined by slit‐lamp biomicroscopy and in vivo confocal microscopy. Confocal microscopy images were used to assess size, shape and reflectivity of the corneal cystic structures.Results Confocal microscopy was able to identify cystic lesions in all cases in which cysts were observed by slit – lamp biomicroscopy. In vivo confocal scans showed multiple brightly reflective round, oval or circular structures with diameter from 10 microns (Incontinentia Pigmenti) to 140 microns (Meesmann‘s Dystophy). Large intraepithelial clefts were observed in Microsporidial Keratitis and Meesmann‘s Dysrophy.Conclusion In vivo confocal microscopy provides a detailed microstructural image of cystic intraepithelial lesions in various corneal disorders and may play a role in appropriate diagnosis.

Microsporidial Keratoconjunctivitis Outbreak among Athletes from Hong Kong Who Visited Singapore, 2012

Microsporidial Keratoconjunctivitis Outbreak among Athletes from Hong Kong Who Visited Singapore, 2012

Vittaforma corneae keratitis in southern India: role of a novel duplex PCR

Microsporidia are obligate intracellular parasites that infect eukaryotic cells and have emerged as major opportunistic human pathogens. Due to the difficulties in definitive laboratory diagnosis and insufficient knowledge, ocular microsporidiosis is infrequently reported in India. To improve diagnostic facilities, we have developed a novel duplex PCR (dPCR) for the simultaneous identification of both genera and species of isolates with microsporidian aetiology that cause keratitis. The material scraped from the corneas of 12 clinically diagnosed microsporidial keratitis patients was subjected to routine microbiological examinations and molecular diagnosis using a novel dPCR that targeted the small-subunit rRNA gene (SSU-rRNA) of microsporidia and Vittaforma corneae using genus- and species-specific primers. Of the 12 corneal scrapes, 6 showed positive results in smears, while dPCR provided positive amplification with both pan-microsporidial and V. corneae species-specific primers for 9 corneal scrapes. The results were validated by sequencing and blast analysis. The sensitivity of this novel dPCR method was higher than that of conventional microscopy in the diagnosis of corneal microsporidial infection. dPCR with specific primers is potentially more sensitive, specific and depends less on more complicated methods for exact identification of the aetiology of microsporidial keratitis.

Microsporidial spores can cross the intact descemet membrane in deep stromal infection

We report a rare case of a deep stromal keratitis with a chronic indolent course, diagnosed as microsporidial keratitis from corneal scrapings. The patient’s condition worsened despite medical therapy and penetrating keratoplasty was performed. The histopathology of the corneal tissue revealed multiple microsporidial spores in the posterior stroma and the endothelial exudates, whereas there was no clinical or histopathological breach in Descemet’s membrane. This is the second report in the literature to report that micropsoridial spores can cross the intact Descemet’s membrane.

Polymicrobial and microsporidial keratitis in a patient using Boston scleral contact lens for Sjogren's syndrome and ocular cicatricial pemphigoid

To report a rare case of microsporidial and polymicrobial keratitis in a patient with Sjogren's syndrome and ocular cicatricial pemphigoid. This is a descriptive case report. A 66-year-old lady diagnosed with Sjogren's syndrome (SS) and ocular cicatricial pemphigoid (OCP) presented to us with microbial keratitis after using a Boston sclera contact lens for a painful epithelial defect. After 9 days of medical treatment, she underwent therapeutic penetrating keratoplasty. 10% potassium hydroxide and calcofluor white wet mount revealed microsporidial spores. Gram positive cocci and Gram variable bacilli on Gram stain were identified as Staphylococcus epidermidis and Corynebacterium accolens in culture. Histopathological examination of the corneal tissue confirmed the presence of microsporidial spores. Microsporidal keratitis can occur in patients with severe ocular surface disease due to SS and OCP. Predisposing factors include dry eye, local and systemic immunosuppression and Boston scleral contact lens. Early surgical intervention may be needed to eradicate the infection.

