Peeling-Off Spiral DALK: 10-Year Experience

The aim of this study was to report the outcomes of "peeling-off spiral" deep anterior lamellar keratoplasty (DALK), a manual DALK technique that allows for a deep, fast, and reliable stromal removal, taking advantage of the lowest adhesion among the posterior stromal lamellae.

This was a retrospective case series of patients who underwent "peeling-off spiral" DALK between January 2014 and September 2024, with at least 1 year of follow-up. Indications for DALK, intraoperative and postoperative complications, residual recipient bed thickness, and postoperative best corrected visual acuity (BCVA) at 1 year of follow-up were evaluated.

A total of 149 DALK eyes (122 patients) underwent "peeling-off spiral" DALK for corneal ectasia (87 eyes), stromal scar (31 eyes), and active infection (31 eyes). In cases of previous hydrops or full-thickness penetrating corneal wound (9 eyes), a modified "assisted peeling-off spiral" DALK procedure was performed, where the peeling of the stroma was aided by a crescent blade to reduce the pulling force and avoid enlargement of the preexisting DM break. Six intraoperative ruptures were recorded (4%); however, 3 were preexisting DM breaks from previous hydrops, 2 were reopenings of previous full-thickness corneal penetrating wounds, and only 1 (0.7% of cases without preexisting breaks) was a new intraoperative DM rupture. The mean residual recipient bed thickness was 40.1 μm at 1 day postoperatively (range 21-131 μm) and 28.4 μm (range 17-85 μm) at 3 months postoperatively. The mean postoperative BSCVA at 1 year of follow-up was 0.73 ± 0.19 (range 0.4-1.0).

"Peeling-off spiral" DALK is a valuable and reliable manual technique that achieves a deep stromal plane, with favorable visual outcomes and a low rate of complications.