Search Results (106)

Exophiala endophthalmitis of exogenous origin is an exceptionally rare but severe ocular infection, characterized by diagnostic delays, limited therapeutic guidance, and frequently poor outcomes. Herein, we report one new case of an 80-year-old woman who presented with severe fungal keratitis progressing to endophthalmitis two years after an uncomplicated cataract surgery. The condition was initially misdiagnosed and treated with topical antibiotics and corticosteroids. By cultivation, microscopy, histopathological, and PCR analysis of the samples, Exophiala dermatitidis was identified as the causative agent. Despite targeted antifungal therapy with voriconazole, the disease rapidly progressed, resulting in corneal perforation and evisceration of the affected eye. The number of confirmed cases of this infection remains very limited. To address this gap, we conducted a structured review of all reported instances of exogenous Exophiala endophthalmitis, in which Exophiala dermatitidis emerged as the predominant causative species. Common predisposing factors included corneal barrier disruption, ocular surgery, diabetes mellitus, and corticosteroid use. Diagnostic confirmation was frequently delayed, and treatment outcomes varied. Amphotericin B-based regimens were associated with poor results, whereas voriconazole, particularly when combined with surgical intervention, demonstrated more favorable outcomes. Exogenous Exophiala endophthalmitis remains underrecognized, with limited evidence to guide management. This entity should be considered in postoperative or trauma-associated intraocular inflammation, and current evidence supports azole-based therapy combined with surgical intervention when indicated. Full article

Rapidly progressive infectious keratitis may involve the anterior uveal tract and lead to anterior segment inflammation, resulting in severe structural damage of the cornea and potentially causing corneal perforation or endophthalmitis if not promptly treated. We report the case of a 63-year-old male admitted to the Emergency Ophthalmology Department of the University Clinical Center in Katowice, Poland, with a rapidly progressive corneal ulcer of the left eye that had not responded to two weeks of outpatient topical antibiotic therapy. The condition developed after ocular trauma sustained while chopping wood. At presentation, visual acuity was limited to light perception with preserved projection. Multimodal imaging, including slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal microscopy, revealed extensive corneal ulceration with severe stromal destruction, progressive corneal melting, and marked anterior segment inflammation, with an imminent risk of perforation. Microbiological cultures identified Pseudomonas aeruginosa. Despite intensive empiric topical antimicrobial therapy targeting both bacterial infection and a possible fungal component related to trauma with organic material, rapid clinical deterioration necessitated emergency therapeutic penetrating keratoplasty (PK). The procedure resulted in rapid resolution of inflammation and improvement in visual acuity, with best-corrected visual acuity (BCVA) reaching 0.3 logMAR during follow-up. At the three-month follow-up, the corneal graft remained clear with stable visual acuity and no recurrence of infection. The patient remains under regular long-term follow-up, with ongoing monitoring of graft clarity, intraocular pressure (IOP), and visual function. This case differs from routine presentations of infectious keratitis by demonstrating exceptionally rapid stromal melting despite promptly initiated empiric topical therapy. Multimodal imaging, particularly AS-OCT provided clinically meaningful information by revealing structural instability and an imminent risk of perforation not fully appreciable on slit-lamp examination, thereby supporting timely urgent keratoplasty. These findings highlight the practical diagnostic value of imaging-based assessment in advanced infectious keratitis and underscore its role in guiding surgical decision-making in eyes at high risk of corneal perforation. Full article

