Diagnosis Of Fungal Keratitis Research Articles

Overview of Mycotic Keratitis.

Keratomycosis is a serious corneal infection associated with high ocular morbidity that can lead to severe vision loss. It is estimated to affect more than 1 million patients annually, most commonly occurring in tropical climates, and represents a growing threat to patients worldwide. Despite aggressive medical management, fungal infections have a higher rate of perforation requiring surgical intervention compared with other infectious etiologies. Early diagnosis and appropriate treatment are keys to preserving vision and saving patients' eyes.Timely diagnosis of fungal keratitis helps minimize corneal damage and scarring and increases the likelihood of a favorable outcome. Studies have shown that correct identification of fungal infections is often delayed up to 2 to 3 weeks after initial presentation. This leads to incorrect or ineffective treatment for many patients. Diagnostic techniques explored in this study include corneal scrapings with staining and culture, visualization with in vivo confocal microscopy, molecular diagnostic techniques including polymerase chain reaction, and recently developed omics-based technologies.Treatment of fungal keratitis begins with topical antifungals. Medical management has been proven to be effective, but with limitations including poor drug penetration and low bioavailability. Cases that do not respond to topical therapy require more invasive and novel treatments to control the infection. We review the clinical trials that have shaped current practice patterns, with focus on the efficacy of topical natamycin as the primary therapy for filamentous fungal keratitis. We explore additional management strategies such as localized intrastromal and intracameral injections of antifungal medications, photodynamic therapy, and surgical intervention.

Modern Technologies in Diagnosis of Fungal Keratitis (Review).

Traumas and infectious diseases of the eye play a leading role in the development of corneal blindness responsible for 1.5-2 million cases of vision loss per year. To date, the issue of reducing the incidence of fungal keratitis is acute and needs to be solved worldwide. Trauma as a risk factor for corneal fungal disease is thought to be prevalent in developing countries due to agricultural involvement, while in developed countries the onset of the disease is predisposed by medical advances such as contact vision correction and modern ophthalmic surgery. Thorough analysis of the pathogenesis gives the possibility to describe the action of fungal enzymes, biofilm formation, and the resistance mechanism, which on the one hand explains the aggressive course of the disease and difficulties in its diagnosis, and on the other hand, it encourages searching for new methods of diagnosis and treatment. The non-specific clinical picture of fungal keratitis, the variety and availability of antibiotics nowadays become an obstacle for rapid detection of this pathology. Low public awareness and late visit to an ophthalmologist are also a barrier to successful combating the increasing incidence of fungal keratitis. Belated diagnosis, increasing resistance of fungi to antibiotics, and lack of registered antifungal ophthalmic drugs justify poor treatment efficacy resulting in decreased visual acuity or vision loss. Existing diagnostic methods need systematization and detailed comparison, identifying the advantages and disadvantages of each. This review considers causative agents and their influence on pathogenesis of the disease, describes difficulties of fungal keratitis diagnosis and possible ways of overcoming these problems using new developments, and also outlines further prospects of research in this direction.

Characteristics of In Vitro Culture and In Vivo Confocal Microscopy in Patients with Fungal Keratitis in a Tertiary Referral Hospital in Central China.

To investigate the characteristics of in vitro culture and in vivo confocal microscopy (IVCM) in patients with fungal keratitis (FK) presented in a tertiary referral hospital in central China. In this noncomparative retrospective study, patients with the diagnosis of FK between October 2021 and November 2022 were reviewed. An IVCM and fungal culture (corneal scraping specimens) were performed, and the characteristics were analyzed. During October 2021 and November 2022, 85 patients were diagnosed with FK. From 63 culture-positive cases, 8 species of fungus were identified. The proportions of isolated fungal species were Fusarium and Aspergillus equally accounting for 33.3% (21 of 63), Alternaria 9.5% (6 of 63), Curvularia 6.3% (4 of 63), Scedosporium apiospermum 6.3% (4 of 63), Paecilomyces lilacinus 3.2% (2 of 63), Exserohilum 3.2% (2 of 63), and Candida 4.8% (3 of 63), respectively. In positive culture cases, IVCM was found to be positive for hyphae or spores in 61 of 63 patients (96.8%). Different fungal species had a variety of cultural characteristics and IVCM manifestations. In a tertiary referral hospital in central China, Fusarium species, Aspergillus species, and Alternaria species were the 3 most common isolated fungal pathogens, and the proportion of Aspergillus species was significantly higher than that in other regions of China. Careful lesion depth examination by IVCM and OCT should be taken before lamellar keratoplasty to avoid postoperative recurrence. Identifying the IVCM image and culture characteristics will facilitate rapid diagnosis and proper treatment, but IVCM cannot yet replace fungal cultures to distinguish between different fungal species.

