title: Ring keratitis associated with topical abuse of a dilute anesthetic after refractive surgery.
abstract: Anesthetic toxic keratitis is rare and presents as a ring keratitis, which is often misdiagnosed as Acanthamoeba keratitis. Here, we report an unusual case of toxic keratitis caused by topical abuse of a dilute anesthetic. A 26-year-old woman presented with bilateral corneal edema, ring infiltrates, pigmented keratic precipitate, Descemets membrane folding, and strong anterior chamber reactions 2 weeks after laser subepithelial keratomileusis surgery. Tracing back her medical history, topical dilute 0.1% proparacaine was prescribed and frequently used for 1 month. Toxic keratitis was suspected. After discontinuation of the topical anesthetic and initiation of treatment with topical 20% autologous serum, complete corneal epithelialization was achieved within 1 week. Corneal infiltrates and anterior chamber reaction gradually subsided. Vision improved from finger counting to 20/20 in the right eye and 20/25 in the left eye, but confocal microscopy showed decreased corneal endothelial cells. Topical abuse of a dilute topical anesthetic can cause severe toxic keratitis and endothelial cell loss. The physician must be aware of the signs of topical anesthetic abuse and should not prescribe even a dilute anesthetic for long-term use. Autologous serum can help in the recovery of toxic keratitis.
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Hou
authors.forename: I-Jong
authors.initials: IJ
authors.lastname: Wang
authors.forename: Fung-Rong
authors.initials: FR
authors.lastname: Hu
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000009:adverse effects*; D042783:Endothelial Cells / Q000187:drug effects / Q000473:pathology; D005260:Female; D006801:Humans; D007634:Keratitis / Q000139:chemically induced*; D011430:Propoxycaine / Q000009:adverse effects*; D054140:Refractive Surgical Procedures / Q000009:adverse effects*
chemical_list: D000779:Anesthetics, Local; C005717:proxymetacaine; D011430:Propoxycaine