Femtosecond Laser-Assisted Intracorneal Keratoprosthesis Implantation

Improving Boston type 1 keratoprosthesis procedure: one-touch femtosecond-assisted preparation and centration of donor carrier tissue

PURPOSE

We describe a technique to avoid decentration of the visual axis of the Boston type 1 keratoprosthesis (Kpro), performing 2 concentric trephinations with femtosecond laser.

METHODS

Two concentric side cuts were performed in a donor cornea using the 150-kHz Intralase FS laser. Within the same applanation procedure, an 8.5-mm-diameter anterior side cut was performed, followed by a concentric 3-mm-diameter anterior side cut.

RESULTS

The technique was successfully replicated in 7 cases.

CONCLUSIONS

Femtosecond laser-assisted double trephination results in a correctly prepared donor cornea, and in an inner side precisely matched with the prosthesis. At the end of the surgery, the Kpro was correctly centered.

Femtosecond-assisted preparation of donor tissue for Boston type 1 keratoprosthesis

We describe a technique for femtosecond laser-assisted preparation of donor tissue for Boston type 1 keratoprosthesis to provide accurate double punching of the donor tissue for optimized alignment in the visual axis. The technique was reproducibly performed in four donor corneas mounted in an artificial anterior chamber. This technique can provide optically centered donor tissue with smooth trephinated edges.

Femtosecond lasers in ophthalmology

PURPOSE

To provide an update and review of femtosecond (FS) lasers in clinical ophthalmology.

DESIGN

Perspective, literature review, and commentary.

METHODS

Selected articles from the literature and the authors' clinical and laboratory studies.

RESULTS

The FS laser employs near-infrared pulses to cut tissue with minimal collateral tissue damage. Although its major use at present is in the cutting of laser in situ keratomileusis flaps, the laser has proven its versatility in laser-assisted anterior and posterior lamellar keratoplasty, cutting of donor buttons in endothelial keratoplasty, customized trephination in penetrating keratoplasty, tunnel creation for intracorneal ring segments, astigmatic keratotomy, and corneal biopsy. Current laboratory studies include all-FS laser refractive keratomileusis sans flap, cutting corneal pockets for insertion of biopolymer keratoprostheses, noninvasive transscleral glaucoma surgery, retinal imaging and photodisruption, presbyopia surgery, and anterior lens capsulorrhexis.

CONCLUSIONS

Advances in ultra-fast laser technology continue to improve the surgical safety, efficiency, speed, and versatility of FS lasers in ophthalmology.

Femtosecond laser-assisted corneal surgery

PURPOSE OF REVIEW

The femtosecond laser has potentially improved the safety and precision of creating corneal flaps in laser in situ keratomileusis (LASIK). This review focuses on recent advances in applying femtosecond laser technology to other corneal procedures.

RECENT FINDINGS

The femtosecond laser is capable of cutting tissue at various depths and patterns with minimal collateral tissue injury. The laser can now be used to perform corneal pockets for ring segments, arcuate wedge-shaped resection in correction of high astigmatism, lamellar dissections in anterior lamellar keratoplasty, donor tissue preparation in Descemet's stripping endothelial keratoplasty, and shaped full-thickness keratoplasty.

SUMMARY

Femtosecond laser-assisted corneal surgery may provide a more precise and safer approach to corneal surgery.

Femtosecond Laser Keratome Creation of Partial Thickness Donor Corneal Buttons for Lamellar Keratoplasty

PURPOSE

To evaluate the thickness and diameter accuracy of the IntraLase femtosecond laser in harvesting corneal discs for lamellar keratoplasty. The stromal bed quality of resected corneas was evaluated by scanning electron microscopy.

METHODS

Two IntraLase units were used to create corneal discs at 225-, 300-, 400-, and 500-microm thickness settings and 7-, 8-, 8.5-, and 9-mm diameter settings (n = 28). Achieved thickness was measured using a digital caliper and achieved diameter was measured using imaging software. Samples were preserved and processed for scanning electron microscopy to observe stromal bed quality.

RESULTS

On both units, the mean deviation from attempted thickness was -9.5 +/- 8.6 microm (range: +6 to -28 microm). All of the obtained corneal discs were circular (horizontal versus vertical diameters, P > .05). The raster pattern produced a smoother stromal bed compared to the spiral pattern.

CONCLUSIONS

The IntraLase femtosecond laser keratome provides depth and diameter accuracy even at increased depth settings. Stromal bed was smooth with the raster pattern and can further be smoothed by excimer phototherapeutic keratectomy treatment. Femtosecond laser lamellar keratoplasty is a promising procedure and clinical data are needed to determine effectiveness.