Apparatus for re-profiling the cornea to correct for hyperopia

Additional devices for surgical correction of corneal shape (1)

The present invention is US Patent Application No. 07/450,672, the filing date of which is December 14, 1989, and US Patent Application No. 07/592,601, the filing date of which is an application filed on October 4, 1990 Part of the continued application.

The present invention relates to a method and device for adjusting the shape of certain parts of the eyeball, and particularly relates to a device that can make a fixed change to the curvature of the cornea.

When the surface of a cornea deviates from the normal shape, it will produce a phenomenon of refraction errors when performing visual observation actions. When an eyeball is in a resting state, that is, when there is no vision adjustment, it can accurately focus the image of some objects located at a distance on the retina. This kind of eyeball can easily and clearly see some objects located at a distance without much effort. Any change that is different from this standard situation will constitute ametropia. When this kind of eyeball is in a resting state, there will be a situation in which it cannot be positioned a certain distance away. The image of one of the objects is precisely focused on the retina. The hyperopic eye system produces a false phenomenon for its refraction, in which, when the eyeball is at rest, some parallel rays from some distant objects will focus on the back of the retina. Some divergent light from some close objects will focus on the far back of the retina. A feature of presbyopia is that the surface of the cornea forms a flat state, so that when light passes through the refraction surface of the cornea, the refraction angle of these rays will be reduced. In this case, these rays will be focused or It is to converge to a certain point behind the retina. This retina partially contains some nerve fibers, which are an enlarged part of the optic nerve. The light waves falling on the retina will be converted into nerve pulsations, and it will be transported to the brain by this optic nerve in order to feel the light. When these parallel rays of light are to be focused on the retina, the hyperopic eye must perform a vision adjustment, such as increasing the convexity of the lens of the eyeball, or it must place a convex lens with sufficient strength on this The front of the eyeball in order to focus these rays on this retina.

The normal way to deal with this type of typical refraction error phenomenon of the eyeball is generally to use a kind of glasses or contact lenses to correct the work. However, as everyone knows, these two kinds of glasses will cause a lot of users. Shortcomings. In recent years, research work has been carried out towards the technical direction of performing surgical operations, so that it can be used to change the phenomenon of this refraction error of the eyeball. These processing techniques are usually referred to as "keratinous membrane refraction techniques" (keratorefractive techniques). Two of these treatment technologies are specifically called keratophakia treatment technology (keratophakia) and another corneal treatment technology (keratomileusis). This other corneal processing technique involves re-grinding a thin piece of the cornea into a structure of concave-convex lens or hyperopic glasses to correct this kind of nearsightedness or hyperopia. An optical lathe for the cornea has been specially developed to perform this surgical procedure. It can also be used to perform the process of the corneal mycosis treatment technique, one of which is ground into a convex lens homograft (homograft). ) Is placed as an inner thin slice so that it can be used to correct aphakic hyperopia (aphakic hypermetropia). The tissue of this allograft (thin slice of the cornea) is frozen with carbon dioxide. This kind of allograft is cut by a contact lens cutting method, that is, it is performed with the required optical power in order to perform the optical correction work that we need to perform on the cornea. In this other corneal processing technology, the front corneal sheet is formed by a lathe, and in this corneal mycosis treatment technology, it uses a lathe to treat a donor. The matrix of the cornea of the eyeball does a kind of shaping work. These techniques can be widely used to correct errors caused by high-level hyperopia and nearsightedness images. These procedures require radial cutting of the cornea at the periphery of the graft to weaken the cornea, so that the pressure from the fluid under these incisions will be under these cuts. Pushing it up will make the curvature of the cornea a bit flatter. Among them, the flattening of the cornea will cause the image refraction error of the eyeball, and the image refraction error cannot be compensated by this graft. A suturing action in these operations can also cause radial asymmetry of the cornea, resulting in astigmatism or confusion. These sutures can also scar or scar the corneal tissue, and the scarred tissue will make it lose its original transparency. Correcting this astigmatism or disordered vision by performing surgery can be achieved by changing the curvature of the cornea asymmetrically. When we imagine an inflated balloon with a spherical surface being pinched between the two palms of the hand, we can easily imagine the effect of using a kind of peripheral deformation force to squeeze objects. Since the volume of air in this balloon is constant, its surface area is also maintained at a certain state. When the ball is squeezed in the direction of the diameter with the hand, it will cause the previous spherical front surface to be deformed in a meridian circle, so that its curvature will change without changing to its periphery. surface. The meridian circles between the extended fingers through this balloon will become steeper and sharper, while the other parts of the meridian circles that cross them at right angles and are not compressed will become relatively steeper. Flat, in which their diameter will be lengthened, and the length of this length is proportional to the degree of shortening of other compressed diameters. This means that the effect of this squeezing action will Make its symmetrical shape change, or make it deliberately form an asymmetrical shape, and this asymmetrical shape is intended to be completed during surgical operations and during suture operations. We can therefore see that, of any effective standard corrective surgery we can find, this process currently used in the corneal refraction technique is the best. We can easily see that under the limited factors of this surgical technique, it will definitely make this kind of operation quite complicated. It is not only necessary to perform the operation on the cornea Many suture openings are formed in the tissue, and it will also form a very complicated suture shape, which will cause the entire eyeball to reorganize. This eyeball will therefore have a hard time facing a problem, that is, it will be difficult to adjust and adapt to this physical and mental trauma.

Among the developments developed in the past few years, some people use a laser light as a tool that can be used to reshape the cornea, which is intended to solve this refraction error. The phenomenon. During these operations, a pulsating laser will remove some tissue from the cornea. The most common and most widely used type is an Iggsam laser (Exemerlaser). ). A basic effect of this kind of laser light on this tissue is a photochemical effect, that is, it will destroy molecular bonds with a considerable amount of energy, causing some tissue fragments to fly at supersonic speeds. Away from this surface, so that it will form a discontinuous or discontinuous space on this surface. This process is referred to as a kind of ablative photodecomposition or ablation process (photoablation).

When using this kind of laser light of Iggsam, it is necessary to inject this light beam into the eyeball in a controlled manner, that is, it needs to make this kind of light beam of equal quality be properly processed and focused, because This optical element must be able to withstand very high energy photons, and because this light column must form a non-uniform structure, so that a new non-uniform optical can be formed on the surface of the cornea. surface. This illumination system contains many components, including some lenses for magnification or focusing, a mirror for guiding the light beam, an adjuster used to make the light beam the same, and the cover can be used to shape this The beam of light, as well as the detector, can be used to measure the intensity of the beam of light and its outline and its orientation. In some of the currently used models, there is a combination structure that simply includes only a lens and a mask, and a mechanism that is complex enough to form a robot. This mechanism contains some components, which can not only be used for Control the parameters of the laser light, and it can also be used to control optical and mechanical components. Because the accuracy of this process is about the accuracy of the submicron (that is, the accuracy is less than 0.00001 per meter), so when implementing this system, it needs great stability, because this The effect of this kind of laser light on the corneal tissue is only a few microseconds long.

The use of this system requires extremely precise and sensitive technology, and it must pay special attention to the biological control work, and it needs to pay attention to the healing of the injured part of the cornea.

Other concepts and reference materials that can be used to correct this corneal refraction error can be found in the following patent precedents and published materials: 4,526,171 Schachar (Schachar)

4,662,370 Hoffman

4,947,871 Grieshaber

4,750,491 Kaufman, et al

Microsurgery of the Kornea (Microsurgery of the Kornea), by Barraquer et al. (J. Barraquer, et al), (1984) Edition Ediciones Scriba, SA

Therefore, according to an object of the present invention is to provide a new and improved corneal refraction technology, this technology includes a method and device, so that it can be used to change the shape of the corneal visual area, and can correct hyperopia The refraction error of the eye, etc., so that it only causes minimal interference to the eyeball system, and this technology is very simple, so that it can eliminate the chance of error, or it can eliminate the eyeball system. Other complications or complications caused by the overall system being disturbed.

Judging from the foregoing objectives and other objectives, the present invention is to provide a method and a device that can be used to scrape, sculpt, or sculpt the cornea, while changing its curvature so as to It can be used to correct this phenomenon of refraction errors.

Another object of the present invention is to provide a mechanical device that can be easily used by a surgeon to scrape, sculpt, or sculpt the cornea so that it can be used for correction A condition of presbyopia that includes a device that can be used to form a surface with a consistent depth and structure.

