Microbial keratitis in Southern Malawi: a microbiological pilot study.

OBJECTIVE: Microbial keratitis (MK) is a significant cause of blindness in sub-Saharan Africa. We investigated the feasibility of using a novel corneal impression membrane (CIM) for obtaining and processing samples by culture, PCR and whole-genome sequencing (WGS) in patients presenting with suspected MK in Malawi. METHODS AND ANALYSIS: Samples were collected from patients presenting with suspected MK using a 12 mm diameter polytetrafluoroethylene CIM disc. Samples were processed using culture and PCR for Acanthamoeba, herpes simplex virus type 1 (HSV-1) and the bacterial 16S rRNA gene. Minimum inhibitory concentrations of isolates to eight antimicrobials were measured using susceptibility strips. WGS was used to characterise Staphylococcus aureus isolates. RESULTS: 71 eyes of 71 patients were included. The overall CIM isolation rate was 81.7% (58 positive samples from 71 participants). 69 (81.2%) of isolates were Gram-positive cocci. Coagulase-negative Staphylococcus 31.8% and Streptococcus species 14.1% were the most isolated bacteria. Seven (9.9%) participants were positive for HSV-1. Fungi and Acanthamoeba were not detected. Moxifloxacin and chloramphenicol offered the best coverage for both Gram-positive and Gram-negative isolates when susceptibility was determined using known antimicrobial first quartile concentrations and European Committee on Antimicrobial Susceptibility Testing breakpoints, respectively. WGS identified known virulence genes associated with S. aureus keratitis. CONCLUSIONS: In a resource-poor setting, a CIM can be used to safely sample the cornea in patients presenting with suspected MK, enabling identification of causative microorganisms by culture and PCR. Although the microbiological spectrum found was limited to the dry season, these preliminary results could be used to guide empirical treatment.

Biophilic Positive Carbon Dot Exerts Antifungal Activity and Augments Corneal Permeation for Fungal Keratitis.

Fungal keratitis (FK) is an infectious eye disease that poses a significant risk of blindness. However, the effectiveness of conventional antifungal drugs is limited due to the intrinsic ocular barrier that impedes drug absorption. There is an urgent need to develop new therapeutic strategies to effectively combat FK. Herein, we synthesized an ultrasmall positively charged carbon dot using a simple stage-melting method. The carbon dot can penetrate the corneal barrier by opening the tight junctions, allowing them to reach the lesion site and effectively kill the fungi. The results both in vitro and in vivo demonstrated that it exhibited good biocompatibility and antifungal activity, significantly improving the therapeutic effect in a mouse model of FK. Therefore, this biophilic ultrasmall size and positive carbon dot, characterized by its ability to penetrate the corneal barrier and its antifungal properties, may offer valuable insights into the design of effective ocular nanomedicines.

Hallazgos de microscopia confocal in vivo de la mucosa de la córnea y la lengua en pacientes con síndrome de Sjögren / In vivo confocal microscopy findings of cornea and tongue mucosa in patients with Sjögren's syndrome

Introducción y objetivos: Nuestro objetivo fue investigar si el síndrome de Sjögren (SS) tenía hallazgos distintivos en la microscopia confocal de la lengua de una manera no invasiva. Materiales y métodos: Este estudio retrospectivo de casos y controles evaluó los hallazgos de la microscopia confocal de córnea y lengua de los ojos derechos de 25 pacientes con ojo seco con deficiencia acuosa y 12 voluntarios sanos sin hallazgos de ojo seco. Hubo un total de 14 pacientes diagnosticados con ojo seco asociado a SS (SSDE), mientras que 11 casos fueron evaluados como ojo seco no Sjögren (NSDE). Resultados: Se observó una diferencia significativa en el recuento de células dendríticas a nivel del nervio subbasal corneal entre los grupos SSDE y NSDE (p=0,018). En el grupo SSDE, las imágenes de microscopia confocal de células inflamatorias dendritiformes hiperreflectantes en la mucosa de la lengua estaban a favor de la inflamación. Sin embargo, estos hallazgos no se encontraron en pacientes con NSDE o en controles. Conclusiones: Este estudio mostró que la microscopia confocal proporcionó una evaluación no invasiva de las células inflamatorias en la lengua de los pacientes con SS.(AU)

