Comparison of fungal and bacterial keratitis between tropical and subtropical Taiwan: a prospective cohort study

The effect of climatic and seasonal factors on the microbial keratitis profile

PURPOSE

To compare retrospective data on microbial keratitis (MK) from two different climatic regions in Turkey over 11 years.

STUDY DESIGN

Retrospective cohort.

METHODS

This retrospective cohort study included patients diagnosed with presumed MK at two referral centers. Center A was located in the subtropical region of Turkey, whereas Center B was located in a continental temperate climate zone. Clinical and laboratory data were also recorded. The results were evaluated for seasonal variations.

RESULTS

This study included data from 665 patients with presumed MK (351 and 314 patients from centers A and B, respectively). The most common predisposing factors were ocular trauma in Center A, prior ocular surgery, and systemic disease in Center B. Severe keratitis was related to prior ocular surgery, presence of systemic disease, and fungal infection at presentation. The culture positivity rate was higher in spring and lower in summer at both centers. Gram-positive bacteria were the most commonly isolated bacteria in both centers in all seasons. The fungal and mixed keratitis ratios were higher in Center A than in Center B. In Center A, filamentous fungi were common pathogens that were found year-round, and peaks were observed in July and October.

CONCLUSION

The results of this study show that climatic and seasonal factors may affect the microbial profile of keratitis. Fungal keratitis appears to be a climatic disease. Understanding the regional profile of MK can aid clinicians in their disease management.

Ocular surface immune transcriptome and tear cytokines in corneal infection patients

Background

Microbial keratitis is one of the leading causes of blindness globally. An overactive immune response during an infection can exacerbate damage, causing corneal opacities and vision loss. This study aimed to identify the differentially expressed genes between corneal infection patients and healthy volunteers within the cornea and conjunctiva and elucidate the contributing pathways to these conditions' pathogenesis. Moreover, it compared the corneal and conjunctival transcriptomes in corneal-infected patients to cytokine levels in tears.

Methods

Corneal and conjunctival swabs were collected from seven corneal infection patients and three healthy controls under topical anesthesia. RNA from seven corneal infection patients and three healthy volunteers were analyzed by RNA sequencing (RNA-Seq). Tear proteins were extracted from Schirmer strips via acetone precipitation from 38 cases of corneal infection and 14 healthy controls. The cytokines and chemokines IL-1β, IL-6, CXCL8 (IL-8), CX3CL1, IL-10, IL-12 (p70), IL-17A, and IL-23 were measured using an antibody bead assay.

Results

A total of 512 genes were found to be differentially expressed in infected corneas compared to healthy corneas, with 508 being upregulated and four downregulated (fold-change (FC) <-2 or > 2 and adjusted p <0.01). For the conjunctiva, 477 were upregulated, and 3 were downregulated (FC <-3 or ≥ 3 and adjusted p <0.01). There was a significant overlap in cornea and conjunctiva gene expression in patients with corneal infections. The genes were predominantly associated with immune response, regulation of angiogenesis, and apoptotic signaling pathways. The most highly upregulated gene was CXCL8 (which codes for IL-8 protein). In patients with corneal infections, the concentration of IL-8 protein in tears was relatively higher in patients compared to healthy controls but did not show statistical significance.

Conclusions

During corneal infection, many genes were upregulated, with most of them being associated with immune response, regulation of angiogenesis, and apoptotic signaling. The findings may facilitate the development of treatments for corneal infections that can dampen specific aspects of the immune response to reduce scarring and preserve sight.

Monitoring the Progression of Clinically Suspected Microbial Keratitis Using Convolutional Neural Networks

Purpose

For this study, we aimed to determine whether a convolutional neural network (CNN)-based method (based on a feature extractor and an identifier) can be applied to monitor the progression of keratitis while managing suspected microbial keratitis (MK).

Methods

This multicenter longitudinal cohort study included patients with suspected MK undergoing serial external eye photography at the 5 branches of Chang Gung Memorial Hospital from August 20, 2000, to August 19, 2020. Data were primarily analyzed from January 1 to March 25, 2022. The CNN-based model was evaluated via F1 score and accuracy. The area under the receiver operating characteristic curve (AUROC) was used to measure the precision-recall trade-off.

Results

The model was trained using 1456 image pairs from 468 patients. In comparing models via only training the identifier, statistically significant higher accuracy (P  < 0.05) in models via training both the identifier and feature extractor (full training) was verified, with 408 image pairs from 117 patients. The full training EfficientNet b3-based model showed 90.2% (getting better) and 82.1% (becoming worse) F1 scores, 87.3% accuracy, and 94.2% AUROC for 505 getting better and 272 becoming worse test image pairs from 452 patients.

