Ophthalmic Instrument

Abstract

An ophthalmic instrument is provided for removing vitreous and fibrous bands from the retina of an eye. The instrument consists of two tubes mounted coaxially within one another, and with an opening adjacent the end of the outer tube. Cutting of the vitreous and fibrous bands is performed by a chopping action set up by the sharp end of the inner tube against the inner surface of the end of the outer tube. The vitreous and fibrous bands which are trapped in the mouth of the instrument are chopped and removed by suction by way of the inner tube. In the instrument to be described, the vitreous is replaced continuously by a saline solution, for example, which is introduced into the instrument by way of a small infusion tube.

Description

BACKGROUND OF THE INVENTION

Many diseases of the blood vessels of the retina cause massive hemorrhage into the vitreous. This hemorrhage is partly re-absorbed, but organized to a large extent as fibrous bands, and these can reduce the vision to blindness by pulling on the retina or preventing light to pass through it.

The role of vitreous in retinal detachment has been recognized for many years. But the vitreous remained more or less untouched until Shafer (1958) replaced it with human vitreous implant. (D. M. Shafer, The Treatment of Retinal Detachment by Vitreous Implant. Transactions American Academy Ophthalmology. Otolaryng. 61:194-200, 1958). Later, Michaelson described in 1960 an instrument capable of cutting the vitreous bands. (Michaelson, Transcleral Division of Mid-Vitreous Membrane Under Visual Control, British Journal of Ophthalmology, 44:634-635, 1960). Cibis in 1964 replaced the vitreous with silicon and devised instruments for cutting the vitreous bands. (P. A. Cibis, Vitreous Transfer and Silicon Injection Transactions American Academy Ophthalmology Oto-laryng. 68:983-997, 1964). Freeman, Schepens, and Anastopoulous introduced their vitreous scissors in 1967 (Vitreous Surgery II Instrumentation and Technique Arch. Ophthal. 77:681-682, 1967). Kasner reported on Vitrectomy in 1968 (D. Kasner Vitrectomy: A New Approach to the Management of Vitreous Highlights Ophthal. 11:304-309, 1968 (published in July 1969)). More recently, Machamer, Buettner and Norton in 1970 developed a vitreous cutter-sucker infusion instrument (Vitrectomy-American Academy Ophthalmology and Otolaryng. Las Vegas 1970).

Because of the nature of vitreous, which is composed of hyaloronic acid and collogen fiber, it is not possible simply to remove the substance by suction and to replace it with a balanced saline solution. The vitreous must be incised. Thus far, the available instruments have been plain scissors, as described in the aforesaid publication by Freeman et al., and the aforesaid instrument devised by Machemer et al., as described in the above identified publication of the American Academy of Ophthalmology and Otolaryng.

The Machamer et al. instrument consists of two tubes mounted coaxially with one another and with a hole in both tubes. The inner tube of the Machamer et al. instrument rotates against the inner surface of the outer tube at one or two rotations per second. However, the Machamer et al instrument does not provide satisfactory results because the rotation of the inner tube ends to cause shearing and traction on the collogen fiber, which result in a pulling effect and a tendency to injure the retina.

The instrument of the present invention is intended to overcome the deficiencies of the prior art instruments, and to provide a more efficient means for removing the vitreous and fibrous bands, this being achieved by sucking out the substances and incising the fiber, the instrument acting as a tissue chopper, as will be described. The rapidity by which the instrument of the invention can chop the collogen fiber can reach a speed of fifty times per second. The instrument of the invention has a feature in that there is no pulling or shearing of the collogen fibers of the vitreous. The instrument can also be used for the removal of the eye lens by incising and sucking out the lens material.

Specifically, the instrument of the invention, as described briefly above, consists of two tubes mounted coaxially within one another, the outer tube having a closed end with an opening adjacent its closed end. The inner tube is driven by electromagnetic means so that it moves reciprocally within the outer tube. The cutting of the vitreous is performed within the instrument by a chopping motion. The sharp end of the inner tube repeatedly strikes the base plate at the end of the outer tube. The vitreous and fibrous bands which are trapped in the mouth of the instrument are chopped and removed by suction by way of the inner tube. As mentioned above, there is no pulling or shearing effect on the fibrous bands or on the vitreous fibers. As also mentioned above, the vitreous is replaced continuously by the instrument of the invention by a saline solution which is introduced into the eye through the instrument by a small infusion tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of an ophthalmic instrument constructed to represent one embodiment of the invention, the instrument of FIG. 1 being shown in conjunction with a manipulator which allows the surgeon to move the instrument in any desired direction, as will be described;

