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Because of its variable presentation and ability to affect all corneal layers, HSVK has several masqueraders and differential diagnoses. For example, any keratitis that creates a dendriform lesion could be mistaken for HSV epithelial keratitis. Infectious masqueraders include Acanthamoeba keratitis, VZVK, adenovirus epithelial keratitis, Epstein-Barr epithelial keratitis, chlamydial keratitis and other varying microbial keratitis...
The Herpetic Eye Disease Study (HEDS) I showed no benefit in combining both oral and topical antivirals, so choose one course of treatment. One exception to this may be prescribing for immunocompromised patients...
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Trifluridine 1% solution: 1 drop Q2hours for 7 days OR
Ganciclovir 0.15% gel: five times per day.
Oral antiviral agents (not FDA approved, but equal efficacy in studies) (Wilhelmus 2010).
Most of the treatment that we talk about when we’re talking about simplex keratitis was learned by the herpetic eye disease study. This was a study that came out in the early ’90s. That was a multicenter study across the world. That came out with just tons and tons of literature. We don’t have time to go into the herpetic eye disease study, but I encourage you to read it. When HEDS came out, the only topical treatment that we had for simplex keratitis was trifluridine, Viroptic. It’s not that great of a drug anymore. One of the things I wanted to talk about was to encourage you guys to use some of the new drugs. If you have epithelial disease, you’re dosing your patient nine times a day with Viroptic. It’s pretty toxic to the epithelium.
After the initial infection, the virus can remain latent in the ophthalmic division of the trigeminal ganglion for the lifetime of the host. HSV reactivation in the latently infected ganglia can lead to corneal scarring, thinning, stromal opacity, and neovascularization. The cumulative effect of numerous infections results in vision loss and eventually blindness if left untreated.
Based on the slit lamp findings, you diagnose Tom with herpes simplex keratitis. You give him a prescription for Valacyclovir 1 g TID, arrange next day ophthalmology follow-up, and give him return instructions to come back if his pain worsens or vision deteriorates.
HSV keratitis is caused by the herpes simplex virus and is an infection of the cornea. The virus remains in the trigeminal nerve when inactive and patients can have reactivations of the virus for the remainder of their life. Immunocompromised patients are at more risk for reactivation of disease. HSV is a serious infection and can lead to permanent vision loss if not treated promptly. Diagnosis is usually clinical and made on fluorescein exam.
There is much controversy surrounding whether an oral antiviral should be added to topical antiviral
therapy in the management of HSV keratitis. According to the first Herpetic Eye Disease Study (HEDS 1), there is
no apparent benefit in the addition of oral acyclovir to corticosteroids and trifluridine in the treatment of HSV
The Herpes virus is ubiquitous in our patient population. Often it is present without
symptoms, however, it may present with pain, irritation, and decreased vision. In high-risk populations a
longer course of treatment is often required.
The most well-known herpetic infection and the most common is infectious epithelial keratitis, said Prof Seitz. It may take the form of dendritic keratitis with branching linear lesions that typically break through the basal membrane of the cornea, with terminal enlargements, and swollen epithelial margins with living virus. If the dendrites become confluent, it may evolve into geographic keratitis.
It is also important to distinguish infectious epithelial keratitis from acanthamoeba keratitis, a rare opportunistic infection that presents with similar non-specific symptoms as bacterial and viral keratitis.
While both Type I and Type II herpes can spread to the eye and cause infection, Type I is by far the most frequent cause of eye infections. Infection can be transferred to the eye by touching an active lesion and then your eye. It is rare to transfer Type II to the eye.
Humans are the only known natural reservoir for HSV. Along with the nose and mouth, the eyes are a main access point.
The diagnosis of HSV keratitis is primarily clinical, although additional tests may be useful in providing confirmation, but never exclusion.[1-4] The Tzanck (Giemsa) smear of multinucleated epithelial cells is a quick test with high specificity but low sensitivity. Viral culture remains the gold standard with high sensitivity for detection of the virus
HSK has a highly variable and unpredictable course
Can be considered as a spectrum of four distinct disease entities (with differing management strategies)...
Herpes simplex keratitis is caused by recurrent infection of the cornea by herpes simplex virus (HSV). The virus is most commonly transmitted by droplet transmission, or less frequently by direct inoculation. Herpes keratitis remains the leading infectious cause of corneal ulcers and blindness worldwide.