Long-term optical quality of the photoablated cornea.
High-order coreal wavefront analysis was performed in a population of 60 myopic eyes that underwent photorefractive keratectomy. Corneal aberration data over 3, 5, and 7 mm pupils were collected for up to three years after surgery. The optical performance of the anterior cornea was characterized by estimation of the modulation transfer function (MTF) and the point-spread function. The high-order corneal wavefront aberrations were shown to stabilize one year after surgery. Over photopic pupils, after an early slight increase, corneal RMS-high-order aberrations (HOA) tended to decrease toward preoperative values. On the other hand, over mid- and large-pupil sizes, corneal HOA significantly increased compared with the preoperative state, while the optical performance of the cornea was diminished. The MTF ratio showed a distinct decline in the optical quality of postoperative corneas at low and middle spatial frequencies over larger pupils in the range between 6 and 19 c/deg, especially for deeper ablations.
Lombardo
Marco
M
Vision Engineering, Via Torrione 2/D, Reggio Calabria, Italy. mflombardo@libero.it
Lombardo
Giuseppe
G
Serrao
Sebastiano
S
D000328:Adult; D003198:Computer Simulation; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery*; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009216:Myopia / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome