QuestionSBA
QuestionChoice
While eye hygiene and warm compresses may help in cases of blepharitis or conjunctivitis, they are not effective for treating viral corneal infections like herpes simplex keratitis.
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Advise eye hygiene and warm compresses
QuestionChoice
This male presenting with a red, painful eye and dendritic corneal lesions on slit lamp examination has a classic presentation of herpetic keratitis (caused by the herpes simplex virus, HSV). His history of Crohn's disease is not directly related to this eye condition, but it is relevant to his overall health. Topical aciclovir eye drops are the first-line treatment for herpetic keratitis. They directly target the herpes simplex virus, reducing viral replication and preventing further damage to the cornea. Early treatment is essential to avoid complications like corneal scarring or vision loss.
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Topical aciclovir eye drops
QuestionChoice
This combination may be useful in other inflammatory eye conditions, such as uveitis, but in herpes simplex keratitis, it could lead to corneal ulceration and scarring, worsening the prognosis.
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Topical corticosteroid eye drops and cyclopentolate
QuestionChoice
Chloramphenicol eye drops are used primarily for bacterial conjunctivitis, which often presents with a red, itchy eye with discharge. This patient's presentation is more consisent with HSV keratitis and so this is not appropriate.
10015675
e
Topical chloramphenicol eye drops
QuestionChoice
While oral aciclovir can be effective in treating systemic herpes infections or severe cases, topical treatment is generally preferred for localised herpetic keratitis. Oral aciclovir is used if there is a lack of response to topical therapy or in severe recurrent cases.
10015672
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Oral aciclovir
Concept
Chapter
# Summary

Herpes simplex keratitis is a leading cause of corneal blindness in the developed world, primarily caused by the reactivation of the dormant herpes simplex virus type 1 (HSV1) in the trigeminal ganglion. Key signs and symptoms include acute pain, photophobia, and epiphora. Dendritic ulcers, which are pathognomonic of the infection, may also be observed under slit lamp examination with fluorescein applied. The condition is diagnosed through clinical examination and confirmed by laboratory investigations. Management typically involves treatment with topical acyclovir, without which corneal scarring and potential blindness may occur.

# Definition

Herpes simplex keratitis is a severe eye infection caused by the herpes simplex virus. It primarily affects the cornea, leading to discomfort, visual distortion, and in severe cases, blindness.

# Epidemiology

This condition represents the most prevalent form of corneal blindness in the developed world, primarily attributed to the reactivation of the herpes simplex virus type 1 (HSV1) in the trigeminal ganglion.

# Aetiology

The primary cause of herpes simplex keratitis is the reactivation of HSV1, which is typically dormant in the trigeminal ganglion. The exact mechanism of reactivation is not entirely understood, but it is believed to be linked to stress, immunosuppression, and ultraviolet exposure.

# Signs and Symptoms

Patients with herpes simplex keratitis commonly present with the following symptoms:
- Acute pain
- Photophobia (sensitivity to light)
- Epiphora (excessive tearing)
Under slit lamp examination with fluorescein staining, pathognomonic dendritic ulcers might be observed.

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# Differential Diagnosis

Other conditions that may present with similar symptoms include:

- Bacterial keratitis: Characterized by severe eye pain, decreased vision, light sensitivity, and discharge.
- Fungal keratitis: Presents with eye pain, redness, blurred vision, discharge, and decreased vision.
- Acanthamoeba keratitis: Symptoms include eye pain, red eye, blurred vision, light sensitivity, and a feeling of something in the eye. More common if history of submergence in contaminated water (swimming/lakes/hot tubs) or eye exposure to soil.

# Investigations

- The diagnosis of herpes simplex keratitis is primarily based on clinical symptoms and the appearance of the cornea. 
- Gold standard for diagnosis is slit lamp investigation with fluoroscein staining
- Laboratory investigations such as viral culture, PCR, or immunofluorescence assay can be used to confirm the diagnosis.

# Management

- Primary management of herpes simplex keratitis involves the use of topical antiviral medication, typically acyclovir. This treatment aims to control the viral infection and prevent corneal scarring, which can result in blindness if left untreated. 
- If recurrent episodes, prophylaxis with oral antivirals may be required.
- In severe cases, corneal transplantation may be necessary.

# References

[NHS UK - Herpes Simplex Eye Infections](https://www.nhs.uk/conditions/herpes-simplex-eye-infections/)
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A dendritic corneal ulcer.
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Dendritic corneal ulcer.jpeg
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1022
Herpes Simplex Keratitis
Topic
16
Ophthalmology
Condition
317
Herpes simplex virus
UkmlaTopic
12
General practice and primary healthcare
Condition
318
Herpes simplex virus
UkmlaTopic
13
Infection
15678
Herpetic keratitis presents with dendritic corneal lesions and is treated with topical aciclovir to prevent complications such as corneal scarring.
Presentation
283
Foreign body in eye
UkmlaTopic
1
Acute and emergency
Presentation
284
Foreign body in eye
UkmlaTopic
19
Ophthalmology
A 21-year-old male comes to eye casualty with a red, painful eye. He has a past medical history of Crohn's disease. On slit lamp examination with fluorescein dye, dendritic corneal lesions are seen.

Given the likely diagnosis, what is the most appropriate management?
a