Conclusions

A CNN-based approach via deep learning applied in suspected MK can monitor the progress/regress during treatment by comparing external eye image pairs.

Translational Relevance

The study bridges the gap between the investigation of the state-of-the-art CNN-based deep learning algorithm applied in ocular image analysis and the clinical care of suspected patients with MK.

Cutibacterium (Formerly Propionibacterium ) acnes Keratitis: A Review

ABSTRACT

Infectious keratitis is a devastating cause of vision loss worldwide. Cutibacterium acnes ( C. acnes ), a commensal bacterium of the skin and ocular surface, is an underrecognized but important cause of bacterial keratitis. This review presents the most comprehensive and up-to-date information for clinicians regarding the risk factors, incidence, diagnosis, management, and prognosis of C. acnes keratitis (CAK). Risk factors are similar to those of general bacterial keratitis and include contact lens use, past ocular surgery, and trauma. The incidence of CAK may be approximately 10%, ranging from 5% to 25% in growth-positive cultures. Accurate diagnosis requires anaerobic blood agar and a long incubation period (≥7 days). Typical clinical presentation includes small (<2 mm) ulcerations with deep stromal infiltrate causing an anterior chamber cell reaction. Small, peripheral lesions are usually resolved, and patients recover a high visual acuity. Severe infections causing VA of 20/200 or worse are common and often do not significantly improve even after treatment. Vancomycin is considered the most potent antibiotic against CAK, although other antibiotics such as moxifloxacin and ceftazidime are more commonly used as first-line treatment.

The epidemiology of infectious keratitis

Infectious keratitis is a rare but potentially severe sight-threatening disease, associated with considerable societal burden, cost and morbidity. This review summarises the most recent evidence for the incidence, risk factors and impact of disease, all of which vary widely according to region, access to health care, socioeconomic and environmental factors, predisposing conditions and causative organisms. The frequency and societal impact of infectious keratitis are significantly higher in low-income countries. In non-viral infectious keratitis, bacterial causes predominate in most regions. Fungi, particularly linked with agricultural trauma, are more frequently associated with infectious keratitis in low-income regions, particularly in India and certain African countries. The disease impact is compounded by poverty and limited access to services and treatment. Early diagnosis, access to appropriate treatment, prophylaxis in ocular trauma, availability of eye protection, awareness of risk factors may be associated with reduced disease severity and vision loss. Evidence for the incidence and burden of disease is lacking in certain regions and well-designed epidemiological studies to identify independent risk factors for the disease and those associated with more severe outcomes may better identify causation and guide resource allocation and preventative strategies.

Ocular streptococcal infections: A clinical and microbiological review

Streptococcus is a diverse bacterial genus that is part of the ocular surface microbiome implicated in conjunctivitis, keratitis, endophthalmitis, dacryocystitis, and orbital cellulitis which can lead to decreased visual acuity and require surgical intervention. The pathophysiology of S. pneumoniae is well established and the role of the polysaccharide capsule, pneumolysin, neuraminidases, and zinc metalloproteinases in ocular infections described. Additionally, key virulence factors of the viridans group streptococci such as cytolysins and proteases have been outlined, but there is a paucity of research on the remaining streptococcus species. These virulence factors tend to result in aggressive disease. Clinically, S. pneumoniae is implicated in 2.7-41.2% of bacterial conjunctivitis cases, more predominant in the pediatric population, and is implicated in 1.8-10.7% of bacterial keratitis isolates. Streptococcus bacteria are significantly implicated in acute postoperative, post-intravitreal, and bleb-associated endophthalmitis, responsible for 10.3-37.5, 29.4, and 57.1% of cases, respectively. Group A and B streptococcus endogenous endophthalmitis is rare, but has a very poor prognosis. Inappropriate prescription of antibiotics in cases of non-bacterial aetiology has contributed to increasing resistance, and a clinical index is needed to more accurately monitor this. Furthermore, there is an increasing need for prospective, surveillance studies of antimicrobial resistance in ocular pathogens, as well as point-of-care testing using molecular techniques.

