Herpes simplex keratitis: challenges in diagnosis and clinical management

Abstract

Herpes simplex virus is responsible for numerous ocular diseases, the most common of which is herpetic stromal keratitis. This is a recurrent infection of the cornea that typically begins with a subclinical infection of the cornea that establishes a latent infection of sensory ganglia, most often the trigeminal ganglia. Recurring infections occur when the virus is reactivated from latency and travels back to the cornea, where it restimulates an inflammatory response. This inflammatory response can lead to decreased corneal sensation, scarring, and blindness. The diagnosis of these lesions as the result of a recurrent herpes simplex virus infection can at times be problematic. Currently, herpetic stromal keratitis is diagnosed by its clinical presentation on the slit-lamp examination, but the literature does not always support the accuracy of these clinical findings. Other diagnostic tests such as polymerase chain reaction assay, enzyme-linked immunosorbent assay, immunofluorescent antibody, and viral cultures have provided more definitive diagnosis, but also have some limitations. That said, accurate diagnosis is necessary for proper treatment, in order to prevent serious consequences. Current treatment reduces the severity of lesions and controls further viral spread, but does not provide a cure.

Characterization of Sex Differences in Ocular HSV-1 Infection and Herpes Stromal Keratitis Pathogenesis of Wild Type and Herpesvirus Entry Mediator Knockout Mice

“…This was also observed in another study in which clinical eye disease scores were slightly lower in females but not significant (20). Clinical examination using a slit-lamp microscope may provide better diagnosis and scoring of HSK as this the primary diagnostic tool in patients (36, 37). However, there were no sex differences in corneal eye disease scores in our results and the other reports of ocular HSV-1 infection and clinical HSK pathogenesis (14, 20).…”

Common eye infections

“…The clinical features of herpes simplex virus keratitis (Table) can be identified on slit lamp examination. 21,22 Epithelial herpes simplex keratitis typically manifests as a dendritic ulcer. To visualise the ulcer, fluorescein staining and a cobalt blue light are needed (Fig.…”

“…5). 21 The treatment is aciclovir ointment five times daily for 14 days. [23][24][25] Stromal herpes simplex keratitis presents with haze or opacity of the stroma, with or without ulceration, scarring or vascularisation.…”

Ocular Glands Become Infected Secondarily to Infectious Keratitis and Play a Role in Corneal Resistance to Infection

“…In 2010, the Centers for Disease Control and Prevention reported that 700,000 clinical visits occurred due to microbial infections of the cornea, or microbial keratitis, in the United States (14). Depending on the pathogen, tissue pathology can occur by direct cytopathic effects (e.g., virus), secreted toxins (e.g., bacteria), or immunemediated damage that can result in opacity and scar formation of the cornea (15,16). Host clearance of the insulting pathogen can also lead to corneal neovascularization (comprised of blood and lymphatic vessel formation), as in cases of herpes simplex virus 1 (HSV-1) keratitis (15).…”