Corneal reprofiling using an annular beam of ablative radiation
US5613965A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 8, 1994 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Dec 8, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2009/00872
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Methods and systems are disclosed for corneal reprofiling employing an annular beam of ablative radiation to correct refractive errors in vision, and/or create "blend zones" in order to reduce any surface discontinuities on the cornea following hyperopia-correcting or astigmatism-correcting procedures. Preferably, the methods and systems of the present invention also operate to change the intensity distribution of the light beam, such that the annulus of radiation has a varying intensity as a function of radius and, thereby, achieves a blending or other desired effect with the least number of pulses. Methods of photorefractive keratectomy (PRK) are disclosed, including the steps of (a) selectively reprofiling a cornea of an eye by removing a volume of corneal tissue with ablative radiation to form a reprofiled region in the optical zone which steepens, at least in part, the central curvature of the cornea; and (b) applying to a peripheral region of the cornea an annular beam of ablative radiation having an intensity which varies radially from a inner to a outer segment of the annular beam to create a blend zone, thereby providing a smooth transition between the repro filed region a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.