Femtosecond laser zigzag deep lamellar keratoplasty treats corneal stromal pathology
BOSTON — A technique that combines femtosecond laser zigzag deep lamellar keratoplasty with Anwar’s big bubble technique yields rapid recovery of corrected distance visual acuity in patients with stromal pathology, primarily keratoconus, according to a speaker here.
Marjan Farid, MD, described the technique to colleagues at the American Society of Cataract and Refractive Surgery annual meeting. Initially using a femtosecond laser, a zigzag incision is made, leaving about a 70-µm tissue bridge posteriorly. In most cases, lamellar dissection is done, leaving a thin posterior stromal bed. The needle insertion with an air syringe is then made into that posterior stroma, thereby baring Descemet’s membrane with a big bubble technique, and the donor cornea, which has been cut with the same zigzag shape, is sutured.
“Several helpful innovations in our most recent cases have given us better success rates,” Farid said, including faster laser and protective DALK scissors (Rhein) for safe dissection and removal of posterior stroma, thus minimizing risk of Descemet’s membrane perforation.
Of 31 patients followed in a retrospective chart review, corrected distance visual acuity improved to about 20/40 by month 3 and continued to improve into the 20/25 to 20/30 range over varying follow-up points out to 3 years for some patients.
Regarding complications, Farid said, “We did have one case of visually significant Descemet’s striae that did have to be converted to a full-thickness keratoplasty.”
Disclosure: Farid is a consultant for Abbott Medical Optics.