MXPA02002309A - Floating phakic refractive lens design for preserving eye dynamics - Google Patents

Abstract

Phakic refractive lens (PRL) for correcting myopia or hyperropia are disclosed. The lens is implanted in the posterior chamber of the eye, with no permanent point of fixation, such that it floats between the patient s iris and natural lens. The lens corrects refractive errors in the eye, while maintaining the fluid dynamics of the eye and not causing stress or damage to eye structures. The lenses are made from a flexible material (such as those having a hardness of from about 20 to about 50 Shore A), having a specific gravity of from about 0.9 to about 1.2 g cm3, and have a mass per unit area of from about 0.03 to about 0.30 mg mm2. The method for using those lenses and surgical kits including those lenses are also disclosed.

Description

DESIGN OF FLOATING REFLECTIVE FAQUICO LENS TO PRESERVE THE NAME OF THE EYE The present application is based on the provisional North American application no. 60/1 52,052, by Zhou and Wilcox, presented on September 2, 1999. Field of the invention A refractory phakic lens (PRL) of the posterior chamber is surgically implanted behind the iris and in front of the natural human crystalline lens for correct myopia or hyperopia. PRL is the only reversible procedure to correct severe refractive errors, both in patients suffering from myopia and hyperopia. However, there are three major complications associated with the implantation of PRL. These are: (1) the elevation of intraocular pressure (IOP); (2) cataract induction; and (3) d isp ersion of the iris pigment. Only when all three of these complications are solved successfully will the PRL technology become acceptable to surgeons and patients. Currently, the elevation of IOP has been successfully controlled by surgical iriditomy (for example, two perforations made in the iris either by laser or by knife). The induction of cataracts and the dispe rsion of the iris pigment remain the major complications for the implantation of the PRL. The present invention aims to define a number of requirements, including the characteristics of the PRL material, for a floating PRL design which preserves the dynamics of the eye. Saying The design of floating PRL solves the problems of cataract induction and iris pigment dispersion caused by the implantation of a PRL. BACKGROUND OF THE INVENTION There are a number of patents that describe the PRL concept of the posterior chamber, and the specific designs of the lens. The patent No. 4,585,456, issued to Blackmore, issued on April 1986, describes an intraocular lens (IOL) composed of flexible materials, which is placed against the natural lens of the eye and is held in place immediately adjacent to the natural lens and the ciliary groove. There are no specific descriptions of the properties of the PRL material, such as softness. The lens does not float in the eye but rather, it is held in place. Other patents describe different means to reduce the elevation of the IOP and to prevent the formation of cataracts by PRL designs and their fixation mechanisms. For example, Fedorov, in U.S. Patent No. 5,480,428, issued January 2, 1996, describes a novel design of the phakic lens, which has an opening through the center of the body or optic. This open perforation allows aqueous flux to flow through the lens body, thereby preventing the elevation of the IOP, but it reduces the optic functioning of the phakic lens. This patent also does not describe the properties of the lens material or the surface properties of the lenses for such designs thereof. Fedorov, in U.S. Patent No. 5,258,025 issued November 2, 1993, describes that inflammation Post-operative, caused by the contact of the support elements with the ocular tissue, is avoided by moving the support elements to the periphery of the phakic lens. Zinn zonules are strong enough to hold the support elements in place without causing inflammation. Again, Fedorov did not specify the material properties of the lenses and the surface properties. Also, this is not a floating lens design. Finally, the published PCT Patent Application WO 98/1 7205, by Valunin et al. , published on April 30, 1998, describes the structure of a phallic IOL, which floats in the eye. Valunin taught that phakic IOL can be made of, for example, silicone, copolymers of silica-methacrylate, poly (methyl methacrylate), poly (hydroxyethyl methacrylate) and collagen / acrylate mixtures. However, no specific properties of a suitable material were defined, such as the area of mass per unit or specific gravity. Therefore, there is a great need to identify the desirable materials for the lenses with the required properties, which in combination with the appropriate lens deifications, can preserve the dynamics of the eye after the implantation of the LRP. The combination of the design of the lenses and the material properties of the lenses makes it possible to avoid the induction of cataracts and the dispersion of the iris pigment. No design of the lenses alone, nor the material properties of the lenses alone can achieve the desired floating characteristics.