An artificial intelligence approach to classify pathogenic fungal genera of fungal keratitis using corneal confocal microscopy images

PURPOSE

Fungal keratitis is a common cause of blindness worldwide. Timely identification of the causative fungal genera is essential for clinical management. In vivo confocal microscopy (IVCM) provides useful information on pathogenic genera. This study attempted to apply deep learning (DL) to establish an automated method to identify pathogenic fungal genera using IVCM images.

METHODS

Deep learning networks were trained, validated, and tested using a data set of 3364 IVCM images that collected from 100 eyes of 100 patients with culture-proven filamentous fungal keratitis. Two transfer learning approaches were investigated: one was a combined framework that extracted features by a DL network and adopted decision tree (DT) as a classifier; another was a complete supervised DL model which used DL-based fully connected layers to implement the classification.

RESULTS

The DL classifier model revealed better performance compared with the DT classifier model in an independent testing set. The DL classifier model showed an area under the receiver operating characteristic curves (AUC) of 0.887 with an accuracy of 0.817, sensitivity of 0.791, specificity of 0.831, G-mean of 0.811, and F1 score of 0.749 in identifying Fusarium, and achieved an AUC of 0.827 with an accuracy of 0.757, sensitivity of 0.756, specificity of 0.759, G-mean of 0.757, and F1 score of 0.716 in identifying Aspergillus.

CONCLUSION

The DL model can classify Fusarium and Aspergillus by learning effective features in IVCM images automatically. The automated IVCM image analysis suggests a noninvasive identification of Fusarium and Aspergillus with clear potential application in early diagnosis and management of fungal keratitis.

Microbial Keratitis in Patients With Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Experience From a Tertiary Centre in Taiwan

PURPOSE

The purpose of this study was to analyze the clinical features, causative microorganisms, antibiotic susceptibility, and treatment outcomes in culture-proven microbial keratitis (MK) in patients with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and to analyze the potential risk factors.

METHODS

We reviewed the medical records of all patients with SJS/TEN who attended our department between 2009 and 2018. Patients with a diagnosis of MK who underwent corneal cultures were enrolled. Demographics; clinical characteristics including ocular findings, treatment, time between onset of SJS/TEN and keratitis; changes in visual acuity; culture results; and antibiotic susceptibility were analyzed. Culture results from prior conjunctival swabs and keratitis were also compared.

RESULTS

Sixteen eyes from 12 patients (mean age 40.1 ± 27.7 years) with MK were identified. These patients had the most severe ocular involvement in the acute stage and had more severe ocular complications (SOCs) in the chronic stage compared with patients with SJS/TEN without MK. There were 26 infection episodes during 4.4 ± 6.9 (1.0-25.8) years of follow-up. Oral nonsteroidal anti-inflammatory drugs accounted for half of the causative drugs. Severe dry eye was the most common predisposing factor, followed by topical steroid use, trichiasis, and lid margin keratinization. Staphylococcus was the most common pathogen, and over half of the gram-positive bacteria were resistant to oxacillin/methicillin. Fungal infections (notably Candida ) accounted for nearly one-third of the causative microorganisms. Culture reports from periodic conjunctival swabs were not consistent with those from corneal scrapings. Recurrence of infection was associated with inferior visual outcome.

CONCLUSIONS

Patients with SJS/TEN with SOCs are subject to recurrent corneal infections, which are responsible for deterioration of vision. Identifying the risk factors and aggressive treatment as early as possible is pivotal for infection control.

A 5-Year Retrospective Analysis of the Risk Factors, Treatment, and Prognosis of Patients With Fungal Keratitis in Heilongjiang, China

PURPOSE

To report the epidemiologic features, laboratory findings, and treatment outcomes of patients with fungal keratitis (FK) during a busy farming period (May, June, and September to November) in Heilongjiang Province, China.

DESIGN

Retrospective, observational case series.

METHODS

In total, 251 patients diagnosed with FK at the Eye Hospital, First Affiliated Hospital of Harbin Medical University, from 2017 to 2021 were identified. Medical records were retrospectively analyzed, and demographic features, risk factors, monthly distributions, clinical characteristics, laboratory findings, treatment strategies, and prognostic data were collected.

RESULTS

The number of FK cases in the busy farming period accounted for 74.1% (186/251) of the total. The mean patient age was 58.2±9.5 years. Males (66.7%) were more likely to develop FK than females (33.3%), and plant-related trauma was the main cause in 80.1% (149/186) of the cases. The most common causative fungal species was Fusarium (34.9%). In vivo confocal microscopy had the highest positivity rate for FK diagnosis (94.6%). The depth of hypopyon, depth of hyphae or spores, and infiltrate width were significantly positively correlated with delayed presentation.

