Overview

Ocular herpes, also known as herpes simplex eye infection, is a common viral infection that affects the eyes, primarily caused by the herpes simplex virus (HSV). This condition most often involves the cornea, the clear outer layer of the eye, leading to a form called herpes simplex keratitis. Ocular herpes can range from mild irritation to serious eye damage and vision loss if not properly treated. The infection can recur multiple times, and with each recurrence, the risk of eye complications increases. Prompt diagnosis and appropriate treatment are crucial in managing symptoms and preventing vision-threatening outcomes.

Causes

The primary cause of ocular herpes is infection with the herpes simplex virus (usually HSV-1), the same virus responsible for cold sores on the lips. Less commonly, HSV-2 (associated with genital herpes) can also cause eye infections, typically through autoinoculation. The virus is highly contagious and can remain dormant in the nerve cells after the initial infection. Certain triggers can reactivate the virus and cause recurrent eye infections. Common triggers include:

• Stress: Physical or emotional stress can weaken the immune system and activate the virus.
• Fever or illness: Other infections can lead to a herpes outbreak.
• Sunlight or UV exposure: Excessive sunlight may trigger ocular herpes in some individuals.
• Eye injury or surgery: Trauma to the eye can activate the dormant virus.
• Weakened immune system: Conditions or medications that suppress immunity can increase the risk of reactivation.

Symptoms

Symptoms of ocular herpes can vary depending on which part of the eye is affected. Common symptoms include:

• Eye redness: Typically affecting one eye, with noticeable redness in the white of the eye.
• Eye pain or discomfort: A mild to severe aching sensation or sharp pain in the affected eye.
• Watery eyes: Increased tearing or discharge from the infected eye.
• Blurred vision: Vision may become blurry due to corneal involvement.
• Light sensitivity (photophobia): Discomfort or pain in response to bright lights.
• Foreign body sensation: A feeling that something is stuck in the eye.
• Swelling of eyelids: In some cases, the eyelids may become swollen and tender.
• Recurrent episodes: Ocular herpes often recurs, with similar symptoms returning over time.

Diagnosis

Diagnosis of ocular herpes involves a comprehensive eye examination by an ophthalmologist. The typical diagnostic process includes:

• Medical history: The doctor will inquire about past herpes infections, cold sores, recurrences, and recent illnesses or stressors.
• Slit-lamp examination: A specialized microscope is used to examine the eye in detail, helping to identify corneal ulcers or characteristic lesions.
• Fluorescein staining: A special dye highlights corneal damage, revealing the classic dendritic (branch-like) ulcers seen in herpes simplex keratitis.
• Viral culture or PCR testing: In uncertain cases, samples from the eye may be taken for laboratory testing to confirm herpes simplex virus infection.

Treatment

While ocular herpes cannot be cured, it can be effectively managed with prompt treatment to relieve symptoms, control viral activity, and prevent complications:

• Antiviral eye drops: Medications such as trifluridine, ganciclovir, or acyclovir drops help stop viral replication in the eye.
• Oral antiviral medications: Oral acyclovir, valacyclovir, or famciclovir are commonly prescribed to manage active infections and reduce recurrence risks.
• Topical corticosteroids: In certain cases, corticosteroid eye drops may be used to reduce inflammation, but always under close supervision of an eye specialist as they can worsen some viral infections if misused.
• Lubricating eye drops: Artificial tears can ease dryness and irritation during an active episode.
• Surgical intervention: In rare, severe cases involving corneal scarring or ulcers, procedures such as corneal debridement or corneal transplantation (keratoplasty) may be necessary.
• Preventive therapy: Long-term, low-dose oral antiviral medication may be recommended in individuals with frequent recurrences.

Prognosis

The prognosis of ocular herpes depends on the severity of the infection and how promptly it is treated. Most people recover well from mild cases without long-term effects. However, recurrent episodes are common, and each recurrence can potentially cause more damage to the cornea. Repeated infections increase the risk of complications, including:

• Corneal scarring: Which can lead to permanent vision impairment.
• Vision loss: Severe or untreated infections can result in significant visual loss.
• Glaucoma or cataracts: Rare but possible complications, especially in severe cases treated with corticosteroids.

With timely diagnosis, appropriate antiviral treatment, and proper follow-up, most patients maintain good vision and manage recurrences effectively. Preventive strategies, including avoiding triggers and taking preventive antiviral medication when necessary, can greatly improve long-term outcomes.