Fuchs' superficial marginal keratitis

We studied three cases of Fuchs' superficial marginal keratitis, an uncommon condition that is characterized by intermittent, recurrent episodes of ocular irritation accompanied by marginal infiltrates and that is followed by progressive marginal superficial stromal thinning. Usually, it has an indolent course with spontaneous remission, and good visual acuity is preserved. In advanced cases, a pseudopterygium develops in the area of marginal thinning. The pseudopterygium encroaches onto the cornea over a period of years, but spares the central cornea. In two of our three cases, the degree of thinning beneath the pseudopterygium became marked. This led to corneal perforation during pseudopterygium excision in one case, and after blunt trauma in the other. These complications indicate the need for special precautions when caring for these patients.