CONCLUSIONS

Patients with a longer time of presentation to the hospital were more likely to undergo surgery because of topical medical therapy failure. The most important measures for FK prevention are the use of eye protection during outdoor work and visiting the hospital for treatment as soon as possible after eye injury.

Deep Learning Approach in Image Diagnosis of Pseudomonas Keratitis

This investigation aimed to explore deep learning (DL) models' potential for diagnosing Pseudomonas keratitis using external eye images. In the retrospective research, the images of bacterial keratitis (BK, n = 929), classified as Pseudomonas (n = 618) and non-Pseudomonas (n = 311) keratitis, were collected. Eight DL algorithms, including ResNet50, DenseNet121, ResNeXt50, SE-ResNet50, and EfficientNets B0 to B3, were adopted as backbone models to train and obtain the best ensemble 2-, 3-, 4-, and 5-DL models. Five-fold cross-validation was used to determine the ability of single and ensemble models to diagnose Pseudomonas keratitis. The EfficientNet B2 model had the highest accuracy (71.2%) of the eight single-DL models, while the best ensemble 4-DL model showed the highest accuracy (72.1%) among the ensemble models. However, no statistical difference was shown in the area under the receiver operating characteristic curve and diagnostic accuracy among these single-DL models and among the four best ensemble models. As a proof of concept, the DL approach, via external eye photos, could assist in identifying Pseudomonas keratitis from BK patients. All the best ensemble models can enhance the performance of constituent DL models in diagnosing Pseudomonas keratitis, but the enhancement effect appears to be limited.

Filamentous Fungal Keratitis in Greece: A 16-Year Nationwide Multicenter Survey

In a multicenter, prospective study of filamentous fungal keratitis in Greece, predisposing factors, etiology, treatment practices, and outcome, were determined. Corneal scrapings were collected from patients with clinical suspicion of fungal keratitis, and demographic and clinical data were recorded. Fungal identification was based on morphology, molecular methods, and matrix assisted laser desorption ionization time-of-flight mass-spectrometry. A total of 35 cases were identified in a 16-year study period. Female to male ratio was 1:1.7 and median age 48 years. Corneal injury by plant material, and soft contact lens use were the main risk factors (42.8% and 31.4%, respectively). Trauma was the leading risk factor for men (68.1%), contact lens use (61.5%) for women. Fusarium species were isolated more frequently (n = 21, 61.8%). F. solani was mostly associated with trauma, F. verticillioides and F. proliferatum with soft contact lens use. Other fungi were: Purpureocillium lilacinum (14.7%), Alternaria (11.8%), Aspergillus (8.8%), and Phoma foliaceiphila, Beauveria bassiana and Curvularia spicifera, one case each. Amphotericin B and voriconazole MIC₅₀s against Fusarium were 2 mg/L and 4 mg/L respectively. Antifungal therapy consisted mainly of voriconazole locally or both locally and systemically, alone or in combination with liposomal AmB. Cure/improvement rate with antifungal therapy alone was 52%, keratoplasty was required in 40% of cases, and enucleation in 8%. In conclusion, filamentous fungal keratitis in Greece is rare, but with considerable morbidity. A large proportion of cases resulted in keratoplasty despite appropriate antifungal treatment.Kindly confirm the given name and family name are correctly identified for all authros.ConfirmedJournal instruction requires a city and country for affiliations; however, these are missing in affiliations 1, 3, 4, 5, 6, 13. Please verify if the provided city and country are correct and amend if necessary.All provided cities and countries are correct.

Case Report: A Rare Fungal Keratitis Caused by Plectosphaerella Cucumerina

PURPOSE

To report a rare case of fungal keratitis caused by Plectosphaerella cucumerina.

METHODS

This study retrospectively reviewed the medical records of a case of fungal keratitis.

RESULTS

Silt-lamp biomicroscopy revealed corneal infiltration and epithelial defects. Anterior segment optical coherence tomography (AS-OCT) and in vivo confocal microscopy (IVCM) were performed to assist in the diagnosis and evaluate corneal conditions. The isolate was identified as Plectosphaerella cucumerina by MALDI-TOF mass spectrometry. The patient was treated with topical 5% pimaricin and oral voriconazole for 1 month and recovered.

