Photorefractive keratectomy
US5163934A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 5, 1987 |
| Grant date | Nov 17, 1992 |
| Priority date | — |
| Expiry date | Aug 5, 2007 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F2009/00872
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Photorefractive keratectomy is accomplished by an excimer laser beam that ablates away corneal tissue in a photo decomposition process. Before this occurs, the epithelium (21) of the cornea (20) is surgically removed to expose Bowman's layer (22) on the anterior surface of the stroma (23) and to begin the laser ablation at Bowman's layer. An excimer laser beam is preferred for this and is rotated during the ablation to average out energy density variations in the beam. The beam is also variably masked concentrically of its axis, during the ablation, to remove corneal tissue to varying depths as necessary for recontouring the anterior stroma. Afterward, epithelium (21) rapidly regrows and resurfaces the contoured area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.