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Purpose: To elucidate a distinctive clinical feature in cases of microsporidial stromal keratitis (MSK)., Method: A retrospective observational study of cases with a histopathological and/or microbiological diagnosis of MSK on corneal biopsy or host corneal button between 2016 and 2022 was conducted., Results: Eighteen cases with a confirmed histopathological and/or microbiological diagnosis of MSK were detected. Careful review of slit-lamp photographs revealed the presence of pigmented keratic precipitates (KPs) beyond the area of stromal keratitis in five out of eighteen cases (27.7%)., Conclusion: The presence of pigmented KPs beyond the area of lesion can alert the clinician to keep microsporidia as a differential cause for stromal keratitis. Management can be tailored accordingly for a better outcome.

Purpose: To investigate the clinical features and visual outcome of infectious keratitis associated with orthokeratology (Ortho-K) lens in Korean pediatric patients., Methods: We retrospectively reviewed medical records of patients diagnosed with Ortho-K lens-related infectious keratitis from June 2005 to April 2020 at a tertiary referral hospital. Patients' demographics, clinical features, microbiological evaluation, and treatment methods were assessed, and factors related to final visual outcomes were analyzed., Results: The study included 26 eyes from 26 patients (19 female and 7 male patients; mean age, 11.9 years), with an average Ortho-K lens wear duration of 33.7 ± 21.2 months. The highest number of cases occurred in summer (11 of 26 cases, 42.3%). Central or paracentral corneal lesions were observed in 25 cases (96.2%), with a mean corneal epithelial defect size of 5.13 mm2. Pseudomonas aeruginosa was the most commonly isolated organism (n = 5), followed by Serratia marcescens (n = 4). All patients responded to medical treatment without needing surgical intervention. 72% of cases achieved favorable visual outcomes (Snellen best-corrected visual acuity [BCVA] >6 / 12), while 8% experienced severe visual impairment (Snellen BCVA ≤6 / 60) due to residual central corneal opacities. Multivariable analysis showed that non-summer seasons (p = 0.043), duration from symptom onset to presentation (p = 0.040), and corneal epithelial defect size (p = 0.002) were significantly associated with final logarithm of the minimum angle of resolution BCVA. Failed autorefraction at presentation due to an Ortho-K-related infectious keratitis lesion was a significant predictor of poor final visual outcome (Snellen BCVA ≤6 / 12; odds ratio, 38.995; p = 0.030)., Conclusions: Ortho-K lens-related infectious keratitis can lead to permanent corneal opacities and potentially devastating visual outcomes in children. Delayed time to presentation, large corneal lesions, failure of autorefraction, and non-summer seasons were associated with poorer outcomes. Proper education and early detection would be key to safe use of orthokeratology lenses in pediatric patients.

Competing Interests: Financial disclosures/conflicts of interest: None reported.

Purpose: The aim of this study was to evaluate the role of anterior segment optical coherence tomography during follow-up of infectious keratitis and to assess response to treatment., Methods: This was a prospective, consecutive, observational clinical series of cases. Twenty-three eyes of 23 patients with clinically proven fungal keratitis were included in the study. The patients received medical treatment according to clinical diagnosis, and follow-up was performed weekly. Slit-lamp examination and photography, and anterior segment optical coherence tomography were performed at initial and follow-up visits until corneal healing occurred. The main outcome measures included infiltrate depth, width, and density; central corneal thickness; minimal corneal thickness; corneal thickness at the site of the lesion; and stromal thickness at the center of the lesion., Results: Twenty-three eyes of 23 patients (17 men and 6 women), mean age 42.5 ± 19 (8-66) years, were clinically diagnosed with fungal keratitis. Localization was central in 14 cases and paracentral/peripheral in 9 cases. Healing time was 6 to 12 weeks. Minimal corneal thickness, corneal thickness at the site of lesion, and stromal thickness at the center of lesion, and also infiltrate width and depth changed significantly from the first visit to the healing stage at the last follow-up (0.009, 0.001, 0.007, 0.001, and <0.001, respectively)., Conclusions: In cases of fungal keratitis, anterior segment optical coherence tomography can provide the clinician with a quantitative assessment of a number of corneal parameters that can be used to determine effectiveness of therapy and confirm complete healing of the lesions that cannot be achieved by clinical evaluation., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To describe a patient diagnosed with Exophiala jeanselmei keratitis., Methods: We report a case of a patient who developed infectious keratitis following laser in situ keratomileusis and chronic topical steroid use for approximately six months in both eyes. An atypical infiltrate containing dark pigmentation was noted in the left eye on the initial presentation. During treatment, the infiltrates of the right eye began to exhibit a similar pigmentation., Results: Early treatment with topical antifungals was initiated in the left eye and later in the right eye once culture results returned. Both eyes recovered with good vision after approximately one month., Conclusions: Patients treated with postoperative topical corticosteroids should be cautioned of potential adverse effects of chronic use and have close follow-up. If infectious keratitis develops, particularly after two weeks, then atypical organisms, such as fungi, should be considered. In addition, our case highlights the significance of recognizing and associating dark-pigmentation with fungal etiologies., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Contact Lens Association of Ophthalmologists.)

To evaluate the efficacy of topical vancomycin and povidone iodine (PI) application on methicillin-resistant Staphylococcus aureus (MRSA) keratitis model in rabbits., MRSA keratitis was induced by injecting 0.1 mL MRSA containing 1000 colony-forming units (CFU) into central cornea of right eyes of 24 New Zealand White rabbits. Animals were divided into four groups ( n  = 6): control (treated with balanced salt solution), 50 mg/mL topical vancomycin, 5% topical PI, and combination; examined before and after treatment, and corneal tissues were harvested for analysis at 9th hour of treatment., Bacterial load was determined as: 7.63 ± 0.82 log10 CFU/g in control group, 6.95 ± 1.66 log10 CFU/g in PI group, 4.67 ± 0.77 log10 CFU/g in combination group, and 4.33 ± 0.71 log10 CFU/g in vancomycin group ( p  = 0.001). Median of total clinical score increased significantly from 7 [range: 5-8] to 11.5 [range: 11-15] ( p  = 0.001) in control group, did not change (6 [range: 5-8] to 7 [range: 5-7]; p  = 0.695) in vancomycin group, increased significantly from 7 [range: 5-8] to 12.5 [range: 10-14] ( p  < 0.001) in PI group, increased significantly from 6.5 [range: 5-7] to 8 [range: 7-9] in combination group ( p  = 0.002). Post-treatment clinical scores for chemosis, conjunctival injection, iritis, hypopyon, epithelial erosion, and corneal infiltrate were significantly lower in vancomycin-treated groups compared to others ( p  < 0.05). In PI-treated groups, especially scores for chemosis, conjunctival injection, epithelial erosion and corneal infiltrate were significantly higher than vancomycin ( p  < 0.05)., Topical vancomycin significantly inhibited bacterial growth in MRSA keratitis. However, PI was ineffective in controlling this growth; additionally, exerted toxic effect on ocular surface. When vancomycin was combined with PI, no additional increase in efficacy of treatment was detected compared to only vancomycin.