Introduction and objectives: We aimed to investigate whether Sjögren's syndrome (SS) had distinctive findings in tongue confocal microscopy in a non-invasive manner. Materials and methods: This retrospective case-control study evaluated corneal and tongue confocal microscopy findings of the right eyes of 25 patients with aqueous deficient dry eye and 12 healthy volunteers without dry eye findings. There were a total of 14 patients diagnosed with SS-associated dry eye (SSDE), while 11 cases were evaluated as non-Sjögren dry eye (NSDE). Results: A significant difference was observed in the dendritic cell count at the corneal subbasal nerve level between the SSDE and NSDE groups (P=.018). In SSDE group, the confocal microscopy images of dendritiform hyperreflective inflammatory cells in the tongue mucosa were in favor of inflammation. However, these findings were not found in patients with NSDE or in controls. Conclusions: This study showed that confocal microscopy provided a non-invasive evaluation of the inflammatory cells in the tongue of SS patients.(AU)

Ocular infections associated with atypical mycobacteria: A review.

Atypical mycobacteria or non-tuberculous mycobacteria (NTM) are a group of acid-fast bacteria that are pathogenic to different parts of the eye. The organisms can cause a spectrum of ocular infections including keratitis, scleritis, uveitis, endophthalmitis and orbital cellulitis. Trauma, whether surgical or nonsurgical, has the highest correlation with development of this infection. Common surgeries after which these infections have been reported include laser in situ keratomileusis (LASIK) and scleral buckle surgery. The organism is noted to form biofilms with sequestration of the microbe at different inaccessible locations leading to high virulence. Collection of infective ocular material (corneal scraping/necrotic scleral tissue/abscess material/vitreous aspirate, etc.) and laboratory identification of the organism through microbiologic testing are vital for confirming presence of the infection and initiating treatment. In cluster infections, tracing the source of infection in the hospital setting via testing of different in-house samples is equally important to prevent further occurrences. Although the incidence of these infections is low, their presence can cause prolonged disease that may often be resistant to medical therapy alone. In this review, we describe the various types of NTM-ocular infections, their clinical presentation, laboratory diagnosis, management, and outcomes.

Microbial keratitis in lattice corneal dystrophy: microsporidia as a new cause.

A patient in his sixth decade presented to us with redness, pain and a deterioration of vision in his left eye. He had previously been diagnosed with lattice corneal dystrophy (LCD). He was diagnosed with microbial keratitis, and mixed infection was confirmed on culture (bacteria and fungus) with a protracted healing period before resolution of keratitis. He presented 2 years later with similar issues in the same eye and was noted to have a second episode of microbial keratitis, with microsporidia spores noted on gram, potassium hydroxide and calcofluor white stains. He was diagnosed with microsporidial stromal keratitis and underwent therapeutic penetrating keratoplasty. Unfortunately, he suffered a recurrence of microsporidial keratitis following surgery with eventual transplant failure. Microsporidia as an infection in LCD has, to our knowledge, not been previously reported. We aim to discuss microsporidial infection and recurrent microbial keratitis in the setting of LCD.

FluoroPi Device With SmartProbes: A Frugal Point-of-Care System for Fluorescent Detection of Bacteria From a Pre-Clinical Model of Microbial Keratitis.

