Official ESCRS | European Society of Cataract & Refractive Surgeons


Clear cornea femto DALK: a novel approach for deep anterior lamellar keratoplasty (DALK) with femtosecond laser assistance

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Session Details

Session Title: Cornea Surgical: Lamellar Corneal Grafts

Session Date/Time: Tuesday 17/09/2019 | 08:30-10:30

Paper Time: 09:00

Venue: Free Paper Forum: Podium 3

First Author: : G.Gerten GERMANY

Co Author(s): :    P. Thiee   U. Oberheide                          

Abstract Details


We developed a novel technique for femtosecond laser-assisted (fs) DALK surgery, which may present some advantages over existing DALK techniques. Currently, DALK is mostly performed in big bubble technique with a mechanical trephine and manual dissection, which carries the risk of perforation or residual stromal tissue layers, both affecting visual outcome. Even if femtosecond lasers are used to cut surface-parallel layers (“deep flaps”), the technique of manually denuding Descemet’s basically stays the same. Femto Bubble DALK may increase the safety of Descemet’s membrane separation and enables the femtosecond laser to work as a trephine in a posterior/anterior direction.


Augenklinik am Neumarkt, Private Ophthalmology Clinic, Technische Hochschule Köln, Department of Applied Optics, Laserforum Köln e.V., Private Research Institute; all located in Cologne, Germany


Femto Bubble DALK technique was applied in 12 eyes of 12 patients with advanced keratokonus or deep stromal scars. Firstly, a tunnel through the corneal stroma was created down to Descemet´s Membrane either mechanically or by fs-Laser. A special cannula was used to inject liquid for separating Descemet’s membrane without compromising stromal’s transparency. Then a femtosecond laser trephined a stromal button in posterior–anterior mode under OCT-guidance. A stromal transplant was sutured onto Patient´s Descemet. After 6 month a complete ophthalmological examination was performed including contact lens VA, Scheimpflug measurement, AS-OCT and endothelial cell count.


The Femto Bubble Technique was successful in 11 out of 12 cases, of which 6 have six months’ results available so far. The femtosecond laser (Alcon LenSx) trephined the central stroma from the liquid separation bubble up to the epithelium with a diameter between 7.4 and 8 mm. Manual removal of tissue remnants on Descemet´s was not necessary. All patients kept their own endothelium with average cell loss < 10%. UCVA increased on average by ≥5 lines up to 0.6 logMAR in all cases. Mean contact lens VA increased from pre OP 0.9 logMAR to 0.2 logMAR post OP.


The combination of liquid bubble Descemet’s dissection and OCT-guided femtosecond laser trephination seems to open a new option for DALK surgery. A complete baring of Descemet’s membrane while avoiding a considerable perforation risk may be achieved. The method has the potential to improve the safety of DALK and to increase visual outcome.

Financial Disclosure:

gains financially from product or procedure presented, receives consulting fees, retainer, or contract payments from a company producing, developing or supplying the product or procedure presented

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