A New Wrinkle
When do LASIK flaps warrant repositioning, and what’s the role of the OD?
Although dislocated, wrinkled LASIK flaps are increasingly rare with the advent of femtosecond lasers, they are still one of the most common LASIK urgencies you’ll encounter. Aggressive DLK or infection may be more devastating complications, but are so rare nowadays that we have difficulty even calculating their incidence. Most LASIK centers only treat a handful of flap complications a year, but prompt intervention can be essential in ensuring long-term quality vision.
Striae presentation can be subtle. Visual acuity is usually the most important metric when judging their severity and assessing the need for surgical revision. If visual acuity is good, the distinction between macro- (folds of the entire flap) and microstriae (usually just wrinkles in the epithelium) must be made. The more common microstriae may happen if the flap curvature does not perfectly match that of the ablated stromal bed. They are usually not visible as negative staining with fluorescein, and will not show a displaced gutter at the flap edge.
Microstriae tend to resolve over several months with little effect on vision. By contrast, macrostriae— usually the result of inadvertent eye rubbing or digital contact shortly after LASIK—will often fluoresce, show an enlarged gutter, and typically are more visually significant.
Ironing Out the Kinks
Consult the surgeon if macrostriae are present, regardless of acuity status, as the location of striae, size of edge gutter and presence of epithelial ingrowth all also factor in the decision. If the striae are peripheral or acuity is very good, you may elect to monitor over time. Striae can resolve over months to years, or may remain visually insignificant for the rest of the patient’s life.
If the comanagement team decides that surgical intervention is necessary, it is usually based on symptoms or risk of progression.
Surgical revision is not without risk; patients must be counseled about the potential for infection, epithelial ingrowth, flap inflammation and reduced visual acuity. If vision is affected by the striae, the risk of surgical intervention is usually easily accepted, given the potential long-term benefits of enhanced vision. Although flaps can be lifted and repositioned several months after the initial surgery, earlier intervention is usually better.
In the accompanying video, the patient was 20/15- UCVA for several weeks, but the team opted for surgical revision due to persistent complaints of poor night vision.
Surgical correction includes lifting and smoothing of the flap. After numbing the cornea with anesthetic, the surgeon will access the flap at the edge near the hinge. A special cannula is used to lift the corner, then separate the flap from the stromal bed, which is then rinsed and polished to remove cells and debris. The posterior surface of the flap is also cleaned, polished and smoothed with a surgical sponge.Finally, the flap is repositioned, with considerable attention paid to smoothing it with an outward sweeping motion from the center. Post-op meds are then begun in the same fashion as the initial surgery.
If you see these patients on the same day as the revision, you will notice mild residual flap wrinkles; these often resolve in a day. Due to the manual manipulation of the flap and stromal interface, it may take several days for acuity to return to acceptable levels, although most patients will report greatly improved vision the very next day. The comanaging OD should stress the importance of eye protection for the next week, especially during sleep (shields are recommended). Over the first several postoperative months, be aware of the increased risk of epithelial ingrowth.
Prompt diagnosis and surgical consultation, followed by patient reassurance, are the keys to successfully managing this infrequent but troubling LASIK complication. Although flap macrostriae can be permanently visually devastating, surgical revision is straightforward and highly successful.