{"id":18658,"date":"2026-10-05T10:51:46","date_gmt":"2026-10-05T10:51:46","guid":{"rendered":"https:\/\/www.eyecliniclondon.com\/blog\/?p=18658"},"modified":"2026-10-05T11:00:32","modified_gmt":"2026-10-05T11:00:32","slug":"herpes-simplex-keratitis","status":"publish","type":"post","link":"https:\/\/www.eyecliniclondon.com\/blog\/herpes-simplex-keratitis\/","title":{"rendered":"Herpes Simplex Keratitis: Symptoms, Recurrence and Treatment"},"content":{"rendered":"

Herpes simplex keratitis affects your cornea and can cause eye pain, redness, light sensitivity and blurred vision. The infection can affect different layers of your cornea, so symptoms and treatment can vary.<\/p>\n

The herpes simplex virus can remain inactive and reactivate later, meaning you may experience repeated episodes. Prompt treatment can help control active disease and reduce the risk of further corneal damage.<\/p>\n

What Is Herpes Simplex Keratitis?<\/h2>\n

Herpes simplex keratitis is an infection or inflammation of your cornea caused by the herpes simplex virus, usually HSV-1. Your cornea is the clear front surface of your eye, so inflammation or scarring can affect your vision.<\/p>\n

Your infection can affect different layers of your cornea, including the surface, deeper stromal layer or endothelium. This is why your symptoms and treatment can vary depending on which part of your cornea is affected.<\/p>\n

How Does Herpes Simplex Reach Your Eye?<\/h2>\n

The herpes simplex virus can remain inactive in your body after an initial infection. It can stay dormant in the nerves that supply sensation to your face and eye and later reactivate.<\/p>\n

When the virus reactivates, it can travel back towards your eye and cause another episode of herpes simplex keratitis. This means your eye infection can recur even when you do not have a visible cold sore.<\/p>\n

What Are the Symptoms of Herpes Simplex Keratitis?<\/h2>\n

Herpes simplex keratitis can cause eye redness, pain, watering, blurred vision and sensitivity to light. You may also feel as though something is stuck in your eye or notice that your vision has become less clear.<\/p>\n

Your symptoms may affect just one eye and can vary depending on which part of your cornea is involved. If you develop sudden symptoms, especially after a previous episode, you should arrange an eye assessment.<\/p>\n

What Does the Typical Herpes Simplex Corneal Lesion Look Like?<\/h2>\n

Herpes simplex keratitis can cause a branching lesion on the surface of your cornea called a dendritic ulcer. Your ophthalmologist can use fluorescein dye and a slit lamp to see these changes more clearly.<\/p>\n

Your lesion can sometimes become larger and form a geographic ulcer. You should not try to identify these changes yourself because other corneal conditions can cause similar symptoms.<\/p>\n

Can Herpes Simplex Keratitis Affect Different Layers of the Cornea?<\/h2>\n

\"\"<\/p>\n

Herpes simplex infection can affect different layers of your cornea. Epithelial keratitis affects the outer surface, while stromal keratitis involves deeper inflammation and can affect your vision more significantly.<\/p>\n

HSV can also affect the endothelium and cause corneal swelling, reduced clarity or inflammation involving the inner cornea. Your ophthalmologist needs to identify which type is affecting you because the treatment can differ.<\/p>\n

Herpes Simplex Corneal Conditions and How They Differ<\/h2>\n\n\n\n\n\n\n\n\n
Type<\/strong><\/td>\nMain area affected<\/strong><\/td>\nCommon features<\/strong><\/td>\nTreatment approach<\/strong><\/td>\n<\/tr>\n<\/thead>\n
Epithelial keratitis<\/td>\nOuter surface of the cornea<\/td>\nDendritic or geographic ulcer, redness, watering, pain, light sensitivity and blurred vision<\/td>\nAntiviral treatment is usually used to control active viral replication.<\/td>\n<\/tr>\n
Stromal keratitis<\/td>\nDeeper stromal layer of the cornea<\/td>\nInflammation, blurred vision, light sensitivity and possible corneal scarring<\/td>\nAnti-inflammatory treatment such as steroid eye drops may be used under specialist supervision, usually alongside antiviral treatment.<\/td>\n<\/tr>\n
Endotheliitis<\/td>\nEndothelial layer at the back of the cornea<\/td>\nCorneal swelling, reduced clarity and blurred vision<\/td>\nAntiviral and anti-inflammatory treatment may be used according to the clinical findings.<\/td>\n<\/tr>\n
Neurotrophic keratopathy after HSV<\/td>\nCorneal nerves and surface healing<\/td>\nReduced corneal sensation and a surface that may heal poorly<\/td>\nManagement focuses on protecting the cornea and supporting healing under specialist care.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u00a0What Is Epithelial Herpes Simplex Keratitis?<\/h2>\n

Epithelial herpes simplex keratitis affects the outer surface of your cornea and can cause pain, watering, redness, light sensitivity and blurred vision. Your ophthalmologist may see a characteristic dendritic ulcer during examination.<\/p>\n

Your treatment usually involves antiviral medicine to control the active infection. You should not use steroid eye drops unless your ophthalmologist specifically recommends them, as inappropriate steroid use can worsen active epithelial disease.<\/p>\n

What Is Stromal Herpes Simplex Keratitis?<\/h2>\n

Stromal herpes simplex keratitis affects the deeper layer of your cornea and is mainly driven by inflammation. You may notice blurred vision, light sensitivity or eye discomfort, and repeated episodes can cause corneal scarring.<\/p>\n

Your treatment may include steroid eye drops to control inflammation alongside antiviral medicine. Your ophthalmologist will monitor you closely because treatment needs to control inflammation while limiting the risk of HSV becoming active again.<\/p>\n