Microsporidial keratitis: Literature review and report of 2 cases in a tertiary eye care center

Microsporidia are getting more recognized as causative organism of ocular, gastrointestinal, renal, pulmonary, and sinus diseases, in both immunocompetent and immunosuppressed patients. Ocular microsporidiosis can be isolated or may present as part of systemic infection. Recent reports showed increasing number of cases of ocular microsporidiosis in immunocompetent individuals. The ocular type occurs mainly in two forms: keratoconjunctivitis form which is mostly seen in immunocompromised individuals and stromal keratitis form seen in immunocompetent individuals. The ocular cases which present with superficial keratitis in acquired immune deficiency syndrome (AIDS) patients differ from the cases seen in immunocompetent individuals which present mainly as deep stromal keratitis.We are presenting the only two documented cases of microsporidial keratitis diagnosed over 25 years of practice in our institution. The cases are diagnosed by identification of the Acid-fast organisms. Ultrastructure and additional information on species identification in one of the cases. Both cases are eventually managed by therapeutic PKP. Diagnosis and treatment modalities are discussed based on a comprehensive literature review.

Microsporidial Keratitis in Patients with Hot Springs Exposure

This retrospective study included 10 eyes of 9 patients diagnosed with microsporidial keratitis. All of them were known to contract this disease after taking baths in hot springs. The disease was diagnosed based on detecting microsporidia in corneal scrapings using Gram stain and the modified Kinyoun's acid-fast stain. The specimens from the last six patients were subjected to PCR and then sequencing. All of them revealed that the microorganism identified has a high similarity to Vittaforma corneae. Repeated debridement of the epithelial lesions successfully eradicated the microsporidial infection in all nine patients.

Microsporidial Stromal Keratitis Successfully Treated With Medical Therapy: A Case Report

To report a case of stromal microsporidiosis that responded to medical treatment with systemic albendazole and topical chlorhexidine. A 14-year-old adolescent girl presented with a 3-month history of recurrent redness, pain, and dense anterior stromal corneal infiltrate. Repeated microbiological evaluation helped identify microsporidia from the fifth scraping. Initial therapy with fluoroquinolones failed; 0.02% topical chlorhexidine gluconate hourly and 400 mg of oral albendazole twice daily and later 0.5% loteprednol etabonate were given for a total of 12 weeks. There was complete resolution of the infection with corneal scarring with no episodes of recurrence at 1 year of follow-up. The final best-corrected visual acuity was 20/30. The diagnosis of microsporidia can be challenging, and corneal scraping should be repeated several times in cases having a high index of suspicion. Medical therapy can prove successful in selected cases where the infection may be limited to midstroma.

Is microsporidial keratitis a seasonal infection in India?

Microsporidia are emerging ocular pathogens. In this study, we describe the seasonal trends of microsporidial keratitis. The incidence of microsporidial keratitis is increasing in India, with a seasonal trend towards disease onset during the monsoon.

Treatment of Microsporidia Keratitis With Topical Voriconazole Monotherapy

Microsporidia are obligate intracellular eukaryotic pathogens known to cause superficial punctate keratitis and stromal keratitis in both immunocompromised and immuno-competent individuals. Traditionally, microsporidia were classified as primitive eukaryotes; however, recent genomic evidence supports their reclassification as fungi.1 Definitive treatment for micro-sporidial keratitis has not been established. Based on the classification of microsporidia as fungi, use of topical antifungal agents may be beneficial as monotherapy. Voriconazole is available through compounding pharmacies in topical form and is effective against several fungal pathogens.2 Herein, we report 2 cases of microsporidial superficial punctate keratitis that were responsive to treatment with topical voriconazole. To our knowledge, this is the first case series of the successful treatment of microsporidial superficial punctate keratitis with topical voriconazole.

Emerging Prevalence of Microsporidial Keratitis in Singapore: Epidemiology, Clinical Features, and Management

