Epithelial defects after LASIK may be secondary to epithelial basement membrane dystrophy, overhydration with preoperative drops, lack of corneal wetting immediately before the microkeratome pass, or intrinsic anomalies or imperfections with a microkeratome. A common cause is subclinical epithelial basement membrane dystrophy. These patients do not have the typical map-like or fingerprint lines of epithelial basement membrane dystrophy. The use of fluorescein dye and a cobalt-blue light may allow visualization of abnormal tear breakup over areas of epithelial irregularity.
The patient presents 18 months after bilateral LASIK with epithelial ingrowth in the right eye and recurrent erosion in the left eye. The epithelial ingrowth in the left eye is clinically significant (>2.0 mm) and is inducing peripheral topographic irregularity despite maintaining BCVA. The “heavy ingrowth” requires urgent management to decrease the risk of a stromal melt. I would make an accurate drawing of the location and extent of the ingrowth and take the patient to the operating room for a flap lift and debridement. I would use a spatula to separate the peripheral flap edge and try to achieve a sharp epithelial edge without a tear. Once the flap is lifted, I would use a crescent blade and scrape the epithelial cells on the bed and flap. It is important to be especially gentle on the flap side because of the possibility of existing melting and thinning. Before the flap is repositioned, I would ensure there are no epithelial cells in the periphery of the bed.
I would insert a bandage contact lens to be removed 1 day postoperatively if the epithelium is intact. I would treat the eye with a topical fluorometholone steroid (eg, Flarex®) and a fluoroquinolone antibiotic (eg, Ciloxan®) 4 times a day for 5 days. Follow-up is critical to detect a recurrence. If a clinically significant recurrence develops, I would repeat the above steps and consider a wide-area PTK of 5 to 8 μm to the bed.
The recurrent erosion of the left eye can be managed with a bandage contact lens, fluoroquinolone antibiotic 3 times a day, and sodium chloride 5% (Muro 128®) 3 times a day. When the epithelium becomes relatively smooth without white or gray patches, the contact lens can be removed and the antibiotic discontinued. This may take several weeks. If the patient continues to have erosions in the same location despite the use of a bandage lens, I would consider a focal area of debridement or anterior stromal micropuncture. If erosions occur in different areas of the cornea, I would consider PTK. The epithelium overlying the flap and not including the flap margin would be debrided and wide-area PTK performed at a depth of 5 to 8 μm. A bandage lens would then be inserted until the epithelium becomes intact.
If the patient does not have satisfactory UCVA despite resolution of the ingrowth and recurrent erosions, I would consider an enhancement by PRK with mitomycin to the flap. I would not recommend lifting the flap. It is important, however, that PRK in cases of epithelial basement membrane dystrophy may result in refractive surprises because of the variable thickness of the overlying epithelium.