Purpose: An increase in fungal and particularly filamentous keratitis has been observed in many geographic areas, mostly in contact lens wearers. This study seeks to characterize long-term trends in fungal keratitis in a continental climate area to provide guidance for diagnosis and treatment., Design: Retrospective multicentric case series., Methods: Cases of microbiology-confirmed fungal keratitis from 2003 to 2022 presenting to tertiary care centers across Canada were included. Charts were reviewed for patient demographics, risk factors, visual acuity, and treatments undertaken., Results: A total of 138 patients were identified: 75 had yeast keratitis while 63 had filamentous keratitis. Patients with yeast keratitis had more ocular surface disease (79% vs 28%) while patients with filamentous keratitis wore more refractive contact lenses (78% vs 19%). Candida species accounted for 96% of all yeast identified, while Aspergillus (32%) and Fusarium (26%) were the most common filamentous fungi species. The mean duration of treatment was 81 ± 96 days. Patients with yeast keratitis did not have significantly improved visual acuity with medical treatment (1.8 ± 1 LogMAR to 1.9 ± 1.5 LogMAR, P = .9980), in contrast to patients with filamentous keratitis (1.4 ± 1.2 LogMAR to 1.1 ± 1.3 LogMAR, P = .0093)., Conclusions: Fungal keratitis is increasing in incidence, with contact lenses emerging as one of the leading risk factors. Significant differences in the risk factors and visual outcomes exist between yeast keratitis and filamentous keratitis which may guide diagnosis and treatment., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Purpose: To report on the outcomes of amniotic membrane transplantation (AMT) for corneal ulceration following infectious keratitis., Method: In this retrospective cohort study of 654 patients with culture-proven infectious keratitis from 8 hospitals in Galicia (Spain), a total of 43 eyes of 43 patients (6.6%) underwent AMT for postinfectious corneal ulceration. The indications for AMT were sterile persistent epithelial defects, severe corneal thinning or perforation., Results: AMT was successful in 62.8% of cases, with 37.2% requiring an additional surgery. Median time to healing was 40.0 days (IQR 24.2-101.7 days) and final BCVA was lower than baseline ( p  = 0.001). Ulcers were large (>3 mm) in 55.8% of cases. Previous herpetic keratitis and topical steroid use were more common in patients who received AMT ( p  < 0.001). 49 microorganisms (43 bacteria and 6 fungi) were isolated., Conclusions: AMT is a therapeutic option for complications following infectious keratitis, which present with a sterile persistent epithelial defect, significant corneal thinning or perforation.

Background/aims: To determine the clinical features, predisposing factors, and management of infectious keratitis caused by Candida spp., Methods: Retrospective chart review., Results: The medical records of 52 patients (54 eyes) with Candida keratitis were available for statistical analysis. Thinning of the corneal stroma was identified in 34 eyes (63.0%), and corneal perforation occurred in 16 eyes (29.6%). Corneal thinning and perforation were more common in Candida albicans compared with non-albicans ( P-val  < .001, P  = .09, respectively). The most common predisposing factors for Candida keratitis were topical steroid use (21 patients, 40.4%), previous corneal transplantation (17 patients, 32.7%), and preexisting ocular surface disease (15 patients, 28.8%). Fourteen eyes (25.9%) required cyanoacrylate glue application and 10 eyes (18.5%) underwent therapeutic penetrating keratoplasty (TPK)., Conclusion: Local immunosuppression and ocular surface disease play an important role in Candida keratitis. C. albicans appears to be more invasive compared with non-albicans spp.

Purpose: To describe the prevalence and antibiotic resistance profiles of Pseudomonas aeruginosa isolated from the Asia Cornea Society Infectious Keratitis Study (ACSIKS)., Methods: All bacterial isolates from ACSIKS underwent repeat microbiological identification in a central repository in Singapore. Minimum inhibitory concentration (MIC) determination was conducted for isolates of P. aeruginosa against thirteen antibiotics from 6 different classes, and categorized based on Clinical Laboratory Standard Institutes' reference ranges. The percentage rates of resistance (non-susceptibility) to each antibiotic included isolates of both intermediate and complete resistance. Multi-drug resistance (MDR) was defined as non-susceptibility to at least one agent in three or more antimicrobial classes., Results: Of the 1493 unique bacterial specimens obtained from ACSIKS, 319 isolates were of P. aeruginosa. The majority of isolates were from centers in India (n = 118, 37%), Singapore (n = 90, 28.2%), Hong Kong (n = 31, 9.7%) and Thailand (n = 30, 9.4%). The cumulative antibiotic resistance rate was the greatest for polymyxin B (100%), ciprofloxacin (17.6%) and moxifloxacin (16.9%), and lowest for cefepime (11.6%) and amikacin (13.5%). Isolates from India demonstrated the highest antibiotic resistance rates of all the centers, and included moxifloxacin (47.5%) and ciprofloxacin (39.8%). Forty-eight of the 59 MDR isolates also originated from India. Antibiotic resistance rates were significantly lower in the other ACSIKS centers, and were typically less than 10%., Conclusions: The antibiotic resistance profiles of P. aeruginosa varied between different countries. While it was low for most countries, substantial antibiotic resistance and a significant number of multi-drug resistant isolates were noted in the centers from India., (© 2024. The Author(s).)

Rationale: Compared with intraocular tuberculosis, ocular tuberculosis with ocular surface involvement is rare. Corneal involvement in ocular tuberculosis may include interstitial keratitis or peripheral ulcerative keratitis. We report a case of peripheral ulcerative keratitis directly caused by tuberculosis., Patient Concerns: A 20-year-old man complained of vision loss and pain in the left eye that had lasted for 1 week. A slit lamp examination of the left eye showed a corneal epithelial defect, interstitial corneal edema, and a white irregular infiltrative lesion and ulcer (with the dimension of 2 × 2.5 mm) in the inferior temporal region., Diagnoses: The corneal ulcer was scraped, and the Mycobacterium tuberculosis deoxyribonucleic acid polymerase chain reaction was positive., Interventions and Outcomes: After a month of oral antituberculosis treatment, the corneal ulcer resolved, and the intraocular inflammation improved., Lessons: Peripheral ulcerative keratitis secondary to tuberculosis can be directly caused by M tuberculosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Infectious keratitis is a leading cause of corneal blindness worldwide with little information known about causative etiologies in Malawi, Africa. This area is resource-limited with ophthalmologist and microbiology services. The Department of Ophthalmology at the Kamuzu College of Health Sciences in Blantyre, Malawi, is a participating site of an international corneal ulcer consortium, capriCORN (Comprehensive Analysis of Pathogens, Resistomes, and Inflammatory-markers in the CORNea). In this study, 50 patients with corneal ulcers were swabbed for pathogen identification using RNA-sequencing. Corneal trauma was reported in 41% and 19% of the patients worked in agriculture. A pathogen was identified in 58% of the cases. Fungal pathogens predominated, followed by viruses and bacteria. Aspergillus, Fusarium, HSV-1, and Gardnerella were the most common pathogens detected. 50% of patients reported treatment with an antibiotic before presentation. Pathogens unusual for infectious keratitis, such as Subramaniula asteroids, Aureobasidium pullulans, and Gardnerella vaginalis, were also detected.

Objectives: The objective of the study was to identify bacterial pathogens and their antimicrobial sensitivity profile associated with cases of canine progressive ulcerative keratitis., Materials and Methods: Analysis of microbial culture and sensitivity results from dogs with progressive ulcerative keratitis presenting to a UK referral practice between December 2018 and August 2020., Results: Positive bacterial cultures were obtained from 80/148 (54%) of the canine ulcers sampled with 99 bacterial isolates cultured. Streptococcus canis (n = 29), Pseudomonas aeruginosa (n = 19), and Staphylococcus pseudintermedius (n = 16) were the most common isolates. Pseudomonas aeruginosa was more likely to be isolated whether the ulcer was clinically malacic at the time of sampling (OR = 10.1, p < .001). Ulcers treated prior to culture with fusidic acid were 7.6 times more likely to be positive than those treated with any other antimicrobial(s). Bacterial isolates demonstrated resistance against neomycin (85%), fusidic acid (78%), and tetracycline (68%). Conversely, isolates were most likely to be sensitive to gentamicin (88%), ofloxacin (77%), ciprofloxacin (73%), and chloramphenicol (64%). Antimicrobial combinations of chloramphenicol or gentamicin with a fluoroquinolone (ofloxacin or ciprofloxacin) or chloramphenicol combined with gentamicin were the most effective on in vitro analysis (over 90% susceptibility of all isolates)., Conclusion: The most common bacterial species associated with canine progressive ulcerative keratitis in a UK referral population were S. canis, P. aeruginosa, and S. pseudintermedius. Combination antimicrobial therapy is recommended pending culture and sensitivity results given the varied antimicrobial susceptibility profiles and significant bacterial in vitro resistance to antimicrobial monotherapy., (© 2023 American College of Veterinary Ophthalmologists.)

Purpose: To report the first case of Rhizopus sp keratitis in a 15-year-old male patient who had undergone a conventional Epi-off CXL procedure for progressive keratoconus., Methods: A 15-year-old male studying at school presented with defective vision in both eyes recently. He was diagnosed with progressive keratoconus in the right eye more than left eye. After the conventional CXL procedure, the patient developed corneal ulcer on third postoperative day., Results: The microbiological diagnosis of both BCL and ulcer revealed Rhizopus sp. The patient responded to topical antifungals, and the ulcer entirely healed with a large central scar., Conclusion: Rhizopus keratitis is rare in a healthy individual. Ours is the first case report of Rhizopus keratitis in patient undergone CXL., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To describe the first case of Pythium insidiosum keratitis masquerading as dematiaceous fungal keratitis in a seropositive male., Case Summary: A 44-year-old seropositive male previously treated for acute retinal necrosis presented with pain and defective vision in the right eye following a mud injury 5 days back. Presenting visual acuity was hand movements close to the face. Ocular examination revealed a 7 × 7 mm dense, greyish-white mid stromal infiltrate with pigmentation and few tentacles. The clinical diagnosis suggested fungal keratitis. Corneal scraping on 10% KOH and Gram stain revealed slender, aseptate hyaline hyphae. Before culture results, the patient was treated with topical 5% natamycin and 1% voriconazole, but the infiltrate progressed. Culture on 5% sheep blood agar revealed white fluffy, submerged, shiny, and appressed colonies, and Pythium insidiosum was confirmed by zoospore formation. The patient was further managed with topical linezolid 0.2% hourly, azithromycin 1% hourly, and adjuvant drugs., Conclusion: This is an uncommon presentation of Pythium keratitis masquerading as dematiaceous fungal keratitis in an immunocompromised male.

Purpose: Fungal keratitis (FK) is an invasive corneal infection associated with significant risk to vision. Although the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway has been recognized for its role in defending against viral infections, its involvement in FK still remains largely unclear. This study sought to elucidate the contribution of the cGAS/STING signaling pathway to the pathogenesis of FK., Methods: The expression of cGAS/STING signaling components was assessed in a murine model of Candida albicans keratitis through RNA sequencing, western blot analysis, immunofluorescence staining, and real-time PCR. Both genetic (utilizing Sting1gt/gt mice) and pharmacological (using C176) interventions were employed to inhibit STING activity, allowing for the evaluation of resultant pathogenic alterations in FK using slit-lamp examination, clinical scoring, hematoxylin and eosin (H&E) staining, fungal culture, and RNA sequencing. Subconjunctival administration of the NOD-like receptor protein 3 (NLRP3) inflammasome inhibitor MCC950 was performed to evaluate FK manifestations following STING activity blockade. Furthermore, the impact of the STING agonist diABZI on FK progression was investigated., Results: Compared to uninfected corneas, those infected with C. albicans exhibited increased expression of cGAS/STING signaling components, as well as its elevated activity. Inhibiting cGAS/STING signaling exacerbated the advancement of FK, as evidenced by elevated clinical scores, augmented fungal load, and heightened inflammatory response, including NLRP3 inflammasome activation and pyroptosis. Pharmacological inhibition of the NLRP3 inflammasome effectively mitigated the exacerbated FK by suppressing STING activity. Conversely, pre-activation of STING exacerbated FK progression compared to the PBS control, characterized by increased fungal burden and reinforced inflammatory infiltration., Conclusions: This study demonstrates the essential role of the cGAS/STING signaling pathway in FK pathogenesis and highlights the necessity of its proper activation for the host against FK.

Background: Ochrobactrum anthropi is widely distributed and primarily infects patients with compromised immune functions . Historically, O. anthropi has been considered to possess low toxicity and pathogenicity; however, recent studies suggest that it may in fact cause severe purulent infections. In this case study, we examine a case of O. anthropi infection following corneal transplantation, exploring the occurrence and outcomes of such post-operative infections., Case Presentation: A retrospective analysis of cases involved examinations, genetic testing for diagnosis, and subsequent treatment. In patients undergoing partial penetrating keratoplasty with a fungal corneal ulcer perforation, anterior chamber exudation and purulence were observed post-surgery. Despite antifungal treatment, genetic testing of the anterior chamber fluid and purulent material confirmed O. anthropi infection. The use of antimicrobial treatment specifically targeting O. anthropi was found to be effective in treating the infection., Conclusion: Inflammatory reactions following corneal transplantation should be should be monitored for the presence of other infections. Genetic testing has significant implications for clinical diagnosis and treatment., (© 2024. The Author(s).)

Purpose: Pseudomonas aeruginosa-induced keratitis is one of the most severe and challenging forms of corneal infection, owing to its associated intense inflammatory reactions leading to corneal necrosis and dense corneal scar with loss of vision. Since mesenchymal stem cells (MSCs) are reported to possess antimicrobial and immunomodulatory properties, they can be tested as an adjuvant treatment along with the antibiotics which are the current standard of care. This study aims to investigate the anti-bacterial and immunomodulatory roles of human bone marrow MSC-derived conditioned medium (MSC-CM) in P. aeruginosa-infected human corneal epithelial cells (HCECs) in vitro., Methods: The effect of MSC-CM on the growth of clinical isolates of P. aeruginosa was evaluated by colony-forming unit assay. The expression of inflammatory cytokines (IL-6 and TNF-α) and an antimicrobial peptide (Lipocalin 2) in lipopolysaccharide-treated MSCs and HCECs was analyzed through ELISA. Corneal epithelial repair following infection with P. aeruginosa was studied through scratch assay., Results: Compared to control (P. aeruginosa (5*10 5 ) incubated in DMEM (1 ml) at 37 °C for 16 h), MSC-CM significantly: i) inhibits the growth of P. aeruginosa (159*10 9 vs. 104*10 9  CFU/ml), ii) accelerates corneal epithelial repair following infection with P. aeruginosa (9% vs. 24% closure of the wounded area after 12 h of infection), and iii) downregulates the lipopolysaccharide-induced expression of IL-6, TNF-α and Lipocalin 2 in HCECs. A combination of MSC-CM with an antibiotic, Ciprofloxacin moderately regulated the expression of IL-6, TNF-α, and Lipocalin 2., Conclusion: MSC-CM holds promise as an adjunctive therapeutic approach for P. aeruginosa-induced corneal epithelial damage., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To evaluate and compare the results of the conjunctival flap (CF) and cryopreserved amniotic membrane graft (AMG) in the management of fungal corneal ulcers either with complications or non-responsive to medical treatment., Study Design: A retrospective observational study., Methods: Medical records of 30 patients with culture-positive fungal corneal ulcer treated with either CF or AMG (15 eyes in each group) in real world settings were retrieved for analysis. After the surgical procedure, patients were followed up on days 1, 7, 14, 21, 30, 60, 90, 120, and 180 to explore the outcomes of the operations along with complications., Results: Infecting fungi were of genus Fusarium (n = 11), Aspergillus (n = 10), Mucor (n = 4) and Penicillium (n = 10). The most common indication was resistant ulcer with perforation. After the procedure, epithelization was completed in 11(73.33%) patients in the CF, and 13 patients in the (86.67%) AMG group. Visual acuity improvement was significantly better in the latter group (CF: 1 [6.67%] vs. AMG: 7 [46.67%], p = 0.023). Flap failure occurred in 4 patients (26.67%) from the CF and 2 (13.33%) from the AMG group. No significant differences were found between the two groups regarding success rate (p = 0.651), epithelialization time (p = 0.691), healing of corneal ulcer (p = 0.651), and postoperative stability (p = 0.651) of the flaps., Conclusions: CF and AMG are both effective for the management of refractory fungal corneal ulcers. However, AMG appears to improve visual acuity better than CF., (© 2024. Japanese Ophthalmological Society.)

Background: To assess the long-term incidence and risk factors for post-keratoplasty infectious keratitis (IK), associated ocular pathogens, and antibiotic resistance profiles., Methods: Cohort study including 2553 consecutive penetrating, endothelial, and anterior lamellar keratoplasties performed between 1992 and 2020. Medical and microbiological records of patients clinically diagnosed with IK were retrospectively reviewed., Main Outcome Measures: cumulative incidence of IK, infectious agent species, and antibiotics resistance profiles., Results: The average follow-up time after transplantation was 112 ± 96 months. Eighty-nine IK episodes were recorded; microbiological tests were positive in 55/89 (62%). The cumulated incidence of postoperative IK was 5.50%/10.25% at 10/20 years. The occurrence of at least one episode of IK after transplantation was associated with lower graft survival in the long term (p < 0.0001). Rejection risk (adjusted Hazard Ratio, 2.29) and postoperative epithelial complications (HR, 3.44) were significantly and independently associated with a higher incidence of postoperative IK. Infectious agents included 41 bacteria, 10 HSV, 6 fungi, and 1 Acanthamoeba. The rate of antibiotic resistance was 0% for vancomycin, 13% for fluoroquinolones, 20% for rifamycin, 59% for aminoglycosides, and 73% for ticarcillin. In 41% of cases, patients were under prophylactic topical antibiotics before the infectious episode. Topical antibiotics were significantly associated with increased resistance to penicillin, carbapenems, and aminoglycosides., Conclusion: IK (mainly bacterial) is a frequent complication of corneal transplantation in the long term. Vancomycin and fluoroquinolones can be considered as first-line treatments. Prolonged postoperative antibiotic preventive treatment is not advisable as it may increase antibiotic resistance., (© 2024 The Authors. Clinical & Experimental Ophthalmology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Ophthalmologists.)

Purpose: To describe the bacterial findings by a targeted sequencing approach from corneal samples of patients with microbial keratitis and factors influencing culture outcome of indirectly inoculated corneal specimen., Methods: Prospective inclusion of patients fulfilling predefined criteria of microbial keratitis. Samples from the corneal lesion were collected and dispensed in liquid transport medium, from which both culture and targeted amplification and sequencing of the V3-V4 region of the 16S rRNA gene were carried out. Additional standard corneal culture from the corneal lesions was also performed. Factors influencing culture outcome of indirectly inoculated corneal samples were identified by a multivariate regression model incorporating quantitative data from sequencing., Results: Among the 94 included patients with microbial keratitis, contact lens wear (n = 69; 73%) was the most common risk factor. Contact lens wearers displayed significant differences in the bacterial community composition of the corneal lesion compared to no lens wearers, with higher abundance of Staphylococcus spp., Corynebacterium spp., and Stenotrophomonas maltophilia. Targeted sequencing detected a potential corneal pathogen in the highest proportional abundance among 9 of the 24 (38%) culture-negative patients with microbial keratitis. Age, bacterial density in the sample, and prior antibiotic treatment significantly influenced culture outcome of indirectly inoculated corneal samples., Conclusion: Targeted sequencing may provide insights on pathogens in both culture negative episodes of microbial keratitis and among subgroups of patients with microbial keratitis as well as factors influencing culture outcome of indirectly inoculated corneal samples., (© 2023. The Author(s).)

Purpose: Microbial keratitis is a sight-threatening condition with a higher incidence in agrarian populations. In countries with a high indigent population, due to financial and other constraints, patients prefer to seek therapy locally rather than travel to advanced centres. The aim of this study is to describe the epidemiology, clinical characteristics, and outcomes of 60 consecutive patients with microbial keratitis managed at a rural centre., Methods: Descriptive case series. All patients clinically diagnosed with infectious keratitis were included. Corneal scrapings were obtained and microbiological identification was done by Gram stain. Anti-microbial therapy was commenced based on smear findings and the patients were followed up till disease resolution., Results: Sixty eyes of 60 patients were diagnosed with microbial keratitis in the study period. The mean age was 47.43 ± 18.69 years. Male:female ratio was 47:53. Risk factors included ocular trauma in the majority of patients (46/60; 76.7%). Microorganisms were identified on 75.6% of smears, with fungal filaments (65.4%) being the most common. Ulcers were central in over half (32/60; 53.3%), and > 3 mm in diameter in over three-fourths (81.6%) of patients. Forty-four patients (73.3%) achieved treatment success whereas 16/60 (26.6%) required referral to our tertiary-eye care facility for management. The median time to resolution was 14 days (IQR 10-26 days)., Conclusion: Our series demonstrates the feasibility of microbiology-guided therapy in microbial keratitis by ophthalmologists at the secondary rural eye-care level. Two-thirds of the patients could be successfully managed at the rural centre and only severe cases needed a referral to tertiary centres., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

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.

Purpose: To compare the efficacy and rapidity of direct microscopic detection of fungal elements from corneal ulcers between 10% potassium hydroxide (KOH) and 1% Chicago Sky Blue 6B (CSB) in 10% KOH (CSB-KOH)., Methods: Thirty patients with clinically suspected fungal keratitis were recruited. Participants with impending corneal perforation were excluded. Two slides were smeared with corneal ulcer scrapings from the ulcer's edge and base for comparison of fungal staining solutions. One slide was infused with KOH, and the other slide was filled with CSB-KOH. Additional scraping was collected for inoculation on Sabouraud dextrose agar for fungal culture. The sensitivity, specificity and rapidity of both stainings were analyzed., Results: The sensitivity of fungal culture, KOH, and CSB-KOH were 43.75% (95% confidence interval [CI], 19.75%-70.12%), 62.50% (95% CI, 35.43%-84.80%), and 87.50% (95% CI, 61.65%-98.45%), respectively. The specificity were 100% (95% CI, 69.15%-100%) of both stainings and fungal culture which analyzed from 16 fungal keratitis cases by laboratory and clinical diagnosis. Mean CSB-KOH examination time was quicker than KOH with the mean time difference of 5.6 minutes (95% CI, 3.22-7.98 minutes) and p-value &lt; 0.001., Conclusions: CSB-KOH was more effective and faster than KOH in detecting fungal elements from corneal ulcers. Therefore, CSB-KOH may be beneficial in diagnosing fungal keratitis and preventing blindness. Moreover, to the best of our knowledge, this is the first use of CSB stain in fungal keratitis detection.

Purpose: The aim of this study was to validate the C-DU(KE) calculator as a predictor of treatment outcomes on a data set derived from patients with culture-positive ulcers., Methods: C-DU(KE) criteria were compiled from a data set consisting of 1063 cases of infectious keratitis from the Steroids for Corneal Ulcer Trial (SCUT) and Mycotic Ulcer Treatment Trial (MUTT) studies. These criteria include corticosteroid use after symptoms, visual acuity, ulcer area, fungal etiology, and elapsed time to organism-sensitive therapy. Univariate analysis was performed followed by multivariable logistic regressions on culture-exclusive and culture-inclusive models to assess for associations between the variables and outcome. The predictive probability of treatment failure, defined as the need for surgical intervention, was calculated for each study participant. Discrimination was assessed using the area under the curve for each model., Results: Overall, 17.9% of SCUT/MUTT participants required surgical intervention. Univariate analysis showed that decreased visual acuity, larger ulcer area, and fungal etiology had a significant association with failed medical management. The other 2 criteria did not. In the culture-exclusive model, 2 of 3 criteria, decreased vision [odds ratio (OR) = 3.13, P < 0.001] and increased ulcer area (OR = 1.03, P < 0.001), affected outcomes. In the culture-inclusive model, 3 of 5 criteria, decreased vision (OR = 4.9, P < 0.001), ulcer area (OR = 1.02, P < 0.001), and fungal etiology (OR = 9.8, P < 0.001), affected results. The area under the curves were 0.784 for the culture-exclusive model and 0.846 for the culture-inclusive model which were comparable to the original study., Conclusions: The C-DU(KE) calculator is generalizable to a study population from large international studies primarily taking place in India. These results support its use as a risk stratification tool assisting ophthalmologists in patient management., Competing Interests: V.L. Perez has financial relationships with Alcon, Dompe, EyeGate, Kala, Trefoil, Novartis, and Oculis. The remaining authors have no conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Fungal keratitis is a major cause of corneal blindness worldwide. Compared to other types of infectious keratitis, fungal keratitis has a relatively poor prognosis because of various factors such as delayed patient presentation and diagnosis. Although associated in earlier studies with poverty and low socioeconomic status, military personnel stationed in tropical and subtropical climates, in low-resource settings, are at risk. Here, we report a case of a 20-year-old active duty contact lens-wearing military service member stationed at Guantanamo Bay who developed a severe vision-threatening fungal keratitis in her left eye. Enhancing health and safety precautions in at-risk settings, maintaining vigilance, and leveraging new imaging modalities will be important to ensure early recognition and treatment., (Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2023. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

The treatment of fungal keratitis (FK) is challenging due to the subacute indolent course, and initial misdiagnosis. In this retrospective case series, we highlight both the diagnostic and therapeutic roles of corneal biopsy together with amniotic membrane transplantation (AMT) in patients with refractory clinically presumed FK. Debulking biopsy and tectonic AMT were performed during the initial presentation. Biopsy specimens were sent for KOH smears and cultures. After KOH smears confirmed the presence of fungal elements, topical voriconazole 1% was prescribed for the first 72 h then tailored according to the clinical response and the culture results. The outcome measures were complete resolution of infection and restoration of corneal integrity. Cases associated with culture proven bacterial keratitis were excluded. Twelve cases were included in the study. KOH smears confirmed the presence of fungal growth in all specimens. Cultures grew Aspergillus in 6/12 cases, sensitive to voriconazole (5/6) and amphotericin (3/6); Fusarium (4/12), sensitive to both voriconazole and amphotericin; and no growth in 2/12 cases. Amphotericin 0.15% eye drops were added to the 7 cases with proven sensitivity and to the remaining 2 culture negative cases. Gradual resolution of infection was seen in all cases after 35.6 ± 7.8 days. In FK, a debulking biopsy simultaneously with AMT help decrease the microbial load, suppress the inflammatory process, support the corneal integrity, confirm the presence of fungal pathogen., (© 2024. The Author(s).)

Purpose: To analyze the influence of infiltrate size, depth, and organism on the outcome of microbial keratitis., Design: Retrospective comparative study., Methods: Medical records of patients with infective keratitis, who reported from January 2015 to December 2019 to a tertiary eye care center, were analyzed. Size and depth of ulcer at presentation were the factors used to group patients, and the influence on the outcome of the organism causing it was analyzed. Grouping was as follows: group A: ulcer size <6 mm/anterior to midstromal infiltrate, group B: ulcer < 6 mm/full-thickness infiltrate, group C: ulcer >6 mm/anterior to midstromal infiltrate, group D: ulcer > 6 mm/full-thickness infiltrate. Patients with viral keratitis or unidentified organism were excluded. Response to treatment and best-corrected visual acuity (BCVA) at the final follow-up were the outcome measures., Results: In the study, 1117/6276 patients were included, with 60.8% patients in group A. A significant improvement in visual acuity was noted in groups A/B compared to groups C/D. Group A had the best response to medical management, irrespective of the organism. Higher risk for surgery was noted in group C compared to group B, with group A as the reference. Overall resolution with medical treatment was noted in 70% miscellaneous keratitis, 64.8% bacterial keratitis, 64.3% mixed keratitis, 62.5% acanthamoeba keratitis, 52.6% fungal keratitis, and 12.1% Pythium keratitis. Bacteria and acanthamoeba responded better to medical management than fungal keratitis, whereas Pythium had the highest risk for surgery., Conclusion: An interplay between virulence of the organism along with depth and size of the infiltrate determines the outcome of microbial keratitis., (Copyright © 2023 Copyright: © 2023 Indian Journal of Ophthalmology.)

