BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein like reference numerals refer to similar components:
FIGS. 1A-H illustrate sectional views of corneas, each overlaid with a resection pattern which includes uncut gaps; and
FIG. 2 schematically illustrates a system for resecting corneal tissue using a resection pattern having an uncut gap.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning in detail to the drawings, FIG. 1A shows the recipient cornea 11 with the profile of the resection pattern 13 overlaid. Such a resection pattern, as with all the resection patterns disclosed herein, are designed to excise corneal tissue 15 from the recipient cornea 11 as part of a corneal transplant procedure. When the cornea 11 is incised with the full resection pattern 13, without any uncut gaps, the corneal tissue 15 bounded by the resection pattern is excised from the cornea 11. However, two uncut gaps 17 are included in the resection pattern 12 shown, so that connecting tissue will continue to secure the corneal tissue 15 to the outer portion of the cornea 11 until such time as that connecting tissue is severed. The overall size of each uncut gap within the resection pattern 13 is left to the discretion of the attending surgeon. The particular location of each uncut gap 17 within the resection pattern 13 is also left to the discretion of the attending surgeon. While two uncut gaps 17 are shown, any number of uncut gaps may be left in the resection pattern, with the number of uncut gaps being at the discretion of the attending surgeon.
By leaving the uncut gaps 17 in the resection pattern 13, tissue along the incision and the internal chambers of the eye remain protected and unexposed to environmental contaminants so long as the corneal tissue 15 remains in place. The patient may therefore be moved between a preparation room, where a resection pattern having uncut gaps is incised, and an operating room, where the transplant procedure takes place, without exposing the patient to risk of the corneal tissue 15 dislodging during the move. Such risk would always be present if the entire resection pattern is incised in a preparation room prior to moving the patient to the operating room.
Once in the operating room, the uncut gaps 17 may be incised using any appropriate surgical instrument. Preferably, a bladed instrument would be used. However, if the uncut gaps are sufficiently small, they could be cut with a more blunt instrument.
FIGS. 1B & 1C show the same resection pattern 13 overlaid on the cornea 11, but with the uncut gaps in different locations. In FIG. 1B, each uncut gap 17 is adjacent the intersection between two sections of the resection pattern 13, which come together at an angle. The uncut gaps 17 are actually disposed on the section of the resection pattern 13 running from the anterior corneal surface 19. In FIG. 1C, each uncut gap 17 is adjacent the posterior corneal surface 21.
FIGS. 1D-1E each shows a resection pattern 23 which has a zig-zag pattern in profile. Again, the uncut gaps 17 may be placed at any desired location within the resection pattern 23.
FIGS. 1G & 1H each show a resection pattern 25 which has a profile forming a straight line between the anterior corneal surface 19 and the posterior corneal surface 21. In FIG. 1G, the uncut gaps 17 are disposed at the posterior corneal surface 21, whereas the uncut gaps 17 in FIG. 1H are disposed at the anterior corneal surface 19.
Referring to FIG. 2, a femtosecond surgical laser 31 generates a pulsed laser beam 33 and directs that beam into the focusing assembly 35, which in turn focuses the pulsed beam 33 into the cornea 37. The controller 39 is a programmable computer which precisely controls the location of the beam focal point within the cornea 37 according to parameters received from the surgeon interface 41. The interface 41 presents the surgeon with several incision patterns from which the desired resection pattern is selected. In addition, the interface 41 presents the surgeon with several options for gap placement from which the surgeon selects the desired gap configuration. The selected options are sent to the controller, and the controller 39 applies the selected gap configuration to the selected resection pattern for purposes of controlling the focusing assembly and incising the resection pattern, with the appropriate gaps, in the cornea. Alternatively, the controller 39 may control the beam 33 emitted from the surgical laser 31 such that the beam 33 would not be emitted as the focusing assembly 35 effectively “scans” the focal point over those parts of the resection pattern where a gap has been located. This alternative technique could be used to maintain the continuity of a pre-established scan pattern.
The surgical laser may be of the type described in U.S. Pat. No. 4,764,930, producing an ultra-short pulsed beam as described in one or both of U.S. Pat. No. 5,984,916 and U.S. Pat. No. RE37,585 to photodisrupt corneal tissues. The focusing assembly may be of the type described in U.S. patent application Ser. No. 11/272,571. The disclosures of the aforementioned patents are incorporated herein by reference in their entirety. Commercial laser systems capable of performing the incisions are available from IntraLase Corp. of Irvine, Calif.
The surgical laser may be used in conjunction with a contact lens (not shown) which is applied to the anterior corneal surface to deform the cornea. Deformation of the cornea in this manner provides multiple advantages which are well known to skilled artisans. For example, U.S. Pat. No. 5,549,632, which is incorporated herein by reference, describes advantages gained in making laser incisions by deforming the shape of the cornea, particularly by application. U.S. Pat. No. 6,863,667 and U.S. patent application Ser. No. 11/258,399, both of which are incorporated herein by reference, describe patient interface devices which deform the cornea and are used to align the surgical laser with the recipient cornea for purposes of making accurate incisions.
Thus, a system and method for resecting corneal tissue using non-continuous initial incisions are disclosed. While embodiments of this invention have been shown and described, it will be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. For example, while the embodiments described relate to a full thickness corneal transplant, the techniques and system are easily adapted for application in a lamellar corneal transplant procedure. Other applications are also possible. The invention, therefore, is not to be restricted except in the spirit of the following claims.
Patent Application
20080058777