What Is HSV Endotheliitis?<\/h2>\n

HSV endotheliitis affects the endothelial layer at the back of your cornea. When these cells become less effective, fluid can build up and cause corneal swelling, reduced clarity and blurred vision.<\/p>\n

Your treatment may include antiviral and anti-inflammatory medicines under specialist supervision. Your ophthalmologist will also monitor your eye pressure and other signs of inflammation during your recovery.<\/p>\n

Why Does Herpes Simplex Keratitis Keep Coming Back?<\/h2>\n

Herpes simplex keratitis can recur because HSV remains dormant in your nervous system after the initial infection. It can later reactivate and travel back towards your eye, causing another episode.<\/p>\n

Your recurrence may sometimes follow illness, stress, ultraviolet light exposure or trauma, although you may not always have an obvious trigger. If your episodes keep returning, your ophthalmologist may discuss preventive antiviral treatment with you.<\/p>\n

Research Insight<\/strong><\/p>\n

The Herpetic Eye Disease Study (HEDS) investigated whether long-term oral acyclovir could reduce recurrences of ocular HSV disease. In 703 immunocompetent patients with previous ocular HSV disease, the cumulative probability of a recurrence during 12 months was 19% with acyclovir compared with 32% with placebo; among patients with previous stromal keratitis, recurrent stromal disease occurred in 14% compared with 28%.<\/p>\n

These findings support the use of preventive antiviral treatment in selected people with recurrent ocular HSV, particularly those with a history of stromal keratitis. Preventive treatment is not automatically needed for everyone, so your ophthalmologist will consider your previous episodes, severity and individual risk before recommending long-term antiviral therapy.<\/p>\n

Does Every Recurrence Cause Corneal Damage?<\/h2>\n

\"\"<\/p>\n

Herpes simplex keratitis does not cause the same amount of damage with every recurrence. A superficial episode may settle without significant lasting changes, while repeated deeper inflammation can increase the risk of corneal scarring and reduced vision.<\/p>\n

Your corneal sensation can also be affected by repeated HSV episodes, which may make healing more difficult. Preventing further recurrences can therefore be particularly important if you have previously had stromal keratitis.<\/p>\n

How Is Herpes Simplex Keratitis Diagnosed?<\/h2>\n

Your ophthalmologist will diagnose herpes simplex keratitis by considering your symptoms, medical history and a detailed examination of your eye. A slit lamp and fluorescein dye can help your specialist identify changes such as a dendritic ulcer.<\/p>\n

Your corneal sensation and signs of inflammation may also be checked. In complicated or uncertain cases, your ophthalmologist may recommend further testing to confirm whether HSV is responsible.<\/p>\n

Evidence Note<\/strong><\/p>\n

Herpes simplex keratitis is usually diagnosed from your symptoms, previous history and examination of the cornea with a slit lamp. Fluorescein dye can help your ophthalmologist identify characteristic epithelial changes such as a dendritic ulcer, while corneal sensation and signs of deeper inflammation may also be assessed.<\/p>\n

Laboratory testing such as a corneal sample or PCR may be considered when the diagnosis is uncertain or the presentation is complicated. A negative test does not necessarily exclude HSV, so your ophthalmologist will interpret any test result alongside the clinical examination.<\/p>\n

How Is Epithelial Herpes Simplex Keratitis Treated?<\/h2>\n

Active epithelial herpes simplex keratitis is usually treated with antiviral medicine. Your ophthalmologist may prescribe an oral antiviral or, in some cases, an antiviral treatment applied directly to your eye.<\/p>\n

You should use the treatment for the period recommended by your ophthalmologist, because prolonged topical antiviral use can irritate your cornea. You should also avoid steroid eye drops unless your ophthalmologist specifically prescribes them for an appropriate reason.<\/p>\n

Clinical Tip<\/strong><\/p>\n

Do not start steroid eye drops yourself if you think you have a recurrence of epithelial herpes simplex keratitis. Steroids can be appropriate for some deeper inflammatory forms of HSV eye disease, but they need to be used under ophthalmic supervision because inappropriate treatment during active epithelial disease can allow the infection to worsen.<\/p>\n

If you have previously been diagnosed with ocular HSV, contact your eye-care team promptly when familiar symptoms return rather than using leftover medication without advice. The correct treatment depends on whether the recurrence involves the corneal surface, deeper layers or another part of the eye.<\/p>\n

How Is Stromal Keratitis Treated?<\/h2>\n

Your stromal keratitis may be treated with steroid eye drops to control inflammation, alongside antiviral medicine to suppress HSV activity. Your ophthalmologist will decide the right treatment for you.<\/p>\n

Your steroid treatment may need to continue for longer and be reduced gradually. You should not change or stop your steroid drops without your ophthalmologist\u2019s advice.<\/p>\n

UK Guidance Note<\/strong><\/p>\n

UK clinical guidance recognises herpes simplex keratitis as a condition that may require prompt eye assessment, particularly when you have pain, redness, light sensitivity or a change in vision.<\/p>\n

If your symptoms are worsening or your vision is affected, prompt assessment is important because the appropriate treatment depends on which part of your cornea is involved. If recurrent disease causes significant corneal scarring and affects your sight, specialist assessment may include discussion of corneal transplantation in appropriate cases.<\/p>\n

Can Antiviral Treatment Help Prevent Recurrences?<\/strong><\/h2>\n

Long-term antiviral treatment may help reduce the chance of recurrent ocular herpes, particularly if you have had repeated or significant episodes. Your ophthalmologist can consider whether it is appropriate based on your previous infections and risk of recurrence.<\/p>\n