Background/Objectives: Fungal keratitis remains a vision-threatening infection, and current amphotericin B (AmphB) eye drops suffer from low corneal residence time, poor aqueous solubility, and the need for frequent dosing. This study develops electrospun nanofiber-based ophthalmic inserts combining polyvinyl alcohol (PVA), gamma-cyclodextrin (γ-CD), and sodium taurocholate (STC) to enhance AmphB solubility and provide a non-invasive, rapidly dissolving ophthalmic dosage form. Methods: γ-CD and STC-enhanced AmphB-loaded PVA nanofiber-based ophthalmic inserts with varying γ-CD and STC concentrations were prepared by electrospinning and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Drug content, in vitro release (Weibull modeling), antifungal activity against Candida albicans, Fusarium solani, and Aspergillus fumigatus, ocular cytocompatibility using the Hen’s Egg Test on Chorioallantoic Membrane (HET-CAM), and accelerated stability (40 ± 2 °C, 75 ± 5% relative humidity, 4 weeks) were evaluated. Results: Bead-free nanofibers with mean diameters between 216 ± 33 nm and 310 ± 35 nm were obtained, and XRD confirmed complete amorphization of AmphB within the PVA nanofiber matrix, forming an amorphous solid dispersion. All formulations showed rapid and nearly complete AmphB release (≈100% within 60 min), with Weibull β values < 0.75, indicating Fickian diffusion-controlled release. AmphB-loaded PVA nanofiber-based ophthalmic inserts produced inhibition zones and broth susceptibility profiles comparable to AmphB in dimethyl sulfoxide (DMSO), demonstrating preserved antifungal activity. HET-CAM scores (0–0.9) classified the inserts as practically non-irritant, and SEM/FTIR after accelerated storage showed no relevant morphological or physicochemical changes. Conclusions: These γ-CD and STC-enhanced AmphB-loaded PVA nanofiber-based ophthalmic inserts provide a non-invasive, rapidly dissolving ophthalmic dosage form that combines amorphous AmphB, immediate drug availability, and good ocular tolerance, supporting their further development as a patient-friendly treatment option for fungal keratitis. Full article

Background/Objectives: Infectious keratitis remains a major cause of blindness worldwide, and many cases progress to therapeutic keratoplasty despite advances in antimicrobial therapy. This systematic review aims to evaluate the outcomes of therapeutic keratoplasty in microbial keratitis and examine factors influencing anatomical success, graft survival, and visual rehabilitation. Methods: A systematic review was conducted following PRISMA guidelines, including English-language studies, published between 2000 and 2025. Studies with ≥10 eyes and ≥6 months follow-up were included. Data on infection control, graft clarity, anatomical success, visual acuity, and complications were extracted. Results: Fourteen studies encompassing 1527 eyes were analyzed. TPK accounted for 89% of procedures; DALK was used selectively for anterior or mid-stromal infections. Overall infection control ranged from 69 to 100%, with globe preservation in 85–100% of cases. Bacterial keratitis had higher cure rates and graft clarity than fungal or Acanthamoeba keratitis. Larger grafts (>8 mm) and deep stromal involvement were associated with increased graft rejection and postoperative complications. DALK offered higher graft survival and lower immunologic risk when the endothelium was spared. Visual outcomes were generally limited, reflecting preoperative disease severity, timing of surgery, and postoperative immunomodulation constraints. Early surgical intervention improved anatomical outcomes in severe fungal keratitis. Conclusions: Therapeutic keratoplasty is an effective globe-preserving intervention in advanced microbial keratitis, but with limited functional outcomes. Further prospective studies are needed to refine surgical indications, postoperative management, and long-term functional results. Full article

Natamycin, a polyene macrolide antifungal, has long been used as a food preservative and is the only Food and Drug Administration (FDA)-approved topical treatment for fungal keratitis. While its safety is supported by specific ergosterol interaction and minimal systemic absorption, current research mainly focuses on short-term effects, often overlooking long-term, developmental, and microbiome-related impacts. In food applications, questions remain about cumulative exposure and potential disruptions to gut microbiota. For ophthalmology, advanced delivery methods like nanocarriers and hydrogels enhance drug penetration but may alter pharmacokinetics and pose formulation challenges. Regulatory approvals have historically depended on established safe use and limited toxicological data, emphasizing the need for more systematic evaluations. Zebrafish (Danio rerio) represent a promising yet underutilized model for addressing significant gaps in research, particularly in the realms of microbiome studies, ocular health, developmental processes, and multigenerational effects. When paired with omics technologies, zebrafish facilitate comprehensive system-level mapping of drug-induced outcomes. This review consolidates existing evidence and positions zebrafish as a vital translational link between in vitro assays, mammalian models, and clinical practice. Additionally, it proposes a framework to ensure the effective and scientifically supported use of natamycin in both food and medicinal applications. Full article

