"Ultrathin" DSAEK tissue prepared with a low-pulse energy, high-frequency femtosecond laser.
OBJECTIVE
To evaluate the endothelial cell survival and stromal bed quality when creating deep stromal cuts with a low-pulse energy, high-frequency femtosecond laser to produce "ultrathin" tissue for Descemet stripping automated endothelial keratoplasty.


METHODS
Seventeen corneas were used for this study. Five corneas were cut with the laser at a depth of 420 to 500 μm to produce a tissue thickness of approximately ≤70 μm. Five corneas served as an uncut comparison group. Vital dye staining and computer digitized planimetry analysis were performed on these corneas. The 7 remaining corneas were cut for scanning electron microscopy evaluation.


RESULTS
The mean central posterior stromal thickness of cut corneas was 60.6 μm (range, 43-72 μm). Endothelial cell damage in cut and comparison corneas was 3.92% ± 2.22% (range, 1.71%-6.51%) and 4.15% ± 2.64% (range, 1.21%-7.01%), respectively (P = 0.887). Low-magnification (×12) scanning electron microscopy revealed a somewhat irregular-appearing surface with concentric rings peripherally. Qualitative grading of higher magnification (×50) central images resulted in an average score of 2.56 (between smooth and rough).


CONCLUSIONS
Ultrathin tissue for Descemet stripping automated endothelial keratoplasty can be safely prepared with minimal endothelial cell damage using a low-pulse energy, high-frequency femtosecond laser; however, the resulting stromal surface quality may not be optimal with this technique.
Sightline Ophthalmic Associates, Sewickley, PA, USA. paulphillipsmd@gmail.com
Paul M
PM
Phillips
Louis J
LJ
Phillips
Hisham A
HA
Saad
Mark A
MA
Terry
Donna B
DB
Stolz
Christopher
C
Stoeger
Jonathan
J
Franks
David
D
Davis-Boozer
D002452:Cell Count; D002470:Cell Survival; D003315:Cornea / Q000601:surgery*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000648:ultrastructure; D057111:Descemet Stripping Endothelial Keratoplasty; D004728:Endothelium, Corneal / Q000648:ultrastructure*; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods*; D008855:Microscopy, Electron, Scanning