Photo-refractive keratectomy
US5505723A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 1994 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Feb 10, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2009/00872
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Methods and apparatus as disclosed for shaping the cornea of a patient's eye such that the epithelial tissue of the patient's cornea is shaped into a preliminary shape, corresponding to a desired final stromal shape, using photoablative radiation, and then the preliminary shape of the epithelial tissue is transferred into the stromal tissue of the cornea using photoablative radiation, thereby shaping the cornea into the desired final stromal shape. The epithelium may be shaped using an erodible mask with a predefined profile of resistance to erosion, or by a graded intensity filter, or by selectively varying the dimension of an aperture that controls the area of the epithelial surface irradiated by the photoablative laser radiation or by other mechanisms that selectively expose regions of the epithelium, or by a scanning laser beam. The epithelium may also be shaped, without using an aperture or a mask, by using a beam of photoablative radiation with substantially uniform intensity distribution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.