title: Corneal toxic changes after cataract extraction.
abstract: Over an 18-month period 10 patients (12 eyes) presented with severe corneal toxic changes after cataract extraction. Defined stages in the keratopathy included punctate epithelial keratopathy, pseudodendrite, central epithelial ulcer and central stromal ulcer. Periods of up to 13 months were required for resolution of the defects. Axial scarring and nonhealing epithelial defects resulted in a final visual acuity of counting fingers and hand movement in two patients. We believe that exposure during the postoperative period to benzalkonium chloride contained in ophthalmic medications represents the most likely cause of the toxic changes and that no single ophthalmic medication can be held responsible. The past ocular histories of the patients included chronic open-angle glaucoma, dry eye syndrome and anterior membrane dystrophy. Prior exposure to benzalkonium-containing antiglaucoma medications, tear film deficiencies or abnormalities of epithelial adhesion may have predisposed the corneas in these patients to the development of benzalkonium-related toxic changes.
authors.affiliation: Department of Ophthalmology, Ottawa Civic Hospital, Ont.
authors.forename: R W
authors.initials: RW
authors.lastname: Zabel
authors.forename: G
authors.initials: G
authors.lastname: Mintsioulis
authors.forename: I M
authors.initials: IM
authors.lastname: MacDonald
authors.forename: J
authors.initials: J
authors.lastname: Valberg
authors.forename: S J
authors.initials: SJ
authors.lastname: Tuft
mesh_terms: D001548:Benzalkonium Compounds / Q000009:adverse effects*; D002387:Cataract Extraction / Q000009:adverse effects*; D003316:Corneal Diseases / Q000139:chemically induced / Q000209:etiology*; D003320:Corneal Ulcer / Q000139:chemically induced / Q000209:etiology; D004848:Epithelium / Q000187:drug effects; D006801:Humans; D009883:Ophthalmic Solutions / Q000009:adverse effects; D014792:Visual Acuity
chemical_list: D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions