title: Contact lens-induced peripheral ulcers with extended wear of disposable hydrogel lenses: histopathologic observations on the nature and type of corneal infiltrate.
abstract: OBJECTIVE
  Contact lens-induced peripheral ulcer (CLPU), a sudden-onset adverse event observed with extended wear of hydrogel lenses, is characterized by a single, small, circular, focal anterior stromal infiltrate in the corneal periphery or midperiphery. The condition is always associated with a significant overlying epithelial loss and resolves in a scar. The aim was to determine, by using histopathologic techniques, the nature and type of the corneal infiltrate of these events.
  
  
  METHODS
  Three CLPUs observed in three patients using disposable hydrogel lenses on an extended-wear schedule were examined. The eye was topically anesthetized, and a corneal section including all of the infiltrate was taken. A small triangular piece of conjunctiva immediately adjacent to the infiltrate was sectioned. The tissue was immediately fixed, processed, stained using hematoxylin and eosin and periodic acid-Schiff stains, and examined by using light microscopy.
  
  
  RESULTS
  The diameter of these three corneal infiltrates varied from 0.3 to 0.6 mm. Histopathology of the corneal sections revealed a focal epithelial loss corresponding to the infiltrated stroma in all three patients. The adjacent epithelium was thinned. Bowman's layer was intact in two patients and had a localized area of loss in the remaining patient. The anterior stroma was densely infiltrated with polymorphonuclear leukocytes and had focal areas of necrosis. The infiltration was most dense in the region immediately underlying Bowman's layer. No other infiltrative cell type was seen in any of the sections. Histopathology of the conjunctiva revealed features consistent with normal conjunctival tissue.
  
  
  CONCLUSIONS
  On histopathology of CLPU, distinctive features (i.e., focal corneal epithelial loss, an intact Bowman's membrane, and a localized infiltration of the anterior stroma with polymorphonuclear leukocytes) were seen. These features suggest that the event is an acute inflammatory process and probably noninfective in nature.
authors.affiliation: Cornea and Contact Lens Research Unit, School of Optometry, The University of New South Wales and the Co-operative Research Centre for Eye Research and Technology, Sydney, Australia.
authors.forename: B A
authors.initials: BA
authors.lastname: Holden
authors.forename: M K
authors.initials: MK
authors.lastname: Reddy
authors.forename: P R
authors.initials: PR
authors.lastname: Sankaridurg
authors.forename: R
authors.initials: R
authors.lastname: Buddi
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: M D
authors.initials: MD
authors.lastname: Willcox
authors.forename: D F
authors.initials: DF
authors.lastname: Sweeney
authors.forename: G N
authors.initials: GN
authors.lastname: Rao
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D003228:Conjunctiva / Q000473:pathology*; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects*; D003320:Corneal Ulcer / Q000209:etiology* / Q000473:pathology*; D004209:Disposable Equipment; D004848:Epithelium / Q000473:pathology; D019573:Epithelium, Corneal / Q000473:pathology*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D009504:Neutrophils / Q000473:pathology
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate