Przydatność diagnostyki in vitro w trudnych przypadkach Acanthamoeba keratitis, wymagających postępowania farmakoterapeutycznego i chirurgicznego
Usefulness of in vitro Diagnostics in Difficult Incidences of Acanthamoeba keratitis Requiring Pharmacotherapy and Surgical Management
Jacek P. Szaflik1, Marcin Padzik2, Lidia Chomicz2, Gabriela Olędzka2, Justyna Izdebska1, Jerzy Szaflik1
1 Katedra i Klinika Okulistyki II Wydziału Lekarskiego Warszawskiego Uniwersytetu Medycznego
Samodzielny Publiczny Kliniczny Szpital Okulistyczny w Warszawie
Kierownik: prof. dr hab. n. med. Jerzy Szaflik
2 Zakład Biologii Medycznej Wydziału Nauki o Zdrowiu Warszawskiego Uniwersytetu Medycznego
Kierownik: prof. n. med. dr hab. Lidia Chomicz
Summary: Purpose: Amphizoic Acanthamoeba strains ubiquitous in environment, recently believed as protozoan vectors of different pathogenic bacteria, viruses and fungi, are the causative agents of vision-threatening human Acanthamoeba keratitis with increasing frequency reported from various parts of the world. Purpose of this study was to present difficult to treat incidences of Acanthamoeba keratitis and usefulness of in vitro diagnosis in proper therapeutic management.
Material and Methods: Three female patients, 26–37 years old, two contact lens wearers and the oldest with history of swimming in a lake, all complaining of photophobia and severe eye pain were admitted to our hospital; two older patients were previously unsuccessfully treated with antibacterial and antifungal medications. The diagnosis was performed by slit-lamp, in vivo confocal microscopy, microbiological and parasitological examinations. Corneal scrapings from all patients, initially examined in the light microscope were cultivated under bacteria – free condition in BSC growth medium (1) due to suspicion of Acanthamoeba infection; genotype of detected amoebae by PCR technique was determined. Status of the protozoan population was monitored during culturing and amoeba survival time was examined. Adequate antibacterial and anti-amoebic management with pharmaceutics or surgical procedures was undertaken.
Results: Active epithelial inflammations with corneal ulcers and bacterial infections were revealed in affected eyes. The antibacterial treatment was successful in one patient only. Cysts were detected by in vivo confocal microscopy in two patients, while trophozoites developed in corneal scraping cultures of all patients. The amoebae were morphologically identified as belonging to Acanthamoeba species, by PCR as T4 genotype. Several amoebic strains detected differed in viability and in vitro surviving time. As anti-amoebic therapy among others with topical propamidine and chlorhexidine as well as antibacterial treatment were disappointing, corneal X-linking was performed in two patients; penetrating keratoplasty with sustained anti-Acanthamoeba treatment were next necessary in this patient infected with the most in vitro viable amoeba strain.
Conclusions: Major risk factors: exposure to contaminated water and the contact lens use influenced Acanthamoeba keratitis cases presented by us. Variability in symptom intensity, differences in resistance to pharmacotherapy and surgical management efficacy appearing in these keratitis incidences correlated with time of surviving the amoebae cultivated from corneal scrapings. In vitro monitoring of dynamics of Acanthamoeba strains isolated from infected eyes may be useful tool both for proper diagnosis and treatment prognosis.
Słowa kluczowe: zapalenie rogówki z owrzodzeniem, trudności z diagnostyką różnicową, mieszana etiologia infekcyjna, zarażenie Acanthamoeba sp., oporność na farmakoterapię, postępowanie chirurgiczne.
Keywords: keratitis with corneal ulceration, difficulties of differential diagnosis, compound infective aetiology, Acanthamoeba sp. infection, resistance to pharmacotherapy, surgical procedures.