Jundishapur Journal of Microbiology, 2013

Microbial corneal diseases are a serious ocular infection and the major cause of ocular morbidity and blindness in the world. The outcomes of fungal keratitis are unfavorable due to the protracted course of the condition and the diversity of respective clinical presentations. Trauma, contact lens wear, foreign material, and prior corneal surgery, may make the most background for permitting invasion by exogenous fungi by injecting the fungal conidia directly in the corneal stroma. Other risk factors consist of blocked naso-lacrimal duct, and ocular surface disease. More than 105 species of fungi, such as Aspergillus spp., Fusarium spp., Candida spp., Rhizopus, Mucor, and other fungi have been identified as the etiological agents of fungal keratitis. The first step of diagnosis begins with clinical suspicion, followed by corneal scrapings or biopsy for direct smear and culture confirming the etiological agent. Slit lamp biomicroscope is used for careful examination of the infected eye and pictorial documents like the ulcer size, site, depth, extent of infiltration, abscess formation, and any perforation are evaluated. Direct smears are prepared by potassium hydroxide wet mount, or Gram's staining. To identify the isolates, a lactophenol cotton blue wet mount is prepared, and diagnosis is based on morphology of the culture media and details of microscopic examination. The results are highly specific but have suboptimal sensitivity varying in different studies. Molecular assays are valuable for the diagnosis of fungal keratitis in patients. Various advantages and limitations are reported for such methods. Overall, PCR is a sensitive and promising tool for the diagnosis of fungal keratitis but the expertise required and the lack of sophisticated facilities renders it inferior to the smear techniques in routine laboratory procedures and is not recommended accordingly. Rapid diagnosis and proper treatment are essential for fungal keratitis, and many patients require several months of therapy until the infiltrate is resolved and epithelial stroma are healed. Patients not responsive to antifungal therapy usually require corneal transplantation.

International Journal of Current Microbiology and Applied Sciences, 2017

The Internet journal of ophthalmology & visual science, 2009

Introduction: Mycotic ulcer is common in rural, remote, agricultural regions of India, where primary medical facilities are lacking. Diagnosis of causative fungus is usually not possible on the basis of available clinical and laboratory tests so the magnitude of mycotic keratitis is underestimated as a factor of corneal blindness. Purpose: To know the incidence of mycotic keratitis among the all corneal blindness cases along with predisposing factors, Setup: Tertiary Care Center (Medical college hospital). Material and Methods: We have included in the present study 201 consecutive cases of corneal ulcer attended hospital during April 2006 to November 2007. Diagnosis of mycotic keratitis was confirmed by history, clinical examination, direct microscopic examination of corneal scraping from the edge of ulcer for fungal hyphae and culture of fungus of corneal scraping and pus from anterior chamber, in different culture medias. Results: 42 cases (20.9%) of fungal corneal ulcer were found to be positive by direct examination and / or by culture. Fungal hyphae were seen by wet mount KOH preparation in 34 (80.9%) and culture growth present in 37 (88.0%) cases. Patients who have both test positive were 31(73.8%). Out of 34 culture grown 23 (54.7%) had pure fungal growth while 14(45.3%) showed fungus with superadded bacterial infections. Aspergillus fumigatus was the commonest causal agent isolated from 12 cases (5.9%) followed by in order to frequency are Aspergillus flavus (3.9 %), Candida (4.48 %), Curvularia (2.98 %), Penicillium (2.49 %) and Fusarium species (1.0 %). Conclusion: This study suggests that in all cases of corneal ulcer, corneal scraping is mandatory for early diagnosis of mycotic keratitis to prevent corneal blindness as there is a high incidence (20.9%) particularly in tropical agricultural regions.

2013

Purpose: The study of fungal invasion and pathogenicity in corneal tissue observed through the histopathological examination of specimens obtained through penetrating keratoplasty ('PKP') of samples obtained from an Eye Bank ('EB'), with the aim of applying findings in diagnosis and treatment of the condition Methods: Retrospective non-comparative case studies on samples collected between January 2006 and June 2011 based on identification data comprised of scant historical information sent by surgeons and material obtained through PKP, consisting of 38 samples from 35 patients. Processing involved special stains for fungi in order to detect the presence thereof, with one to three colourations being performed in accordance with diagnostic difficulty in relation to each sample. Results: Patients were predominantly male (20 compared to 15 females), and the most represented age group was 60+ years of age (1/ 3 of the patients). Mycotic keratitis was detected in 6.4% (n= 597) of cases referred to the EB and in 1.65% (n= 2310) of transplants using corneal material provided by the EB over the last five years. According to historical information provided by surgeons, 39.5% (n= 38) of cases were due to perforation of the cornea. A statistical table was prepared using transplant data. 11 specimens (n= 38) were due to an anterior corneal graft. Yeasts were present in 63% (n= 38), and 50% (n= 38) of corneal tissue had mild or non-existing inflammation. 13% (n= 38) had whole Descemet layers, while 45% (n= 38) presented fungi on the corneal surface. Conclusion: Corneal grasping and confocal microscopy may be performed successfully after treatment has been initiated, although in corneal ulcers samples should ideally be collected with a spatula for laboratory testing in vivo. The high prevalence of yeasts in the samples we looked at may be due to morphologic changes in corneal tissue of fungal origen. Intraocular penetration of the fungi is facilitated by changes to the Descemet layer, and assisted by the fungi's own properties. Therefore systemic treatment is justified from the outset.

