Good visual outcomes of DALK help offset technical difficulty

Paris—Deep anterior lamellar keratoplasty (DALK) is associated with favorable anatomic and functional outcomes that make it an interesting alternative to penetrating keratoplasty (PK) for the surgical treatment of keratoconus, said Pierre Fournie, MD, at the European Society of Cataract and Refractive Surgeons meeting.

Dr. Fournie presented 2-year follow-up data from a series of 15 eyes of 15 patients treated at Hopital Purpan, Toulouse, France. All had contact lens-intolerant keratoconus

The predescemetic membrane dissection was performed using either air or viscoelastic injection. All eyes had suture removal at 3 to 6 months after surgery and topical steroid treatment was also stopped after 3 to 6 months. He reported that there were no graft failures and only a single patient lost best-corrected visual acuity (BCVA).

Visual acuity analyses showed that at 1 year, BCVA averaged 20/40 and had improved by a mean of 6 lines compared with preoperatively.

Mean keratometric astigmatism was stable at 6 months after selective suture removal and at 1 year, no eye had 6 D or more of astigmatism. Comparison of pre- to postoperative keratometry measurements showed a decrease of about 10 D.

Specular microscopy data revealed a mean decrease in endothelial cell count of 22.5% during the first 3 months after surgery but with no further change thereafter. However, there were a number of complications. Intraoperatively, perforations of Descemet's membrane occurred in 5 eyes (33%) and included two large perforations that had to be converted to PK. Among the postoperative complications, two grafts showed delayed epithelialization.

"DALK has many advantages compared with PK as it is extraocular surgery, avoids graft rejection, better preserves the endothelium, and is associated with an easier postoperative course. Given those benefits and the encouraging visual outcomes in these eyes, our interest in DALK continues even though it is a more technically difficult procedure," Dr. Fournie said.