Corneal dendritic changes

Introduction Herpes simplex virus infection of dendritic keratitis cornea has a range of clinical manifestations that often lead to repeated corneal inflammation, angiogenesis, scar formation and vision loss. Dendritic keratitis symptoms and signs of initial (primary) infection are usually a characteristic of self-limiting conjunctivitis, may be associated with blister blepharitis. Recurrence (secondary) usually epithelial keratitis (also Dendritic keratitis, characterized by a dendritic lesion of the corneal epithelium, similar to the veins of the leaves, with a spherical end. Early symptoms are foreign body sensation, tearing, photophobia and conjunctival hyperemia. With repeated recurrence, corneal sensation diminishes or disappears, which may cause corneal ulceration and permanent corneal scar formation. Discoid keratitis involves the corneal stroma, which is a discoidal localized edema and opacity in the deep cornea, accompanied by iritis, often occurring after epithelial keratitis. Discoid keratitis may represent the body's immune response to the virus. It is not an epithelial defect caused by repeated herpes simplex virus that does not heal or heal very slowly. It is called painless ulcer. Treatment of dendritic keratitis with topical treatment (eg 1% fluoroside eye drops, 9 times daily or 3% adenosine eye ointment 5 times a day) is often effective. Even need to take oral acyclovir 400mg, 5 times a day. If the epithelium around the dendritic lesion is loose and edematous, swabbing with a cotton swab tip for debridement can accelerate healing before starting drug therapy. Epithelial keratitis locally disables corticosteroids, but later when the corneal stroma (disc keratitis) or uveal membrane is involved, the combination of corticosteroids and antiviral drugs may be effective. In cases with uveitis, 1% atropine eye drops are beneficial. Cases that have not healed after 1 week and cases involving the corneal stroma or uvea should be treated with an ophthalmologist. Herpes zoster ophthalmicus may be associated with orbital inflammation, conjunctivitis, keratitis, scleritis, uveitis, retinopathy (acute retinal necrosis), optic neuritis, ophthalmoplegia, and the like. 60% of them can develop herpes zoster keratitis, which causes corneal scars and seriously affects vision. There has been a tendency to increase gradually in recent times and it is worthy of vigilance.

Cause

Varicella and herpes zoster virus (VZV) are the same virus. Different immune status can lead to chickenpox or herpes zoster. After the initial infection of VZV, the virus is lurking in one or more viruses. In the nerve cells of the spinal ganglia or in the cells of the sensory ganglia of the brain, when the body's immunity declines, the virus is reactivated, descending along the sensory nerve fibers to the skin, proliferating in a certain sensory nerve and the area of the eye, and herpes zoster occurs. It is most common in the first branch of the trigeminal nerve.

The disease is caused by recurrent infection of varicella zoster virus (VZV). The virus is latent in the trigeminal ganglion. When the cellular immune function is decreased or induced by other external stimuli, the virus is activated and propagated. Patients with morbidity, immunodeficiency, such as AIDS patients, cell transplant patients, and patients with a history of cancer, recent surgery, and history of trauma, are also prone to recurrent infection of VZV lurking in the body.

an examination

Related inspection

Eye and sacral area CT examination of cornea

When there are specific signs of skin, eye and cornea, it is generally not difficult to diagnose, the atypical signs are rare, and the cases with less rash are often misdiagnosed as HSK. The author believes that when keratitis or other eye signs appear, and the following characteristics are present Should be suspected of VZV.

1. A history of unilateral facial rash.

2. Skin scars or brownish precipitates in this area.

3. The iris shrinks.

4. The anterior chamber is calm (more concentrated than other uveitis pigments).

Differential diagnosis

False dendritic keratitis: dendritic keratitis associated with herpes zoster, because its morphology is very similar to HSV dendritic keratitis, the main difference is that its corneal lesions are slightly elevated, slightly higher than the corneal surface, light, Moderate fluorescein staining, unlike HSK with sulcus depression, staining is obvious; the end of its dendritic lesion does not have a terminnal bulb like HSK, so it is called pseudodendritic keratitis. the difference.

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