Ocular Herpes: Symptoms, Types, Causes and Treatment

Ocular herpes is a group of eye diseases caused by herpes viruses, most commonly herpes simplex virus (HSV) and varicella zoster virus (VZV). While these viruses are well-known for causing cold sores or chickenpox, they can also infect the eye, sometimes leading to serious, vision-threatening complications. Understanding the symptoms, types, causes, and treatments of ocular herpes is crucial for early detection, prevention of complications, and preserving vision.

Symptoms of Ocular Herpes

Ocular herpes can present with a wide variety of symptoms, which can range from mild discomfort to severe pain and vision loss. Early recognition is vital to ensuring prompt treatment and preventing long-term damage. Since these symptoms often overlap with other eye conditions, being able to identify key features is essential for both patients and clinicians.

Symptom	Description	Severity	Source(s)
Redness	Eye appears bloodshot	Mild to severe	1 4 7
Watering	Increased tear production	Mild	1 4
Discharge	Watery or mucoid	Mild	1
Itching	Irritation, urge to rub eyes	Mild	1
Lid Swelling	Puffy eyelids	Mild to moderate	1
Pain	Soreness, often persistent	Mild to severe	1 3 7
Photophobia	Sensitivity to light	Moderate to severe	1 3
Blurred Vision	Loss of visual clarity	Moderate to severe	1 4 5 7
Vesicles/Ulcers	Small blisters or sores	Mild to moderate	1 3 4
Dendritic Ulcers	Branching corneal lesions	Moderate to severe	1 4 5 9
Chronicity	Recurrent or prolonged symptoms	Variable	1 5 7

Table 1: Key Symptoms

Common and Subtle Presentations

Ocular herpes often begins with non-specific symptoms such as redness, watering, and mild irritation. These can mimic conjunctivitis or allergies, making early diagnosis challenging. Discharge and itching are also frequent, but not unique to herpes infections 1.

Severe and Vision-Threatening Signs

As the infection progresses or recurs, more distinctive signs may develop:

• Pain and Photophobia: These indicate deeper involvement, such as keratitis (corneal inflammation) or uveitis (inflammation inside the eye) 1 3.
• Vesicles and Ulcers: Small blisters on the eyelids or around the eye are suggestive of herpes infection. Dendritic (branching) ulcers on the cornea are classic for HSV keratitis 1 4 5.
• Blurred Vision: This can result from corneal haze, scarring, or intraocular inflammation, and signals a need for urgent evaluation 4 5 7.
• Chronicity: Unlike other viral eye infections, ocular herpes may recur. Chronic inflammation, relapsing symptoms, or prolonged course are key clues 1 5 7.

Less Common Symptoms

• Systemic Symptoms: Mild fever, malaise, and upper respiratory tract infection can accompany primary infection 1.
• Severe Complications: In some cases, optic neuropathy or retinitis may develop, especially with herpes zoster 2 3.

Recognizing Patterns

Not all patients experience all symptoms. Some may have only mild discomfort, while others develop aggressive, sight-threatening disease. Recognizing the pattern—especially recurring or unresponsive symptoms—should raise suspicion for ocular herpes.

Types of Ocular Herpes

Ocular herpes is not a single disease but rather a spectrum of disorders affecting different parts of the eye. The two main viruses involved are herpes simplex virus (HSV) and varicella zoster virus (VZV), each causing distinct clinical presentations.

Type	Virus	Main Features	Source(s)
Herpes Simplex Keratitis	HSV-1	Corneal ulcers (dendritic), scarring	4 5 7 9 11
Stromal Keratitis	HSV-1	Deep corneal inflammation, scarring	5 7 11
Endotheliitis	HSV-1	Swelling of corneal endothelium	9
Blepharoconjunctivitis	HSV-1	Lid & conjunctival involvement	1 4 7
Herpes Zoster Ophthalmicus (HZO)	VZV	Skin rash, neuralgia, eye inflammation	2 3 6 8 13
Uveitis	HSV-1/VZV	Intraocular inflammation	3 4 9
Retinitis/Optic Neuropathy	HSV-1/VZV	Rare, severe, vision-threatening	2 3 8

