Intrastromal refractive surgery with ultrashort laser pulses: in vivo study on the rabbit eye.
BACKGROUND
Femtosecond (fs) laser pulses may offer new possibilities in the field of refractive surgery, especially when using the laser as a microkeratome. By induction of nonlinear absorption processes the laser can be used to perform intrastromal cuts. The conventional microkeratome, associated with numerous potential side effects, can possibly be replaced. Furthermore, refractive lenticules can be prepared within the stroma and removed in a single-step operation.


METHODS
In 10 rabbits, cuts were made to create both a lamellar flap and an intrastromal refractive lenticule. The flap was lifted, the lenticule was extracted and, finally, the flap was repositioned (intrastromal laser keratomileusis, ILK). The corneal samples were collected up to 120 days after treatment and processed for histopathological analysis.


RESULTS
All flaps could be opened and prepared lenticules could be extracted in one piece by the surgeon. The treated corneas developed a mild wound healing reaction, comparable to that known from excimer laser in situ keratomileusis (LASIK) studies. The wound healing was restricted to the flap-stroma interface, most pronounced at the periphery of the flaps.


CONCLUSIONS
The use of the fs-laser offers new possibilities in preparation of corneal flaps, possibly providing advantages over conventional microkeratomes. Furthermore, the fs-laser has the potential to create intrastromal refractive lenticules for complete refractive procedures (ILK).
Heisterkamp
Alexander
A
Laser Zentrum Hannover eV, Hollerithallee 8, 30419, Hannover, Germany. ah@lzh.de
Mamom
Thanongsak
T
Kermani
Omid
O
Drommer
Wolfgang
W
Welling
Herbert
H
Ertmer
Wolfgang
W
Lubatschowski
Holger
H
D000818:Animals; D003319:Corneal Stroma / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005123:Eye / Q000473:pathology; D053685:Laser Therapy / Q000379:methods; D013508:Ophthalmologic Surgical Procedures; D011817:Rabbits; D054140:Refractive Surgical Procedures; D013524:Surgical Flaps; D014945:Wound Healing