CONCLUSION

Fungal keratitis caused by Plectosphaerella cucumerina is rare. AS-OCT and IVCM can help locate the lesion and diagnose fungal keratitis. Furthermore, MALDI-TOF mass spectrometry showed potential prospects in the identification of filamentous fungi. Plectosphaerella cucumerina rarely infects humans and is sensitive to antifungal agents such as pimaricin and voriconazole.

Update on fungal keratitis in France: a case-control study

PURPOSE

To report an epidemiological update of documented fungal keratitis (FK) in a French tertiary ophthalmological centre from 2014 to 2018 in comparison with a previous period from 1993 to 2008.

METHODS

Sixty-two consecutive FK documented by microbiological corneal scrapings were compared with the 64 FK of the previous study. Amphotericin B and voriconazole eye drops were administered hourly. Population characteristics, clinical findings, aetiological organisms and treatments were analysed.

RESULTS

The most frequently identified fungi were Fusarium (61%), Aspergillus (6.5%) and Candida (5%). Thirty out of 44 cases examined with in vivo confocal microscopy (IVCM) presented filaments. Ten required conventional cross-linking, 9 therapeutic penetrating keratoplasty, and 2 enucleation. Risk factors significantly associated with the absence of response to medical treatment were patient age (p = 0.01), presence of a deep stromal infiltrate at presentation (p = 0.04) and high numbers of filaments in IVCM images (p = 0.01). The two populations were comparable in age, but not in sex ratio males/females (18/44 versus 37/26 in the previous study; p = 0.001). The frequency of contact lens-associated infection increased from 35.5% to 71% (p = 0.0001) between the two periods. Since then, filamentous FK increased from 69% (44/64) to 95% (59/62) (p = 0.0001). A history of keratoplasty was less frequently reported during the last period (3.2% (2/62) versus 17% (11/64) of cases (p = 0.01)). A clear decrease in the frequency of therapeutic keratoplasty was noted from 39% (25/64) to 14% (9/62) (p = 0.02).

CONCLUSION

The frequency of filamentous keratomycosis is currently increasing. Elderly patients and the presence of numerous filaments in IVCM are associated with poor clinical outcomes.

Infectious keratitis in Vietnam: etiology, organisms, and management at Vietnam National Eye Hospital

AIM

To report the etiologies, risk factors, treatments, and outcomes of infectious keratitis (IK) at a major Vietnamese eye hospital.

METHODS

This is a retrospective review of all cases of IK at Vietnam National Eye Hospital (VNEH) in Hanoi, Vietnam. Medical histories, demographics, clinical features, microbiological results, and treatment outcomes were reviewed.

RESULTS

IK was diagnosed in 1974 eyes of 1952 patients, with ocular trauma being the greatest risk factor for IK (34.2%), frequently resulting from an agriculture-related injury (53.3%). The mean duration between symptom onset and presentation to VNEH was 19.3±14.4d, and 98.7% of patients had been treated with topical antibiotic and/or antifungal agents prior to evaluation at VNEH. Based on smear results of 1706 samples, the most common organisms identified were bacteria (n=1107, 64.9%) and fungi (n=1092, 64.0%), with identification of both bacteria and fungi in 614 (36.0%) eyes. Fifty-five of 374 bacterial cultures (14.7%) and 426 of 838 fungal cultures (50.8%) were positive, with the most commonly cultured pathogens being Pseudomonas aeruginosa, Streptococcus pneumonia, Fusarium spp., and Aspergillus spp. Corneal perforation and descemetocele developed in 391 (19.8%) and 93 (4.7%) eyes, respectively. Medical treatment was successful in resolving IK in 50.4% eyes, while 337 (17.1%) eyes underwent penetrating or anterior lamellar keratoplasty. Evisceration was performed in 7.1% of eyes, most commonly in the setting of fungal keratitis.

CONCLUSION

Ocular trauma is a major risk factor for IK in Vietnam, which is diagnosed in almost 400 patients each year at VNEH. Given this, and as approximately one quarter of the eyes that develop IK require corneal transplantation or evisceration, greater emphasis should be placed on the development of prevention and treatment programs for IK in Vietnam.