In particular, the method provided according to the present invention generally includes surgical plastic surgery on the cornea of the eyeball, so that it can be used to change the radius of the cornea and make it possible to correct this refraction. Wrong phenomenon. One of the steps involved in such a method includes the following steps, that is, forming a stable ring corneal image for a simulated cornea with correct refraction quality. Next, it forms a corneal image for a cornea to be corrected. The two corneal membrane images are compared to determine the amount of refraction error, that is, to determine whether it is hyperopia, nearsightedness, astigmatism or chaotic vision. An orthopedic tool is designed so that it contains at least one, but preferably a plurality of blades with sharpened edges. The shape of the blade is sufficient to scrape or sculpt the cornea, and it can therefore be used. Change the radius of the cornea so that this radius can be made into the radius of the simulated cornea. The plastic tool is then placed in a support sleeve, and the support sleeve is closely and adjacently arranged on the eyeball, so that the blades will touch the cornea tangentially, that is, at a single point Touch this cornea everywhere. The shaping tool is then rotated or oscillated until the radius of the cornea has been corrected to the radius of the simulated cornea. This plastic tool includes a device that can be used to make very precise changes in the axial depth, and this change in the axial depth is necessary during this surgical operation.

Another object of the present invention is to provide a plastic surgery tool that can apply a non-scraping pressure to a central area of the cornea that is located in front of the line of sight, so that the cornea is located in the center of the line of sight. In an area of the outer annulus area outside the central area, it will come into contact with the sharpened blades, which can be used to scrape the outer part, so that it can change the radius of curvature of the cornea, And it can be used to correct this kind of refraction error phenomenon such as presbyopia.

The correction work system of hyperopia needs to make it have a steeper cornea curve. One of the main purposes of the present invention is to achieve the work of making the cornea steeper, which includes scraping an area or annulus on the front surface of the cornea. The annulus is located at the center of a line of sight of the cornea and extends beyond a place with a diameter of approximately 1.5 mm.

A device with a specific shape or type that can be used to achieve the objectives of the invention includes a cylindrical positioning ring that can be temporarily attached to one of the sclera of the eyeball, where this The sclera surrounds the cornea to be reshaped. Usually, it does not need to apply a vacuum suction force to the positioning ring, but if it needs to form such a vacuum state, the vacuum suction device can be used to provide this vacuum state. Some positioning pins are arranged at the top of the positioning ring. If necessary, a vacuum device can be provided to form a state of communication with the vacuum ring device. A cylindrical support sleeve contains a device which is arranged at the bottom end of the support sleeve, and the positioning pins of the device and the cylindrical support sleeve are internally connected to each other. At an outer part of the support sleeve is formed a kind of thread with a predetermined pitch, for example about 40 threads per inch, a kind of fine micrometer type adjusting pitch. Screwed on the support sleeve is a guide sleeve, and the guide sleeve has a predetermined thread pitch formed in the inside of the guide sleeve so as to be rotatably combined with the support sleeve. A shaping tool is rotatably and axially movably accommodated in the positioning ring, the supporting sleeve and the guiding sleeve. A collar mechanism is arranged on the shaping tool so that the shaping tool can be rotatably supported on the guide sleeve. This plastic surgery tool includes a plurality of blades with sharpened blades arranged at the bottom end of the positioning ring. The shape of the blade is designed so that it can scrape, carve or form the inside of the cornea. A correct curvature is needed. One type of this plastic tool includes a central pressure cushion placed at the center of its bottom end, and this central pressure cushion is made of a non-abrasive and friction-reducing material For example, such materials are Teflon or other polymer materials. Extending axially outward from the central pressure cushion is a plurality of blades with curved and sharpened blades. The radius of curvature of these blades is larger than the radius of curvature of the frontal surface area or annulus of the cornea described earlier. Another type of this plastic tool includes some straight and sharpened blades.

Another object of the present invention is to provide a device that can be used to make incisions or cuttings on the outer side of a cornea and a surface located in the front, which uses scraping, engraving, and/or engraving. Workers who perform this kind of incision in a way that they can perform plastic surgery on the cornea, and can correct this refraction error, and after performing this plastic surgery, the chance of inflammation is quite high. This kind of inflammation is rare or almost impossible, and this kind of thin layer or thin layer of epithelial cells of the cornea will complete regeneration in the shortest time.

Another object of the present invention is to achieve the corneal plastic work as described in the previous object, in which it allows the epithelial cells of the cornea to grow from other areas that have not been scraped, and It will not return to its original curvature or curve.

The preferred embodiments of the present invention will be described in detail with the attached drawings as follows, so that the present invention can be further understood. Among them: Figure 1 is a schematic diagram showing a horizontal cross-sectional schematic diagram of an eyeball .

Figure 2 is a schematic diagram showing a hyperopic eye, which can adjust the cornea so that the radius of curvature of the eyeball can be shortened.

Figure 3 is a detailed schematic diagram showing a horizontal cross-sectional schematic diagram of the front part of an eyeball and the structure of various layers of the cornea.

Figure 4 is an exploded view showing the basic components of a device of the present invention.

Figure 5 is a bottom view of a plastic tool, which is a schematic view taken from the section line 5-5 of Figure 4.

Figure 6 is a top view showing the structure of a positioning ring of the present invention.

Figure 7 is a schematic partial cross-sectional view of the plastic tool device of the present invention, which is set at an initial position on the cornea of a patient.

Figure 8 is a schematic diagram of the assembly of the device of the present invention, which has an electronic indicator device.

Figure 9 is a cross-sectional view of the positioning ring, where the positioning ring is set on an eyeball.

Figure 10 is a partial schematic diagram of another alternative embodiment of the present invention.

Before explaining the details of the present invention in detail, it must be understood that the present invention is not only intended to be limited to the embodiments such as the detailed structure and arrangement of the components shown in the drawings. The present invention may include other embodiments, which may be implemented or realized in various different ways. It must be understood that the wording or special terms and special terms used here are only intended to be used for narrative purposes, and are not intended to be used to limit the present invention.

First, please refer to Figure 1. This drawing is a horizontal cross-sectional view of the eyeball to show the sphere of the eyeball. This sphere is similar to a sphere with a forward-protruding spherical part (12). This The spherical part represents the cornea. Therefore, this eyeball actually contains two slightly modified spheres, and one of the spheres is set in front of the other sphere. The place in front of these two parts is a cornea with a relatively small radius of curvature.

This eyeball contains three concentric coverings so that it can be used to cover a variety of different transparent media through which light must pass before reaching the photosensitive retina. The outermost covering system is a fibrous protective part. The five-sixth part of the protective part is white and opaque. It is also called the sclera of the eye (13), and Sometimes, this part corresponds to the white part of the eyeball, which can be seen from the front of the eye. And the front one-sixth of the outer layer is the transparent cornea (12).

A middle covering body is mainly the blood vessel tissue and the role of supplying nutrients. This covering body contains the choroid (14), the ciliary body (15) and the iris (17). The general function of the choroid (14) is to maintain the retina (18) in position. The function of the muscles of the ciliary body is to suspend the lens (21) and to adjust the lens. The iris (17) is the foremost part of the middle covering body of the eyeball, and it is arranged in a frontal plane. This kind of iris is a thin disc-shaped body, which corresponds to the partition of a camera, and it forms a state of perforation with a circular opening near its center, that is, The so-called pupil (19). The size of this pupil will change so that it can be used to adjust the amount of light that can reach this retina (18). This kind of pupil will also shrink and do the work of adjustment, so that it can make its focus become sharper and can reduce the phenomenon of spherical aberration. The iris can divide the space between the cornea (12) and the lens (21) into a front chamber (22) and a rear chamber (23). The innermost layer of the covering is the retina (18), which includes some nerve elements that form the actual receiving part so that it can be used to form a visual image.

This retina (18) is a part of the brain, because it is a protrusion of the forebrain, and its optic nerve (24) can be used as a kind of fiber bundle, and the retina of the brain Connect to the forebrain. A layer of rods and cones are set just below a pigmented epithelial cell, and this pigmented epithelial cell is set on the anterior wall of the retina. This layer of rods and cone system are intended to be used as visual cells. The user, so that it can be used to convert physical energy (light) into nerve pulses.

The vitreous body (26) is a transparent colloidal paste-like substance, which fills four-fifths of the volume of the back of the eyeball. At its side part, it can support the ciliary body (16) and the retina (18). A dish-shaped depression located at the front can be used to house the lens (21).

The lens (21) of the eyeball is a transparent double convex body, which has a crystalline appearance, and is arranged between the iris (17) and the glass body (26). The axial diameter of this lens can change significantly with the adjustment of eyesight. A kind of ciliary zonules (27) contains some transparent fibrous material passing between the ciliary body (16) and the lens (21), and this ciliary zonules can be used to support the lens in positioning Place, and it allows the muscles of the ciliary body to act on the lens.

Next, please refer to the cornea (12) again. The transparent fiber coating system located in the outermost layer is similar to the case glass of a watch. The curvature of the cornea is slightly larger than the curvature of the rest of the eyeball, and it is essentially a perfect spherical body. However, the curved surface at one of the meridians of the cornea will be more curved than the curved surface at other places, which will cause astigmatism or chaotic eyesight. The central one-third of the cornea is the so-called visual area, and a slightly flattened phenomenon will be formed outside this visual area, and the cornea will face its periphery. It forms a relatively thick state. The place where the greatest light of the eyeball is refracted occurs on the surface of the cornea.

Next, please refer to the schematic diagram in Figure 2, which shows a sphere of an eyeball. This eyeball has a cornea (12), and a normal curve of the cornea is represented by a solid line (39). . If parallel rays (41) pass through the surface of the cornea (39) as shown in Figure 2, these rays will be refracted by the surface of the cornea and will eventually be transformed into the retina (18) near the eyeball. The place. For the purpose of discussion here, the graphic shown in Figure 2 does not fully show the effect of light refraction on this lens or other parts of the eyeball. The eyeball system shown in Figure 2 is a hyperopic condition, so the beam of light (41) will be refracted and gathered at a certain point (42) at a point behind the retina. If a circumferential pressure exerts pressure on a string-shaped part of the cornea, the wall part of the cornea will be forced to form a relatively steep state. This is due to the fact that the volume of the liquid in the front chamber (22) remains unchanged, so that the front part of the cornea, including the visual area (the inner third of the cornea) One of the areas) will form a relatively steep curve, so that a curve as shown by the dashed line (44) can be formed (shown exaggeratedly in the figure). The light (41) will then be refracted from the relatively steep surface (44), and the angle of refraction is relatively large so that the refracted light will be concentrated at a relatively short distance, for example, making this light You can focus directly on this retina (18).

Now please refer to Figure 3. This diagram is a more detailed diagram of the front part of the eyeball. This diagram shows the various layers of the cornea, including an epithelial cell (31). The epithelial cell line on its surface can be used to maintain the transparency of the cornea. These epithelial cells are rich in glycogen, enzymes, and acetylcholine, and their activities can regulate the blood cells of the cornea and the matrix that can pass through the cornea (32 ) To control the transport of water and electrolytes.

A thin layered substance (33) located in the front as a limiting effect is a Bowman's membrane. This thin layered substance is set in the epithelial cells (31) and essence or matrix of the cornea. (32) The place between. This matrix (32) contains some thin-layered substances in the form of fibril bundles and parallel to each other, and this thin-layered substance traverses the entire cornea. Most of the fiber bundles of these fibril bundles are parallel to this surface, and some of these fiber bundles are in an inclined state, especially the fiber bundles located in the front. The fibril bundles located in some replacement thin-layered substances and the fiber bundles located in a thin-layered substance adjacent to it are arranged in a state close to right angles to each other. A thin layered substance (34) behind which acts as a limiting function is a kind of Descement's membrane. This Dexman's film is a very strong film, which forms a sharp state from this matrix, and it can resist the pathological processing of the cornea.

Endothelial cells (36) are the last layer of this cornea, which includes a single layer of cells. One side of the edge (37) of a foreign tissue is in the transfer area between the conjunctiva (38) and the sclera (13), and the other side is between the conjunctiva and the cornea (12) Inside the transfer area between.

