Herpes Simplex Keratitis
What Is Herpes Simplex Keratitis?
Herpes simplex keratitis develops when the herpes simplex virus, most commonly type 1, infects the cornea. This virus lives in nerve tissue and can travel to the eye even if you have never had a visible cold sore.
Once the virus reaches the cornea, it can damage the cells on the surface or deeper layers of your eye. The infection may occur for the first time or reactivate from a dormant state in your nerves.
Unlike pink eye, which affects the conjunctiva (the clear membrane on the white part of your eye and inside your eyelids), HSK targets the cornea itself. Pink eye often clears on its own or with simple treatments, while HSK requires antiviral medication.
HSK can cause more serious complications, including scarring and vision loss. Pain and light sensitivity can be significant with HSK, though symptoms vary from person to person. The key difference is that HSK involves the cornea and can blur your vision, while typical pink eye usually does not affect clarity of sight. Redness from keratitis often appears around the colored part of your eye rather than spreading evenly across the white.
Epithelial keratitis affects only the top layer of the cornea. We often see a distinctive tree-like pattern of inflammation when we examine the eye with special dyes and lights.
Stromal keratitis goes deeper into the middle layers of the cornea and is more serious. It can lead to scarring, cloudiness, and permanent vision problems if not treated quickly and carefully.
HSV can also cause other patterns of corneal disease. A geographic ulcer is a larger, irregularly shaped epithelial defect. Immune stromal keratitis involves inflammation without active virus in the tissue, while stromal necrosis is a rarer and more severe form. Endotheliitis, sometimes called disciform keratitis, affects the deepest corneal layer and can cause swelling and clouding. HSV infection may also trigger inflammation inside the eye, called anterior uveitis, which can raise eye pressure.
After your first episode, the herpes simplex virus does not leave your body. It hides in nearby nerve tissue, where it can stay quiet for months or years.
Certain triggers may wake the virus and lead to another episode of HSK. Each recurrence increases the risk of deeper damage and lasting vision changes.
Recognizing the Symptoms of HSK
Pain in or around the affected eye is a common symptom of HSK, though the intensity can vary. Some people experience intense discomfort, while others may have less pain than expected because the virus can reduce corneal sensation. The redness is often most noticeable around the colored part of the eye, a pattern called limbal or ciliary injection.
You may also notice excessive tearing as your eye tries to wash away the infection. This tearing is different from the watery discharge of typical pink eye.
Many people with HSK find bright lights uncomfortable or even painful. You might prefer to stay in dimly lit rooms or wear sunglasses indoors.
Blurred vision can develop from swelling and inflammation in the cornea. The blurriness may be mild at first but can worsen as the infection progresses.
A gritty or scratchy sensation is common with HSK, even though nothing is actually stuck in your eye. This foreign body feeling comes from damage to the corneal surface.
- The sensation may be constant or may get worse with blinking
- It often feels like sand or an eyelash is trapped under your lid
- Rubbing your eye will not relieve the discomfort and may make it worse
- The feeling usually affects only one eye
Some symptoms suggest a more serious infection or complication that needs urgent attention. Sudden or severe vision loss, intense pain that does not improve, or visible white or cloudy patches on the cornea all require same-day evaluation. Additional warning signs include halos around lights with eye pain, severe headache or nausea with eye pain, and being unable to keep the eye open due to pain or light sensitivity.
If you wear contact lenses and develop significant eye pain, redness, light sensitivity, or vision changes, seek care immediately, as several sight-threatening infections require prompt treatment. If you have a known history of HSK and notice symptoms returning, contact our eye doctor promptly. Immunocompromised patients should also seek urgent evaluation for any new eye symptoms. Early treatment can prevent deeper damage and preserve your vision.
Who Gets Herpes Simplex Keratitis?
If you have ever had cold sores around your mouth or nose, you carry the herpes simplex virus. The virus can travel along nerves and reach the eye even if your cold sores are not active.
People with a history of genital herpes, usually caused by type 2, can also develop eye infections, though this is less common. Either form of the virus has the potential to infect the cornea.
Conditions or medications that weaken your immune system make it easier for the herpes virus to reactivate. This includes certain autoimmune diseases, cancer treatments, and long-term use of immune-suppressing drugs.
- Organ transplant recipients on anti-rejection medications
- Patients undergoing chemotherapy
- People with HIV or other immune disorders
- Those taking high doses of corticosteroids for other conditions
Eye injury or surgery can sometimes trigger reactivation of the herpes virus if you already carry it in your nerve tissue. Eye surgery, including LASIK or cataract surgery, may also lead to reactivation in people with a history of HSV.