SUMMARY OF THE INVENTION The object of the present invention is to provide a PRL, with a design and properties of correct lens materials, which can be placed in the posterior chamber of the human eye for the correction of refractive errors. Also, it is the object of the present invention to provide a PRL which can float in the aqueous humor and which is very flexible and soft. The flotation action and the soft nature of the PRL will preserve the dynamics of the eye so that the induction of cataracts of the human crystalline lens will be avoided, and the dispersion of the iris pigment will be eliminated. A further object of the present invention is that this floating design and these benefits are achieved by selecting biocompatible materials that have defined properties, and selecting other parameters, such as a surface area of mass for a low value (grams). mm2), from the PRL. It is still another object of the present invention, which due to the softness of the PRL material and the floating nature of the PRL design, when the iris contracts, it can move freely and steadily on the anterior surface of the PRL, without cause the dispersion of the iris pigment. These and other objects are recorded by a refractory phakic lens for implantation in the posterior chamber of the eye, the lens having no permanent fixation in the posterior chamber beyond simple floating in the aqueous humor when placed between the iris and the eye. natural crystalline lens, the lens having the following properties: (a) an area of mass sur- face per unit from about 0.03 to about 0.30 mg / mm2, preferably from about 0.05 to about 0.13 mg / mm2; (b) the specific gravity of the materials used for said lenses is from about 0.9 to about 1.2 grams / cm 3; and (c) the lens must be flexible, and preferably, the hardness of the material used for said lens should be from about 20 to about 50 Shore A. Brief Description of the Drawings Figure 1 is a sectional view of the eye which shows the positioning of the lens of the present invention. Figure 2 is a top view of a side view of a lens of the present invention (see Example 2). Figure 3 is a top view and a side view of a prior art intraocular lens with fixed locator (see Example 3). Figure 4 is a top view and a side view of a lens of the present invention (see Example 4). Detailed Description of the Invention There are many factors that affect the formation of cataracts after the implantation of an LRP. First, if a PRL makes contact directly with a natural crystalline lens, stress is caused in the crystalline lens. As a result, sle 'can develop a subcapsular cataract. Then, the disturbance of the dynamics of the eye can also induce the formation of catheter rats. Because the PRL is placed between the iris and the natural human crystalline lens, it almost blocks the entire pupil. Although an iridotomy is usually performed Successfully avoiding the elevation of the IOP, blocking the pupil by the PRL still inhibits the free exchange of aqueous humor between the anterior chamber and the posterior chamber of the eye, thus disturbing the dynamics of the eye. This can result in the accelerated formation of cataracts. A design of floating PRL will maximize the exchange of aqueous humor between the posterior chamber and the anterior chamber, preserving the dynamics of the eye. As a result, it avoids the induction of cataracts. Finally, the PRL of the present invention is so flexible and soft that it yields to the iris when a contact occurs. The iris feels the PRL as if it were part of the aqueous humor, avoiding the dispersion of the iris pigment. The main characteristic of the design of the floating PRL of the present invention is that it has no permanent fixing mechanism whatsoever. The PRL (1) simply fta in the aqueous humor (2) as illustrated in Figure 1. In that figure, the PRL is placed in the eye between the iris (3) and the natural lens (4). The lens has a structure of the type shown in PCT Patent Application 98/17205, issued to Valunin, et al. , published on April 30, 1998, and US Patent No. 6,01, 5,435, issued to Valunin et al. , issued January 1, 2000, both incorporated herein by reference. Therefore, the lens does not cause any permanent stress against the human crystalline lens. Due to its floating nature, the PRL is constantly changing its location within the limits determined by the haptic. When the iris (3) contracts and moves towards the center of the anterior surface of the LRP, the iris can exert some pressure by means of the PRL to the natural crystalline lens (4). Due to its floating nature, the PRL has no pressure points some located against the human crystalline lens. This floating PRL simply transmits the pressure in any direction as if it were part of the aqueous medium. Of is > In this way, the stress on the natural crystalline lens caused by the movement of the iris is dissipated by the floating PRL in almost the same way as the aqueous humor. As a result, the induction of cataracts is minimized by the implantation of the PRL. The second feature of the design of the floating PRL is that it allows the iris to move freely and constantly on its anterior surface, without causing the dispersion of the iris pigment. When the iris contracts or dilates, the PRL gives way to the movement of the iris due to the floating characteristic and the softness of the PRL material. The iris "feels" the PRL as if it were part of the aqueous substance, so that the dispersion of the iris pigment is avoided. The third feature of the floating LRP design is that it allows the aqueous humor to flow from the posterior chamber to the anterior chamber. In healthy eyes, this flow happens constantly. An ideal PRL would have a large surface area and a small mass. The materials used to manufacture the PRLs must be very soft and flexible. All these properties are critical factors for the formulation of a floating PRL to allow the maximum flow of aqueous humor.

