Abstract | PURPOSE: METHODS: Forty-nine patients (98 eyes) underwent PRK using an excimer laser platform. Patients were subdivided into three groups according to their preoperative spherical equivalent refraction and amount of cylinder component: the low- myopia, the high- myopia, and the astigmatism group. Preoperative and 1-, 3-, and 6-year postoperative root-mean-square values of coma, spherical aberration (SA), and total high-order aberrations ( HOA) were calculated over 3.50- and 6.00-mm pupil diameters. Modulation transfer function (MTF) values and point spread functions were calculated to describe the impact of myopic PRK on the optical performance of the cornea during follow-up. RESULTS: The amount of postoperative SA was higher (P < 0.05) than the preoperative state in both the low- and the high- myopia groups over 3.50- and 6.00-mm pupil sizes. The postoperative increase of coma was statistically significant (P < 0.05) only in the high- myopia group over both pupil sizes. Total- HOA increased (P < 0.05) after PRK in all the study groups over 6.00-mm pupil. A distinct increase in the ratios of MTF was calculated over 6.00-mm pupil, at low and middle spatial frequencies in the range between 5 and 15 cyc/deg, especially after the deepest myopic ablations. CONCLUSIONS: The high-order wavefront aberration of the anterior cornea stabilized 1-year after PRK for the treatment of myopia up to -9.00 D. The effect of induced HOA on the image optical quality of the cornea was increased mainly after the correction of high myopia over scotopic pupil.
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Authors | Sebastiano Serrao, Giuseppe Lombardo, Pietro Ducoli, Marco Lombardo |
Journal | Investigative ophthalmology & visual science
(Invest Ophthalmol Vis Sci)
Vol. 52
Issue 2
Pg. 846-57
(Feb 11 2011)
ISSN: 1552-5783 [Electronic] United States |
PMID | 21051709
(Publication Type: Journal Article)
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Topics |
- Adult
- Astigmatism
(physiopathology, surgery)
- Cornea
(physiology)
- Corneal Topography
- Corneal Wavefront Aberration
(physiopathology)
- Female
- Follow-Up Studies
- Humans
- Lasers, Excimer
(therapeutic use)
- Male
- Myopia
(physiopathology, surgery)
- Photorefractive Keratectomy
- Refraction, Ocular
(physiology)
- Visual Acuity
(physiology)
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