Purpose: Rapid and accurate diagnosis of microbial keratitis (MK) could greatly improve patient outcomes. Here, we present the development of a rapid, accessible multicolour fluorescence imaging device (FluoroPi) and evaluate its performance in combination with fluorescent optical reporters (SmartProbes) to distinguish bacterial Gram status. Furthermore, we show feasibility by imaging samples obtained by corneal scrape and minimally invasive corneal impression membrane (CIM) from ex vivo porcine corneal MK models. Methods: FluoroPi was built using a Raspberry Pi single-board computer and camera, light-emitting-diodes (LEDs), and filters for white-light and fluorescent imaging, with excitation and detection of bacterial optical SmartProbes: Gram-negative, NBD-PMX (exmax 488 nm); Gram positive, Merocy-Van (exmax 590 nm). We evaluated FluoroPi with bacteria (Pseudomonas aeruginosa and Staphylococcus aureus) isolated from ex vivo porcine corneal models of MK by scrape (needle) and CIM with the SmartProbes. Results: FluoroPi provides <1 µm resolution and was able to readily distinguish bacteria isolated from ex vivo models of MK from tissue debris when combined with SmartProbes, retrieved by both scrape and CIM. Single bacteria could be resolved within the field of view, with limits of detection demonstrated as 103 to 104 CFU/mL. Sample preparation prior to imaging was minimal (wash-free), and imaging and postprocessing with FluoroPi were straightforward, confirming ease of use. Conclusions: FluoroPi coupled with SmartProbes provides effective, low-cost bacterial imaging, delineating Gram-negative and Gram-positive bacteria directly sampled from a preclinical model of MK. Translational Relevance: This study provides a crucial stepping stone toward clinical translation of a rapid, minimally invasive diagnostic approach for MK.

An X-ray inactivated vaccine against Pseudomonas aeruginosa Keratitis in mice.

Pseudomonas aeruginosa (P. aeruginosa) is one of the most prevalent pathogens of bacterial keratitis. Bacterial keratitis is a major cause of blindness worldwide. The rising incidence of multidrug resistance of P. aeruginosa precludes treatment with conventional antibiotics. Herein, we evaluated the protective efficiency and explored the possible underlying mechanism of an X-ray inactivated vaccine (XPa) using a murine P. aeruginosa keratitis model. Mice immunized with XPa exhibit reduced corneal bacterial loads and pathology scores. XPa vaccination induced corneal macrophage polarization toward M2, averting an excessive inflammatory reaction. Furthermore, histological observations indicated that XPa vaccination suppressed corneal fibroblast activation and prevented irreversible visual impairment. The potency of XPa against keratitis highlights its potential utility as an effective and promising vaccine candidate for P. aeruginosa.

Effect of Corneal Collagen Cross-Linking on Subsequent Corneal Fungal Infection in Rats.

Purpose: The purpose of this study was to determine whether corneal collagen cross-linking (CXL) alters fungal susceptibility and increases the severity of keratitis through macrophage activation in rats. Methods: Four weeks following CXL pretreatment, the corneal epithelium of adult rats was removed and inoculated with Candida albicans (C. albicans; CXL + inoculation group). The non-CXL-pretreated corneas were also inoculated with C. albicans (inoculation group). Clinical scoring and histopathological examination were performed to determine the severity of fungal keratitis. Immunofluorescence and confocal microscopy imaging were applied to determine the effects of CXL treatment on corneal local macrophage content. Real-time polymerase chain reaction (RT-PCR) and Western blots were used to evaluate mRNA and protein expression. Flow cytometry assays were performed to detect M1- and M2-type macrophages. Results: CXL pretreatment (CXL + inoculation) resulted in higher infection success rate and more severe fungal keratitis than inoculation alone (inoculation group). On days 1, 3, and 7 following fungal infection, the increase in macrophage infiltration and IL-1ß, MMP-9, and VEGFA expression was greater in the CXL + inoculation group than in the inoculation group. Number of M1- and M2-type macrophages, M1 to M2 ratio, M1-type macrophage genes, inducible nitric oxide synthase (iNOS), and tumor necrosis factor (TNFα) expression were higher in the CXL + inoculation group compared with the inoculation group. Conclusions: Our data demonstrate that CXL may increase the colonization of macrophages and activate more M1-type macrophages to increase fungal susceptibility and severity of keratitis. Translational Relevance: This study may aid long-term risk assessment and treatment of the complications of CXL.

A 5-Year Review of Coinfections in Acanthamoeba keratitis From South India.

