title: Tolerance to topical preparations: cold or warm?
abstract: Ocular irritation from topical preparations is related to their viscosity, osmolarity, and pH value. We investigated the effect of temperature on ocular discomfort in 40 volunteers without a history of neuropathy and keratopathy. The dilating drops, tropicamide and phenylephrine were available at two different temperatures, 4 degrees C ("cold") versus 20 degrees C ("warm"). Each patient received cold drops in one eye and warm drops in the fellow eye. Ocular discomfort was similar in both groups. Eyes that received cold drops had a delayed irritation versus an instantaneous irritation with the warm drops. Cold drops may have a transient anesthetic effect on pain nerve endings that fades once the drops warm up to body temperature.
authors.affiliation: Montefiore Medical Center/Albert Einstein College of Medicine, New York.
authors.forename: A M
authors.initials: AM
authors.lastname: Mansour
mesh_terms: D000287:Administration, Topical; D003080:Cold Temperature; D003315:Cornea / Q000187:drug effects; D006358:Hot Temperature; D006801:Humans; D010656:Phenylephrine / Q000008:administration & dosage*; D011680:Pupil / Q000187:drug effects; D013696:Temperature; D014331:Tropicamide / Q000008:administration & dosage*
chemical_list: D010656:Phenylephrine; D014331:Tropicamide