Now please refer to Figure 4, which is an exploded view showing the assembly of the basic components of the device of the present invention. These components include a cylindrical positioning ring (50), this positioning ring has an elastic ring (52), this elastic ring is extended from the bottom end of the positioning ring, so as to be able to contact a patient The eye that the patient wants to undergo surgery (please also refer to Figure 9). If necessary, a vacuum connection hose (54) can be provided to connect the inside of the elastic ring (52) to a vacuum pump pressure source device, and this vacuum pump pressure source can be used to connect the components of this combination Keep or fix it on the eyeball so that it can be used for the surgical procedure described here, and it can be used to remove a part of the cornea to be sacrificed. It can use a low vacuum pressure of no more than 8 inches of mercury to perform this action. Many locating pins (58) are arranged on the upper part of the locating ring so that they can be used to receive a cylindrical support sleeve (60). These pins can be embedded in a flange part ( 64) Inside the opening (62) inside. An opening (66) that can be used for visual inspection is provided for the surgeon. In another embodiment, the support sleeve (60) may be transparent to facilitate visual inspection during surgery. The outer part of the cylindrical support sleeve (60) includes a large number of threads (68) extending along its length. These threads are a very fine micrometer type thread, such as a thread with a diameter per inch Between 35 and 50, preferably 40 threads. An index or scale (70) is provided in the body of the cylindrical support sleeve so that the surgeon can use it to perform a visual inspection relative to a rotatable position of a guide sleeve (72). The guide sleeve includes some internal micrometer-type threads so as to engage with the threads (68) of the cylindrical support sleeve. The guide sleeve includes an outer handle part (74) and an index, which is generally represented by a reference number (76), such as a millimeter or micrometer type measurement mark set on the guide sleeve The lower part of the tube. The inner part (78) of the cylindrical support sleeve can be used to rotatably accommodate a shaping tool (80). The shaping tool includes a collar (82), and the collar system can lie on the upper surface (83) of the guide sleeve (72) so that it can be axially upwards or upwards together with it. Down Mobile action. The top end of the plastic tool may include a patterned area (84), so that the surgeon can use his fingers to rotate the plastic tool and/or can be used to swing the plastic tool (80). At the bottom of this plastic tool, there are many, such as four sharp curved blades (86, 87, 88 and 89) used to perform surgery. These blades use some pins (90, 91). , 93 and 95) are retained in the body of the shaping tool (80) radially or laterally. The blades (86, 87, 88, and 89) are held in the transverse direction with respect to the longitudinal axis of the shaping tool (80). The blades used in the present invention are made of surgical steel. Located at the center and near the blades (86 and 88) is a central pressure cushion (92), which is made of a non-abrasive and friction-reducing material. Producers, such as Nylon and Teflon. The role of this central pressure cushion has a dual meaning, that is, it can prevent the central area of the cornea from being scratched, and it can be applied to the central area due to the pressure of the liquid inside the eyeball. The pressure in order to force the outer ring of the cornea (as indicated by A in Figure 2) to bulge outward and touch these blades. As I will explain in more detail here, these blades are intended to be used to contact the outer front area or annulus of the cornea, so that they can be used to shorten the effective radius of the cornea, that is, these The blade is mainly used to contact and scrape the annulus located in area A, as shown in Figure 2. 88 and 89) are maintained in the transverse direction with respect to the longitudinal axis of the shaping tool (80). The blades used in the present invention are made of surgical steel. Located at the center and near the blades (86 and 88) is a central pressure cushion (92), which is made of a non-abrasive and friction-reducing material. Producers, such as Nylon and Teflon. The role of this central pressure cushion has a dual meaning, that is, it can prevent the central area of the cornea from being scratched, and it can be applied to the central area due to the pressure of the liquid inside the eyeball. The pressure in order to force the outer ring of the cornea (as indicated by A in Figure 2) to bulge outward and touch these blades. As I will explain in more detail here, these blades are intended to be used to contact the outer front area or annulus of the cornea, so that they can be used to shorten the effective radius of the cornea, that is, these The blade is mainly used to contact and scrape the annulus located in area A, as shown in Figure 2. 88 and 89) are maintained in the transverse direction with respect to the longitudinal axis of the shaping tool (80). The blades used in the present invention are made of surgical steel. Located at the center and near the blades (86 and 88) is a central pressure cushion (92), which is made of a non-abrasive and friction-reducing material. Producers, such as Nylon and Teflon. The role of this central pressure cushion has a dual meaning, that is, it can prevent the central area of the cornea from being scratched, and it can be applied to the central area due to the pressure of the liquid inside the eyeball. The pressure in order to force the outer ring of the cornea (as indicated by A in Figure 2) to bulge outward and touch these blades. As I will explain in more detail here, these blades are intended to be used to contact the outer front area or annulus of the cornea, so that they can be used to shorten the effective radius of the cornea, that is, these The blade is mainly used to contact and scrape the annulus located in area A, as shown in Figure 2.

