Microwave thermal keratoplasty for myopia: keratoscopic evaluation in porcine eyes.
OBJECTIVE
Microwave thermal keratoplasty applies microwave energy to elevate the temperature of the paracentral stroma of the cornea to its thermal shrinkage temperature of about 60 degrees C. A suitable pattern of shrinkage in the paracentral cornea can flatten the central cornea. A surface cooling system preserves the epithelium during the procedure.


METHODS
Fourteen enucleated porcine eyes were treated with a prototype microwave thermal keratoplasty applicator that heated in a ring pattern with inner diameter of 3.2 mm and width of 0.7 mm. The change in corneal power was quantified by a videokeratoscope. Slit-lamp microscope examinations and histological assessments were made.


RESULTS
The 3-mm simulated keratometry reading showed an average of 6.60+/-6.00 D (standard deviation) of flattening. The region of opacity associated with shrinkage extended to 62% (+/-26%) of the corneal thickness. The epithelium was intact in all eyes.


CONCLUSIONS
Microwave thermal keratoplasty applied in the paracentral cornea may flatten the central cornea.
Trembly
B S
BS
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA.
Hashizume
N
N
Moodie
K L
KL
Cohen
K L
KL
Tripoli
N K
NK
Hoopes
P J
PJ
D000818:Animals; D003319:Corneal Stroma / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D004564:Electrocoagulation / Q000379:methods*; D008872:Microwaves; D008954:Models, Biological; D009216:Myopia / Q000473:pathology / Q000601:surgery*; D013552:Swine; D016896:Treatment Outcome