Bacterial keratitis is a vision-threatening infection of the cornea that is typically treated with antibiotics. However, antibiotics sometimes fail to eradicate the infection and do not prevent or repair the damage caused directly by the bacteria or the host immune response to the infection. Our group previously demonstrated that treatment of Pseudomonas aeruginosa keratitis in rabbits with innovative cold atmospheric plasma (iCAP) resulted in reduced edema, ulcer formation, and bacterial load. In this study, we investigated the efficacy of iCAP treatment in methicillin-resistant Staphylococcus aureus (MRSA). New Zealand white rabbits were infected intrastromally with MRSA then treated with iCAP, moxifloxacin, vancomycin, or combination of iCAP with each antibiotic to assess the safety and efficacy of iCAP treatment compared to untreated controls and antibiotics. iCAP treatment significantly reduced bacterial loads and inflammation, improved anterior chamber clarity, and prevented corneal ulceration compared to untreated controls and antibiotic treatment. Safety assessments of grimace test scores and tear production showed that iCAP was not significantly different from either antibiotic treatment in terms of distress or tear production. Combination iCAP/antibiotic treatment did not appear to provide significant added benefit over iCAP alone. Our findings suggest that the addition of iCAP may be a viable tool in reducing damage to the cornea and anterior chamber of the eye following S. aureus keratitis., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: To summarize the evidence base on the use of topical corticosteroids for infectious keratitis., Methods: Narrative review., Results: Infectious keratitis is a painful condition that often results in visually significant corneal stromal scarring, even when antimicrobial therapy is successful. Corticosteroids may reduce inflammation and subsequent scar formation and while relieving the acute ocular pain associated with a corneal ulcer. However, corticosteroids also reduce the host immune response, which could hinder the ability to clear infection. The safety and effectiveness of corticosteroids depends to a large part on the efficacy of the antimicrobials being used to treat the underlying infection. Randomized trials have found that corticosteroids are safe and effective for herpetic keratitis when used with appropriate antiviral therapy, and are safe for bacterial keratitis when used with broad spectrum topical antibiotics. The effectiveness of corticosteroids for bacterial keratitis has not been shown conclusively, although more advanced bacterial corneal ulcers may do better with corticosteroids. No randomized trials have assessed the safety and effectiveness of steroids for fungal or acanthamoeba keratitis. Animal studies suggest corticosteroids may be harmful in fungal keratitis, and observational human studies have found that steroids are harmful for fungal and acanthamoeba keratitis when started prior to anti-amoebics., Conclusions: Topical corticosteroids, when used as an adjunct to antimicrobial therapy, may be beneficial if the antimicrobial being used can effectively clear or suppress the infection, such as in bacterial and herpetic keratitis. Randomized trials would be helpful to further delineate the role of corticosteroids for infectious keratitis., Competing Interests: The author has no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To determine the demographic and microbiological profile involved in the causation of corneal ulcers in Eastern India during the COVID era., Method: Patients presenting with corneal ulcers fulfilling the inclusion and exclusion criteria were taken as the case. The study duration was from January 2021 to December 2021. Socio-demographic details and information about risk factors were noted. A detailed corneal examination followed by corneal scraping was performed for microbiological evaluation., Results: In 1 year, 99 infective corneal ulcer patients were evaluated. Farmers (24.2%) were found to be maximally affected by corneal ulcers. The peak in cases was recorded from October to December (38.4%). Ocular trauma was the commonest risk factor (42.4%). The majority (80.8%) of patients were already on some topical antimicrobials. 22.2% of samples showed fungal filaments on KOH mount; 54.5% of these cases turned out to be culture-positive. 17.56% of KOH-negative samples turned out to be culture-positive (fungal). Overall, the culture positivity rate was 28.28% out of which fungal isolates were 89.28% and bacterial isolates were 10.72%. Fusarium species were identified as the most common organism contributing 42.85%, followed by Aspergillus fumigatus (14.28%). 10.72% of cases were culture positive for Pseudomonas aeuroginosa., Conclusion: Trauma with the organic matter was the predominant cause of fungal keratitis. In this study, fungal keratitis was found to be more common. Fusarium was the most common isolate., Competing Interests: None

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., (© 2023 American College of Veterinary Ophthalmologists.)

Purpose: To study epidemiological data, laboratory results, and risk factors associated with microbial keratitis., Methods: We conducted a retrospective study of corneal sample cultures from patients with microbial keratitis from January 2010 to December 2019. Results were analyzed according to the etiological diagnosis of bacterial, mycotic, or parasitic infection and were associated with related risk factors., Results: We analyzed 4810 corneal samples from 4047 patients (mean age 47.79 ± 20.68 years; male 53.27%). The prevalence of bacterial, fungal, and Acanthamoeba infections were 69.80%, 7.31%, and 3.51%, respectively. The most frequently isolated bacteria were coagulase-negative Staphylococcus (CoNS) (45.14%), S. aureus (10.02%), Pseudomonas spp. (8.80%), and Corynebacterium spp. (6.21%). Among CoNS, the main agent was S. epidermidis (n=665). For mycotic keratitis, Fusarium spp. (35.42%) and Candida parapsilosis (16.07%) were the most common agents among filamentous and yeasts isolates, respectively. Contact lens use was associated with a positive culture for Acanthamoeba spp. (OR = 19.04; p < 0.001) and Pseudomonas spp. (OR = 3.20; p < 0.001). Previous ocular trauma was associated with positive fungal cultures (OR = 1.80; p = 0.007), while older age was associated with positive bacterial culture (OR = 1.76; p = 0.001)., Conclusions: Our findings demonstrated a higher positivity of corneal sample cultures for bacteria. Among those, CoNS was the most frequently identified, with S. epidermidis as the main agent. In fungal keratitis, Fusarium spp. was the most commonly isolated. Contact lens wearers had higher risks of positive cultures for Acanthamoeba spp. and Pseudomonas spp. Ocular trauma increased the risk of fungal infection, while older age increased the risk of bacterial infection.

The epidemiology of corneal ulcers in Vietnam has not been well characterized. In this report, we reviewed retrospectively the microbiological data of patients with a clinical diagnosis of corneal ulcer at the microbiology laboratory of Vietnam National Eye Hospital from January 1, 2010 to March 31, 2023. We observed a seasonal pattern for fungal and microsporidial keratitis, with an annual peak in November, and an inverse relationship between fungal keratitis and inclement weather. The November peak coincided with one of the major harvesting seasons in Vietnam. We also observed increasing numbers of microsporidial and Acanthamoeba keratitis cases in recent years. Knowledge of these trends are helpful in guiding empirical treatment of corneal infections and preventing corneal blindness.

Purpose: To evaluate the efficacy and safety of hypochlorous acid (HOCI) eye drops in the treatment of fungal keratitis., Methods: A total of 96 patients (96 eyes) with fungal keratitis were randomly divided into two groups: group Ι (conventional treatment + topical HOCI eye drops); The group II (conventional treatment). According to its severity, those patients were divided into grade Ι or grade II. Use of fungal scraping and culture to identify the type of fungal infection, slit lamp examination, and corneal fluorescein staining to observe regression, and confocal corneal microscopy to assess fungal mycelial changes. The main outcome measures were the success rate, healing time, visual recovery, and complications. The Kaplan-Meier curve method was used to analysis of the survival function of days to cure between the two groups., Results: There were no statistical differences between the two groups in terms of general condition, medical history, and grading. Corneal scraping results showed that all patients had filamentous fungi. For grade Ι patients, all patients were cured, and the patients in Group I showed faster healing speed than that in Group II ( t = -3.665, p  < .01). For grade II patients, the recovery time ( t = -4.121, p  < .01) and the disappearance of hypopyon ( t = -4.291, p  < .01) were significantly faster in the combination group. In grade Ι and II patients, the final visual acuity and the incidence of complications such as corneal neovascularization, cataract, and hyphema showed no differences in both groups. The survival curve showed that the healing rate of ulcers in the combination treatment group was faster than that in the conventional treatment group ( χ 2 = 14.332, p  = .001)., Conclusion: HOCI can accelerate the healing of fungal keratitis without obvious complications, indicating a promising future in the field of keratitis treatment.