The following description is not intended to be used as a limitation, it is intended to be used as an example of explanation, it is a typical plastic tool (80), the diameter of the working end of this plastic tool is 10 cm It has a central pressure cushion (92) with a diameter of 2 mm. This central pressure cushion (92), as shown in Figure 7, extends slightly below the inner ends (94, 96, 98, and 100) of the four blades (86, 87, 88, and 89), approximately 0.1 mm distance. The radius of this blade will be slightly larger than the radius of this cornea. For example, referring to Figure 7, the radius from the center of the cornea (103) is 7.9 mm, and the radius of curvature of this blade is 10 mm. Therefore, relative to the gaze axis (104), the concentric circles that first contact the cornea tangentially by the blades occur at a coaxial diameter (106), and the appropriate diameter is about 4 Mm, and the final contact circle (108) occurs in a place with a diameter of 6 mm.

Please refer to Figure 10, which shows an alternative embodiment according to the present invention. Instead of a curved blade, in some embodiments, one or more straight blades (120) intersecting each other include a non-sharp central area (122), and in this embodiment The central area (122) is located less than 0.001 inches above the sharp edges (124 and 126). The central area (122) is provided for the purpose of applying a pressure not used for scraping to the central area, for example, it has a diameter of approximately 2 mm, so as to make the outer side of the cornea The annulus (A) will protrude and bear against these scraping blades (124 and 126).

Instructions

In the operation method of this device and the method of performing this operation, first of all, it must make an optical measurement of the eyeball, and determine what shape the cornea must have, so that the eyeball can be in an optical angle It is operated in the correct way, that is, it is intended to be used to correct the phenomenon of refraction errors. Typically, it uses a photographic image of a keratinous image, and it uses a placito ring (placito ring) target. This kind of image is formed by the light refracted from some placed annular bodies on a standard spherical surface with the same size as the cornea, so that it can be formed in a similar way to an aerial survey map. And produce an image. Then, it will perform the measurement of the topography of the eyeball to be corrected, so that it can be used for comparison purposes, and can provide the surgeon with some necessary reference materials, which can be used to correct these refraction errors The phenomenon. The eyes of these patients will be anaesthetized with a local anesthetic and placed in an inclined position. Typically, the setting direction of a TV image keratoscope/comparator is set to provide visual information immediately so that it can help the surgeon. When this happens, the next operation action is to place the positioning ring (50) on the eyeball. The size of the positioning ring can be changed due to various operations, but its size is best set so that the elastic ring (52) can lie on the scleral part of the eyeball, and relative to the eye The central visual axis of the cornea is concentric. Once the circular positioning ring (50) is placed at the location and held at the location, if necessary, it can also use a vacuum source not shown in the figure to pass through the pipeline (54) And keep the positioning ring at the location, and when the positioning ring is at the location, the cylindrical support sleeve (60) will then be placed on it, which uses those The hole (62) is fixed by the combination of the positioning pin (58). The shaping tool (80) is then inserted into the cylindrical support sleeve (60) to the position shown in Figure 7, so that the blades (86 to 89) are in the shape of the edge of the knife. The bottom arc will initially and tangentially touch the cornea. This contact action can be determined electronically, such as the one shown in Figure 8. When the guide sleeves (72) are gradually rotated in a gradual manner, they can be commanded and controlled by a caliper or a device for measuring indicators (70 and 76). , So that the surgeon can continuously increase the axial depth of this scraping or engraving operation. The tissue of the cornea can be removed, and the increment that can be used to change the refractive index is about 0. 25 diopters. The scraping action of the cornea, the cutting action or the sculpting action at the expense of certain parts, is operated by manual operation, that is, the hand/finger is used to rotate or oscillate the shaping tool ( 80). However, it must be understood that other machinery and equipment or motor-operated devices that can be used to produce such artificial rotation capabilities and actions will also be included in the scope of the present invention.

