Apparatus and method for performing laser thermal keratoplasty with minimized regression
US6520956B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Oct 1, 1999 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Oct 1, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2009/00872
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Apparatus and method for preforming laser thermal keratoplasty capable of treating treatment areas with shapes that reduce regression. Both contact and non-contact apparatuses and methods are provided. The apparatus includes laser sources, a projection optical system, observation system, and control system. In some embodiments, the projection system uses two steering mirrors or a mask to control laser beam position on the cornea. This projection system enables precise control of the area of corneal heat shrinkage using relatively low-powered lasers, such as diode lasers. Desired changes in corneal refractive power are produced by selected patterns of photothermal shrinkage of corneal collagen tissue. The selected patterns are arrangements of oblong shapes that are preferably tapered at the ends of the long axis. The oblong shape and tapering distribute tension in the cornea over a wider area of collagen shrinkage and improve the stability of refractive correction. The long axes of the oblong treatment areas are preferably oriented radially for hyperopia correction and circumferentially for astigmatism correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.