Comparisons of deep learning algorithms for diagnosing bacterial keratitis via external eye photographs

Bacterial keratitis (BK), a painful and fulminant bacterial infection of the cornea, is the most common type of vision-threatening infectious keratitis (IK). A rapid clinical diagnosis by an ophthalmologist may often help prevent BK patients from progression to corneal melting or even perforation, but many rural areas cannot afford an ophthalmologist. Thanks to the rapid development of deep learning (DL) algorithms, artificial intelligence via image could provide an immediate screening and recommendation for patients with red and painful eyes. Therefore, this study aims to elucidate the potentials of different DL algorithms for diagnosing BK via external eye photos. External eye photos of clinically suspected IK were consecutively collected from five referral centers. The candidate DL frameworks, including ResNet50, ResNeXt50, DenseNet121, SE-ResNet50, EfficientNets B0, B1, B2, and B3, were trained to recognize BK from the photo toward the target with the greatest area under the receiver operating characteristic curve (AUROC). Via five-cross validation, EfficientNet B3 showed the most excellent average AUROC, in which the average percentage of sensitivity, specificity, positive predictive value, and negative predictive value was 74, 64, 77, and 61. There was no statistical difference in diagnostic accuracy and AUROC between any two of these DL frameworks. The diagnostic accuracy of these models (ranged from 69 to 72%) is comparable to that of the ophthalmologist (66% to 74%). Therefore, all these models are promising tools for diagnosing BK in first-line medical care units without ophthalmologists.

Fungal Keratitis: Diagnostic Characteristics of the Potassium Hydroxide Preparation With Calcofluor White in Northern California

PURPOSE

The incidence of fungal keratitis demonstrates significant geographic and climatic variation. We report on the characteristics of the potassium hydroxide/calcofluor white (KOH-CFW) preparation observed at a tertiary center in Northern California, a region with a low incidence of fungal keratitis.

METHODS

Culture-proven cases of microbial keratitis during a 5-year period were retrospectively reviewed. The sensitivity, specificity, and posttest probabilities were determined for the KOH-CFW assay. These results were compared with documented clinical impression and values reported in the literature.

RESULTS

Three hundred three of 368 episodes of microbial keratitis during the study period documented the results of a fungal culture, KOH-CFW assay, and a clinical impression. Twenty-one (6.9%) of these cultures were positive for fungal organisms. The sensitivity and specificity of the KOH-CFW test were 29% and 93%, respectively. Clinicians' initial clinical impression based solely on patients' history and examination, without the aid of any histopathologic or biochemical test results, demonstrated a sensitivity and specificity of 33% and 89%, respectively.

CONCLUSIONS

The observed sensitivity and specificity of the KOH-CFW preparation are significantly lower than many previously reported values. In regions with low incidence of fungal keratitis, the KOH-CFW preparation may have diagnostic performance similar to that of the clinical impression formed only on the basis of history and physical examination.

First Report of a Case of Ocular Infection Caused by Purpureocillium lilacinum in Poland

This report describes the first case of an ocular infection induced by Purpureocillium lilacinum in Poland. The patient was a 51-year-old immunocompetent contact lens user who suffered from subacute keratitis and progressive granulomatous uveitis. He underwent penetrating keratoplasty for corneal perforation, followed by cataract surgery due to rapid uveitic cataract. A few weeks later, intraocular lens removal and pars plana vitrectomy were necessary due to endophthalmitis. The patient was treated with topical, systemic, and intravitreal voriconazole with improvement; however, the visual outcome was poor. The pathogen was identified by MALDI-TOF MS.

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

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.

Do Ophthalmic Solutions of Amphotericin B Solubilised in 2-Hydroxypropyl-γ-Cyclodextrins Possess an Extended Physicochemical Stability?

Fungal keratitis is a sight-threatening disease for which amphotericin B eye drops is one of the front-line treatments. Unfortunately, there are currently no commercial forms available, and there is little data concerning the long-term stability of compounded formulations based on intravenous dosages forms. New formulations of amphotericin B ophthalmic solutions solubilised with γ-cyclodextrins have shown promising in-vitro results, but stability data is also lacking. The objective of this study was therefore to investigate the stability of a formulation of ready-to-use amphotericin B solubilised in 2-hydroxypropyl-γ-cyclodextrins (AB-HP-γ-CD), for 350 days. An amphotericin B deoxycholate (ABDC) formulation was used as a comparator. Analyses used were the following: visual inspection, turbidity, osmolality and pH measurements, amphotericin B quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. AB-HP-γ-CD formulation showed signs of chemical instability (loss of amphotericin B) after 28 and 56 days at 25 °C and 5 °C. Adding an antioxidant (ascorbic acid) to the formulation did not improve stability. ABDC formulation showed signs of physical instability (increased turbidy and amphotericin B precipitation) after 28 days and 168 days at 25 °C and 5 °C. As such, AB-HP-γ-CD formulation does not provide long-term stability for ophthalmic amphotericin B solutions.