Ophthalmic zoster: mucous plaque keratitis.

Data taken from 1221 patients attending the Zoster Clinic of Moorfields Eye Hospital over the past 15 years were used to characterise the clinical appearance and behaviour of zoster mucous plaque keratitis (MPK). The typical greyish branching plaques are usually accompanied by a limbitis, stromal keratitis, or decrease in corneal sensation and are commonly associated with cataract, raised intraocular pressure, or corneal ulceration. MPK may begin at any time within two years of onset of the rash, but when it appears after three months there are more complications. Usually MPK settles within one month if appropriate treatment with topical steroids and acetylcysteine drops is given, but surgical intervention is sometimes required to control glaucoma or neuroparalytic keratitis or to remove cataracts. The results of surgery are surprisingly good.