FIG. 2 is a side section of the instrument of FIG. 1;

FIG. 3 is a side section, like FIG. 2, but of merely a fragment of the instrument, to show the components thereof in an operating position different from that shown in FIG. 2;

FIG. 4 is a somewhat schematic representation of appropriate apparatus for providing suction to the instrument of FIG. 1, and also for providing a replacement fluid for introduction into the eye as the operation progresses; and

FIG. 5 is a fragmentary schematic representation of the instrument of FIG. 1, and showing the manner in which the instrument cuts and removes the vitreous substance.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

The instrument of the invention includes a housing 10 which, as shown in FIG. 2 encloses a solenoid 12. The solenoid 12 includes a usual electric coil 12a, and a plunger 12b. The plunger 12b is biased upwardly in FIG. 2 by means of a spring 12c. However, when the solenoid 12 is energized, the plunger 12c is drawn into the coil 12a against the bias of the spring 12c. A cutting suction tube 14 extends through the plunger 12b, with the plunger being affixed to the tube 14, so that as the plunger is moved rapidly up and down due to the successive energizing and deenergizing of the solenoid, the tube 14 also moves rapidly up and down.

The tube 14 is coaxial with a further tube 16, the latter tube extending down from the lower part of the housing 10. The outer tube 16 forms a tubular housing for the inner tube 14. The lower end of the outer tube 16 is closed by means, for example, by a plate 18, an opening 20 being provided in the wall of the outer tube adjacent the plate 18, as shown. The lower end of the inner tube 14 has a cutting surface formed on it as designated 14a. In a constructed embodiment, for example, the inner tube had an outer diameter of 1.2 millimeters, whereas the tubular housing 16 had an outer diameter of 1.5 millimeters.

The tube 14 is coupled, for example, by means of a flexible suction tube 24 to an appropriate vacuum source. The representation of FIG. 2 shows the inner tube 14 in a position in which the spring 12c causes its cutting end 14a to be displaced away from the inner surface of the plate 18. In the view of FIG. 3, however, the solenoid is energized, so that the cutting surface of the inner tube 14 is moved down against the inner surface of the plate 18.

As best shown in FIG. 5, the representation A shows the vitreous substance being drawn in through the opening 20 adjacent the lower end plate 18 of the outer tube 16. In the representation A, the inner tube 14 is displaced up from the inner surface of the end plate 18, and the representation A corresponds to the representation of FIG. 2. In FIG. 5, the representation B is similar to that of FIG. 3, in which the lower tube 14 is moved down, so that its cutting surface coacts with the inner face of the end plate 18, and a portion of the vitreous substance is trapped within the center tube, as shown. In the representation C of FIG. 5, the severed portion of the vitreous substance is drawn upwardly through the inner tube 14 by suction.

As mentioned above, the vitreous in the eye is replaced continuously by a saline solution which is introduced into the eye by way of a small infusion tube 30, the infusion tube having a diameter, for example, of the order of 0.3 millimeters. The infusion tube 30 is fastened to the side of the outer tube 16, as shown in FIGS, 2, 3 and 5, for example. The infusion tube 30 is coupled to a source of the saline solution by way, for example, of a flexible tube 32.

The saline solution may be supplied to the infusion tube 30 by means of the apparatus shown in FIG. 4 and, at the same time, a suction may be established in the inner tube 14 by the same apparatus. The aparatus shown in FIG. 4 comprises essentially two syringes 50 and 52 which are mounted in axial alignment with one antoher, and which are operated by a common plunger 54. The flexible tube 32 is coupled to the syringe 52, as shown, whereas the flexible tube 24 is coupled to the syringe 50.