To investigate the incidence and epidemiologic factors involved in the development of microsporidial keratitis. The association of host immune status and clinical pattern, clinical features, and the role of fluoroquinolone monotherapy in treatment are also examined. Retrospective, noncomparative case series. All cases (124 patients, 134 eyes) of microsporidial keratitis confirmed with modified trichrome stain positive of corneal scrape over a 4-year period. Epidemiologic factors were observed. Host immune status with human immunodeficiency virus (HIV) serology and CD4/CD8 analysis was performed when consent was obtained. Visual acuity (VA) and slit-lamp examination throughout the course of keratitis was recorded. Treatment used included topical fluoroquinolones (ciprofloxacin 0.3%, moxifloxacin 0.5%, gatifloxacin 0.5%, levofloxacin 0.5%, or norfloxacin 0.3%) as monotherapy or in combination with topical fumagillin and/or systemic albendazole. Where corneal edema developed, ultrasound corneal pachymetry was recorded. Demographic features and epidemiologic factors, including host immune status. Clinical features and disease course, including the response to different therapeutic regimes. Patients ranged in age from 11 to 68 years (mean, 31.9; median, 30) with a male:female ratio of 8:1 (females n = 17 [13.7%]). We performed HIV serology and CD4/CD8 in 45.9% of cases (n = 57); all the cases tested were negative with normal T-cell indices. Epidemiologic factors included soil exposure (50%), contact lens wear (21.1%), and topical steroid treatment (17.1%). The VA on presentation ranged from 20/20 to 20/100 (median, 20/30) with no loss in lines of VA on resolution. Common features were follicular papillary conjunctivitis and coarse punctate epithelial lesions in 3 patterns--diffuse, peripheral, and paracentral--evolving into nummular keratitis before resolution. Resolution occurred in 99% of cases on topical fluoroquinolone monotherapy. Four patients had recurrent disease that resolved with repeat fluoroquinolone or fluoroquinolone/oral albendazole combination. Two new clinical features were identified--diffuse endotheliitis (19.4%) with corneal edema and limbitis. This study identifies an increasing incidence of microsporidial keratitis in Singapore with a strong correlation with prior soil exposure. Diffuse endotheliitis and limbitis have not been described and resolves with topical steroid therapy. Topical fluoroquinolone monotherapy is a valid treatment option.

Is Microsporidial Keratitis A Seasonal Infection in India.

Is Microsporidial Keratitis A Seasonal Infection in India.

Deep Anterior Lamellar Keratoplasty to Treat Microsporidial Stromal Keratitis

To describe deep anterior lamellar keratoplasty (DALK) as a surgical option to treat a case of severe microsporidial stromal keratitis in an immunocompetent patient. This study is a descriptive case report. A 42 year-old Pakistani woman had an 8-year history of symptoms in the left eye. She had been previously provisionally diagnosed as suspected herpes simplex keratitis or Thygeson keratitis. At presentation, her best-corrected visual acuity was 20/20 OD and 20/200 OS. Examination of the left cornea revealed irregular, central, deep stromal opacification with keratitic precipitates and occasional cells in the anterior chamber. Investigations for mycobacteria, syphilis, and a tetraplex test were normal; all other hematological/biochemistry/virology investigations were normal-she was not found to be immunocompromised. A corneal biopsy confirmed microsporidial infiltration of the stroma. After intensive medical treatment with topical fumagillin and oral albendazole without resolution, DALK was performed with total stromal replacement using the big-bubble technique. One year postoperatively, the graft remained clear with no evidence of recurrence and best-corrected visual acuity was 20/40 OS. Microsporidial stromal keratitis is rare. Conventional surgical treatment for such a condition has been penetrating keratoplasty. DALK may be considered an option for visual rehabilitation in these cases.

A case of bilateral microsporidial keratitis from Bangladesh – infection by an insect parasite from the genus Nosema

An HIV-negative patient from Bangladesh with bilateral keratitis was found to be infected with a microsporidian parasite belonging to the genus Nosema. Significantly, the patient had bathed in a rural pond 7 days prior to the development of ocular symptoms. Nosema parasites are common insect parasites and the source of this microsporidial infection was possibly from mosquito larvae developing in the pond in which the patient bathed. The reduced temperature of the human eye and its immune status may have allowed a poikilothermic insect parasite to establish infection in the cornea of a homeothermic human host. This case highlights the opportunistic potential of insect microsporidial parasites to infect immunocompetent humans as well as those who are immunodeficient.

Microsporidium Stromal Keratitis: In Vivo Confocal Findings

To relate the clinical signs, histopathologic features, and in vivo confocal biomicroscopy findings of a case of stromal microsporidial keratitis and to describe the use of in vivo confocal microscopy to monitor treatment effect. An immunocompetent male patient presented with unilateral indolent stromal keratitis. Stromal microsporidiosis was confirmed after corneal biopsy. He underwent examination that used in vivo confocal microscopy (Heidelberg Retina Tomograph II and Rostock Cornea Module) before and after treatment with topical fumagillin and oral albendazole. Clinicopathologic correlation of the confocal scan was performed. Corneal biopsy showed extracellular microsporidium spores aligned along keratocytes and corneal lamellae. In vivo confocal scans showed similar morphology, with bright dots aligned along keratocytes. Treatment with antimicrobials and topical steroid gave resolution of active keratitis, correlating with disappearance of the bright spores on repeat in vivo confocal scanning. The in vivo confocal microscopy appearance of microsporidial keratitis corresponds to the histologic features from biopsy material. Treatment response may be monitored by using this technique, although definitive diagnosis requires corneal biopsy.