EPITHELIAL INGROWTH AFTER LASIK

To discuss treatment of epithelial ingrowth after LASIK

Maastricht University Medical Centre

A 39-year-old female presented to our clinic with photophobia. She has had laser in situ keratomileusis (LASIK) done abroad in 2004 and re-done in 2019, and has had photophobia and fluctuations in her visual acuity ever since the enhancement despite using steroid drops. The uncorrected distance visual acuity (UDVA) was 20/25 and 20/20 in her right and left eye, respectively, with a refraction of +0.50/-0.50x150 and +0.25/-0.00x0 diopters. Slitlamp examination showed grade 3 epithelial ingrowth (Probst/Machat classification) in both eyes inferior with melting flap edges, the latter more so in the left eye.

After careful consideration we planned the patient for surgery to lift the LASIK flap of the left eye and scrape the epithelial ingrowth. After applying alcohol 20% for 15 seconds and intensive irrigation, the melting flap was sutured back in place to obtain tight apposition. During the next 7 months, sutures were removed and steroids were cautiously tapered. So far no epithelial ingrowth has re-occurred. The patient will return in the upcoming weeks to evaluate the resulting astigmatism.

Epithelial ingrowth occurs when surface epithelium can migrate into the space between the corneal flap and the underlying stromal bed. The invading cells may become necrotic, which can lead to melting. Eyes prone to epithelial defects, postoperative inflammation, enhancement procedures, flap misalignment or corneal irregularities are known risk factors. Depending on the gradation, epithelial ingrowth can be observed, treated with steroid drops or operated on by lifting and irrigating the flap.

Ingrowth of epithelium into the corneal flap interface is a relatively uncommon complication of LASIK. When visual acuity becomes impaired because the ingrowth passes the visual axis (pupillary zone), the first line of treatment is steroid drops. When these fail and the cornea starts to melt, it is necessary –though tricky- to lift and irrigate the flap.