Table 2: Main Types of Ocular Herpes

Herpes Simplex Keratitis (HSK)

• Caused by HSV-1; most frequent ocular manifestation.
• Begins as epithelial keratitis (surface ulcers), often with classic dendritic (branching) patterns on the cornea.
• Can progress to stromal keratitis, which involves deeper corneal layers, causing scarring and potential vision loss 4 5 7 9 11.
• Chronic or recurrent, leading to cumulative damage 5 7.

Blepharoconjunctivitis

• Involvement of eyelids (vesicles, ulcers) and conjunctiva.
• More common in primary infections, especially in children.
• May be self-limited or recur as chronic blepharoconjunctivitis 1 4 7.

Herpes Zoster Ophthalmicus (HZO)

• Caused by reactivation of VZV (the same virus that causes chickenpox and shingles).
• Involves the ophthalmic branch of the trigeminal nerve.
• Classic features: painful skin rash (often on the forehead or eyelid), severe neuralgia, and variable eye involvement (conjunctivitis, keratitis, uveitis) 2 3 6 8 13.
• May lead to postherpetic neuralgia and chronic complications 2 3.

Uveitis and Other Intraocular Disease

• Both HSV and VZV can cause uveitis (inflammation of the iris and internal eye structures).
• Presents with pain, redness, blurred vision, and light sensitivity.
• Rarely, the posterior segment of the eye (retina, optic nerve) can be affected, especially in immunocompromised individuals 3 8.

Key Differences Between HSV and VZV Ocular Disease

• HSV: More likely to recur, typically affects cornea and eyelids, chronic inflammation is a key problem 4 5 7.
• VZV (HZO): Often follows a single, severe episode, more likely to cause neuralgia, skin rash, and multiple ocular complications 2 3 8.

Causes of Ocular Herpes

Understanding how and why ocular herpes occurs helps inform both prevention and management. These infections are the result of complex interactions between viral biology, host immunity, and external factors.

Cause	Mechanism/Trigger	Risk Factors	Source(s)
HSV-1 Infection	Primary or reactivated infection	Close contact, stress, immunosuppression	4 5 7 8 9 11
VZV Reactivation	Dormant virus reactivates in nerve	Age, immunosuppression	2 3 6 8
Immune Dysfunction	Impaired defense or overreaction	Immunocompromised, autoimmune	5 8 11
Trauma/UV Light	Triggers viral reactivation	Ocular surgery, injury, sun exposure	5 8

Table 3: Causes and Risk Factors

Herpes Simplex Virus (HSV-1)

• Widespread virus; most people are infected in childhood.
• Transmitted via close contact—often asymptomatic.
• Virus remains dormant in trigeminal ganglion, reactivating later due to triggers such as stress, illness, UV light, or local trauma 4 5 7 8.
• Once reactivated, virus travels down nerve fibers to the eye, causing recurrent disease 8 9.

Varicella Zoster Virus (VZV)

• Causes chickenpox in primary infection; remains dormant in sensory nerves.
• Reactivation leads to shingles (herpes zoster), and when the ophthalmic branch of the trigeminal nerve is involved, it results in HZO 2 3 6 8.
• Risk increases with age, declining immunity, or immunosuppressive conditions 2 3 8.
• Vaccination reduces risk, but many adults remain unvaccinated 2.

Role of Immunity

• The immune system usually keeps these viruses in check.
• Immunosuppressed patients (due to HIV, chemotherapy, organ transplantation) are at much higher risk for severe or atypical presentations, including posterior segment disease 5 8.
• Overreaction of the immune system, especially in recurrent HSV keratitis, can cause further tissue damage (immunopathology) 5 11.

Environmental and Physical Triggers

• Ocular surgeries, trauma, or even excessive sun exposure can trigger reactivation of HSV or VZV in susceptible individuals 5 8.
• Not all exposures result in disease, but awareness of these triggers can help in prevention.

