Beyond the Hospital – Bacterial and Fungal Keratitis in Private Ophthalmic Care

Abstract

Introduction Infectious keratitis (IK) has been reported as the leading cause of corneal blindness worldwide, but is potentially avoidable by timely and accurate diagnosis followed by appropriate treatment. Bacterial pathogens remain the most frequently isolated organisms in IK. Fungal keratitis, although less common, is often associated with delayed healing and may require prolonged management. While most studies on IK originate from hospital-based settings, little is known about the incidence and characteristics of cases managed in office-based ophthalmic practices.

Methods This investigator-initiated, retrospective, single centre chart review investigated cases of bacterial and fungal keratitis managed in an office-based, primary care ophthalmology clinic in Switzerland. We reviewed electronic patient charts for positive bacterial or fungal culture or polymerase chain reaction results, from anterior-segment scrapings and contact lenses. Antimicrobial susceptibility testing of clinically relevant isolates was performed according to the EUCAST guidelines at the time of isolation.

Results Between 2014 and 2024, we identified 112 patients, 52 (46.4%), of whom were female. The median (IQR, range) age was 46 (33 to 63, 13 to 94) years. Across all cases, we detected 157 bacterial and 10 fungal isolates. Staphylococcus epidermidis was the most commonly isolated microorganism, followed by other coagulase-negative Staphylococci and Staphylococcus aureus.

Discussion This study overviews bacterial and fungal species distribution among keratitis cases encountered in an office-based ophthalmology setting over ten years. The findings illustrate the microbial diversity seen in private practice, with a predominance of staphylococcal species and a small but notable number of fungal isolates. These findings highlight the importance of maintaining local diagnostic vigilance.

Zusammenfassung

Einleitung Die infektiöse Keratitis (IK) gilt weltweit als eine der häufigsten Ursachen kornealer Erblindung und ist potenziell vermeidbar durch eine frühzeitige und korrekte Diagnosestellung mit anschließender adäquater Therapie. Bakterielle Erreger stellen weiterhin die am häufigsten isolierten Mikroorganismen bei IK dar. Pilzkeratitiden sind zwar seltener, gehen jedoch häufig mit einer verzögerten Abheilung einher und erfordern nicht selten eine langwierige Behandlung. Während die meisten Studien zur IK aus Spital-basierten Versorgungssettings stammen, ist über die Inzidenz und die Charakteristika von Fällen, die in Praxis-basierten augenärztlichen Einrichtungen behandelt werden, bislang wenig bekannt.

Methoden In dieser Untersucher-initiierten, retrospektiven Ein-Zentrum-Studie wurden Fälle von bakterieller und fungaler Keratitis untersucht, die in einer augenärztlichen Praxis in der Schweiz behandelt wurden. Elektronische Patientendossiers wurden hinsichtlich positiver bakterieller oder fungaler Kultur- oder Polymerase-Kettenreaktions-(PCR-)Ergebnisse aus Vorderabschnittsabstrichen und Kontaktlinsen ausgewertet. Die antimikrobielle Resistenztestung klinisch relevanter Isolate erfolgte gemäß den zum Zeitpunkt der Isolierung gültigen EUCAST-Richtlinien.

Ergebnisse Zwischen 2014 und 2024 wurden 112 Patientinnen und Patienten identifiziert, von denen 52 (46,4 %) weiblich waren. Das mediane Alter (IQR, Spannweite) betrug 46 (33–63, 13–94) Jahre. Insgesamt wurden 157 bakterielle und 10 fungale Isolate nachgewiesen. Staphylococcus epidermidis war der am häufigsten isolierte Mikroorganismus, gefolgt von weiteren Koagulase-negativen Staphylokokken und Staphylococcus aureus.

Diskussion Diese Studie gibt einen Überblick über die Verteilung bakterieller und fungaler Erreger bei Keratitisfällen, die über einen Zeitraum von 10 Jahren in einer augenärztlichen Praxis behandelt wurden. Die Ergebnisse verdeutlichen die mikrobielle Vielfalt in der privatärztlichen Praxis mit einer Dominanz staphylokokkaler Spezies sowie einer kleinen, aber relevanten Anzahl fungaler Isolate. Diese Befunde unterstreichen die Bedeutung einer konsequenten lokalen diagnostischen Wachsamkeit.

Keywords

bacterial keratitis - fungal keratitis - private ophthalmic care - microbiology - infectious keratitis

Schlüsselwörter

bakterielle Keratitis - fungale Keratitis - private Augenheilkunde - Mikrobiologie - infektiöse Keratitis

Publication History

Received: 02 November 2025

Accepted: 29 December 2025

Article published online:
23 February 2026

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