PURPOSE: To ascertain the frequency of coinfections in Acanthamoeba keratitis, the nature of copathogens involved, and to analyze the implications in the context of current research on amoebic interactions. METHODS: A retrospective case review from a Tertiary Care Eye Hospital in South India. Smear and culture data for coinfections in Acanthamoeba corneal ulcers were collected from records over a 5-year period. The significance and relevance of our findings in the light of current research on Acanthamoeba interactions were analyzed. RESULTS: Eighty-five cases of culture-positive Acanthamoeba keratitis were identified over a 5-year period (43 of them being coinfections). Fusarium was most commonly identified species, followed by Aspergillus and the dematiaceous fungi. Pseudomonas spp was the commonest bacterial isolate. CONCLUSION: Coinfections with Acanthamoeba are common at our centre, and account for 50% of Acanthamoeba keratitis. The diverse nature of the organisms involved in coinfections suggest that such amoebic interactions with other organisms are probably more widespread than recognized. To the best of our knowledge, this is the first documentation from a long-term study of pathogen diversity in Acanthamoeba coinfections. It is possible that Acanthamoeba itself may be virulence enhanced and secondary to the co-organism, breaching the ocular surface defenses in an already compromised cornea. However, observations from the existing literature on Acanthamoeba interactions with bacteria and certain fungi are based mainly on nonocular or nonclinical isolates. It would be illuminating if such studies are performed on Acanthamoeba and coinfectors from corneal ulcers-to ascertain whether interactions are endosymbiotic or virulence enhanced through amoebic passage.

Immunity to pathogenic fungi in the eye.

Fusarium, Aspergillus and Candida are important fungal pathogens that cause visual impairment and blindness in the USA and worldwide. This review will summarize the epidemiology and clinical features of corneal infections and discuss the immune and inflammatory responses that play an important role in clinical disease. In addition, we describe fungal virulence factors that are required for survival in infected corneas, and the activities of neutrophils in fungal killing, tissue damage and cytokine production.

Evaluation of a commercial NGS service for detection of bacterial and fungal pathogens in infectious ulcerative keratitis.

OBJECTIVES: To compare results from a commercial next-generation sequencing (NGS) service to corneal cytology and culture for identification of causative organisms in veterinary patients presenting for infectious ulcerative keratitis (IUK). PROCEDURE: Swabs for corneal aerobic and fungal cultures and DNA swabs for NGS were submitted for canine and equine normal controls (n = 11 and n = 4, respectively) and IUK patients (n = 22 and n = 8, respectively) for which microbrush cytology specimens confirmed the presence of infectious organisms. The sensitivity of the NGS results was compared with bacterial and fungal culture results. Concordance between the NGS and culture results was determined. RESULTS: The NGS results were positive for bacterial and fungal organisms in 5 and 1 normal and 18 and 1 IUK cases, respectively. Bacterial and fungal cultures were positive for 7 and 2 normal and 20 and 5 IUK cases, respectively. Sensitivity of NGS was 82.14% (95% confidence interval (CI), 63.11% to 93.94%) and specificity was 76.47% (95% CI, 50.10% to 93.19%). Concordance (complete and partial) between identified bacterial and fungal organisms was found in 79% and 100% of cases, respectively. NGS identified organisms in 3 culture-negative IUK samples. CONCLUSION: A commercial NGS service may be useful in the identification of causative agents in IUK cases with a sensitivity greater than the sensitivity previously reported for aerobic culture. Further testing is needed to determine the clinical significance of additional organisms isolated by NGS from infected cases, as well as organisms isolated from normal corneas.

Infectious keratitis caused by Klebsiella spp.: predisposing factors, presentation, and management.