Treatment of Ocular Herpes

Effective management of ocular herpes is essential to prevent vision loss. While there is currently no cure for herpes viruses, modern antiviral therapies and adjunctive treatments have significantly improved outcomes.

Treatment	Approach	Main Indication	Source(s)
Antivirals (Oral)	Acyclovir, Valacyclovir	Acute and recurrent HSV/VZV	9 10 13
Topical Antivirals	Ganciclovir gel, Acyclovir ointment	Epithelial keratitis	9 14
Corticosteroids	Topical/systemic	Stromal keratitis, inflammation	5 10
Novel Agents	DNA aptamers, Kinase inhibitors	Resistant/refractory cases	12 15
Vaccination	HZ vaccine	Prevents HZO (shingles)	2 13
Supportive Care	Lubricants, pain management	Symptom relief	3 5 10

Table 4: Treatment Approaches

Antiviral Therapy

• Oral Antivirals: Acyclovir and valacyclovir are mainstays for both HSV and VZV ocular infections. They reduce viral replication, shorten disease duration, and lower the risk of recurrence and complications 9 10 13.
  • For HZO, prompt initiation is critical to prevent serious complications 2 3 13.
  • Valacyclovir offers better bioavailability but is not conclusively superior to acyclovir in outcomes 13.
• Topical Antivirals: Ganciclovir gel (0.15%) and acyclovir ointment are effective for superficial herpetic keratitis, with ganciclovir being well-tolerated and widely used in Europe 9 14.

Corticosteroids

• Used to reduce inflammation in stromal keratitis and uveitis.
• Always combined with antivirals to avoid worsening viral replication 5 10.

Novel and Adjunctive Therapies

• DNA Aptamers: Experimental therapies targeting viral entry proteins may offer new approaches for resistant cases 12.
• Kinase Inhibitors (e.g., BX795): Show promise in preclinical studies, especially against drug-resistant HSV 15.
• Interferons and Immunomodulators: Sometimes used in refractory or severe disease 10.

Vaccination

• Herpes Zoster Vaccine (HZV): Significantly reduces incidence of HZO in older adults. The recombinant vaccine (RZV) is more effective than live-attenuated vaccine (ZVL) 2.
• Vaccination is underutilized; increased uptake could prevent many cases of HZO and related vision loss 2.

Supportive and Preventive Care

• Lubricating drops, pain control, and management of complications are important adjuncts 3 5 10.
• Patient Education: Awareness of triggers, prompt recognition of symptoms, and adherence to therapy are key to reducing recurrences.

Special Considerations

• Immunosuppressed Patients: Require more aggressive and sometimes prolonged therapy 5 8.
• Refractory or Resistant Cases: May require alternative or experimental agents 12 15.

Conclusion

Ocular herpes is a multifaceted disease with the potential for serious, lifelong vision impairment. Early recognition, appropriate classification, and timely treatment are essential to prevent complications.

Key Takeaways:

• Ocular herpes can cause a wide range of symptoms, from mild irritation to severe pain and vision loss 1 4 5 7.
• Multiple clinical types exist, primarily caused by HSV-1 (keratitis, blepharoconjunctivitis) and VZV (herpes zoster ophthalmicus) 2 3 4 5 7.
• Infections result from primary infection or reactivation of dormant virus, often triggered by stress, immunosuppression, or trauma 4 5 7 8.
• Effective treatments include oral and topical antivirals, corticosteroids, and supportive care; newer therapies and vaccines are improving prevention and outcomes 2 9 10 12 13 14 15.
• Vaccination against shingles in older adults is underused but can substantially reduce the risk of herpes zoster ophthalmicus and its complications 2.
• Patient education and awareness of symptoms, triggers, and the importance of early treatment are crucial in preventing vision loss.

Through ongoing research and improved clinical strategies, the outlook for patients with ocular herpes continues to improve. Early intervention, prevention, and innovation remain the cornerstones in the fight against this sight-threatening disease.