Abstract:
The intraocular lens (IOL) fixation device includes an elongate handle having a slender, elongate neck extending therefrom. The neck terminates at a head section. The head section includes a rotator, upon which a plurality of radiating vacuum holding legs extends outward, the end of each leg having a suction cup attached thereto. The legs and the suction cups include hollow channels that communicate with a source of vacuum in order to facilitate gripping of the IOL. Upon insertion of the IOL and proper placement of the head over the IOL, activation of vacuum firmly holds the IOL through the suction cups. The rotator is rotated to accurately align the IOL within the capsular bag. The IOL fixation device also includes irrigation means for selective irrigation of the target area.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to ophthalmic surgery, and particularly to an intraocular lens fixation device that provides precise, accurate alignment of an intraocular lens with minimal risk during the ophthalmic surgical procedure. 
     2. Description of the Related Art 
     An intraocular lens (IOL) is a synthetic lens used to correct various eye-related impairments, such as cataracts, astigmatism, and refractive errors. The impaired crystalline lens in the eye is replaced by the IOL through implant surgery. IOLs have been very effective in correcting vision, but the implant procedure is a precise, delicate and risky surgery that, if not performed correctly, can lead to potential infection, loosening of the lens, lens rotation, inflammation, nighttime halos, and some loss to potential vision. 
     Many different types of IOLs are available. Each type is specifically designed to correct a certain type of eye defect or vision impairment, e.g., multifocal IOLs for simultaneous viewing of both long and near distances, and accommodating IOLs for both long and midrange near distance vision. Another type of IOL is a tonic IOL. The tonic IOL has been recently introduced to correct astigmatism in patients undergoing cataract surgery. With accurate IOL calculations and surgical technique, tonic IOLs can minimize or eliminate the need for spectacles following cataract surgery. It has been estimated that about 15-20% of patients with cataracts have astigmatism and will benefit from this lens. 
     To maximize the benefits of these premium lenses, accurate positioning or alignment is extremely important. The accuracy of new diagnostic tools, such as Lens Star® or IOL Master®, has contributed to the success of these lenses. When incorrectly placed, however, post-operative vision accuracy will be compromised, depending upon the degree of misalignment. For example, 15° off-axis will result in a 33% vision drop, which is not infrequent. Several studies have shown that a difference of about 10-30° of misalignment between the targeted and the achieved axis was seen in about 30-60% of the cases. Some of these cases showed a misalignment of about 45° or more. An acceptable misalignment of 5° or less was only seen in about 40% of cases. Most of these errors can be attributed to human error. 
     Diagnostic instruments measuring IOL power and astigmatism, such as IOL Master® or Lens Star®, are very accurate and reproducible. The discrepancy between the targeted and the achieved axis is due to identification of the proper axis, preoperative markings, and/or intra-operative misalignment. Preoperative marking of the cylinder axis is associated with significant human error. In practice, most surgeons do not have the patient in a sitting position to perform accurate axis markings. The markings are usually performed in the operating room in a semi-sitting position. With cyclotorsion, the chance of marking the axis accurately is minimal. In addition, most surgeons use methylene blue ink, which may fade by the time the patient is prepared for surgery, or the ink dilutes widely over 5-10°, which is another potential risk for error. 
     Intraoperative axis misalignment is mostly seen with inexperienced surgeons, which fortunately improves over time. However, chances of misalignment still exist. Due to manual rotation of the tonic IOL, centering of the IOL is not always accurate. This can cause post-op lens rotation that may lead to misalignment. Another cause of surgical error with IOL rotation is when the visco-elastic is not completely removed during surgery. This will result in clockwise rotation of the IOL. In addition to improper axis alignment, manual rotation of the tonic IOL imposes risks of capsule rupture or zonular damage in cases with weak capsule. 
     The current microsurgical instruments being used in this type of surgery do not appear to reduce the risks of misalignment. Most typical instruments are a type of forceps that can grab an edge of the IOL for manual rotation of the IOL. This is prone to human error, as mentioned above, with the attendant risk of capsular rupture. 
     In light of the above, it would be a benefit in the art of ophthalmic surgery to provide a device that can provide precise, accurate alignment of IOL with minimal risk to surrounding tissue during surgery. Thus, an intraocular lens fixation device solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The intraocular lens (IOL) fixation device includes an elongate handle having a slender, elongate neck extending therefrom. The neck terminates at a head section. The head section includes a rotator, upon which a plurality of radiating vacuum holding legs extend outward, the end of each leg having a suction cup attached thereto. The legs and the suction cups include hollow channels that communicate with a source of vacuum in order to facilitate gripping of the IOL. Upon insertion of the IOL and proper placement of the head section over the IOL, activation of the vacuum firmly holds the IOL through the suction cups. The rotator is rotated to accurately align the IOL within the capsular bag. The IOL fixation device also includes irrigation means for selective irrigation of the target area. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an environmental, perspective view of an intraocular lens fixation device according to the present invention. 
         FIG. 2  is a perspective view of the intraocular lens fixation device of  FIG. 1 . 
         FIG. 3  is a partial side-view in section of the intraocular lens fixation device of  FIG. 2 , showing details of the head section. 
         FIG. 4  is a partial top view of the intraocular lens fixation device of  FIG. 1 , showing the head section holding the IOL. 
         FIG. 5  is a partial bottom view of the intraocular lens fixation device of  FIG. 1 , showing of the head section adjusted for holding the IOL. 
         FIG. 6  is a top view of an alternative embodiment of an intraocular lens fixation device according to the present invention. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The intraocular lens fixation device (hereinafter referred to as an IOL fixation device), a first embodiment of which is generally referred to by the reference number  10 , provides precise alignment positioning of an IOL with minimal risk to the lens capsule or capsular bag, and with minimum human error. As shown in  FIGS. 1 and 2 , the IOL fixation device  10  includes a housing having an elongate handle  12  that tapers at one end to an elongate neck  14 . The handle  12  is preferably dimensioned to fit comfortably in the user&#39;s hand. The handle  12  can be gnarled, can have protrusions of various shapes, can be striated, can be covered or coated with friction-enhancing material, or can otherwise be configured to enhance grip. The neck  14  is preferably slender or of much smaller width or diameter than the handle  12  so that the distal end of the neck  14  can be easily manipulated during surgery. 
     Referring to  FIGS. 2 and 3 , the distal end of the neck  14  includes a head section  16 , from which precise and accurate alignment of the IOL can be made. As shown, the handle  12  and neck  14  are substantially hollow. The head section  16  houses a rotator  20 . The rotator  20  is preferably a single-piece unit having, from the top down in  FIG. 3 , a pulley wheel  22 , a central support  24 , and a circular disc or flange  26  extending below the bottom of the head section  16 . 
     One end of a cable  18  is trained around a circular groove  23  formed in the pulley wheel  22 , and the other end of the cable  18  is operatively attached to a motor  19  (shown in  FIG. 2 ). A power cord  11  provides power to the motor  19 . Selective activation of the motor  19  rotates the rotator  20  through the interaction of the cable  18  rotating the pulley wheel  22 . The motor  19  is preferably reversible so that the rotator  20  can be rotated in the opposite direction, if required or desired by the user. Additionally, the motor  19  can be an electric or pneumatic type motor. 
     The central support  24  is preferably a cylindrical segment interconnected to the pulley wheel  22  and the flange  26 . The central support  24  includes a throughbore or opening  25  communicating with a hollow vacuum passage  27  extending into the flange  26 . 
     A plurality of vacuum holding legs  30  extend radially from the flange  26 , and a suction cup  34  is attached to the distal end of each leg  30 . The suction cups  34  are configured to gently but firmly hold onto the IOL TI via vacuum. The IOL fixation device  10  may, e.g., have four holding legs  30  that include two pairs of legs symmetrically spaced about the flange  26 . The legs  30  of each pair are angularly spaced at an acute angle. The mid-angle of each pair defines a virtual axis therebetween. As shown in  FIGS. 2 and 4 , the top of the pulley wheel  22 , which is exposed on top of the head section  16 , includes an alignment marker or indicia  21 . The alignment marker  21  is preferably a straight line or other similar indicia formed by a groove, etching, paint, or the like. This line is aligned with the virtual axis between each pair of holding legs  30 . In use, the arrangement of the holding legs  30  and the alignment marker  21  provides a visual guide for the user, so that the user can properly align the IOL fixation device  10  with corresponding alignment markers AM, e.g., dots, on the tonic IOL TI as shown in  FIG. 4 . 
