title: Linear interstitial keratitis:  a distinct clinical entity revisited.
abstract: OBJECTIVE
  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.
authors.affiliation: University of Nevada School of Medicine, Las Vegas, NV, USA.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Calvo
authors.forename: Shameema
authors.initials: S
authors.lastname: Sikder
authors.forename: Nick
authors.initials: N
authors.lastname: Mamalis
authors.forename: Mark D
authors.initials: MD
authors.lastname: Mifflin
mesh_terms: D003319:Corneal Stroma / Q000473:pathology*; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007634:Keratitis / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D008297:Male; D011239:Prednisolone / Q000031:analogs & derivatives / Q000627:therapeutic use; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; C009935:prednisolone acetate; D011239:Prednisolone