IP Innovative Publication Pvt. Ltd., 2019

Purpose: 1. To study the clinical and microbiological aspects of fungal keratitis; 2. To study the predisposing and prognostic factors. 3. To study the clinical course management and outcomes of fungal keratitis; 4. To study the morphological features of corneal ulcer; To study the complications and final visual outcome. Material and Methods: This study was carried out in Maharashtra in Marathwada region, over 31 patients, the patients who were showing signs and symptoms of fungal keratitis with special significance to predisposing and prognostic factors microbiological investigation management and follow up. The data was assessed on the basis of simple percentages and ratios. Results: Fungal corneal ulcer was predominantly found more in the age group of 51-60. Majority of fungal corneal ulcer were found in rural area. Majority of cases were more common in males as compared to female. Majority of fungal corneal ulcer patients had history of trauma as predisposing factor. Majority of trauma cases were because of vegetative material. Majority of fungal corneal ulcer were related to farming activities. Inferior quadrant of cornea was most frequently involved in fungal corneal ulcer. Majority of fungal corneal ulcer were having rolled out margins. Majority of cases had thick and fibrinous hypopyon. Hypopyon was present in majority of fungal corneal ulcer patients. Distribution of fungal corneal ulcer studied. Aspergillus niger18(58.06%); Fusarium 8(25.80%); Cladosporium 3(9.67%); Penicillium 2(6.45%). Keywords: Fungal corneal ulcer, Fungal keratitis, Hypopyon.

Journal of Infection in Developing Countries, 2010

Background: Mycotic keratitis is a fungal infection of the cornea. This infection is difficult to treat and it can lead to severe visual impairment or blindness. It is worldwide in distribution, but is more common in the tropics and subtropical regions. Trauma is the major predisposing factor, followed by ocular and systemic defects, prior application of corticosteroids, and prolonged use of antibiotic eye-drops. The objective of this study was to determine causative agents and to identify the predisposing factors of mycotic keratitis. Methodology: Corneal scrapings from 90 corneal ulcer patients with suspected fungal etiology were subjected to direct examination by 10% KOH mount, Gram stain and culture. Results: This study included 90 subjects with corneal ulcers, based on clinical suspicion, of whom 41 cases were diagnosed with mycotic keratitis in the laboratory. Among these 41 cases, culture showed fungal growth only in 36 cases whereas the remaining five cases were positive only by potassium hydroxide (KOH) preparation. Males were more commonly affected and were mostly in the age group of 31-40 years. Aspergillus flavus was the most common fungus isolated followed by fusarium solani. Conclusion: Rapid diagnosis and early institution of antifungal therapy is necessary to prevent ocular morbidity and blindness. Although culture helps in definite diagnosis and identification, direct microscopic detection of fungal structures in corneal scrapes or biopsies permits a rapid presumptive diagnosis.

BMC Ophthalmology, 2011

Background: Mycotic keratitis is an important cause of corneal blindness world over including India. Geographical location and climate are known to influence the profile of fungal diseases. While there are several reports on mycotic keratitis from southern India, comprehensive clinico-microbiological reports from eastern India are few. The reported prevalence of mycotic keratitis are 36.7%,36.3%,25.6%,7.3% in southern, western, north-eastern and northern India respectively. This study reports the epidemiological characteristics, microbiological diagnosis and treatment outcome of mycotic keratitis at a tertiary eye care center in eastern India. Methods: A retrospective review of medical and microbiology records was done for all patients with laboratory proven fungal keratitis.

Cornea, 2002

Purpose. To report the epidemiological features and laboratory results of 1,352 cases of fungal keratitis diagnosed at the L.V. Prasad Eye Institute (LVPEI) in south India. Methods. The medical and microbiology records of 1,352 culture proven cases (1,354 eyes) of fungal keratitis diagnosed at the LVPEI between January 1991 to December 2000 was retrospectively reviewed for demographic features, risk factors, seasonal variation, and laboratory findings. Results. Males (962) were affected significantly more (p < 0.0001) than females (390). Of 1,352 patients, 853 (64.4%) were in the younger age group (16-49 years). Ocular trauma predisposed to infection in 736 (54.4%) of 1,354 eyes. There was a higher incidence of fungal keratitis during the monsoon and winter than summer. A fungal cause was established by smears of corneal scrapings in 1,277 (95.4%) eyes. The potassium hydroxide preparation (KOH), Calcofluor white (CFW), Gram-, and Giemsastained smears revealed fungus in 1,219 (91.0%), 1,224 (91.4%), 1,181 (88.2%), and 1,139 (85.1%) eyes, respectively. Fusarium (506, 37.2%) and Aspergillus species (417, 30.7%) predominated the hyaline fungal spectrum (1,133) and Curvularia species (39, 2.8%) were the highest among the dematiaceous isolates (218). Conclusions. To the best of our knowledge, this review presents the epidemiological features and laboratory results of the largest series of fungal keratitis ever reported in the literature. Keratomycosis is predominant in young adults with trauma as the major predisposing factor. With fungal keratitis being a major ophthalmologic problem in the tropical regions of the world, data available on the epidemiological features of a large series would greatly help medical practitioners at primary and secondary health care centers in the management of the disease. A simple KOH preparation of corneal scraping alone is highly beneficial in confirming the diagnosis.