     The holding legs  30  are preferably constructed from flexible PMMA (polymethylmethacrylate), which is an inert form of biocompatible plastic safe for use in surgical environments. Other similar plastics can also be used. Each leg  30  is hollow and includes a channel  32  communicating with the vacuum passage  27 . Similarly, each suction cup  34  includes a hollow channel  36  communicating with the channel  32  in the corresponding leg  30 . The suction cups  34  are preferably constructed from soft silicon that can safely hold the IOL TI without damaging the same. The vacuum is supplied from an exterior remote source via the vacuum line  15  and the vacuum chamber  13  inside the housing. It is noted that relevant parts of the housing are sealed to insure vacuum operation. 
     During this type of surgery, periodic irrigation is required to maintain anterior chamber depth in the eye. To facilitate irrigation, the IOL fixation device  10  also includes an irrigation channel  17  inside the housing communicating with an irrigation outlet or hole  40 . The irrigation outlet  40  is preferably disposed proximate to, or a relatively short distance away from, the holding legs  30 , as shown in  FIGS. 3 and 5 . This arrangement allows the user to apply irrigation fluid in situ, rather than having to re-manipulate the IOL fixation device  10  or to use a separate, remote irrigation tool. Such measures minimize potential widening of the initial incision or rupture of the lens capsule. The application of the irrigation fluid can be facilitated by a syringe mechanism  42  having an interior source of fluid (not shown) or a rear connection to a remote pump and source of fluid. 
     In use, the tonic IOL TI is inserted into the eye through a small incision in the usual manner, after removal of the impaired lens. An axis alignment marker based on pre-operative IOL calculations and measurements is marked or placed over the eye. Prior to insertion of the IOL fixation tool  10 , the rotator  20  is rotated via selective activation of a button  44  to operate a motor that aligns the alignment marker  21  with the alignment markers AM on the IOL TI. The head section  16  is carefully inserted through the incision until the head section  16  overlies the IOL TI. Centering is performed through readjustment, as needed. Once centered, vacuum is activated to commence negative airflow, as indicated by the arrows  50  in  FIG. 3 . This causes the suction cups  34  to gently but firmly adhere to the surface of the IOL TI. At this point, irrigation may be applied to maintain anterior chamber depth, as indicated by the arrows  52 . The rotator  20  is again activated to gently rotate the IOL TI into the proper position outlined by the axis alignment marker. Once the IOL TI is properly placed, vacuum is deactivated, and the IOL fixation device  10  is gently removed from the eye. 
     In contrast with conventional IOL implant procedures, the IOL fixation device  10  substantially minimizes some of the more common human errors that can occur. Throughout the above procedure, there is minimal maneuvering of the IOL fixation device  10 . The major manipulation of the IOL fixation device  10  occurs mainly in the insertion and extraction of the head section  16 . Meanwhile, the rotator  20  and the suction cups  34  perform the rotation for alignment, while the IOL fixation device  10  is stationary. Thus, manual rotation is eliminated. This also eliminates some of the potential rupturing of the lens capsule due to inadvertent and overt manipulation of a surgical tool by the surgeon. Moreover, a majority of the delicate and stressful repetitious handling of the conventional forceps type devices are eliminated thereby. 
     The above IOL fixation device  10  is an example of an automatic microsurgical tool. As briefly mentioned, the selective activation of the rotator  20  is facilitated by the button  44 . The button  44  can be configured or pre-programmed with various functions. For example, a combination of button presses can be used to rotate the rotator  20  in opposite directions, or to operate the vacuum. 
       FIG. 6  discloses an alternative embodiment of an IOL fixation device  100 . This IOL fixation device  100  is an example of a manual microsurgical tool, which eliminates the motor, power cord and button operation. In place thereof, the IOL fixation device  100  includes a manual dial  144  having the pulley cable  18  operatively attached thereto. The user rotates the dial  144  to rotate the rotator  20 . In all other respects, the IOL fixation device  100  operates and functions substantially the same as the IOL fixation device  10 . 
     It is to be understood that the IOL fixation device  10 ,  100  encompasses a variety of alternatives. For example, the IOL fixation device  10 ,  100  can be constructed from surgical grade plastics, metals, composites and/or combinations thereof. The IOL fixation device  10 ,  100  can also include selectively operable LED lights for illuminating target areas during surgery. The IOL fixation device  10 ,  100  can also be operatively connected to precision imaging and adjusting devices, such microscopes and computers, to assist alignment procedures. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.