A bracket 56 (FIG. 4) on the common plunger 54 is coupled by way of a line 58 to a take-up spool 60, the take-up spool being operated, for example, by an electric motor 62. As the motor is energized, it causes the spool 60 to rotate, which, in turn, causes the line 58 slowly to draw the common plunger 54 to the left in FIG. 4. The syringe 52 constitutes the source of the saline solution which is introduced to the infusion tube 30 by way of the flexible tube 32. To that end, the syringe 52 is filled with the appropriate saline replacement solution. As the plunger 54 moves to the left, it forces an appropriate replacement solution out of the syringe 52 and through the flexible lead 32 to the infusion tube 30. The syringe 50, on the other hand, constitutes the vacuum source for the flexible suction tube 24. At the same time, the common plunger establishes a suction through the flexible lead 24, so that the inner tube 14 may perform its desired function.

The instrument, as shown in FIG. 1, may be held by the surgeon in a manipulator 61, the manipulator being equipped with a ball joint 63 through which the tubular housing 16 of the instrument protrudes. By holding the manipulator, the surgeon can turn the instrument to any desired inclination, and set it at that inclination. The manipulator may be attached to the operating table, for example, and it can be adjusted to have any desired angular position prior to the operation.

Any appropriate electrical circuit may be provided for driving the solenoid 12 at a desired rate.

To remove and replace the vitreous substance, the solenoid 12 is activated by an intermittent electric current which causes the inner tubular member 14 to move back and forth within the tubular housing 16, as the solenoid is energized and deenergized. As described above, for each downward stroke of the inner tubular member 14, its cutting end incises and traps a portion of the vitreous substance drawn into the tubular housing through the opening 20, and this substance is drawn upwardly through the tube 14 by the suction exerted by the apparatus of FIG. 3.

As the vitreous body is cut and drawn through the inner tubular member 14, it is replaced with appropriate replacement fluid which is fed to the eye through the tubular member 30. The apparatus is adjusted to that the amount of fibrous substance removed and the amount replaced by the replacement fluid is always equal. The removing and replacing of the vitreous body is accomplished by the apparatus of FIG. 4 in the manner described above. The apparatus of FIG. 4 permits equal removal and replacement of the eye fluid, thereby maintaining the correct pressure within the eye.

As mentioned above, the instrument of the invention can also be used for lens removal from the eye. When used for such a purpose, the opening 20 in the tubular housing 16 is made larger than the opening used for vitreous removal. The reason for this is that the lens, being of a more solid and curved configuration, will fit more easily into the enlarged opening for cutting and removal by suction by the instrument of the invention.

The instrument described above has been used successfully, and has been found to perform with a high degree of efficiency in performing its intended function. The instrument may be operated at high speed, and there is no pulling or shearing effect on the fibrous bands or vitreous substance. The instrument also provides, as described, for the vitreous in the eye to be replaced continuously by an appropriate replacement solution, such as saline. The instrument is easy to manipulate inside the vitreous. Moreover, the instrument may be produced at a relatively low cost.

While a particular embodiment of the invention has been shown and described, modifications may be made. For example, the outer diameter of the instrument can be made smaller than 1.5 millimeters; the instrument can be equipped with optic fibers for illumination within the eye; the instrument's tip can be made very flat, and the inner tube can be made as a flat blade for cutting the membrane close to the surface of the retina. It is intended to cover in the following claims all modifications which come within the spirit and scope of the invention.

Claims

What is claimed is:

1. An ophthalmic instrument for re-ceiving vitreous, lens, and the like, from the eye, said instrument including:

an elongated tubular housing having an open end and a closed end, and having an opening in the side wall thereof adjacent said closed end;

a tubular member mounted coaxially within said tubular housing in sliding contact with the inner surface of said tubular housing and extending through the open end thereof, said tubular member providing a passage for the vitreous material, and the like, to remove such material from the interior of said tubular housing, and said tubular member having an annular cutting edge facing said closed end of said tubular housing;

electrically actuated means for producing relative axial movement between said tubular housing and said tubular member whereby said tubular member incises substances drawn into said opening in said tubular housing;

means coupling said tubular member to a suction pressure source to draw the incised substances from said housing up through said tubular member; and

an infusion tube mounted externally on said tubular housing for introducing a replacement fluid into the eye during the operation of the instrument, when the tubular housing is inserted into the eye, to maintain constant pressure within the eye.

2. The combination defined in claim 1, and which includes further means coupling said infusion tube to a pressurized source of replacement fluid.

3. The instrument defined in claim 1, and which includes a manipulator for supporting the instrument, said manipulator having a ball joint therein through which said tubular housing protrudes, so as to permit positioning of the instrument at any desired angular position.