PURPOSE: To study predisposing factors, clinical presentation and management strategies for Klebsiella keratitis. METHODS: A retrospective case review was performed on clinical records of culture-proven Klebsiella keratitis cases in a tertiary referral center over an 8-year period (from 2012 to 2020). RESULTS: Thirty eight episodes of culture-proven Klebsiella keratitis were identified in 37 patients. The mean age of the patients was 62.9 years (range, 24-101). Multiple predisposing factors were identified in 33 eyes including history of previous keratoplasty (n = 11) history of ocular trauma (n = 7), preexisting ocular surface disease (n = 7) and diabetes (n = 6). Corrected distance visual acuity (CDVA) at presentation was light perception (LP) in 16 patients, hand motion (HM) in 12, counting fingers (CF) at 50 cm in 5, CF at 1 m in 1, CF at 2 m in 2. One patient had a CDVA of 3/10. On initial examination Hypopyon was detected in 21 eyes. Descemet's membrane folds were present in 1 eye. Corneal thinning was identified in 20 eyes and perforation occurred in 4 patients. Corneal ulcer progressed to endophthalmitis in one patient. Microbiologic sensitivity testing showed that 89.5% isolates were sensitive to amikacin (34/38),88.9%sensitive to ceftazidime (32/36),94.4% were sensitive to gentamicin (34/36),97.2% sensitive to ciprofloxacin (35/36), and 100% to levofloxacin (26/26).Ultimately, one or more surgical procedures was needed in 21 patients. CONCLUSION: Previous keratoplasty, history of ocular trauma, ocular surface disease and systemic disease such as diabetes are major risk factors for Klebsiella keratitis. In most of the patients, surgical and tectonic procedures were necessary to control the infection.

Utility of investigation for suspected microbial keratitis: a diagnostic accuracy study.

PURPOSE: The true disease status of a population with suspected microbial keratitis (MK) cannot be verified. There is not an accurate (gold) reference standard to confirm infection and inter-test comparisons of sensitivity and specificity therefore lead to bias with questionable estimates of test utility. We present an alternative method to report results. METHODS: We used a decision to treat as the definition for MK. We retrospectively compared the results of corneal culture and polymerase chain reaction (PCR) as these are objective tests available for the three principal groups of pathogens. We then estimated the potential contribution of positive results, either alone or in combination, to support the working diagnosis. RESULTS: We included 2021 (77.4%) eyes with suspected bacterial keratitis, 365 (14.0%) with suspected acanthamoeba keratitis, and 226 (8.6%) with suspected fungal keratitis, all treated between July 2013 and December 2019. In these groups, there were 51.6% positive culture and 6.5% positive PCR results for bacteria, 19.0% and 40.5% for acanthamoeba, and 28.3% and 15.0% for fungi. Between groups the differences in the proportions of positive results from culture and PCR was statistically significant (P < 0.001). The added benefit of PCR to the result of culture in identifying a potential pathogen was 1.4% for bacteria (P = 0.6292), 24.4% for acanthamoeba (P = 0.0001), and 5.8% for fungi (P = 0.3853). CONCLUSIONS: For suspected MK a comparison of the test positivity rate is an easily comprehensible outcome measure of test utility.

Transcriptional profiling specifies the pathogen-specific human host response to infectious keratitis.

Purpose: Corneal infections are a leading cause of visual impairment and blindness worldwide. Here we applied high-resolution transcriptomic profiling to assess the general and pathogen-specific molecular and cellular mechanisms during human corneal infection. Methods: Clinical diagnoses of herpes simplex virus (HSV) (n=5) and bacterial/fungal (n=5) keratitis were confirmed by histology. Healthy corneas (n=7) and keratoconus (n=4) samples served as controls. Formalin-fixed, paraffin-embedded (FFPE) human corneal specimens were analyzed using the 3' RNA sequencing method Massive Analysis of cDNA Ends (MACE RNA-seq). The cellular host response was investigated using comprehensive bioinformatic deconvolution (xCell and CYBERSORTx) analyses and by integration with published single cell RNA-seq data of the human cornea. Results: Our analysis identified 216 and 561 genes, that were specifically overexpressed in viral or bacterial/fungal keratitis, respectively, and allowed to distinguish the two etiologies. The virus-specific host response was driven by adaptive immunity and associated molecular signaling pathways, whereas the bacterial/fungal-specific host response mainly involved innate immunity signaling pathways and cell types. We identified several genes and pathways involved in the host response to infectious keratitis, including CXCL9, CXCR3, and MMP9 for viral, and S100A8/A9, MMP9, and the IL17 pathway for bacterial/fungal keratitis. Conclusions: High-resolution molecular profiling provides new insights into the human corneal host response to viral and bacterial/fungal infection. Pathogen-specific molecular profiles may provide the foundation for novel diagnostic biomarker and therapeutic approaches that target inflammation-induced damage to corneal host cells with the goal to improve the outcome of infectious keratitis.

