This invention relates to a medical device that is useful in aiding physicians to make complex multi-plane incisions in a patient. More particularly this invention relates to a form that distorts a portion of a patient's body in such a way that allows the physician to make a straight line planar incision in the distorted portion of the patient's body to form a complex multi-plane incision in the patient's body when the form is removed from the patient's body.
In various surgical procedures, the physician typically has to make an incision in the patient in order to remove unwanted tissue, repair damaged tissue, or implant a device to improve the patient's well being. In certain cases, all three of these activities or a combination thereof must be done in a single procedure. For example, in cataract surgery, the physician removes the natural lens that has been clouded by a cataract from the patient's eye and replaces it with an artificial lens that will improve the patient's eyesight. In order to perform this procedure, an incision is made in the cornea or sclera of the eye. This provides the physician with access to the patient's lens. The clouded lens is cut loose and removed. There are a number of different procedures that are used to remove a patient's lens that has a cataract. Two of the more common techniques are known as extracapsular surgery and phacoemulsification. In extracapsular surgery, the physician removes the lens leaving behind the posterior capsule. In phacoemulsification, the physician fragments the lens by ultrasonic vibrations. The lens is simultaneously irrigated and aspirated. After the lens is removed, the physician then inserts an artificial lens known as an intraocular lens (IOL) into the eye behind the iris. Two tiny C-shaped arms connected to the IOL eventually become scarred into the side of the eye and hold the IOL firmly in place.
Although cataract surgery is considered routine, it is not foolproof. For example, the incision through which the devices that are used to perform the procedure are inserted must provide an opening that is substantially the same circumference as the probes and other surgical devices that are used to perform the procedure. This minimizes trauma to the eye and facilitates rapid healing of the eye after the procedure. In addition, in the case of phacoemulsification, if the incision is too small, corneal tissue surrounding the incision may contact the ultrasound probe and be burned. Alternatively, if the incision is too large, leakage from the eye after the procedure may occur causing iris prolapse and subsequently endothelial cell loss.
Another common problem with cataract surgery is suture induced astigmatism. Since an incision is made in the eye to perform the procedure, some mechanism must be used to ensure that the incision remains closed during the healing process to prevent a path for infection into the eye and so that the eye heals properly. In the past, sutures have been used to close the incision. However, the use of sutures in the eye to seal the incision after the cataract surgery may alter the shape of the eye. Such an alteration of the shape of the eye may result in astigmatism. In addition, the use of sutures may cause other complications such as eye irritation, suture abscesses, suture extrusion and foreign body reaction,
In an effort to avoid the use of sutures in cataract surgery, new sutureless techniques have been developed. These sutureless techniques involve the same standard procedures used to remove the cataract and implant the IOL but require the physician to make an incision in the eye having a particular shape or geometry. By making an incision having a particular geometry, the normal internal pressure in the eye pushes against the eye at the location of the incision to keep the incision closed.
One particular sutureless technique that is currently being used is known as the clear cornea approach and requires a particular incision that is self-sealing to be made in the eye. The shape of one particular incision comprises a pair of contiguous circular segments that have their centers of radius on opposite sides of the incision, i.e. the incision has a substantially S shaped geometry. Unfortunately, because of the complex, multi-plane geometry of the incision, it is difficult to form consistently. This problem is especially acute for new physicians and physicians who do not perform this technique often enough to maintain their proficiency. If such incisions are improperly formed, a number of complications can occur. For example, endophthalmitis, induced astigmatism, damage to the cornea, the iris or other intraocular tissue can occur, and impaired intraoperative vision of the physician can result.