Contact Lens Overwear and Contamination

2.11 Contact Lens Overwear and Contamination

Presentation
A patient who wears hard, impermeable contact lenses may come to the ED in the early morning complaining of severe eye pain, after he has fallen asleep with his lenses in or stayed up late, leaving his lenses in for more than 12 hours. Extended-wear soft lenses can cause a similar syndrome when left in for days or contanimated with irritants. The patient may not be able to open his eyes for examination because of pain and blepharospasm. He may show obvious corneal injury, with signs of iritis and conjunctivitis, or show no visible findings at all without fluorescein staining.
What to do:



Instill topical anesthestic drops.



Perform a complete eye exam including pupillary reflexes, funduscopy, and inspection of conjunctival sacs. Use a slit lamp if available.



If you see any ulcerations on the cornea, call for ophthalmologic consultation right away. Acanthameba infections from soft lenses can damage the eye rapidly, and may require excision and hospitalization.



Instill fluorescein dye (use single-dose dropper or wet a dyeimpregnated paper strip and touch it to the tear pool in the lower conjunctival sac), have the patient blink, and examine under cobalt blue or ultraviolet light for the green fluorescence of dye bound to devitalized corneal epithelium. This staining should demonstrate central corneal uptake of fluorescein without sharply demarcated borders.



Sketch the area of corneal injury on the patient record, rinse out the dye and instill tobramycin or gentamycin ointment in the lower conjunctival sac.



Prescribe analgesics (e.g., naproxen, ibuprofen, oxycodone) and give the first dose.



Instruct the patient to avoid wearing his lenses until cleared by the ophthalmologist, and to seek ophthalmologic followup within one day.
What not to do:



Do not discharge a patient with topical anesthetic ophthalmic drops for continued administration: they potentiate serious injury.



Do not let a patient re-use contaminated or infected soft lenses.



Do not patch contact lens abrasions or early ulcerative keratitis.



Do not prescribe antibiotic ointments that do not provide prophylaxis against Pseudomonas (e.g., erythromycin and sulfas).



Do not use steroid-containing drops or ointments.
Discussion
Hard contact lenses and extended-wear soft lenses left in place too long deprive the avascular corneal epithelium of oxygen and nutrients from the tear film. This produces diffuse ischemia, which usually heals perfectly in a day, but can be exquisitely painful as soon as the lenses are removed. Soft lenses can absorb chemical irritants, allergens, bacteria and ameba if they soak in a contaminated cleaning solution. There are approximately 25 million contact lens wearers in the US. Adverse reactions range from minor transient irritation to corneal ulceration and infection that may result in permanent loss of vision from corneal scarring. Pseudomonas is most commonly associated with contact lens-related keratitis. It is for this reason that the management of these cases should differ from routine care given to mechanical corneal abrasions not caused by contact lenses. Occlusive patching and corticosteroid medications favor bacterial growth and are therefore not recommended in the setting of contact lens use.
References:



Schein Oliver D: Contact lens abrasions and the nonophthalmologist. Am J Emerg Med. 1993;11:606-608.