CLINICAL

  ANTERIOR

HINDER HSV KERATITIS

HOW TO TAME THE SLEEPING TIGER THAT THREATENS SIGHT

RECENTLY A 30-year-old male presented via urgent referral from a fellow optometrist in the community. He said he was diagnosed with a corneal ulcer OD and reported pain, light sensitivity, ocular redness and reduced vision. The patient added he was a contact lens wearer and recently slept in his contact lenses. Further, he told me he experienced these symptoms before, but they always resolved after discontinuing contact lens wear for a few days.

Past medical history revealed cold sores. Upon examination, the patient had a central area of epithelial keratitis, though not the classic dendritic lesions associated with herpes simplex virus (HSV), making a definitive diagnosis impossible. As a result, I obtained a corneal culture, sent it to a third-party lab and decided to go with my gut and treat the condition as HSV while I awaited lab results.

Here, I discuss the etiology, symptoms, clinical signs, management options, as well as the ICD-9 codes associated with HSV keratitis and what happened with this patient.

ETIOLOGY

HSV-1 and HSV-2 are DNA viruses that can infect humans and cause ocular disease with complications that can decrease vision permanently if not treated appropriately. HSV-1 more commonly infects the eye. Primary HSV-1 infections can cause patients to have flu-like symptoms, such as malaise and fever. After the initial infection, the virus lies dormant in the nervous system until stress triggers reactivation, causing an attack on the immune system. Acquired HSV is common with almost all adults having HSV-1 in their nervous system. Some patients experience recurring breakouts several times a year, making this condition seem more prevalent to optometrists. HSV-1 and HSV-2 involve the uveal tract, corneal endothelium, corneal stroma, the lids, conjunctiva and, most commonly, the corneal epithelial tissue. Less commonly, patients with HSV-1 may have stromal keratitis, uveitis, endotheliatis and decreased corneal sensitivity from neurotrophic keratitis.

This patient had severe primary HSV with a vesicular rash affecting the periorbital tissue and lids.

Using dyes, such as fluorescein, rose bengal and lissamine green, can help you evaluate epithelial keratitis caused by HSV. In addition, you should try to obtain a corneal culture to determine HSV keratitis, especially in a patient without a previous history of the virus. You must be careful in contact lens patients when you see an atypical case presentation that lacks classic dendritic lesions, as you want to make sure it’s not an infectious keratitis from contact lens use. In most cases, culture results take several days to weeks. Future point-of-care diagnostics that promise greater efficiency, less expense and better sensitivity and specificity are currently in development.

SYMPTOMS

• Foreign body sensation

• Tearing

• Photophobia

• Pain

• Decreased vision

CLINICAL SIGNS

• Vesicular rash with or without pre-auricular lymphadenopathy (pertaining to lids and the periorbital area)

• Conjunctival hyperemia

• Characteristic branching of the corneal epithelium

• Dendrites

• Large geographic ulcers

• Stromal keratitis (less common)

• Uveitis (less common)

• Endotheliatitis (less common)

• Decreased corneal sensitivity from neurotrophic keratitis (less common)

MANAGEMENT OPTIONS

Currently, three management options exist, which depend on the severity of the condition.

• Topical antiviral. Two are currently available: (1) trifluridine 1% (Viroptic, Pfizer), which is dosed one drop q2h while awake until the corneal ulcer has re-epithelialized and decreased to one drop q4h for the next seven to 10 days to ensure the virus outbreak stops (the drug must be refrigerated for the best efficacy); and (2) Ganciclovir (Zirgan, Bausch + Lomb), which is dosed five times a day until the corneal ulcer is healed and three times a day for seven days to ensure the virus outbreak stops.

• Topical steroid. This should be dosed q.i.d. for seven to 14 days and tapered as the inflammation improves when stromal keratitis, uveitis and endotheliatis are present.

• Oral antiviral. In primary cases of HSV, epithelial toxicity and severe cases of stromal keratitis, oral acyclovir (Zovirax, GlaxoSmithKline) should be dosed 400mg five times a day. Some studies have shown higher doses, such as 2g a day of oral acyclovir, are just as effective as topical antivirals in treating epithelial keratitis. Also, consider prescribing an oral antiviral as prophylaxis with valacyclovir (Valtrex, GlaxoSmithKline) dosed at 500mg t.i.d. PO for seven to ten days, and famciclovir (Famvir, Novartis) dosed at 250mg t.i.d. PO for seven to 10 days. Even lower dosages, such as 400mg acyclovir b.i.d. or Valtrex 500mg qd, can be used for months for recurring and chronic cases of HSV, as well as prior to surgery. Keep in mind that surgery can induce stress and reactivate a latent virus. Many patients take steroids after surgery, so oral antivirals help decrease the chance of HSV reactivation.

BOTTOM LINE

I prescribed the aforementioned patient a topical antiviral. As he didn’t have a dendritic ulcer with terminal end bulbs and was an admitted contact lens abuser, I also prescribed a fluoroquinolone q.i.d. in case the ulcer was infectious. The patient returned two days later and reported he didn’t purchase either medication I prescribed because of insurance problems and lack of time. Surprisingly enough, his signs and symptoms improved with no therapeutic treatment of any kind! This gave me the answer to the etiology even before the culture results returned from the lab: His body’s own immune response to the HSV outbreak began to fight the virus, causing his symptoms to get better. If it had been infectious, the keratitis would have worsened. This patient was young and had a good outcome even though he was non compliant to my prescription. Immunocompromised or elderly patients are usually not this lucky. OM

JOSH JOHNSTON, O.D., F.A.A.O. practices at Georgia Eye Partners. He focuses on ocular surface disease and has extensive experience in comanaging cataract and refractive surgery patients. Email him at drj@gaeyepartners.com, or visit tinyurl.com/OMcomment to comment.