This retrospective case series compared outcomes of 125 corneal transplantations for keratoconus: 100 with penetrating keratoplasty (PK) and 25 with deep anterior lamellar keratoplasty (DALK) using either the modified Anwar technique or manual lamellar keratoplasty. Visual acuity results with the Anwar technique were similar to PK and significantly better than results with the manual DALK technique. The Anwar technique also produced fewer postoperative complications than PK.
PK was associated with a higher rate of allograft rejection, and ultimately led to late graft failure in three cases. It was also complicated by a higher incidence of postgraft glaucoma, cataract and wound dehiscence. DALK with the modified Anwar technique; however, was associated with a higher risk of intraoperative complications. Four cases of microperforation and one case of macroperforation (that required conversion to PK) were encountered.
In a companion editorial, John E. Sutphin, Jr, MD, professor and chair of the Ophthalmology Department at the University of Kansas Medical School, writes that the study provides compelling evidence that DALK may offer not only a safer alternative to PKP, but may offer better visual outcomes when properly performed.
"The principal barriers to the widespread adoption of DALK are increased technical difficulty and longer surgical times when compared with PKP. In addition, DALK is in direct competition with laser-assisted keratoplasty (LAK). Management of keratoconus with LAK provides faster wound healing and decreased suture retention time, which may reduce the time necessary for visual rehabilitation, compared with traditional keratoplasty. LAK is, however, more expensive and not easily accessible to all surgeons.
"Nonetheless, as the authors suggest, the increased safety of DALK and the potential for better visual outcomes in expertly performed procedures justifies the effort required for corneal surgeons to master the procedure and the additional operating room time."