Linear interstitial keratitis: A distinct clinical entity revisited

Purpose: Few reports in the ophthalmic literature describe rare corneal lesions of the stroma that present in a horizontal linear fashion. Although some differences exist among the small number of reported cases, we believe that all these cases represent a distinct clinical entity appropriately titled linear interstitial keratitis. In an attempt to expand the knowledge of this condition of unknown etiology, we present 3 cases of linear interstitial keratitis. Methods: Case series (3 cases are presented) and literature review. Results: All 3 patients (aged 21-22 years) presented with horizontal linear stromal infiltrates. One patient presented with a corneal perforation, requiring a closure with 3 interrupted sutures. Another patient required a penetrating keratoplasty because of a visually significant central scar. All 3 patients responded to topical steroids. Conclusions: Linear interstitial keratitis is a rare clinical entity and its histopathologic etiology remains undetermined. Current available technology including specular microscopy, anterior segment optical coherence tomography, and more sensitive serological testing may permit a better understanding of this disease.