Background/Objectives: Antimicrobial resistance (AMR) in ocular infections has become a serious concern with major implications for vision preservation. Bacterial AMR contributed to 4.71 million deaths worldwide in 2021, and ophthalmology mirrors these trends with multidrug resistance rates as high as 66% documented in some regions and persistently high methicillin resistance among common ocular pathogens. Across regions and care settings, traditional empiric therapies are losing effectiveness against an expanding range of pathogens, resulting in slower recovery, more complications, and, in many cases, permanent vision loss. This review aims to synthesize recent clinical, microbiologic, and pharmacologic evidence on ocular AMR, focusing on recent studies to capture current resistance patterns, therapeutic challenges, and evolving management strategies. Methods: Most included papers were published between 2020 and 2025, with additional foundational studies referenced where appropriate. Reports and systematic reviews addressing bacterial, viral, fungal, and parasitic ocular pathogens were evaluated to characterize current resistance mechanisms and management strategies across ocular pathogens. Results: The eye’s anatomic and physiologic barriers limit drug penetration, often promoting resistance and reducing therapeutic efficacy. Resistance mechanisms vary by pathogens; Pseudomonas keratitis is driven mainly by efflux pumps and biofilm formation, while CMV retinitis’ mutations in UL97 and UL54 are linked with clinical failure, and in MRSA associated Staphylococcus keratitis, the presence of mecA necessitates vancomycin-based therapy across bacterial, viral, fungal, and parasitic infections, with mechanisms such as β-lactamase production, efflux pump overexpression, target-site mutation, and biofilm formation contributing to poor response to standard therapy. MDR Pseudomonas keratitis remains the leading cause of rapidly progressive corneal infection with high risk of perforation and vision loss, while resistant CMV retinitis continues to threaten sight in immunocompromised patients despite antiviral advances. MDR organisms are recalcitrant to treatment and may lead to longer treatment courses and potentially worse outcomes and are discussed in detail within the manuscript. Conclusions: Ocular AMR represents an urgent and expanding clinical challenge. This review centers on the two most encountered multidrug-resistant organisms and their corresponding ocular sites, Pseudomonas aeruginosa (anterior segment) and CMV (posterior segment), while contextualizing them within the broader spectrum of resistant bacterial, viral, fungal, and parasitic pathogens. Despite growing awareness of AMR in ophthalmology, comprehensive surveillance data and longitudinal epidemiologic studies remain limited, making it difficult to track evolving resistance trends or guide region-specific therapy. Preserving vision in the AMR era will require faster diagnostics, improved ocular drug-delivery systems, and pathogen-specific therapies. Full article

Background/Objectives: Fungal keratitis (FK) is a current challenge in ophthalmology due to its association with severe visual impairment and the limitations of current antifungal therapies. We aim to evaluate the antifungal activity of essential oils (EOs) from the aromatic and medicinal plants Cymbopogon citratus and Lavandula pedunculata against selected FK pathogens collected from FK patients in two Portuguese hospitals. Methods: The antifungal activity of the EOs was tested at concentrations of 25%, 50%, 75%, and 100% for up to 7 days using the solid-phase disk diffusion in vitro assay. Results: Candida albicans was the most prevalent pathogen (28.6%), followed by Candida parapsilosis (21.4%) and Dicyma olivacea (14.2%). The other identified species were Aspergillus fumigatus and Scedosporium boydii (7.1%). Clinical diagnostic methodologies showed agreement with the molecular identification. Cymbopogon citratus EO showed higher antifungal activity than Lavandula pedunculata EO. The highest antifungal activity was observed against Aspergillus fumigatus and Scedosporium boydii (inhibition zone diameter, IZD = 90.0 mm) after 7 (Cymbopogon citratus EO) or 3 days of incubation (Lavandula pedunculata EO). While the antifungal activity of Cymbopogon citratus EO was maintained during the study (for Aspergillus fumigatus, Candida albicans, and Scedosporium boydii), the antifungal activity of Lavandula pedunculata EO decreased with time. Conclusions: Cymbopogon citratus EO and Lavandula pedunculata EO showed optimal antifungal activity against molds (Aspergillus fumigatus and Scedosporium boydii) after 3 days of incubation. Against yeasts (Candida albicans and Candida parapsilosis), the EOs showed lower activity. Our study sheds light on the development of new pharmacological strategies for FK based on EOs extracted from aromatic and medicinal plants. Full article