Innate Immune System Activation, Inflammation and Corneal Wound Healing.

Corneal wounds resulting from injury, surgeries, or other intrusions not only cause pain, but also can predispose an individual to infection. While some inflammation may be beneficial to protect against microbial infection of wounds, the inflammatory process, if excessive, may delay corneal wound healing. An examination of the literature on the effect of inflammation on corneal wound healing suggests that manipulations that result in reductions in severe or chronic inflammation lead to better outcomes in terms of corneal clarity, thickness, and healing. However, some acute inflammation is necessary to allow efficient bacterial and fungal clearance and prevent corneal infection. This inflammation can be triggered by microbial components that activate the innate immune system through toll-like receptor (TLR) pathways. In particular, TLR2 and TLR4 activation leads to pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) activation. Similarly, endogenous molecules released from disrupted cells, known as damage-associated molecular patterns (DAMPs), can also activate TLR2, TLR4 and NFκB, with the resultant inflammation worsening the outcome of corneal wound healing. In sterile keratitis without infection, inflammation can occur though TLRs to impact corneal wound healing and reduce corneal transparency. This review demonstrates the need for acute inflammation to prevent pathogenic infiltration, while supporting the idea that a reduction in chronic and/or excessive inflammation will allow for improved wound healing.

Effect of Increasing Povidone-Iodine Exposure on Corneal Epithelium and Impact on Donor Rim Cultures.

PURPOSE: The purpose of this study was to assess the effect of a second povidone-iodine (PVP-I) application at the time of donor tissue recovery on overall tissue quality and to analyze the rate of positive fungal and bacterial rim cultures before and after implementing increased PVP-I exposure. METHODS: The left cornea was recovered after a single application of PVP-I, while the right cornea was recovered after double PVP-I application in research-consented donors. The epithelial cell death rate was estimated using viability assay in corneal whole mounts under 10× objective (n = 5). Clinical characteristics of epithelium, stroma, and endothelium; positive rim culture rate; and incidences of infectious postoperative adverse reactions were compared for a period of 14 months before and after implementation of increased PVP-I protocol. RESULTS: The average epithelial cell death rate was unaltered between single and double PVP-I exposure groups. We observed a modest 10% increase in the number of tissues with mild edema after implementation of increased PVP-I exposure. Nonetheless, the percentage of tissues with moderate or severe edema was unaltered. The average positive rim culture rate decreased from 1.17% to 0.88% (P = 0.075) after implementation of the double PVP-I soak procedure. There has been only one report of infectious postoperative adverse reactions since this procedure change. By contrast, there were 5 reports for a period of 14 months before implementation of this protocol. CONCLUSIONS: These results indicate that new donor preparation methods with an additional 5 minutes of PVP-I exposure do not affect tissue quality, reduce positive rim cultures, and lead to lower incidence of postoperative infection.

Repeated High-Fluence Accelerated Slitlamp-Based Photoactivated Chromophore for Keratitis Corneal Cross-Linking for Treatment-Resistant Fungal Keratitis.

PURPOSE: The purpose of this study was to report a case of fungal keratitis resistant to standard-of-care antimicrobial treatment and successful resolution, thanks to the repeated high-fluence accelerated photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL). METHODS: This was a case report. RESULTS: A 79-year-old male patient with previous Descemet membrane endothelial keratoplasty presented with a corneal ulcer that was resistant to topical antimicrobial therapy and amniotic membrane placement. Fungal keratitis was diagnosed, and the cornea was on the verge of perforation. After over a month of topical and systemic therapy without marked improvement, the patient underwent 2 repeated high-fluence accelerated CXL procedures (7.2 J/cm2 using a UV irradiation of 30 mW/cm2 for 4 minutes) over an interval of 8 days (accumulated fluence of 14.4 J/cm2), which resulted in significant clinical improvement, with consolidation into a quiescent scar. CONCLUSIONS: PACK-CXL protocols delivering a total UV fluence of 5.4 J/cm2 (as per the original Dresden protocol for corneal ectasia cross-linking) can be an effective primary therapy for initial or superficial corneal infections because approximately half of the energy is absorbed in the first 100 µm of a riboflavin-soaked cornea. However, fungal keratitis may require higher fluences than 5.4 J/cm2 because, unlike ectatic corneas, corneal ulcers are not transparent, and the infection may involve deep stroma. This case illustrates how repeated high-fluence accelerated PACK-CXL can be used to successfully treat fungal keratitis resistant to conventional topical and systemic medications.

Clinical and microbiological analysis of fungal keratitis in Toronto, Canada: A 20-year study.

Fungal keratitis is a devastating and difficult-to-treat ocular infection with high morbidity. Understanding geographic microbiological and clinical trends helps to guide rapid and effective treatment. We therefore report the characteristics and outcomes of fungal keratitis in Toronto,ON Canada, over a 20-year period. An electronic search of microbiology records at University Health Network, Toronto, ON, Canada identified all patients with positive corneal fungal culture over a 20-year period seen at our tertiary referral cornea practice. Review of corresponding patient charts identified demographic and microbiological details, clinical course, treatment regimen, and final outcomes associated with each episode of culture-positive fungal keratitis. A total of 46 patients with 51 discrete fungal keratitis episodes were included. Five patients experienced recurrent fungal keratitis. Candida species accounted for 60.8% of positive fungal cultures, followed by Filamentous species at 35.3%. Preferred initial anti-fungal treatment was topical amphotericin at 36.7% followed by topical voriconazole at 32.6%. Surgical intervention was required in 48.9% with therapeutic penetrating keratoplasty being the most common procedure (22.4%). Final visual acuity (VA) of <20/200 was attributed to 58% of patients in this study. Risk factors for poor outcomes included poor VA, topical steroid use at presentation, Candida involvement, history of ocular surface disease, organic ocular trauma, or prior corneal transplantation. Candida is the most frequent keratomycotic pathogen in Toronto. Risk factors for poor visual outcome include prior corneal transplantation, ocular surface disease/trauma, or pre-existing topical steroid use. Early suspicion, diagnosis and treatment are paramount for best clinical outcomes. LAY SUMMARY: Fungal keratitis can cause severe vision loss without effective treatment. In Toronto, Candida had been the most common species over a 20-year period. Poor clinical outcome was associated with low presenting visual acuity, previous corneal transplant, topical steroid use, trauma, and Candida involvement.

Clinical characteristics of external bacterial ocular and periocular infections and their antimicrobial treatment patterns among a Ghanaian ophthalmic population.

Empirical antimicrobial therapy is linked to a surge in antimicrobial resistant infections. However, an insight on the bacteria etiology of ocular infections is essential in the appropriation of choice of antimicrobial among clinicians, yet there remains a dearth of data from Ghana. We investigated the bacteria etiology of external ocular and periocular infections and antimicrobial treatment patterns among a Ghanaian ophthalmic population. A multicenter study design with purposive sampling approach was employed. Patients demographics and clinical data were collated using a pretested structure questionnaire. Cornea specimens and conjunctival swabs were obtained for bacterial isolation following standard protocols. About 95% (98/103) of ocular samples were positive for bacteria culture. The proportion of Gram-negative bacteria was 58.2%, and the predominant bacteria species were Pseudomonas aeruginosa 38.8% and Staphylococcus aureus 27.6%. Conjunctivitis 40.0% and keratitis 75.0% were mostly caused by Pseudomonas aeruginosa. The routinely administered antimicrobial therapy were polymyxin B 41.2%, neomycin 35.1% and ciprofloxacin 31.6%. Participants demographic and clinical characteristics were unrelated with positive bacteria culture (p > 0.05). Our results showed a markedly high burden of ocular bacterial infections and variations in etiology. Bacterial infection-control and antimicrobial agent management programs should be urgently institutionalized to prevent the emergence of resistant infections.