Femtosecond laser meets DALK in big bubble
Using a femtosecond laser may provide a safe and effective means to standardise the “big-bubble” technique in deep anterior lamellar keratoplasty (DALK) procedures in eligible patients, according to Luca Buzzonetti MD.
“Our preliminary results suggest that the combination of the femtosecond laser and big-bubble technique could help to standardise this approach in DALK procedures, thereby reducing the learning curve for surgeons and also minimising the risks of intraoperative complications,” he told delegates at the XXXIV Congress of the ESCRS in Copenhagen, Denmark.
There are a number of advantages to using a femtosecond laser in DALK procedures, said Dr Buzzonetti. “Using the femtosecond laser increases accuracy in donor and recipient cut and provides a customised procedure to improve the contact between donor/recipient and interface. It also improves the healing process and enables surgeons to reach a deeper stromal depth in order to achieve the big bubble. Finally, it also makes suturing easier,” he said.
In the new big-bubble full femtosecond laser-assisted (BBFF) technique, Dr Buzzonetti uses a proprietary femtosecond laser (IntraLase®, Abbott Medical Optics) to create an intrastromal channel that is used as a pathway for the insertion of the air injection cannula.
He reported that the BBFF technique was tested in 10 eyes affected by keratoconus. The approach uses a 9.0mm diameter mask with a fissure 0.7mm wide positioned into the interface cone of the laser. The laser then performs a circular lamellar cut 100µm above the thinnest point, with photodisruption occurring only in the area of the corneal stroma corresponding to the fissure in order to create a deep stromal channel, explained Dr Buzzonetti, Chief, Department of Ophthalmology, Bambino Gesù Hospital, Rome, Italy.
Once that has been achieved, an arcuate incision is then performed from the corneal surface to the deep stromal channel to provide the entrance through the channel. After the removal of the lamella, the air needle is inserted into the stromal channel and air is injected to achieve a big bubble. After big-bubble formation, debulking of the anterior two-thirds of the corneal stroma is performed and the corneal stromal tissue excised. The donor lamella is then fitted into place using interrupted sutures.
In this study the big bubble was successfully achieved in nine out of 10 eyes and all procedures were completed as DALK, said Dr Buzzonetti.
“There are a lot of advantages to BBFF. We can work at a pre-defined corneal depth and the technique is independent of corneal keratometry. There is no steep learning curve involved and a high percentage of big bubbles can be obtained with a decreased risk of inadvertent perforation. The only significant downside is economic, due to the high cost of the femtosecond laser,” he said.
Luca Buzzonetti: email@example.com