Contact lens wearers face a higher risk of various eye infections, and improper lens hygiene can create openings for infections to develop. If you have a history of herpes simplex, we may recommend extra caution with contact lenses.
Physical or emotional stress can lower your resistance and allow the virus to reactivate. Severe illness, fever, or even excessive sun exposure can serve as triggers.
Many patients notice that their HSK episodes occur during or after periods of high stress, lack of sleep, or other viral infections. Recognizing your personal triggers can help you stay alert for early symptoms.
How Our Eye Doctor Diagnoses HSK
We begin by asking about your symptoms, including when they started, whether you have had similar episodes before, and if you have a history of cold sores or other herpes infections. Your answers help us focus our examination.
During the eye exam, we look for signs of inflammation, unusual patterns on the cornea, and changes in your vision. We also check the pressure inside your eye and assess the surrounding structures.
Fluorescein is a safe orange dye that we place on the surface of your eye. It glows bright green under a special blue light and highlights areas of damage.
When we examine your eye with a slit lamp microscope, epithelial HSK often reveals a branching, tree-like pattern called a dendritic ulcer. This distinctive appearance helps us confirm the diagnosis and rule out other causes of corneal inflammation.
Most cases of HSK are diagnosed clinically based on the appearance of your cornea under the slit lamp. Laboratory testing is reserved for atypical cases, severe or recurrent infections, treatment-resistant disease, or when the diagnosis is uncertain, especially in immunocompromised patients.
If testing is needed, we may take a small sample from the surface of your eye for laboratory analysis. The sample can be tested for the presence of herpes simplex virus.
- Polymerase chain reaction tests for rapid and accurate virus detection
- Viral culture to grow and identify the virus, though this method is slower
- Corneal scraping to examine cells under a microscope
- Anterior segment imaging may help assess stromal swelling or scarring when needed
Several other conditions can mimic HSK, and we carefully consider these possibilities before starting treatment. Bacterial keratitis, including infections with bacteria like Pseudomonas, can occur especially in contact lens wearers. Acanthamoeba keratitis is another serious infection linked to contact lens use and water exposure. Varicella zoster virus can cause corneal inflammation with patterns that may look similar to HSV. Fungal infections and autoimmune diseases can also affect the cornea.
Accurate diagnosis is critical because the wrong treatment can worsen the infection. Using topical steroids for undiagnosed epithelial keratitis or infectious corneal ulcers can lead to serious complications. Our goal is to be certain of the diagnosis, especially before recommending steroids or changing our treatment approach.
Treatment Approaches for Herpes Simplex Keratitis
Antiviral medications are the foundation of HSK treatment. We may prescribe antiviral eye drops, oral antiviral pills, or both, depending on the severity and location of your infection.
Treatment options include the following approaches, chosen based on your specific case and what is available:
- Topical ganciclovir gel or trifluridine drops for epithelial disease where available
- Oral acyclovir, valacyclovir, or famciclovir as alternatives or for deeper disease, recurrent infections, and in immunocompromised patients
- Long-term suppressive oral antiviral therapy to prevent recurrences in patients with frequent episodes or severe disease
- Dose adjustments for patients with kidney disease when using oral antivirals
- Antibiotic drops are not used to treat HSV and may be added only if there is concern for secondary bacterial infection with significant epithelial breakdown
Corticosteroid eye drops reduce inflammation and can help prevent scarring in certain forms of HSK. However, steroids are generally avoided in active epithelial HSV keratitis because they can allow the virus to spread and worsen the infection.
For stromal keratitis, endotheliitis, or anterior uveitis caused by HSV, we may use corticosteroid drops along with antiviral coverage and close monitoring. The timing and use of steroids is individualized based on the type and severity of your infection. Steroid drops must be prescribed and supervised by an ophthalmologist due to the risk of worsening the infection and raising eye pressure.
You will need frequent follow-up visits to ensure the virus does not reactivate and that your eye pressure remains safe during steroid treatment.
In some cases of epithelial keratitis, we may gently remove the infected cells from the surface of your cornea using a cotton swab or other instrument. This technique, called debridement, can speed healing and reduce the amount of virus on the eye.
Debridement is usually done with numbing drops in the office and is followed by antiviral treatment. Most patients tolerate the procedure well and notice improvement within a few days.
Severe or recurrent stromal keratitis may require longer courses of antiviral medication and careful steroid tapering. We monitor you closely for signs of increased eye pressure, cataract formation, or worsening infection.
