Phototherapeutic smoothing as an adjunct to photorefractive keratectomy in porcine corneas.
OBJECTIVE
To study the smoothing effect of phototherapeutic keratectomy (PTK) using masking fluids as an adjunct to standard photorefractive keratectomy ablations.


METHODS
Six fresh porcine corneas underwent -6.00, -10.00, and -15.00 D sphere ablations using the VISX Star excimer laser. Multizone treatments to a maximum 6.5 mm radially symmetrical bed were used with a fluence of 160 mJ/cm2. Three of the treatments were supplemented with a thin layer of balanced salt solution and 6 microm of full beam PTK. The corneas were examined by electron microscopy.


RESULTS
Smoother treatment zones were apparent in corneas undergoing PTK following PRK. The effect was more marked at higher dioptric ablations.


CONCLUSIONS
PTK may improve surface smoothness after PRK, especially for higher dioptric ablations.
Horgan
S E
SE
Cornea & External Disease Service, Moorfields Eye Hospital, London, United Kingdom.
McLaughlin-Borlace
L
L
Stevens
J D
JD
Munro
P M
PM
D000818:Animals; D003315:Cornea / Q000601:surgery* / Q000648:ultrastructure*; D054018:Lasers, Excimer; D008855:Microscopy, Electron, Scanning; D009216:Myopia / Q000473:pathology / Q000601:surgery; D018903:Photorefractive Keratectomy / Q000379:methods*; D011897:Random Allocation; D012029:Refraction, Ocular; D013552:Swine