During this operation, the central pressure cushion (92) can be rotated together with the shaping tool (80), and in another embodiment, the central pressure cushion can be adjusted relative to the shaping tool. Rotation, and the central pressure cushion can rest against the central part of the cornea. This central pressure cushion can be used as a protective device, and it can also be used as another device. A kind of pressure can be applied to this cornea. That is, when the central pressure cushion (92) abuts on the cornea, it will form a small round protrusion, which will protrude upward and intervene between these blades. (86-89), and where you can face the blades outward, and when the plastic tool is rotated, the protrusion will be scraped preferentially without causing any damage to the central part of the cornea In the case of scraping, at least it will not produce any scraping in the diameter of the central pressure cushion (92), that is, in the embodiment described here, the diameter is about 1 mm to 2 Around millimeters. As described above, this initial movement of setting the eyeball makes it contact at a tangent ring part, which is about 2 mm away from the visual axis. Around, or with a diameter of 4 mm, this ring-shaped part will be scraped first. When the shaping tool advances in the axial direction, the scraped annulus will widen, so its inner diameter will become smaller, and its outer diameter will become larger, until its diameter is about 6 Up to about millimeters. When the inner cutting diameter reaches the center of the pressure cushion, or, for example, when the outer diameter reaches about 6 mm, it will reach the limit of its cutting limit. When the shaping tool is removed, and when the eyeball returns to its normal shape, the shaved annular area has a changed radius, which is shorter than its original radius. The reason is that the convex annular part formed by pressing the central pressure cushion (92) has been scraped off. This concept needs to measure the radius of the cornea so that the radius of the normal blade will make its initial tangent contact part form a circular part with a diameter of 4 mm.

In one of the embodiments, a presbyopic eye (hyperopia) has an initial radius of 7.9 mm, and it is sharpened to become a radius of 7.5 mm, so it is in Figure 2 One of the focal points (42) will move to a certain point located in the retina (18), thus making it possible to correct this refraction error phenomenon. When the surgeon of the main knife performs a scraping action, he will rotate the guide sleeve (72) so that the guide sleeve will rotate relative to the cylindrical support sleeve (60) to form an axial increment The movement action of using this increment measurement index (76) relative to an indicator arrow or other index (70) to obtain this increase. Typically, this kind of guide sleeve is engraved with a scale so that it has a separation distance of 25 or 50 kilograms, so that when it rotates one turn relative to each marked separation distance, it can form And it can be adjusted by one hundredth of a millimeter. Through the conditions of use, the surgeon can start to determine the amount of movement he needs to move down, so that he can achieve what it needs to do in the cornea through the rotation and/or oscillation of these knives The amount of change. After this rotating action lasts for a few seconds, it can cause a small amount of corneal material to be removed from the cornea. After each such increment is completed, the plastic tool can be removed, and then corneal image photos or other measuring devices can be used to determine whether the refraction error has been corrected. Because in the process of performing this kind of corneal plastic surgery, the device used and the method of performing the surgery all use very small increments of movement, so it is very important that its first contact setting action must be It needs to be very precise and accurate. In many cases, the surgeon can use a visual device to perform this operation, and in other cases, it can provide an electronic detection device set on the cornea and the blade of the plastic tool. Time, so that it can be used to correctly set this plastic tool, and can make it can repeatedly remove the amount of cornea scraping.

A first contact electrode (110) is a place where it can be detachably connected to a conductive tool (90). A second electrode is placed on the patient's body at point (112). These wires are connected to a low-voltage power source (114), which includes a warning device or an indicator light (116) device. When the blade touches the cornea, the warning or indicator light will emit light or other warning indication signals to indicate the initial contact point, and from this initial contact point, the You can start measuring how much it will move down. Typically, when the guide sleeve (72) is rotated downward, a predetermined amount of the corneal material will flow into the plastic tool. The rotation or swing of the plastic tool (80) will then begin to change the shape of the cornea. It then needs to do some measurement work to determine whether it needs to remove more corneal material. If more corneal material needs to be removed, then it needs to set a new depth, and then repeat the procedure. The shaping tool is designed so that it can be removed and replaced with another shaping tool without changing the setting of the depth of the guide sleeve (72). Typically, this predetermined depth of removal is about two thousandths of an hour (.002"). In many cases, it must operate many cycles, and after each cycle is executed, it needs Do some measurement work. Before and after performing each plastic surgery procedure, a curve diagram of the cornea generated by a nomogram used in conjunction with a computer will help the surgical operation The doctor allows him to regularly monitor the amount of removal of this epithelial cell layer and/or in some cases, to monitor the amount of removal of this Bowman's layer. I found that in a period of about 24 to 48 hours In a period of less than 72 hours, the scraped part of the surface will regenerate the epithelial cells. The epithelial cells will regenerate and grow to its original thickness again. The situation is as well as clarity and transparency, but it now has a changed radius.