- Extended oral antiviral therapy to suppress the virus
- Slow reduction of steroid drops to avoid rebound inflammation
- Possible use of additional medications to control eye pressure
- Neurotrophic keratopathy or metaherpetic ulcers may develop after repeated infections, requiring careful lubrication, epithelial support, and surface management
- Long-term suppressive oral antiviral therapy is often recommended for patients with recurrent disease to reduce future episodes and preserve vision
- Consideration of corneal transplant if scarring is severe and vision is permanently reduced
Even with proper treatment, HSK can lead to complications such as glaucoma, cataracts, or corneal scarring. We schedule regular follow-up visits to check your progress and adjust your medications as needed.
If you notice new symptoms, worsening pain, or changes in your vision during treatment, contact our office right away. Early detection of complications allows us to intervene before permanent damage occurs.
Caring for Your Eyes During and After Treatment
Good eye hygiene supports the healing process and reduces the risk of secondary infections. Wash your hands before and after applying eye drops, and avoid touching or rubbing your eyes.
- Use a clean tissue to blot away excess tearing
- Avoid wearing eye makeup until the infection has cleared
- Wear sunglasses outdoors to reduce light sensitivity
- Get plenty of rest and stay well hydrated
- Avoid activities that could injure your eye
- Do not wear contact lenses until your eye doctor clears you; discard and replace any lenses and lens case that were used around the time of your infection
- Do not use leftover steroid drops or numbing drops at home
- Do not patch the eye unless specifically instructed by your eye doctor
- Avoid sharing eye drops, towels, or washcloths; practice strict hand hygiene to prevent spreading the virus
Even if your symptoms improve quickly, it is critical to finish the full course of antiviral medication. Stopping treatment early can allow the virus to resurge, lead to incomplete healing, and increase the risk of recurrence or progression of the infection.
If you experience side effects from your medications, let us know rather than stopping them on your own. We can often adjust the dose or switch to a different medication that you tolerate better.
We will ask you to return for follow-up visits to check how well your cornea is healing. These appointments let us see if the infection is clearing and if any complications are developing.
The frequency of visits depends on the severity of your infection. Mild epithelial disease may require only one or two follow-ups, while stromal keratitis often needs closer monitoring over several weeks or months.
Because the herpes virus remains in your body, preventing recurrences is an ongoing effort. Managing stress, getting adequate sleep, and protecting your eyes from injury all help reduce the chance of reactivation.
In some cases, we may recommend long-term suppressive antiviral therapy, especially if you have had multiple episodes or severe disease. This approach can significantly lower the risk of future flare-ups and preserve your vision.
Frequently Asked Questions
Herpes simplex virus can be shed and spread through direct contact with secretions or lesions, such as sharing towels or touching active cold sores. Eye-to-eye spread of HSK is uncommon in practice, but it is possible if you touch the infected eye and then touch another person's eye or your own other eye. Careful hand hygiene is important to prevent transmission. You can transfer the virus from one of your own eyes to the other by touching the infected eye and then the healthy one, so avoid touching your eyes and wash your hands frequently.
Many people recover well from a single episode of epithelial HSK without lasting vision problems, especially when treated promptly. However, repeated infections or stromal keratitis can lead to corneal scarring, which may permanently reduce vision. Neurotrophic changes and complications from treatment can also affect long-term outcomes. Early treatment and careful management of recurrences give you the best chance of preserving your sight.
Uncomplicated epithelial keratitis usually heals within one to two weeks with antiviral treatment. Stromal keratitis takes longer, often several weeks to months, and may require extended medication and follow-up. Your individual healing time depends on the severity of the infection, how quickly treatment began, and whether complications develop.
We generally recommend avoiding contact lenses during active infection and for some time after healing is complete. Once your cornea has fully recovered and we confirm that the infection is gone, you may be able to resume lens wear with extra precautions. Some patients may need to switch to daily disposable lenses or glasses to reduce the risk of future problems.
Currently, there is no vaccine available to prevent herpes simplex virus infection or HSK, although research is ongoing. There is also no cure that completely eliminates the virus from your body. However, antiviral medications effectively control the infection, and long-term suppressive therapy can reduce recurrences, allowing most people to maintain good vision and quality of life.
Getting Help for Herpes Simplex Keratitis
If you experience eye pain, redness, blurred vision, or light sensitivity, contact our eye doctor as soon as possible. Prompt evaluation and treatment of HSK can prevent serious complications and protect your vision for the long term.