Surgery – Instruments – Light application
Patent
1994-12-08
1997-03-25
Shay, David M.
Surgery
Instruments
Light application
606 2, 606 10, 606 14, A61N 502
Patent
active
056139659
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 and an unablated region of the cornea. Optical lens elements also are disclosed having a generally conic front face and a rear face which is generally perpendicular to the path of the incident beam. Light passing through this optical element will be refracted into an annular beam. Variations in the intensity profile of the annular beam can be introduced by employing an initial beam which has a non-uniform profile, or by modifying the shape of either the front face or the rear face of the optical element.
REFERENCES:
patent: 4724522 (1988-02-01), Belgorod
patent: 4729372 (1988-03-01), L'Esperance, Jr.
patent: 4887592 (1989-12-01), Loertscher
patent: 4941093 (1990-07-01), Marshall et al.
patent: 4973330 (1990-11-01), Azema et al.
patent: 4994058 (1991-02-01), Raven et al.
patent: 5019074 (1991-05-01), Muller
patent: 5102409 (1992-04-01), Balgorod
patent: 5152759 (1992-10-01), Parel et al.
patent: 5256853 (1993-10-01), McIntyre
patent: 5281211 (1994-01-01), Parel et al.
Rioux, M. et al. (1978) "Linear, annular, and radial focusing with axicons and applications to laser machining" Applied Optics 17 (10): 1532-1536.
Engellenner Thomas J.
Rainville Peter J.
Shay David M.
Summit Technology Inc.
LandOfFree
Corneal reprofiling using an annular beam of ablative radiation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Corneal reprofiling using an annular beam of ablative radiation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Corneal reprofiling using an annular beam of ablative radiation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2199763