Bacterial and viral keratitis

Abstract

Milda Vabalaitė1*, Lauryna Ivanauskaitė1 1Lithuanian University of Health Sciences, Medical Academy, Faculty of Medicine Abstract Introduction. Infectious keratitis is a microorganism-induced damage to the cornea that often results in severe and often irreversible visual disturbances. This pathology is caused by a variety of microorganisms, including bacteria, viruses, fungi, and protozoa. The aim of this review: to analyze literature about risk factors, symptoms, diagnosis and treatment of bacterial and viral keratitis. Methods. We analyzed medical publications using international databases like PubMed, ScienceDirect, Wiley Online Library. Results and conclusions. The most commonly detected bacterial pathogens are Staphylococcus aureus, plasma non-coagulating Staphylococci, Pseudomona aeruginosa, Streptococcus pneumoniae. Of the viral pathogens, keratitis is most commonly caused by Varicella-zoster virus, Cytomegalovirus, Adenovirus, Herpes Simplex virus. The development of bacterial and viral keratitis is influenced by various risk factors such as previous eye trauma, long-term contact lens wear, previous eye surgery, dry eye syndrome, eyelid deformity, long-term use of immunosuppressants, and topical steroids. The diagnosis of infectious keratitis can be suspected in the presence of decreased visual acuity, eye pain and redness, fear of light, tearing, discharge from the eyes, swelling of the eyelid. To clarify the diagnosis of bacterial and viral keratitis, tests are performed – visual acuity assessment, biomicroscopy, intraocular pressure is measured, corneal scraping smear is performed. The gold standard for detecting the bacterial agent is a culture of corneal scrapings. The main treatment for bacterial keratitis is antibacterial. Polymerase chain reaction (PCR), ELISA, and tissue culture studies are performed to confirm the pathological agent of viral keratitis. The main treatments for viral keratitis are antiviral medicines acyclovir or ganciclovir and the inhibition of inflammation by corticosteroids. Common and specific cases of viral keratitis are Adenovirus and Herpes Simplex-induced keratitis, the diagnosis and treatment of which require knowledge of specific symptoms and treatment options. Keywords: viral keratitis, adenoviral keratitis, bacterial keratitis, infectious keratitis, Herpes simplex virus.