Dendritiform Keratopathy Associated with Exposure to Polyquarternium-1, a Common Ophthalmic Preservative.

To describe dendritiform keratopathy associated with exposure to polyquaternium-1, a common preservative found in contact lens solutions and tear replacement products.Case series.Sixteen patients who demonstrated dendritiform keratopathy during topical ophthalmic exposure to polyquaternium-1.Records were reviewed of all patients diagnosed with dendritiform keratopathy between 1999 and 2014 who had documented exposure to contact lens care disinfecting solutions or artificial tear solutions containing polyquaternium-1. Patients were excluded who had coexisting potential causes for dendritiform keratopathy, such as prior herpes simplex keratitis, varicella-zoster viral keratitis, the linear form of Thygeson's superficial keratitis, epithelial regeneration line, Acanthamoeba keratitis, mucus plaque keratopathy, medication-related keratopathy, or limbal stem cell deficiency characterized by conjunctivalization of the corneal epithelium.Effect of discontinuation of exposure to polyquaternium-1 on the dendritiform keratopathy.Sixteen patients demonstrated dendritiform keratopathy after exposure to the preservative polyquaternium-1. Thirteen patients had a history of recent exposure to contact lens disinfecting solutions (Opti-Free, Equate) containing polyquaternium-1. Three patients used a tear replacement product (Systane) containing a polyquaternium-1 preservative. Four patients were treated with antiviral medications for presumed herpes simplex keratitis; 4 patients underwent diagnostic testing for Acanthamoeba keratitis. Two additional patients were diagnosed sequentially with herpes simplex keratitis, then Acanthamoeba keratitis before referral. All dendritiform lesions resolved within 2 to 6 weeks after elimination of exposure to polyquaternium-1.Ophthalmic products containing polyquaternium-1 may cause dendritiform keratopathy that may be confused with infections of the superficial cornea, such as herpes simplex virus keratitis or Acanthamoeba keratitis.