P246 Neglected keratitis caused by Exserohilum rostratum from the arid region of north-west India leading to vision loss—a case report

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMObjectivesTo report a case of complete loss of vision due to delay in diagnosis of fungal keratitis caused by Exserohilum rostratum in an immunocompetent patient from the arid area of north-west India.MethodA 65-year-old female farmer was admitted to ophthalmology with a history of pain, redness, watering, and foreign body sensation in the left eye for 2 months. She had a history of trauma by splinters 2 months back. On ocular examination, a large corneal ulcer of about 7 × 8 mm size at 2-8‘o’ clock position in the left eye was present with diffuse corneal edema. She had no history of diabetes mellitus, hypertension, tuberculosis, COVID-19, and steroid eye drops instillation. There was no relevant previous history of any ocular surgery also. She was negative for hepatitis-B and human immune deficiency virus on serology. All her hematological parameters were within normal limits.Patient was treated with moxifloxacin, carboxy methyl cellulose eye drops, and Neosporin eye ointment for around 2 months at primary health care facilities and later referred to our hospital for further management.Corneal scraping of the patient was sent to our laboratory for potassium hydroxide mount and culture identification.ResultsFungus was identified as E. rostratum on the basis of gross, macroscopic, and microscopic morphology. Gram's staining was bacteriologically negative while true fungal hyphae were seen. In KOH mount pigmented, septate, and branched true hyphae were seen. Bacterial culture was reported sterile.Lactophenol cotton blue mount of culture revealed dematiaceous hyphae along with 4-9 septate elongated, ellipsoid macroconidia of 14-90 μm with prominent dark conspicuous hilum and geniculate conidiophore arranged sympodially. On the basis of these characteristics, it was diagnosed as E. rostratum.After the diagnosis patient was switched over to topical natamycin 5% two hourly and oral itraconazole 200 mg BD from moxifloxacin and neosporin. To which the patient responded symptomatically. Ulcer healed in a month leaving behind a lateral scar. However, vision is permanently compromised and the patient is advised for therapeutic penetrating keratoplasty (TPK).Conclusion Exserohilum rostratum is generally regarded as a pathogen in hot and humid climates. However, the isolation of this organism in our area highlights the pathogenic potential of this emerging fungus in arid climates also. Ophthalmologists need to be made aware of the significance of prompt mycological identification to prevent vision loss.

Diagnosis of Fungal Keratitis in Low-Income Countries: Evaluation of Smear Microscopy, Culture, and In Vivo Confocal Microscopy in Nepal.

Clinically diagnosing fungal keratitis (FK) is challenging; diagnosis can be assisted by investigations including in vivo confocal microscopy (IVCM), smear microscopy, and culture. The aim of this study was to estimate the sensitivity in detecting fungal keratitis (FK) using IVCM, smear microscopy, and culture in a setting with a high prevalence of FK. In this cross-sectional study nested within a prospective cohort study, consecutive microbial keratitis (MK) patients attending a tertiary-referral eye hospital in south-eastern Nepal between June 2019 and November 2020 were recruited. IVCM and corneal scrapes for smear microscopy and culture were performed using a standardised protocol. Smear microscopy was performed using potassium hydroxide (KOH), Gram stain, and calcofluor white. The primary outcomes were sensitivities with 95% confidence intervals [95% CI] for IVCM, smear microscopy and culture, and for each different microscopy stain independently, to detect FK compared to a composite referent. We enrolled 642 patients with MK; 468/642 (72.9%) were filamentous FK, 32/642 (5.0%) were bacterial keratitis and 64/642 (10.0%) were mixed bacterial-filamentous FK, with one yeast infection (0.16%). No organism was identified in 77/642 (12.0%). Smear microscopy had the highest sensitivity (90.7% [87.9–93.1%]), followed by IVCM (89.8% [86.9–92.3%]) and culture (75.7% [71.8–79.3%]). Of the three smear microscopy stains, KOH had the highest sensitivity (85.3% [81.9–88.4%]), followed by Gram stain (83.2% [79.7–86.4%]) and calcofluor white (79.1% [75.4–82.5%]). Smear microscopy and IVCM were the most sensitive tools for identifying FK in our cohort. In low-resource settings we recommend clinicians perform corneal scrapes for microscopy using KOH and Gram staining. Culture remains an important tool to diagnose bacterial infection, identify causative fungi and enable antimicrobial susceptibility testing.

Clinical and Mycological Features of Fungal Keratitis: A Retrospective Single-Center Study (2012-2018)

Objectives:To present the demographic, etiological, clinical, and mycological characteristics and treatment results of fungal keratitis patients admitted to our clinic.Materials and Methods:The medical records of patients diagnosed with fungal keratitis between October 2012 and 2018 were reviewed. The diagnosis of fungal keratitis was confirmed mycologically and/or cytologically. Treatment response was defined as complete infiltrate resolution and re-epithelization with medical treatment and minor surgical interventions. Patients who underwent penetrating keratoplasty or evisceration due to clinical deterioration despite treatment were classified as treatment nonresponders and were compared with responders in terms of demographic, etiological, and clinical characteristics.Results:Seventy-two (12.8%) of 559 patients diagnosed with microbial keratitis in the 6-year period were fungal keratitis. Of these, 38 cases (38 eyes) without polymicrobial etiology were included in the study. The patients’ mean age was 44.9±19.0 years (range: 2-80) and males predominated (14 females [36.8%], 24 males [63.2%]). Trauma (63.6%) was the most common predisposing factor in patients younger than 40 years old, whereas pathologies impairing ocular surface immunity were the leading risk factor (48.1%) in patients older than 40 years. Filamentous fungi were detected in 34 (89.5%) cases, while yeasts were found in 4 (10.5%) cases. Among 26 cases with positive cultures, Aspergillus species were the most common pathogens (42.3%). Infiltrate size before treatment was larger in nonresponders (14/38, 36.8%) compared to treatment responders (19/38, 50%) (p=0.049). In addition, rates of treatment response were higher in cases in which the infiltrate was located paracentrally compared to other cases (p=0.036).Conclusion:Fungal keratitis is an important public health problem in our region. Ocular trauma is a leading etiology in men under the age of 40 years. In the 6-year period, we observed that the main causes of fungal keratitis were filamentous fungi, and most commonly Aspergillus species. In cases presenting with large and central lesions, aggressive treatment options should be considered and these patients should be followed up more closely.

Fungal Keratitis in a Tertiary Hospital in Malaysia

BackgroundFungal keratitis is one of the commonest causes of corneal blindness in developing countries including Malaysia. We aim to evaluate the sociodemographic background, clinical features, predisposing factors, laboratory findings, management, complications, and visual outcome of patients with fungal keratitis in a tertiary hospital in Malaysia.MethodsA retrospective review of medical and microbiology records of all patients treated for corneal ulcer from 2015 to 2019 at Hospital Sultanah Bahiyah was performed. Sociodemography, predisposing risk factors, clinical characteristics, causative organisms, and final visual outcome were analyzed.ResultsWe identified 103 patients with a diagnosis of fungal keratitis. The majority of the patients were of Malay ethnicity (85.4%) and male gender (81.6%), with an age range of 21 to 60 years (94.1%). Ocular trauma was the main predisposing factor in 82 (79.6%) patients. Poor visual improvement was observed in groups with ulcer more than 4mm (67.5%), presence of hypopyon (50.9%), and high intraocular pressure (75.0%) upon presentation. Fusarium spp. (19.4%) was the commonest fungus isolated followed by Aspergillus spp. (5.8%). All patients were prescribed either topical, oral, intracameral, or combined therapy, whereas 20 (19.4%) patients required surgical intervention, of which 16 (15.5%) underwent penetrating keratoplasty and three (2.9%) required evisceration.ConclusionThe epidemiological, socioeconomic, and predisposing factors may facilitate timely diagnosis and prompt treatment to achieve a better visual outcome and minimize complications including corneal blindness.

Masked comparison of trypan blue stain and potassium hydroxide with calcofluor white stain in the microscopic examination of corneal scrapings for the diagnosis of microbial keratitis

Purpose:To evaluate the efficacy of trypan blue in direct microscopic examination of corneal scrapings in the diagnosis of non-viral microbial keratitis.Methods:In a prospective, interventional, masked study, 82 consecutive patients were investigated. Direct microscopic examination of the corneal scrapings involved three smears stained with potassium hydroxide with calcofluor white (KOH + CFW), Gram stain (not analyzed), and trypan blue stain and culture for bacteria, fungus, and Acanthamoeba. While KOH + CFW stained slides were examined under a fluorescence microscope, trypan blue-stained slides were examined by two microbiologists (masked to KOH + CFW and culture results) under normal light microscopy. Thirty samples were reexamined for interobserver and intraobserver variability.Results:Out of 82 samples, fungal/fungus-like elements were seen in 48 (58.5%) in KOH + CFW and 38 (46.3%) in trypan blue stain. One microsporidial case, detected in KOH + CFW was negative in trypan blue stain (culture not done). Fungal growth was positive in 23 out of 81 (28.3%) cases cultured, single bacterial species in 18 (22.2%), Pythium insidiosum in three, mixed bacteria and fungus/Pythium in 7 (8.6%), Acanthamoeba in none and 30 (37.0%) samples were sterile. With culture as gold standard, the respective sensitivity (84.9%, 75.7%) and specificity (90.9%, 68.2%) of KOH + CFW stain and trypan blue stain were comparable (p = 0.16, P = 0.06). The interobserver linear weighted kappa score between the two microbiologists was 1.00 while it was 0.86 for intraobserver agreement.Conclusion:Trypan blue stain, an easily available dye to ophthalmologists, is highly efficacious in the diagnosis of fungal keratitis.

Fungal Keratitis in the Egyptian Delta: Epidemiology, Risk Factors, and Microbiological Diagnosis

ABSTRACT Purpose The current study evaluates the epidemiological characteristics, risk factors, and microbiological diagnosis of fungal keratitis among patients living in the Egyptian Delta. Methods 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. Results 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. Conclusion 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.

Identification and molecular characterization of Subramaniula asteroides causing human fungal keratitis: a case report

BackgroundKeratitis due to by filamentous fungi are not easy to diagnose thus causing a delay in correct therapy. There are many descriptions of keratitis due to Candida, Fusarium and Aspergillus genera. Subramaniula genus has only recently been reported to cause human infections and there are few descriptions of eye infections due to this filamentous fungus. Diagnosis of fungal keratitis is usually based on microscopic and cultural techniques of samples obtained by corneal swabbing or scraping. Considering the amount of time required to obtain culture results it is wise to use other diagnostic methods, such as molecular analyses. Therapeutic options against these fungi are limited by low tissue penetration in the eye due to ocular barriers. We describe the first case of S. asteroides human keratitis treated with isavuconazole.Case presentationWe describe a rare case of fungal keratitis unresponsive to antimicrobial treatment in a 65-year-old male patient without a history of diabetes or immunological diseases. He reported that the onset of symptoms occurred during a long holiday in Cape Verde Island. Initial treatment with topical antibiotics associated to steroids were ineffective, allowing a slow clinical progression of disease to corneal perforation. On admission in our Hospital, slit-lamp examination of the left eye showed conjunctival congestion and hyperemia, a large inferior corneal ulceration with brown pigment, corneal edema, about 3 mm of hypopyon and irido-lenticular synechiae. The slow clinical progression of the disease to corneal perforation and the aspect of the ulcer were consistent with a mycotic etiology. Molecular methods used on fungal colonies isolated by Sabouraud’s dextrose agar cultures allowed the identification of Subramaniula asteroids from corneal scraping. Antimicrobial test showed a good susceptibility of this filamentous fungus to voriconazole and isavuconazole. Moreover, this fungal keratitis was successfully treated with isavuconazole, without side effects, observing a progressive clinical improvement.ConclusionsMolecular methods may be useful for the identification of filamentous fungal keratitis on scraping samples thus shortening the time of diagnosis. Systemic therapy by isavuconazole could be useful to treat the filamentous fungal keratitis, reducing the possible adverse effects due to the use of voriconazole by systemic administration.

1165. Epidemiology, management and outcomes of fungal keratitis: A single center study from tertiary hospital in Thailand

BackgroundFungal keratitis is known as an important cause of sight threatening infection worldwide. Variation of clinical characteristics and treatment have been observed among different geographic regions. Currently, clinical data of fungal keratitis in South East Asia remain scarce.MethodsA retrospective single study was conducted at King Chulalongkorn Memorial Hospital in Thailand. Medical records of patient with diagnosis of fungal keratitis between January 2016 and December 2018 were reviewed. Cases were identified using ICD-10 code. Data on demographics, clinical presentations, investigations and outcomes were collected. Mycological diagnosis was made in patients who had clinical presentation compatible with fungal keratitis and positive fungal detection in clinical specimen.ResultsDuring study period, fungal keratitis was diagnosed in 59 pts including 31 by mycological and 28 by clinical diagnosis. KOH preparation of corneal scraping was positive in 19 of 53 pts (35.8%). Culture from cornea, aqueous and vitreous yielded positive result in 18 of 53 (33.9%), 2 of 14 (14.3%), respectively. ITS sequence analysis was positive in 7 of 15 (46.7%) from cornea, 1 of 6 (16.7%) from aqueous and 2 of 2 (100%) from vitreous. Culture and molecular detection from clinical specimens provided additional mycological diagnosis in 8 and 5 cases with negative KOH preparation. Fusarium was the most common pathogen (33%) followed by Paecilomyces (9.7%), Aspergillus (6.4%), Candida (6.4%). Ten patients (32.2%) had only positive KOH preparation. All patients received treatment with topical antifungal agent, while 38 pts (64%) required systemic, 24 pts (40.7%) received intrastromal, 22 pts (37.2%) received intracameral and 3 pts (5.1%) received intravitreal antifungal therapy. Operation was performed in 21 pts (35.6%) which 6 (28.5%) required evisceration. Twenty-three patients (39%) had visual improvement after complete treatment.ConclusionFungal keratitis is not an uncommon disease. Fusarium was the most common etiologic agent similar to study from other region. Unfavorable outcomes were observed in majority of cases. Appropriate fungal culture and molecular detection from clinical specimens can be considered as they may increase diagnostic yield in some patients.Disclosures All Authors: No reported disclosures

