Safety of incomplete incision patterns in femtosecond laser–assisted penetrating keratoplasty

Purpose

To evaluate the wound integrity of incomplete contoured corneal incisions created with a femtosecond laser at a refractive surgery center followed by subsequent patient transfer to a separate surgical facility for penetrating keratoplasty (PKP).

Setting

Private tertiary referral center, Indianapolis, Indiana, USA.

Methods

This retrospective consecutive interventional case series comprised 46 eyes that had femtosecond laser PKP. Incomplete contoured incisions were created in the recipient cornea at a refractive surgery center. Patients were then transferred to an ambulatory surgical center for PKP.

Results

The indications for PKP included keratoconus, corneal scarring, bullous keratopathy, corneal dystrophy, and failed graft. Three incision contours were used: top hat (n = 26), mushroom (n = 13), and zigzag (n = 7). The incomplete portion of the incision was 70.0 to 300.0 μm in length. Leaving 150.0 to 300.0 μm of the lamellar ring cut incomplete did not ensure wound stability, whereas leaving 70.0 to 75.0 μm of the anterior side cut or posterior side cut incomplete provided excellent wound stability. In all eyes, the partial-thickness incisions enabled safe transport of the patient to the operating room without wound rupture, even with subsequent placement of a retrobulbar injection and a Honan balloon.

Conclusion

Incomplete femtosecond laser incision patterns that left some collagen lamellae intact maintained sufficient corneal strength to allow safe movement of the patient to a surgical facility for PKP.