The Emergency Physician must be familiar with the proper technique of removing soft and hard contact lenses from patients who are unable to do so on their own. Patients with altered mental status are at risk of corneal damage if contact lenses remain in place. Healthy individuals who wear contact lenses overnight experience a 4- to 15-fold increase in the risk of corneal injury compared with those who remove their contact lenses daily.1 The explanation for this increased risk of injury is based on the development of corneal hypoxia and an immune response to antigens present on the lens surface, both of which lead to an inflammatory response and susceptibility to infectious organisms.1 This results in an increased incidence of ulcerative keratitis, Pseudomonas aeruginosa infection, and corneal neovascularization.2,3
ANATOMY AND PATHOPHYSIOLOGY
Contact lenses rest on a three-layer tear film (i.e., outer lipid, middle aqueous, and inner mucus layer) that covers the corneal and conjunctival epithelium. This tear layer provides oxygen and nutrients to the avascular cornea. The cornea receives nutrition from blood vessels at the limbus and the aqueous humor. It is believed that contact lenses increase tear evaporation and disrupt the three-layer tear film.4 This leads to the lack of corneal oxygenation and the symptoms of dry eye.4 A dry eye causes discomfort and corneal edema with resultant hazy vision. The normal blinking action initiates contact lens movement and a “fresh” flow of oxygenated tears over the cornea in an awake patient. Blinking is not present in the sleeping or comatose patient.
The normal resting position of the contact lens is over the cornea. It may occasionally drift from the center of the eye and relocate. It may relocate over the sclera, in various parts of the eye socket, or under the upper eyelid. Thorough exploration of all aspects is essential when evaluating an individual for the presence of contact lenses prior to their removal. Inspect under the lower eyelid margin and eversion of the upper eyelid. This requires double eversion of the eyelid for identification and retrieval (Chapter 185).5 Failure to adequately perform this examination can lead to the mistaken belief that a contact lens does not exist. A contact lens that remains in place acts as a foreign body and can lead to chronic irritation, inflammation, and development of a mass. Mass development from a retained contact lens typically occurs in the upper fornix of the eyelid.5
Contact lenses must be removed from any patient who is unconscious or suffers an ocular injury. Remove contact lenses before fluorescein stain is used to examine the eye. Fluorescein can permanently stain the contact lens material. Give patients the opportunity to remove their own contact lenses if there are no contraindications (i.e., immobilization or ocular trauma). Patients are usually quite adept at removing ...