Background: Fungal keratitis remains a serious threat to vision, often progressing despite medical therapy and requiring surgical intervention. Therapeutic deep anterior lamellar keratoplasty (DALK) and therapeutic penetrating keratoplasty (TPK), are frequently required but carry risks of infection recurrence and graft rejection. As timely identification of the etiological agent is essential for improving the outcomes in infectious keratitis, in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) are instrumental in providing insights that can guide better therapeutic decision-making and improving outcomes in fungal keratitis. Case Description: We report the cases of two previously healthy patients (case one, 56-year-old woman; case two, 38-year-old man), who have presented in our service with unilateral infectious keratitis after ocular trauma with vegetable matter during outdoor activities, with a visual acuity of counting fingers and hand motion, respectively. Slit-lamp examination revealed unilateral extensive corneal infiltrates suggestive for fungal etiology in both cases. In vivo confocal microscopy (HRT-3, Heidelberg Retina Tomograph 3/Rostock Cornea Module, Heidelberg Engineering, Heidelberg, Germany) identified lesions suggestive for Candida Albicans and Acanthamoeba coinfection in case one and filamentous fungal keratitis in case two. Anterior segment optical coherence tomography (MS-39, CSO, Italy) was used to monitor the extent and morphology of the infiltrates. The patients underwent therapeutic DALK and TPK, respectively, with good results at the one-year follow-up. Conclusions: Our cases illustrate the advantages of incorporating IVCM and AS-OCT as complementary imaging techniques into clinical practice. IVCM and AS-OCT in fungal keratitis could lead to an earlier diagnosis, more accurate dynamic treatment response evaluation, and the identification of high-risk features for aggressive fungi for a more tailored medical and surgical management. Full article

The genus Alternaria comprises several species of dematiaceous hyphomycetes known to cause opportunistic infections in humans. Over the past two decades, fungal infections have emerged as a significant cause of morbidity and mortality, particularly among immunocompromised individuals. Such infections often occur following disruption of the skin or corneal epithelial barrier, especially in patients with pre-existing ocular conditions or compromised immune status. This case report describes a rare instance of fungal keratitis (FK) caused by Alternaria citri in a 71-year-old male who presented with an acute onset of eye infection. The patient showed a favorable response to treatment with voriconazole. Full article

Background: The study aimed to assess the diagnostic and therapeutic management of infectious keratitis at a tertiary referral center, focusing on how microbiological analysis influences clinical outcomes. Methods: A retrospective review was conducted on 220 patients (221 eyes) with infectious keratitis treated between November 2021 and January 2025. Data collected included clinical presentation, microbiological findings, treatment approaches, and outcomes. Statistical analyses examined the relationships between microbiological results, improvements in visual acuity, and the need for rescue surgery. Results: Bacterial keratitis accounted for 64% of cases, followed by viral (20%), fungal (13%), and Acanthamoeba (3%). Microbiological testing was performed in 107 cases, with a culture positivity rate of 75.7%. Positive microbiological findings were significantly associated with better visual acuity (p = 0.019) and a reduced, though not statistically significant, need for rescue surgery. Use of contact lenses and ocular trauma were independent risk factors for culture positivity. Delayed referral (more than 15 days) was linked to longer treatment durations and a higher likelihood of surgical intervention (p < 0.001). Microbiological diagnosis correlates with improved visual outcomes and a decreased need for surgical procedures. Conclusion: Early referral and targeted therapy are essential for optimizing prognosis. The use of contact lenses and cases of ocular trauma should prompt early diagnostic sampling. Full article

Fungal keratitis is a severe infection that often requires surgical intervention and is associated with poor outcomes. Penetrating keratoplasty allows for the complete removal of the fungal infiltrate and thus can be a turning point in therapy. The depth of pathogen invasion, which cannot always be reliably assessed by slit lamp examination, can be accurately determined through histological analysis of the corneal trephinate. In this study, we histologically analyzed two corneal trephinates obtained during an emergency keratoplasty performed for uncontrollable mycotic infections. In case 1, caused by Candida albicans, the infiltrate remained localized at the site of pathogen entry. In contrast, in case 2, Fusarium falciforme demonstrated extensive tissue invasion, spreading destructively throughout the cornea. This invasion pattern suggests that Fusarium keratitis is difficult to control due to its aggressive spreading behavior within the tissue. This explains the high rate of penetrating keratoplasty required in such cases. Full article

Background: Fungal keratitis is a serious ophthalmic problem due to low antifungal medication penetration and bioavailability at the ocular surface, necessitating novel delivery strategies for successful therapeutic outcomes. This study created amphotericin B-loaded silk fibroin nanoparticles (AmB-SFNs) as a targeted drug delivery platform for long-term ocular antifungal therapy. Methods: Silk fibroin-chitosan nanoparticles were produced using a precipitation technique, with chitosan coating for mucoadhesion and polyethylene glycol-400 surface stability. Clinical fungal isolates from keratitis patients were identified as species by morphological and molecular analysis, followed by in vitro antifungal susceptibility testing. Results: The optimized formulation produced spherical AmB-SFNs with an average diameter of 220 nm, a positive zeta potential of +34 mV, and a maximum amphotericin B entrapment effectiveness of 76%. Molecular identification confirmed that all five clinical isolates were Fusarium solani. AmB-SFNs showed strong antifungal activity against all tested isolates, with a minimum inhibitory dose of 50 μg/mL (0.25% w/v). Conclusions: The developed nanoparticulate system has optimal characteristics for enhanced corneal drug delivery, such as appropriate particle size for tissue penetration and mucoadhesive properties for prolonged ocular residence time, suggesting that this nanoparticulate system warrants further investigation in vivo to evaluate its potential for clinical translation in treating Fusarium keratitis and as a platform for topical ophthalmic therapies. Full article

Infectious keratitis (IK), including bacterial, fungal, parasitic, and viral etiologies, continues to represent a significant cause of ocular morbidity in the United States and around the world. Corneal scraping for smears and cultures remains the gold standard in diagnosing IK; however, molecular diagnoses, including metagenomic deep sequencing (MDS), are promising emerging diagnostic tools. Despite recent interest in procedural treatment such as riboflavin photoactivated chromophore corneal collagen cross-linking (PACK-CXL) and Rose Bengal photodynamic antimicrobial therapy (RB-PDAT), medical treatment advances have remained stagnant. Methods: This review highlights IK pathogens obtained from corneal cultures at Bascom Palmer Eye Institute (BPEI) from 2011 to 2021 and provides the current BPEI algorithms for initial management of IK or as a referred clinically worsening patient. The roles of corticosteroid therapy, PACK-CXL, and RB-PDAT for IK are also summarized. Results: A total of 9326 corneal cultures were performed at BPEI between 2011 and 2021, and only 3609 (38.7%) had a positive organism identified, of which bacteria were the most common (83.4%). Fortified vancomycin and tobramycin are recommended as first-line medical therapy for IK patients based on culture sensitivity data for the top Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria. PACK-CXL and RB-PDAT may benefit IK patients with corneal melting and fungal IK, respectively. Conclusions: Drug holidays, minimizing contamination, and optimizing sample order are crucial to maximizing corneal culture positivity. PACK-CXL and RB-PDAT are promising procedural advancements for IK therapy. Full article

To determine the incidence, causative organisms, and treatment effectiveness for microbial keratitis (MK) in the Southwest of England. Retrospective analysis of 872 corneal scrapes (January 2018–December 2022). Microbiology results were evaluated for organism growth and antimicrobial sensitivity. Data were divided into two groups for trend analysis (A: 2018–2020, B: 2021–2022). Of the 872 scrapes, 357 (39.6%) were culture positive. Bacteria accounted for 90.2% of cases, followed by viruses (2.8%), fungi (2.5%), mixed bacterial growth (2.5%), and Acanthamoeba (2.0%). The estimated incidence of MK was 9.69/100,000/year. Group B had a significantly higher overall MK incidence, with no change in pathogen distribution. Pseudomonas aeruginosa was the most frequent isolate (69 cases, 19.3%). In vitro sensitivity to fluoroquinolones was 94.4% for Gram-positive and 98.6% for Gram-negative bacteria. All fungal isolates were sensitive to at least one antifungal. Bacterial pathogens dominate MK in the Southwest of England, with over 90% sensitivity to chloramphenicol, fluoroquinolones, and aminoglycosides, indicating low antimicrobial resistance. Fluoroquinolones remain the recommended first-line therapy for MK. Fungal and protozoal keratitis are rare (<3% of cases), supporting bacteria-focused empirical treatment with close monitoring. Full article

Objectives: Microbial keratitis is a precursor to corneal scarring, the fifth-leading cause of blindness and visual impairment worldwide. Despite its significance, there is a paucity of data quantifying the recurrence rates of keratitis and the subsequent corneal damage. This study aims to address this gap by providing a comprehensive analysis of the frequency and origin of keratitis recurrences and its impact on visual deterioration. Methods: We retrospectively analyzed a cohort of 1303 patients diagnosed with microbial keratitis at the Independent Public University Eye Hospital in Warsaw, Poland, between January 2018 and December 2023. All adult patients with at least one documented episode of infectious keratitis were included in the study. Patients were divided into two cohorts: Group 1: patients with recurrent keratitis (n = 233) and Group 2: patients with the first episode of keratitis (n = 1070). Results: The recurrence rate of keratitis was 17.88% (233 of 1303 patients), regardless of etiology. Visual acuity on admission did not differ significantly between the recurrent and naïve groups. However, among patients with at least three episodes, visual acuity was worse (median logMAR for 1 vs. 2 vs. 3 recurrences were the following: 0.30 (0.08–0.67) vs. 0.60 (0.12–1.30) vs. 0.44 (0.20–0.92), accordingly, p = 0.049). Univariate logistic regression identified contact lens usage as a significant risk factor for recurrence (OR 2.37, 95% CI: 1.84–3.08, p < 0.001), also including its inappropriate use (OR 2.25, 95% CI: 1.42–3.66, p = 0.001). In terms of etiology, bacteria were the most common identified cause of keratitis in both the recurrent and naïve groups, accounting for 38.36% (90 cases) in Group 1 and 47% (503 cases) in Group 2. Viruses were the second most prevalent etiology, representing 31.33% (73 cases) in Group 1 and 19.91% (213 cases) in Group 2. Furthermore, a multivariate logistic regression model indicated that advanced age, delayed treatment, fungal etiology, and post-corneal transplant status were strongly associated with worse visual outcomes. Conclusions: Although each recurrence contributes to cumulative vision loss, the majority of patients with recurrent keratitis present with a useful visual acuity (0.3 to 0.60 logMAR). Our study identified older age, fungal etiology, delayed treatment, and post-keratoplasty keratitis as the most significant risk factors for visual deterioration. These findings underscore the need for targeted interventions in populations at higher risk of adverse visual outcomes. Full article