Abstract:
The invention provides an eye fixation system that allows accurate positioning, stabilization and safe and efficient manipulation of the eye and surgical instrumentation used during procedures and surgeries of the anterior and posterior segments of the eye.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 61/682,770, filed Aug. 14, 2012, the contents of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The recent introduction of small gauge vitrectomy instrumentation in vitreoretinal surgery provides a great opportunity for more efficient, less traumatic and safer surgery. A trocar system is used through which instruments are introduced and exchanged throughout the procedure. 
     Introduction and removal of the trocars require several instruments and maneuvers that are typically implemented in multiple steps. These include: (a) stabilization of the eye; (b) location of the correct trocar position in pars plana in such a way that the natural lens is not traumatized by the introduction of the trocar or instruments and in such a way as not to introduce the instruments through the retina resulting in tears that can lead to retinal detachment; (c) dragging of the conjunctiva to cause a misalignment of entry points in conjunctiva and sclera; (d) removal of the sharp blade introducing the trocar; (e) positioning of the irrigation cannula; (e) repeating the key steps above three times in the most common three port pars plana vitrectomy surgery. 
     Completion of these steps is crucial to the initiation of the procedure in a safe and efficient manner. Presently these are performed using multiple instruments that are repeatedly exchanged for the performance of the individual steps and for the performance of each of the three sclerotomies. 
     SUMMARY 
     The present invention is for an eye fixation and stabilization system and accurate instrument positioning system which can be utilized for the fixating and stabilizing the eye and locating the accurate position for instruments to be positioned, introduced and manipulated during eye surgery, eye procedures and eye exams. It can be used in anterior segment surgery as exemplified but not limited to cataract surgery and refractive surgery as well as for vitreoretinal procedures and posterior segment surgeries as exemplified by but not limited to vitrectomy and intravitreal injections, providing a universal tool for stabilization, fixation and accurate positioning and manipulation of other instruments. 
     In one aspect, the invention provides an instrument having a handle, one end of which a swiveling, extended ring is attached. The extended ring includes (a) an internal edge with an internal circumference that approximately coincides with the limbus; (b) an external edge with an external circumference that is about 4 millimeters from the internal edge; (c) four windows at the external edge; and (d) a mark at each windows indicating a position that is about 3.5 millimeters from the internal edge. The extended ring has an inside surface that contacts the eye when the instrument is placed on the eye, the inside surface being roughened for improved contact with the eye thereby allowing the eye to be manipulated. 
     In some embodiments, the handle of the instrument is attached to the extended ring through two prongs on one end of the handle, each prong being secured to a tab on the internal edge of the extended ring using a pin inserted through the prong and tab. 
     In another aspect, the invention provides an extended ring that includes (a) an internal edge with an internal circumference that approximately coincides with the limbus; (b) an external edge with an external circumference that is about 4 millimeters from the internal edge; (c) four windows at the external edge; (d) a mark at each window indicating a position that is about 3.5 millimeters from the internal edge; and (e) two tabs on the upper edge of the extended ring to facilitate handling. The extended ring has an inside surface that contacts the eye when the instrument is placed on the eye, the inside surface being roughened for improved contact with the eye thereby allowing the eye to be manipulated. 
     Thus, in some embodiments, the positioning device is used for eye fixation and stabilization, as well as to assist in accurate instrument positioning, introduction and/or manipulation during eye examinations, surgeries or procedures. In some embodiments, the positioning device can be used in anterior segment surgery such as, for example, cataract surgery and refractive surgery, as well as for vitreoretinal procedures and posterior segment surgeries such as, for example, virectomy and intravitreal injections. 
     Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification and the knowledge of one of ordinary skill in the art. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described below. 
     All patents and publications referenced or mentioned herein are indicative of the levels of skill of those skilled in the art to which the invention pertains, and each such referenced patent or publication is hereby incorporated by reference to the same extent as if it had been incorporated by reference in its entirety individually or set forth herein in its entirety. Applicants reserve the right to physically incorporate into this specification any and all materials and information from any such cited patents or publications. 
     Other features and advantages of the invention will be apparent from the following detailed description and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view of instrument 1 from the underside of the swiveling extended ring  20  showing swiveling extended ring  20  attached to one end of handle  10  through two-prong end portion  14 . 
         FIG. 2  is an enlarged view of underside  22   b  of the swiveling extended ring  20  shown in  FIG. 1 . 
         FIG. 3  is an enlarged top view of swiveling extended ring  20  attached to one end of handle  10  through tabs  30 , two-prong end portion  14  of handle  10 , and pin  16 . 
         FIG. 4  is a top view of instrument 1 placed on a model of an eye. 
         FIG. 5  is a top view of an embodiment of an extended ring of the invention without a handle, in particular, extended ring  20  without attached handle  10 . 
     
    
    
     DETAILED DESCRIPTION 
     The general purpose of the present invention is to position and stabilize the eye during various procedure, surgeries and examinations performed on the eye and allow the accurate positioning and manipulation of various instruments while reducing the number of instruments exchanges to a bare minimum. 