Importance: Microbial keratitis (MK) is a common cause of unilateral visual impairment, blindness, and eye loss in low-income and middle-income countries. There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes., Objective: To evaluate the diagnostic performance of the Aspergillus-specific lateral-flow device (AspLFD) to identify Aspergillus species causing MK in corneal scrape and corneal swab samples of patients presenting with microbial keratitis., Design, Setting, and Participants: This diagnostic study was conducted between May 2022 and January 2023 at the corneal clinic of Aravind Eye Hospital in Madurai, Tamil Nadu, India. All study participants were recruited during their first presentation to the clinic. Patients aged 15 years or older met the eligibility criteria if they were attending their first appointment, had a corneal ulcer that was suggestive of a bacterial or fungal infection, and were about to undergo diagnostic scrape and culture., Main Outcomes and Measures: Sensitivity and specificity of the AspLFD with corneal samples collected from patients with MK. During routine diagnostic scraping, a minimally invasive corneal swab and an additional corneal scrape were collected and transferred to aliquots of sample buffer and analyzed by lateral-flow device (LFD) if the patient met the inclusion criteria. Photographs of devices were taken with a smartphone and analyzed using a ratiometric approach, which was developed for this study. The AspLFD results were compared with culture reports., Results: The 198 participants who met the inclusion criteria had a mean (range) age of 51 (15-85) years and included 126 males (63.6%). Overall, 35 of 198 participants with corneal scrape (17.7%) and 17 of 40 participants with swab samples (42.5%) had positive culture results for Aspergillus species. Ratiometric analysis results for the scrape samples found that the AspLFD achieved high sensitivity (0.89; 95% CI, 0.74-0.95), high negative predictive value (0.97; 95% CI, 0.94-0.99), low negative likelihood ratio (0.12; 95% CI, 0.05-0.30), and an accuracy of 0.94 (95% CI, 0.90-0.97). Ratiometric analysis results for the swab samples showed that the AspLFD had high sensitivity (0.94; 95% CI, 0.73-1.00), high negative predictive value (0.95; 95% CI, 0.76-1.00), low negative likelihood ratio (0.07; 95% CI, 0.01-0.48), and an accuracy of 0.88 (95% CI, 0.73-0.96)., Conclusions and Relevance: Results of this diagnostic study suggest that AspLFD along with the ratiometric analysis of LFDs developed for this study has high diagnostic accuracy in identifying Aspergillus species from corneal scrapes and swabs. This technology is an important step toward the provision of point-of-care diagnostics for MK and could inform the clinical management strategy.

Background: To compare the performance of conventional, semi-nested and real-time panfungal ITS PCRs for diagnosing fungal keratitis (FK) and develop genus-specific real-time PCR for the most common aetiology of FK., Methods: This multicentric study includes 232 corneal samples from suspected FK patients from four centres across India between November 2019 through August 2021. A total of 87 corneal buttons were included for the comparison of conventional, semi-nested and real-time ITS PCRs, of which 68 were from confirmed FK patients. Of these 87 samples, 44 (microscopy and culture positive for Aspergillus sp. and/or Fusarium sp.) were used for the standardisation of genus-specific real-time primers/probes. Subsequently, the best method showing highest sensitivity and specificity was validated in 188 samples., Results: On Bayesian comparison, conventional ITS2 PCR showed best performance (sensitivity and specificity of 55.88% and 100%, respectively). Since, real-time ITS2 PCR was also considerably efficient (sensitivity and specificity of 51.47% and 84.21%, respectively) in comparison with the conventional PCR but faster, cost-effective, and less labor-intensive, ITS-2 real-time PCR is a suitable method that can be applied along with culture and microscopy. During validation, real-time PCR with genus-specific primers showed 61.76% and 91.18% sensitivity with specificity of 98.05% and 79.22%, respectively, for Aspergillus sp. and Fusarium sp. Aspergillus probe, Fusarium probe and duplex PCR showed sensitivity of 52.94%, 50% and 54.41% with specificity of 92.86%, 82.47% and 75%, respectively. No cross-reactivity of genus-specific PCRs was observed during standardisation., Conclusions: ITS-2 real-time PCR can be applied as an adjunct with conventional methods for the diagnosis of FK. The genus-specific duplex real-time PCRs are rapid which reduces the turnaround time (TAT) avoiding the need for sequencing., (© 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Background/objectives: To report the incidence, microbiological profile and in-vitro antimicrobial susceptibilities of microbial keratitis (MK) in the East of England (EoE) over a 6-year period., Subjects/methods: A retrospective study of patients diagnosed with MK who underwent corneal scraping at participating trusts, within the EoE, between 01/01/2015-01/07/2020. Analysis was performed on MK isolate profiles, in-vitro anti-microbial sensitivities and trends over time., Results: The mean incidence of IK, in the EoE, was estimated at 6.96 per 100 000 population/year. 1071 corneal scrapes were analysed, 460 were culture positive (42.95%) of which 87.2% were bacteria (50.3% gram-positive and 49.7% gram-negative), 2.4% polymicrobial, 9.3% fungi and 1.1% acanthamoeba. The most common organisms were pseudomonas spp (29.57%). There was a non-statistically significant trend (NST) in increasing incidence of pseudomonas spp, staph aureus and serratia (p = 0.719, p = 0.615, and p = 0.099 respectively) and a declining NST in Fungi (p = 0.058). Susceptibilities in-vitro to, penicillin classes, fluoroquinolone and aminoglycosides were 76.7% and 89.4%, 79.2% and 97.2% and 95.4 and 96.1% to gram-positive and gram-negative bacteria respectively. Gram-negative organisms were increasingly resistant to cephalosporins with a 19.2% reduction in sensitivity over time. (p = 0.011). Ceftriaxone showed the greatest decrease in sensitivity of 41.67% (p = 0.006)., Conclusion: In the EoE, MK is relatively prevalent though likely underestimated. Profiles are similar to other UK regions with the exception of a higher fungal and lower acanthamoeba incidence. Common first and second-line antimicrobial selection provides, on the whole, good coverage. Nevertheless, anti-microbial resistance, to cephalosporins, was observed so selection should be carefully considered when treating MK empirically., (© 2023. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

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., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Contact Lens Association of Ophthalmologists.)

Resistant Gram-negative bacteria are a growing concern in the United States, leading to significant morbidity and mortality. We identified a 72-year-old female patient who presented with unilateral vision loss. She was found to have a large corneal ulcer with hypopyon. Culture of corneal scrapings grew extensively drug-resistant Pseudomonas aeruginosa. Treatment involved a combination of systemic and topical antibiotics. Whole genome sequencing revealed the presence of bla VIM-80 , bla GES-9 , and other resistance determinants. This distinctive organism was linked to an over-the-counter artificial tears product.