The Effectiveness of PCR in Diagnosis of Fungal Keratitis

Fungi implicated in mycotic keratitis include different species. Conventional methods for the diagnosis of fungal keratitis include staining of corneal scarpings, culture medium (Sabouraud agar) for isolating fungi.Purpose. To evaluate the effectiveness of polymerase chain reaction (PCR) for the detection of fungal etiology in comparison with the conventional diagnostic methods in cases with suspected fungal corneal ulcer.Patients and methods. Seven patients with severe corneal ulcers with more than 3 weeks duration. Corneal scarpings and corneal buttons from seven patients who had undergone therapeutic keratoplasty were used for microbiological and PCR analysis. PCR diagnostic kits for the differential detection of Candida albicans DNA and total fungi DNA (DNA Fungi), which allows to identify most pathogenic fungi without determining their species were used. Microbiological methods: microscopy of gramstained smears, culture techniques, including selective for fungi agar Saburo with chloramphenicol.Results. PCR: Fragments of all corneas removed from keratoplasty (6 patients) revealed fungal-common DNA (Fungi DNA) and did not detect Candida albicans DNA, which correlated with sowing results on Saburo medium (mold fungi found in 5 of 6 corneas). Fungi DNA was also detected in the corneal scraps taken prior to surgery; however, growth of fungi during sowing on various nutrient media was not found.Conclusion. Corneal fungal ulcers are a serious disease, often leading to visual disability. The rapid determination of etiology and the correct choice of therapy determines the outcomes of the disease. The advantage of PCR over the culture method: the speed of obtaining results (4 hours instead of 3–7 days); high sensitivity, which allows detecting fungi not only in the tissue of the removed cornea, but also in scrapes from the cornea ulcer of patients who previously received antifungal therapy. The presence of commercial kits for differential detection of fungal-common DNA and DNA of Candida albicans extends the possibilities of PCR in the screening diagnosis of fungal keratitis and the selection of drugs before determining the type of pathogen.

Epidemiology and Clinical Management of Fusarium keratitis in the Netherlands, 2005-2016.

Introduction: Recognizing fungal keratitis based on the clinical presentation is challenging. Topical therapy may be initiated with antibacterial agents and corticosteroids, thus delaying the fungal diagnosis. As a consequence, the fungal infection may progress ultimately leading to more severe infection and blindness. We noticed an increase of fungal keratitis cases in the Netherlands, especially caused by Fusarium species, which prompted us to conduct a retrospective cohort study, aiming to describe the epidemiology, clinical management, and outcome.Materials and Methods: As fungi are commonly sent to the Dutch mycology reference laboratory for identification and in vitro susceptibility testing, the fungal culture collection was searched for Fusarium isolates from corneal scrapings, corneal swabs, and from contact lens (CL) fluid, between 2005 and 2016. All Fusarium isolates had been identified up to species level through sequencing of the ITS1-5.8S-ITS2 region of the rDNA and TEF1 gene. Antifungal susceptibility testing was performed according to the EUCAST microbroth dilution reference method. Antifungal agents tested included amphotericin B, voriconazole, and natamycin. In addition, susceptibility to the antisepticum chlorhexidine was tested. Ophthalmologists were approached to provide demographic and clinical data of patients identified through a positive culture.Results: Between 2005 and 2016, 89 cases of Fusarium keratitis from 16 different hospitals were identified. The number of cases of Fusarium keratitis showed a significant increase over time (R2 = 0.9199), with one case in the first 5 years (2005–2009) and multiple cases from 2010 and onwards. The male to female ratio was 1:3 (p = 0.014). Voriconazole was the most frequently used antifungal agent, but treatment strategies differed greatly between cases including five patients that were treated with chlorhexidine 0.02% monotherapy. Keratitis management was not successful in 27 (30%) patients, with 20 (22%) patients requiring corneal transplantation and seven (8%) requiring enucleation or evisceration. The mean visual acuity (VA) was moderately impaired with a logMAR of 0.8 (95% CI 0.6–1, Snellen equivalent 0.16) at the time of Fusarium culture. Final average VA was within the range of normal vision [logMAR 0.2 (95% CI 0.1–0.3), Snellen equivalent 0.63]. CL wear was reported in 92.9% of patients with Fusarium keratitis. The time between start of symptoms and diagnosis of fungal keratitis was significantly longer in patients with poor outcome as opposed to those with (partially) restored vision; 22 vs. 15 days, respectively (mean, p = 0.024). Enucleation/evisceration occurred in patients with delayed fungal diagnosis of more than 14 days after initial presentation of symptoms. The most frequently isolated species was F. oxysporum (24.7%) followed by F. solani sensu stricto (18%) and F. petroliphilum (9%). The lowest MICs were obtained with amphotericin B followed by natamycin, voriconazole, and chlorhexidine.Conclusion: Although Fusarium keratitis remains a rare complication of CL wear, we found a significant increase of cases in the Netherlands. The course of infection may be severe and fungal diagnosis was often delayed. Antifungal treatment strategies varied widely and the treatment failure rate was high, requiring transplantation or even enucleation. Our study underscores the need for systematic surveillance of fungal keratitis and a consensus management protocol.