     The instrument can be used for a variety of procedures such as stabilization for cataract, LASIK and other refractive eye surgeries. A novel application of this specific instrument is described in further detail for the case of small gauge vitreoretinal surgery (trans pars plana vitrectomy (TPPV)). 
     The device of the invention is handheld instrument 1 that has a handle  10  at the end of which there is a swiveling extended “ring”  20  (or portion of a ring or arc). Handle  10  has elongated shaft  12  and two-prong end portion  14 . The handle is attached to the extended ring  20  through two-prong end portion  14 . The central portion of the ring (or portion of a ring or arc) has dimensions commensurate with the diameter of the cornea and is intended to approximately coincide with the limbus. Thus, the central portion has an internal edge  24  ( FIG. 1, 2 ) with an internal circumference approximately coincides with the limbus when the instrument is placed on the eye as shown in  FIG. 4 . The extended ring has external edge  26  with an external circumference that is larger than internal circumference of internal edge  24  as shown in  FIGS. 1 and 2 . The external edge is positioned at a distance commensurate with the placement of a trocar in a phakic eye. This distance is often taken to be 4 mm from the limbus. There are four of small window  28  at external edge  26  of the extended ring. The windows angular and radial position allow for the accurate and safe positioning of the trocars. Mark  32  near the window allows for the sometime preferred positioning for a pseudophakic eye. Mark  32  can be placed next to each window as shown in  FIG. 3 . Often that measurement is taken to be 3.5 mm from the limbus. The size of the windows is also such as to allow the safe introduction of the trocars and removal of the blades and other instruments (e.g. trocar cannula  48  and trocar system  50 ,  FIG. 4 ), as well as the stabilization of the trocar during the introduction of the infusion cannula without necessitating the use of another instrument. The extended ring inside surface  22   b  (the one facing the eye) has a roughened surface in order to improve on the grasping ability of the eye and prevents slipping. It also allows full control and manipulation of the globe including rotation around a vertical axis (visual axis) to expose the areas of the eye needed for positioning before and after introduction of the trocars and this even in smaller eyes. 
       FIG. 1  illustrates instrument 1 of the invention. Handle  10  includes shaft  12  and two-prong end portion  14 . Swivel extended ring  20  includes internal edge  24 , external edge  26 , inside surface  22   b  and four of windows  28 .  FIG. 2  is an enlarged bottom view of one end of instrument 1 showing extended ring  20  with inside surface  22   b , internal edge  24 , external edge  26 , four of windows  28  attached to two-prong end of handle  10 .  FIG. 3  is an enlarged top view of one end of instrument 1 showing extended ring  20  with outside surface  22   a , internal edge  24 , external edge  26 , four of windows  28  attached to two-prong end portion  14  of handle  10 .  FIG. 4  illustrates instrument 1 on an eye showing window  28  is of a size sufficient to accommodate instrument  48  and  50 . Another embodiment of the invention is shown in  FIG. 5 , which illustrates an embodiment of the invention in which extended ring  20  with tab  30  is without handle  10 . 
     In the current methods of small gauge vitreoretinal surgery, the introduction of the trocars involve several instruments which are exchanged multiple times each in three cycles, one for each port, for the completion of the safe and effective introduction of the trocar systems. The current instrument is positioned once and plays the role of stabilization, accurate measurement, removal of blade, introduction of the irrigation cannula, without the need for exchange of other instruments as the instrument is placed only once on the eye for the completion of the all cycles of trocar placement. 
     Procedures for which an instrument of the invention can be used include cataract surgery, refractive surgery including LASIK, anterior segment taps, vitreoretinal surgery and intravitreal injections including anti-VEGF, steroids, antibiotics and any pharmaceutical to be injected intravitreally. 
     The device of the invention can be made of material consistent with the materials used for similar surgical instruments. It can be made for repeated multiple uses and should be made in such a fashion as to allow for sterilization in the same fashion and along other surgical instruments. It can also be made in a disposable form for single usage to eliminate the need for repeat sterilization and allow for all the advantages typically associated with the use of disposable instruments. 
     The specific embodiments of the invention described above do not limit the scope of the invention described in the claims. 
     OTHER EMBODIMENTS OF THE INVENTION 
     While the invention has been described in conjunction with the detailed description, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims. 
     The specific methods and devices described herein are representative of preferred embodiments and are exemplary and not intended as limitations on the scope of the invention. Other objects, aspects, and embodiments will occur to those skilled in the art upon consideration of this specification, and are encompassed within the spirit of the invention as defined by the scope of the claims. It will be readily apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, or limitation or limitations, which is not specifically disclosed herein as essential. The methods and processes illustratively described herein suitably may be practiced in differing orders of steps, and that they are not necessarily restricted to the orders of steps indicated herein or in the claims. 
     As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Under no circumstances may the patent application be interpreted to be limited to the specific examples or embodiments or methods specifically disclosed herein. 
     The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intent in the use of such terms and expressions to exclude any equivalent of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention as described in the statements of the invention and as claimed. Thus, it will be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. In addition, the invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention.