Ocular Herpes Simplex.

Ocular herpetic disease may be neonatal, primary, or recurrent.

Neonatal disease occurs secondary to passage through an infected birth canal, and is usually HSV type 2.

Primary ocular herpes may present as a blepharitis (grouped eyelid vesicles on an erythematous base), conjunctivitis, or keratoconjunctivitis.
Patients with keratoconjunctivitis commonly note pain, irritation, foreign body sensation, redness, photophobia, tearing, and occasionally decreased visual acuity. Follicles and preauricular adenopathy may be present. Initially, the keratitis is diffuse and punctate, but after 24 hours, fluorescein demonstrates either serpiginous ulcers or multiple diffuse epithelial defects. True dendritic ulcers are rarely seen in primary disease.

Ocular Herpes Simplex. This patient has a history of ocular herpes simplex since childhood. Grouped vesicles on an erythematous base with periorbital erythema are seen. Honey-colored crusts suggest secondary impetigo

Recurrent: Most ocular herpetic infections are manifestations of recurrent disease rather than a primary ocular infection.
These may be triggered by ultraviolet laser treatment, topical ocular medications (β-blockers, prostaglandins), and immunosuppression (especially ophthalmic topical glucocorticoids).
Recurrent disease most commonly presents as keratoconjunctivitis with a watery discharge, conjunctival injection, irritation, blurred vision, and preauricular lymph node involvement. Corneal involvement initially is punctate, but evolves into a dendritic keratitis. The linear branches classically end in bead-like extensions called terminal bulbs. Fluorescein dye demonstrates primarily the corneal defect; the terminal bulbs are best seen with rose stain. In addition to the dendritic pattern, fluorescein stain may instead take on a geographic or ameboid shape, secondary to widening of the
dendrite.


Most patients (80%) with herpes simplex keratitis have decreased or absent corneal sensation in the area of the dendrite or geographic ulceration. Deeper corneal stromal inflammation may also occur (disciform keratitis). Recurrent disease can also present with iritis or with blepharitis, with vesicles grouped in focal clusters.

Management
There is a high association in neonatal ocular herpes infections between ocular HSV disease and serious systemic or neurologic infection, and an emergency pediatric or infectious disease consult is necessary. IV acyclovir is indicated, and the ocular disease itself may be treated with topical antivirals (idoxuridine, vidarabine, trifluorothymidine). Other sexually transmitted diseases such as chlamydia or gonorrhea should be explored.

Treatment of those with primary ocular herpes (beyond the neonatal period) presenting as blepharitis or periocular dermatitis consists of good local hygiene and a prophylactic topical antiviral such as trifluorothymidine or idoxuridine ointment. Patients with corneal involvement should additionally
receive topical antibiotics to prevent secondary bacterial infection.

In those with recurrent disease, topical antivirals (trifluridine, ganciclovir, acyclovir, vidarabine) are effective, as is oral acyclovir. If the cornea is involved, trifluorothymidine and topical antibiotics are added. Ophthalmology consultation is required in patients with ocular HSV disease. Episodes of recurrent stromal disease may be limited by the long-term use of low-dose oral antivirals.

Important Learning Points
1. Most ocular HSV infections are manifestations of recurrent disease.
2. Corneal disease is the most prevalent form of ocular HSV disease.
3. Oral antivirals are now frequently used for keratitis because of their convenience, although topical optical antivirals are equally effective.
4. HSV dendrites, when stained with fluorescein, appear as branching lesions with terminal bulbs.
5. Corneal hypesthesia may be easily overlooked in the initial evaluation of a red eye. If a topical anesthetic has been given, a reexamination 1 hour later is helpful for evaluating hypesthesia.