Long-Term Outcomes Of Deep Anterior Lamellar Keratoplasty Performed With The Big Bubble Technique And Femtosecond Laser Mushroom Configuration (Famk)

To evaluate the outcomes of Femtosecond-Assisted Mushroom Keratoplasty (FAMK), focusing on the frequency of Type 1 Big Bubble (BB1) formation and the stability of corneal curvature assessed by tomographic examination after suture removal.

Ophthalmology Clinic, Department of Surgery, Dentistry, Maternity and Infant, University of Verona, Verona, Italy

This retrospective study included 75 eyes affected by various corneal pathologies that underwent FAMK. All procedures were performed using the Victus 80 kHz femtosecond laser, enabling the creation of a mushroom-shaped incision on both the recipient cornea and the donor tissue. Postoperative follow-up examinations were conducted at 9–12 months and at 3 and 6 months after suture removal. Best-corrected visual acuity (BCVA) and corneal curvature parameters were recorded using the AS-OCT (Anterior Segment-Optical Coherent Tomography) MS39 (CSO, Italy).

The “mushroom-shaped” configuration was successfully achieved in all cases. BB1 formation occurred in 82.4% of eyes. Failure of BB1 formation and intraoperative perforation were observed in 17.6% and 10.8% of cases, respectively. Conversion to penetrating keratoplasty (PKP) was required in 5% of procedures. Mean BCVA improved significantly from 1.10 ± 0.75 logMAR preoperatively to 0.65 ± 0.65 logMAR at 9–12 months postoperatively (p = 0.0003). Keratometric values measured at 3 mm, 6 mm, and 7 mm before and after suture removal showed no statistically significant differences (p = 0.34, p = 0.32, and p = 0.93, respectively).

FAMK is a safe and effective surgical technique, characterized by a high rate of BB1 formation and a low conversion rate to PKP. In line with current literature, the procedure provides significant improvement in visual acuity and, importantly, demonstrates stability of corneal curvature following suture removal.