eye disorders
Herpes Simplex Keratitis
Symptoms and Signs of Herpes Simplex Keratitis
The initial (primary) infection is usually nonspecific self-limiting conjunctivitis, often in early childhood and usually without corneal involvement. If the cornea is involved, symptoms include foreign body sensation, lacrimation, photophobia, and conjunctival hyperemia. Sometimes vesicular blepharitis (blisters on the eyelid) follows, symptoms worsen, vision blurs, and blisters break down and ulcerate, then resolve without scarring in about a week. Recurrent ocular herpes affects the cornea. Three main types of herpes simplex keratitis are Epithelial keratitis (dendritic keratitis) Disciform keratitis (localized endotheliitis) Stromal keratitis Reactivation of latent herpes simplex can be triggered by UV light exposure (eg, intense sunlight, corneal cross-linking [an ultraviolet light treatment that stiffens the cornea], or laser refractive procedures), fever, menstruation, significant systemic physical stress (eg, burns or multiple fractures), immunosuppression, or use of glucocorticoids (topical ophthalmic, periocular injection, intraocular injection, or systemic). Recurrences usually take the form of epithelial keratitis (also called dendritic keratitis), with tearing, foreign body sensation, and a characteristic branching (dendritic or serpentine) lesion of the corneal epithelium with bulb-like terminals that stain withfluorescein. Multiple recurrences may result in corneal hypoesthesia or anesthesia, ulceration, permanent scarring, opacification, thinning of the corneal stroma, and decreased vision. Most patients with disciform keratitis, which involves the corneal endothelium primarily, have a history of epithelial keratitis. Disciform keratitis is a deeper, disc-shaped, localized area of secondary corneal stromal edema and haze accompanied by anterior uveitis. This form may cause ache, photophobia, and reversible vision loss. Stromal keratitis is likely to cause necrosis of the stroma and severe ache, photophobia, foreign body sensation, ulceration, permanent scarring, opacification, neovascularization, thinning of the corneal stroma, and irreversible decreased vision. 