18 June 1999 Measuring effects of refractive surgery on corneas using Taylor series polynomials
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Proceedings Volume 3591, Ophthalmic Technologies IX; (1999) https://doi.org/10.1117/12.350598
Event: BiOS '99 International Biomedical Optics Symposium, 1999, San Jose, CA, United States
Abstract
Corneal topographers have made it possible to accurately map corneal shape. We applied this technology to model the post- refractive surgery cornea using Taylor series polynomials. Topography data was taken from 58 patient eyes with photorefractive keratectomy (PRK) or astigmatic photorefractive keratectomy (PARK). We looked at the changes the cornea underwent surgically, as well as the healing process. We compared the post-ablation cornea to the pre-ablation cornea and to the intended correction using novel topography maps. From the refractive map, we quantified the spherical aberration as areas of defocus on the cornea. From the pre-op exam to the first post-op exam, we measured 0.19±0.10 mm radius decrease in PRK and a 0.13±0.08 mm radius decrease in PARK in the areas where rays come to within two diopeters of defocus. As this change occurs within the optical zone, this corresponds to an increase in spherical aberration for both the PRK and the PARK patient. As the patient healed, we found additional decrease in radius of the zones of best vision in PRK patients, whereas we found no significant decrease in PARK patients. This corresponds to increased spherical aberration in the PRK patient.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jacob A. Corbin, Stanley A. Klein, Corina van de Pol, "Measuring effects of refractive surgery on corneas using Taylor series polynomials", Proc. SPIE 3591, Ophthalmic Technologies IX, (18 June 1999); doi: 10.1117/12.350598; https://doi.org/10.1117/12.350598
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