Purpose: This pilot study assessed the safety and efficacy of low-temperature plasma (LTP) as an adjuvant treatment for mild to moderate fungal keratitis (FK)., Methods: Thirty FK patients were randomized into LTP (n = 15) and control (n = 15) groups. Patients were followed up for 3 months. The best-corrected visual acuity (BCVA), ulcer size, and hypopyon height were measured; healing time or complications were documented and compared., Results: More patients in the LTP group healed completely (11/15 in 48 days) compared with the control group (4/15 in 59.5 days), and those patients had a deeper initial ulcer depth and exhibited better BCVA improvements. Four patients failed after LTP treatment due to perforation, increased inflammatory infiltration, or hypopyon; those with more hypopyon were more likely to fail., Conclusions: LTP could be a promising adjuvant therapy to topical antifungal drugs for mild to moderate FK.

Microbial keratitis, a nonviral corneal infection caused by bacteria, fungi, and protozoa, is an urgent condition in ophthalmology requiring prompt treatment in order to prevent severe complications of corneal perforation and vision loss. It is difficult to distinguish between bacterial and fungal keratitis from image unimodal alone, as the characteristics of the sample images themselves are very close. Therefore, this study aims to develop a new deep learning model called knowledge-enhanced transform-based multimodal classifier that exploited the potential of slit-lamp images along with treatment texts to identify bacterial keratitis (BK) and fungal keratitis (FK). The model performance was evaluated in terms of the accuracy, specificity, sensitivity and the area under the curve (AUC). 704 images from 352 patients were divided into training, validation and testing set. In the testing set, our model reached the best accuracy was 93%, sensitivity was 0.97(95% CI [0.84,1]), specificity was 0.92(95% CI [0.76,0.98]) and AUC was 0.94(95% CI [0.92,0.96]), exceeding the benchmark accuracy of 0.86. The diagnostic average accuracies of BK ranged from 81 to 92%, respectively and those for FK were 89-97%. It is the first study to focus on the influence of disease changes and medication interventions on infectious keratitis and our model outperformed the benchmark models and reaching the state-of-the-art performance., (© 2023. The Author(s).)

Infectious keratitis refers to a group of corneal disorders in which corneal tissues suffer inflammation and damage caused by pathogenic infections. Among these disorders, fungal keratitis (FK) and acanthamoeba keratitis (AK) are particularly severe and can cause permanent blindness if not diagnosed early and accurately. In Vivo Confocal Microscopy (IVCM) allows for imaging of different corneal layers and provides an important tool for an early and accurate diagnosis. In this paper, we introduce the IVCM-Keratitis dataset, which comprises of a total of 4001 sample images of AK and FK, as well as non-specific keratitis (NSK) and healthy corneas classes. We use this dataset to develop multiple deep-learning models based on Convolutional Neural Networks (CNNs) to provide automated assistance in enhancing the diagnostic accuracy of confocal microscopy in infectious keratitis. Densenet161 had the best performance among these models, with an accuracy, precision, recall, and F1 score of 93.55%, 92.52%, 94.77%, and 96.93%, respectively. Our study highlights the potential of deep learning models to provide automated diagnostic assistance for infectious keratitis via confocal microscopy images, particularly in the early detection of AK and FK. The proposed model can provide valuable support to both experienced and inexperienced eye-care practitioners in confocal microscopy image analysis, by suggesting the most likely diagnosis. We further demonstrate that these models can highlight the areas of infection in the IVCM images and explain the reasons behind their diagnosis by utilizing saliency maps, a technique used in eXplainable Artificial Intelligence (XAI) to interpret these models., (© 2023. The Author(s).)

Purpose: To assess the effectiveness and safety of continuous lavage with 1% voriconazole (CL) for moderate and severe fungal keratitis., Methods: Thirty-one patients were randomized to receive topical eye drops either alone (T) or combined with continuous 1% voriconazole lavage (CL-T). The primary outcome was the cure rate at 3 months. The secondary outcomes were the 6-day efficacy, 3-day infiltration size and depth, hypopyon height, central corneal thickness (CCT), epithelial defect size, and subject feelings and clinical signs assessment scores., Results: At 3 months, the cure rate was comparable between the groups in patients with moderate fungal keratitis (66.7% vs. 62.5%, P = 0.60). However, among severe cases, 4 cases (44.4%) in the CL-T group healed successfully, while none in the T group; this difference was not significant (P = 0.08), although it was very close to 0.05. This may be related to the small sample size. After 6 days, the percentage of patients with "worsened" ulcers in the CL-T group was lower than that in the T group (0% vs. 31%, P = 0.043). The infiltration size, infiltration depth, and hypopyon height in the CL-T group were smaller than those in the T group after 3 days (all P < 0.05). There was no difference in CCT, epithelial defect size, subject feelings scores, or clinical signs scores between groups., Conclusion: These outcomes suggest that CL is an effective and safe adjuvant method for controlling the progression of moderate and severe fungal keratitis., Trial Registration Number: ChiCTR2100050565., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The aim of this study was to identify characteristics of infectious keratitis predictive of poor outcome to develop a web-based predictive calculator., Method: A retrospective chart review was performed at the Duke Eye Center. Two hundred fifteen adult patients with culture-proven infectious keratitis presenting between January 1, 2016, and December 31, 2020, were separated into a derivation set (136 patients, 53 positives; 83 controls) and a temporal validation set (79 patients, 26 positives; 53 controls). The poor outcome group consisted of patients requiring penetrating keratoplasty for visually significant scarring, penetrating keratoplasty for ulcer progression, or evisceration/enucleation for endophthalmitis. Univariable analysis was performed followed by stepwise multivariable logistic regression to obtain a predictive model in the derivation data set. Culture-naïve and postculture models were constructed. Discrimination and calibration were assessed using the area under the curve (AUC) and calibration plots, respectively., Results: The culture-naïve model consisted of corticosteroid drop use postsymptom onset [Odds Ratio (OR) = 2.3, P = 0.054], decreased vision (OR = 2.4, P = 0.001), and increased ulcer area (OR = 1.017, P = 0.017). The postculture model additionally included fungal keratitis (OR = 5.4, P = 0.006) and elapsed time from symptoms to organism-sensitive therapy (OR = 1.027, P = 0.014). The models were summarized by the acronym C-DU(KE). The AUCs for the culture-naïve model were 0.794 in the derivation set and 0.850 in the validation set. The AUCs for the postculture model were 0.898 in the derivation set and 0.946 in the validation set. Calibration plots indicated goodness of fit in the data sets for both models. The calculator was deployed under the URL: https://duke-eye-calculator.shinyapps.io/Corneal&#95;Ulcers/ ., Conclusions: The C-DU(KE) calculator permits a data-driven prediction of outcome in infectious keratitis that can supplement clinical judgment., Competing Interests: V. L. Perez—Alcon, Dompe, EyeGate, Kala, Trefoil, Novartis, Oculis, National Institutes of Health/National Eye Institute R01EY030283 (V.L.P.) and R01EY024485 (V.L.P.), Duke NIH Center Core Grant, and Duke Research to Prevent Blindness Unrestricted Grant (V.L.P.). The remaining authors have no conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)