Innovative Publication , 2017

Background: This study was conducted to isolate the common fungi from the corneal ulcer of the patients and to treat fungal keratitis with appropriate antifungal drugs. Methods: All the patients with corneal ulcer who visited the Ophthalmology OPD at SSMCH, Tumkur were evaluated. Further, all the cases of corneal ulcer were examined with slit lamp biomicroscopy and corneal scrapings taken are subjected to KOH preparation and those with fungal etiology were identified and taken up for the study. The patients were taken into the study irrespective of the previous disease and previous medication. Results: Out of 20 patients recognised as fungal corneal ulcer, most of the patients belong to the age of 11 to 50 years as they are the working population. The patients with fungal corneal ulcer showed minimal symptoms than signs we lead to delayed avail to treatment. The earliest time the patient visited the hospital after the onset of the disease, was 2 days and the longest duration was 2 months. Those patients with a history of agricultural trauma had either remained negligent in early stage or tried all possible remedies within their easy reach in their initial conditions and come only when the pain became intractable with loss of vision. Conclusion: A high index of suspicion should be raised in cases with history of trauma and clinical features highly suggestive of fungal corneal ulcer (dry elevated surface, stromal infiltration with hyphate margins). 10% KOH smear is a rapid and sensitive method of diagnosis which is confirmed by SDA cultures that is the most sensitive and specific test available. Aspergillus and Fusarium are the most common isolates. Fluconazole and Natamycin are the drugs of choice in most filamentous keratitis. Most of the cases heal with some grade of opacity, ultimately requiring a therapeutic Penetrating Keratoplasty to regain useful vision.

Ophthalmology, 2002

To evaluate the host and agent factors in the progression of mycotic keratitis through the microbiologic evaluation and histologic study of human corneal buttons obtained at the time of therapeutic keratoplasty. Design: Retrospective noncomparative consecutive case series. Materials: One hundred sixty-seven corneal buttons from 148 patients of microbiologically diagnosed and treated cases of mycotic keratitis who underwent therapeutic keratoplasty between January 1995 and May 1998. Methods: Therapeutic penetrating keratoplasty, review of microbiologic results, histopathologic and microbiologic evaluation of the corneal buttons of mycotic keratitis Main Outcome Measures: Histologic evaluation of the buttons for morphologic changes, degree and distribution of inflammatory cells, presence or absence of fungal filaments, and their degree and distribution within the corneal buttons. Results: The diagnosis of fungal infection was made on corneal scrapings in 36 cases; whereas in 131 (78%), the fungus was grown in cultures and identified as Aspergillus in 55 (42%), Fusarium in 42 (32%), unidentified hyaline fungi in 22 (17%), dematiaceous (unidentified) in 4 (3%), and others in 8 (6%). The mean interval between diagnosis and keratoplasty was 19 (Ϯ40) days. From the keratoplasty specimen, the fungus was identified at histologic examination in 127 of 167 (76%) buttons and grown by culture techniques in 76 of 115 (66%) buttons. The fungal species identified in the corneal button were Fusarium in 30 (39%); Aspergillus in 25 (33%); unidentified hyaline in 19 (25%), and others in 2 (3%). Fungus-positive corneal buttons had early surgery (mean, 15 days) compared with fungus-negative (39 days) corneal buttons (P ϭ 0.0005), with 93% fungus positivity in the buttons removed within 2 weeks and 42% after 2 months. In the fungus-positive buttons, there was an inverse correlation between the degree, distribution of inflammatory cells, and fungal filaments (r ϭ Ϫ0.255, P ϭ 0.024; r ϭ Ϫ0.199, P ϭ 0.027), respectively. The factors necessitating an early keratoplasty were heavy fungal load, deeper penetration of fungus, and possibly insufficient inflammation to combat infection. A granulomatous reaction was noted in the posterior stroma and around the fragmented Descemet's membrane in 23 buttons (13.8%), independent of fungal species. Inflammation was unaffected by elimination of fungus and increasing interval between diagnosis and treatment. Conclusions: Rapid progression of mycotic keratitis in the early phases is by agent factors such as heavy load and deeper penetration of the fungus, insufficient inflammatory response, and possibly relative ineffectiveness of antifungal agents. Progression in the later phase of mycotic keratitis need not necessarily be agent mediated; it could be either host-modulated, species-related, or drug resistance, thereby suggesting that ideal treatment regimens should include sensitivity-based antifungal therapy aided by in vivo monitoring of fungal filaments.