Corneal Cross-linking as an Adjunct for The Management of Refractory Fungal Keratitis.

PURPOSE:To evaluate the effectiveness of ultraviolet (UV)-A/Riboflavin corneal cross-linking (CXL) for the treatment of the refractory cases of fungal keratitis.METHODS:In this prospective interventional study, 9 patients with the diagnosis of fungal keratitis that were referred to our emergency eye center were included. These patients were resistant to conventional treatment and underwent therapeutic UV-A/Riboflavin CXL. Response to the treatment was considered as good if rapid epithelialization and rapid decrease in stromal infiltration was occurred after PACK-CXL, and poor when the emergency transplantation was necessary to eradicate the infection.RESULTS:Nine patients treated with CXL due to recalcitrant fungal keratitis. Culture of the corneal scrapings showed Aspergillus species in 4 patients, Candida albicans in 1 patient and Fusarium species in the remainder of them. CXL was performed from 1 to 20 days after the presentation of corneal ulcers (Mean: 9.12 ± 4.02; range: 5–20 days). Postoperatively, the mean time to epithelialization was 14.25 ± 2.38 days, and mean time to resolution of stromal infiltration was 22.5 ± 7.29 days, in responsive cases. Four out of 9 eyes showed good response, and five patients showed no response, and corneal transplantation was performed to eradicate the infection. There was no statistically significant difference in mean depth of infiltration and mean size of ulcer between responsive and unresponsive patients (P = 0.86 and 0.08, respectively).CONCLUSION:Although UV-A/Riboflavin CXL is not a definite treatment for all of the fungal keratitis, it seems promising in the management of some refractory cases.

Clinical analysis of microbiologically proven fungal keratitis according to prior topical steroid use: a retrospective study in South Korea

BackgroundTo compare the clinical characteristics and treatment outcomes of microbiologically proven fungal keratitis between users and non-users of prior topical steroids (PS and NPS, respectively).MethodsEighty-three cases with microbiologically proven fungal keratitis between January 2000 and December 2016 were reviewed retrospectively. Diagnosis of fungal keratitis was made through potassium hydroxide smear, culture, PCR, or biopsy. Baseline epidemiology, predisposing factors, clinical characteristics, microbiological profiles, and treatment outcomes were evaluated and compared between the PS and NPS groups. Treatment failure was defined as any case with complications or requiring surgery. The risk factors for treatment failure were evaluated using multivariate logistic regression in the overall cohort.ResultsA total of 30 cases with PS group and 53 cases with NPS group were included. Of these, sixteen fungal isolates were identified in the PS group and 14 isolates in the NPS group. Candida was the most common organism in both groups (6 cases, respectively), while Aspergillus (4 cases) was found only in the PS group (p = 0.103). No significant differences were observed in the mean age, sex, occupational distribution, epithelial defect size, hypopyon, and presenting best-corrected visual acuity (BCVA) between the two groups. Differences were observed between the PS and NPS groups in terms of previous ocular surface disease (OSD) (43.3% vs. 22.6%, p = 0.048) and deep infiltration (53.3% vs. 32.1%, p = 0.057). Regarding treatment outcomes, final BCVA < 0.1 (60% vs. 44.2%, p = 0.133), the use of voriconazole (topical 10% vs. 0%, p = 0.044; systemic 23.3% vs. 1.9%, p = 0.003), surgical intervention (43.3% vs. 20.8%, p = 0.029), and treatment failure (46.7% vs. 22.6%, p = 0.023) were more common in the PS group than in the NPS group. The significant risk factors for treatment failure were hypopyon (odds ratio [OR] 6.01, p = 0.005) and deep infiltration (OR 4.38, p = 0.013).ConclusionsPrevious OSD and deep infiltration were more common in the PS group compared to the NPS group. The PS group also experienced worse disease progression and treatment outcomes. These results highlight the need for paying attention to the use of steroids in clinical practice.

