Monday, October 20, 2008

Abstract: LASIK and the ocular surface

Nice succinct summary of the major ocular surface complications LASIK can present. Note in particular the reference to RCE happening to people who already had a poorly adhering epithelium. This is one of the reasons that if you're going to get laser surgery, you need to be evaluated really, really thoroughly by a specialist first... Mild ABMD is not obvious, and I know plenty of people who did not have it diagnosed before LASIK... and in a few cases, the first thing that caused them to learn about it was when their epithelium sloughed off after surgery. (By the way, that hurts. A lot.)

LASIK and the ocular surface.
Cornea. 2008 Sep;27 Suppl 1:S70-6.
Toda I.

Wound healing after LASIK sometimes compromises homeostasis of the ocular surface. Diffuse lamellar keratitis is a post-LASIK inflammatory condition in the interface that appears during the first week after LASIK. The etiology of diffuse lamellar keratitis is unknown, but the association with allergic reaction to detergent, bacteria, and other chemicals is suspected. The condition is mostly self-limiting. Topical and/or oral corticosteroids may be effective against stage 2 disease, whereas flap lift and irrigation might be required in stage 3. Epithelial ingrowth occurs in about 1% of LASIK eyes. Although most cases heal spontaneously, some require surgical removal. There are 2 known mechanisms for epithelial ingrowth: epithelial invasion and epithelial implantation. Epithelial invasion grows in 2 distinct ways--outside invasion and flap epithelial invasion. The latter type is often seen after enhancement and may be treatment resistant. Patients with compromised attachment of corneal epithelium before LASIK may develop recurrent corneal erosion, which sometimes requires phototherapeutic keratectomy. Subepithelial opacity after viral infection, even long after infection, often recurs after LASIK and affects refraction and visual acuity. Topical corticosteroid may be effective to prevent recurrence. Dry eye is a common complication after LASIK. Although post-LASIK dry eye is usually temporary, some patients complain of severe symptoms that may negatively influence their satisfaction with the outcome. For example, functional visual acuity significantly decreases after LASIK. The possible mechanisms for post-LASIK dry eye may be associated with loss of neurotrophic effect, damage of goblet cells, and altered corneal shape.


Some of you whose lives have been turned upside down for a couple of years by severe post LASIK dry eye might get a giggle out of this understatement from the abstract:

Although post-LASIK dry eye is usually temporary, some patients complain of severe symptoms that may negatively influence their satisfaction with the outcome.


For the laypeople reading this, don't forget "usually" can mean anywhere between 51% on up (and doctors, before you're tempted to tell me I'm overdramatizing things, go back and read the published studies that showed between 15 and 36% of patients having unresolved dry eye 6 months after surgery).

And any doctor that is surprised 24/7 pain can make you dissatisfied with an elective surgery, please raise your hand (grin).

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