Clinical outcome after air-assisted manual deep anterior lamellar keratoplasty for fungal keratitis poorly responsive to medical treatment.

PurposeFungal keratitis remains an important disorder because of difficulty in its diagnosis, and some patients do not respond to medical treatment using antifungal local and systemic agents. This study was carried out to determine the therapeutic value of air-assisted manual therapeutic deep anterior lamellar keratoplasty (TDALK) in the treatment of fungal keratitis not curable by antifungal chemotherapy.MethodsSeventeen patients (18 eyes) who were referred to Fukuoka University Hospital and treated surgically from January 2006 to April 2018, in whom a diagnosis of fungal keratitis was confirmed by typical clinical findings and microbiological or histological analysis of corneal specimens, and who were poorly responsive to topical and systemic antifungal medication, whereas the lesion had not resulted in corneal perforation, were enrolled in this study and were treated by air-assisted manual TDALK. Clinical outcomes including treatment course, therapeutic success rate, visual acuity outcomes and graft clarity rate were analyzed.ResultsThe most common pathogen was Fusarium, followed by Candida and Aspergillus. Beneficial therapeutic results (a clear or translucent graft) were achieved in 15 of 18 eyes (83%). There was no recurrence of infection and resulting visual acuity ≤0.15 logarithm of minimal angle of resolution unit was achieved in 15 eyes (83%). Intraoperative microperforation of Descemet’s membrane (DM) was not observed in any patients.ConclusionAir-assisted manual TDALK can be effective for treating severe fungal keratitis. In addition, air-assisted manual TDALK might be an alternative procedure to big-bubble DALK, because it can provide ambulatory vision and can preserve potentiality of vision with less risk of intraoperative perforation of DM.

Application of image recognition-based automatic hyphae detection in fungal keratitis.

The purpose of this study is to evaluate the accuracy of two methods in diagnosis of fungal keratitis, whereby one method is automatic hyphae detection based on images recognition and the other method is corneal smear. We evaluate the sensitivity and specificity of the method in diagnosis of fungal keratitis, which is automatic hyphae detection based on image recognition. We analyze the consistency of clinical symptoms and the density of hyphae, and perform quantification using the method of automatic hyphae detection based on image recognition. In our study, 56 cases with fungal keratitis (just single eye) and 23 cases with bacterial keratitis were included. All cases underwent the routine inspection of slit lamp biomicroscopy, corneal smear examination, microorganism culture and the assessment of in vivo confocal microscopy images before starting medical treatment. Then, we recognize the hyphae images of in vivo confocal microscopy by using automatic hyphae detection based on image recognition to evaluate its sensitivity and specificity and compare with the method of corneal smear. The next step is to use the index of density to assess the severity of infection, and then find the correlation with the patients' clinical symptoms and evaluate consistency between them. The accuracy of this technology was superior to corneal smear examination (p < 0.05). The sensitivity of the technology of automatic hyphae detection of image recognition was 89.29%, and the specificity was 95.65%. The area under the ROC curve was 0.946. The correlation coefficient between the grading of the severity in the fungal keratitis by the automatic hyphae detection based on image recognition and the clinical grading is 0.87. The technology of automatic hyphae detection based on image recognition was with high sensitivity and specificity, able to identify fungal keratitis, which is better than the method of corneal smear examination. This technology has the advantages when compared with the conventional artificial identification of confocal microscope corneal images, of being accurate, stable and does not rely on human expertise. It was the most useful to the medical experts who are not familiar with fungal keratitis. The technology of automatic hyphae detection based on image recognition can quantify the hyphae density and grade this property. Being noninvasive, it can provide an evaluation criterion to fungal keratitis in a timely, accurate, objective and quantitative manner.

Comparative study of impression smear with conventional mechanical corneal scrapping by potassium hydroxide (10%KOH) in diagnosis of fungal keratitis

Background: Diagnosis of fungal keratitis remains a challenge to an ophthalmologist due to variety of presentation of patients. If a prompt, aggressive and early treatment is not started disease turns indolent resulting in sloughing of cornea, serious loss of vision, possible perforation and loss eye. Methods: This observational study was conducted in upgraded department of ophthalmology, BRD Medical College, Gorakhpur, India among 50 patients of suspected fungal keratitis. Results: Fungal keratitis is more common in young males of rural area. Most of fungal corneal (>5 mm) with presence of hypopyon, pigmentation and satellite lesion as consistent features. KOH smear with impression smear technique was positive in 36 (72.0%), out of total 50 cases. KOH smear with conventional mechanical scrapings was positive in 35 (70.0%), out of total 50 cases. Sensitivity of impression smear technique as compared to conventional scraping was 100.0%. Sensitivity of mechanical scraping technique as compared to impression smear technique was 92.11%. Conclusions: Impression cytology is a recent diagnostic tool in fungal keratitis. It has various advantages over mechanical scraping like no expensive equipments like slit lamp and operation microscope required. Impression smear KOH mount is comparative to conventional mechanical corneal scraping KOH examination in making and tentative diagnosis of fungal keratitis and can be accurately replied upon for initiation antifungal therapy.

Fungal keratitis: Rapid diagnosis using methylene blue stain

Earlier and accurate diagnosis of the fungal infection in the cornea is necessary for effective treatment. In developing countries, microscopical evaluation is the most valuable and rapid diagnostic tool. Therefore we aimed to investigate the efficacy of methylene blue (MB) staining in comparison with potassium hydroxide (KOH) and calcofluor white (CW) stain. Corneal scraping from 48 cases with suspected fungal keratitis were included in the study from January 2014 to December 2014. The specimens were subjected to direct examination by MB, 10% KOH and CW stain. The staining results were confirmed with fungal culture and strain identification. Topical amphotericin B was started for all positive fungal cases; 39 (81.25%) were proven fungal cases. Positive rate of calcofluor white, MB and 10% KOH staining were 79.2%, 75% and 68.75% respectively. CW showed higher sensitivity and specificity (99.44% and 90.91% respectively), followed by MB (92.31% and 80.0% respectively) and lastly KOH 10% (84.62% and 71.43% respectively). 71.8% of cases had healed scars and only 4 patients (10.3%) required keratoplasty (PK). Direct microscopic detection of fungal structures by MB staining in corneal scrapes is a fast and effective method for the early diagnosis of fungal keratitis.

Contact-Lens-Associated Purpureocillium Keratitis: Risk Factors, Microbiologic Characteristics, Clinical Course, and Outcomes

ABSTRACTPurpose: To study the risk factors, microbiologic characteristics, clinical course, and outcomes of patients with Purpureocillium keratitis at a tertiary eye care center in south Florida. Materials and Methods: All medical records during a seven-year period starting January 1, 2007, were reviewed. Twenty-eight culture-proven Purpureocillium keratitis cases with complete medical records presenting to our institution were included in this retrospective, observational case series. Data collected included predisposing factors, therapeutic interventions, treatment duration, and visual outcomes. Results: Twenty patients (71.4%) had a history of soft contact lens use, with only two for therapeutic use. Other identified risk factors were trauma and immunosuppression. Fifteen patients (53.6%) received topical corticosteroid treatment prior to the diagnosis of fungal keratitis. Thirteen patients (46.4%) were on Natamycin treatment prior to Purpureocillium identification. As a group, the average best-corrected visual acuity (BCVA) at presentation was 1.1 logMAR; upon the final evaluation, it was 1.0 logMAR. The BCVA on last evaluation for the eight patients presenting to our institution within two weeks of onset of symptoms was 0.3 log MAR, and all patients in this group responded to medical management. The final BCVA for 20 patients presenting two weeks after onset of symptoms was 1.2 logMAR. There was a significant difference in the final BCVA between Group 1 and Group 2 (p = 0.004), but no difference in steroid use or previous treatments. Previous steroid use tended to extend time to presentation and was significantly associated with a worse final visual outcome (1.2 versus 0.6 logMAR; p = 0.0474). Previous Natamycin use was significantly associated with a worse final visual outcome (1.4 versus 0.6 logMAR; p = 0.014). Conclusion: Purpureocillium keratitis can have devastating consequences to visual function and even lead to enucleation. Physicians should make every effort to arrive at an earlier microbiological diagnosis, as this is associated with better outcomes and less need for surgical intervention. The first line use of voriconazole is recommended, and steroid use should be avoided, as their previous use is associated with worse visual outcomes.