Those skilled in the art will understand that the specific gravity of the aqueous humor of the human eye is approximately equal to that of water (1 gram / cm 3) and that any article that can float in the water should have a weight equal to, or slightly less than 1 gram / cm3. However, some materials with a much larger specific gravity (such as 1.2 g / cm3, as shown in Example 5) than that of aqueous humor, can still be used to achieve a floating design. The following example clearly illustrates the way in which material that is heavier than water can be used to make a PRL that floats in water. It was surprisingly discovered that PRLs made of a medical grade silicone with a specific gravity of 1.05 float on the surface of the water, while an intraocular lens for cataracts (IOL) made of the same medical grade silicone, does not float on the surface of the water (see Axles 2 and 3). The silicone PRL can be forced into the water. However, as soon as the force is released, the silicone PRL floats back to the surface of the water. On the other hand, the IOL for cataracts of the prior art, made of the same silicone material, can only float on the surface of the water when it is placed in a very careful way on that surface of the water. When the water is slightly disturbed, or the IOL for the vessels is forced into the water, it does not float on the surface of the water again. The only difference in this set of experiments is the shape of the PRL (Figure 2) and OL for cataracts (Figure 3). As illustrated in Figure 2, the PRL has a relatively large surface area. The linear dimensions are approximately 6 x 1 1 mm. This is equivalent to a surface area of approximately 1 32 mji2. Generally, PRLs with such configurations and as illustrated in Figure 2, weigh approximately 1.5 mg or less. Therefore, the surface area of mass per unit for the PRL is approximately 0.1 1 mg / mm2. On the other hand, the IOL for cataracts (see figure 3) generally has an optical diameter of 6 mm and weighs approximately 20 mg. Therefore, the surface area of mass per unit for the I OL for cataracts is approximately 0.31 mg / mm2. The silicone used in this case is a typical rofobic material with a 95 ° contact angle. The hydrophobicity of the PRL creates a considerable tension of the surface between the PRL and the water. This tension >The ion of the surface is the driving force to maintain the floating PRL. There is an equilibrium between two opposing forces: gravity and surface tension. Preferred hydrophobic materials for use in the present invention have a contact angle of about 80 ° or more, more preferably about 90 ° or more. PRLs made from materials with a specific gravity greater than about 1.0 have a tendency to not float in water. However, the surface tension between the hydrophobic PRL and the water keeps the PRL floating on the surface of the water, even in the case that its specific gravity is greater than about 1.0. Increasing the specific gravity will decrease the flotation capacity while increasing the surface area or reducing the mass of the PRL or both, the flotation capacity will be increased. Due to the material, The determination factor for a floating PRL is the ratio of the surface area of mass per unit. As shown in the previous example, the surface area of mass per unit for the PRL of the present invention is approximately 0.1 1 mg / mm2 and for the IOL for cataracts of the prior art, it is approximately 0.31 mg / mm2 Therefore, it is concluded that if a surface area of mass per unit of PRL is equal to or greater than about 0.31 mg / mm2, it can not be used effectively for a floating lens design. Therefore, the mass surface area per unit of the lenses of the present invention should be from about 0.03 to about 0.30, preferably from about 0.05 to about 0.30, and more preferably from about 0.05, to about 0.1. 3 mg / mm2. The comparison of the silicone PRL and I OL for silicone cataracts provided in the above explanation (ie, Examples 2 and 3), is for the purpose of illustration only. It is clearly shown that the surface area of mass per unit, and not the specific gravity, is the determining factor for a floating PRL design. This principle is applied to PRLs made of a hydrophobic material as well. It is important to mention that it is not necessary for a PRL to float on the water surface to obtain the benefits of the present invention. In fact, it is more desirable to have a PRL which can float in the water instead of on the surface of the water. This is due to the fact that the interior of the eye is filled with aqueous humor and the PRL is suspended in the aqueous humor. To simulate a PRL implanted in the eye, a PRL which can temporarily float in the water when the water is slightly disturbed, has complied with the design feature. This is because, in healthy eyes, the aqueous humor always floats from the posterior chamber to the anterior chamber. When such a flow occurs, it is very important that the PRL floats to allow the aqueous humor to pass through, thus preserving the eye's dynamics. In addition, the aqueous fluid flow avoids the direct contact of the PRL with the natural crystalline lens and thus prevents the induction of cataracts by the implantation of a PRL. It has been found that PRLs made of hydrophilic materials, such as poly (hydroxyethyl methacrylate) (polyH EMA), the classic example of a hydrogel material, can temporarily float in water, when the criterion of the surface area per mass is has fulfilled. When fully hydrated in water, the polyHEMA hydrogel has a contact angle of 34 °. The preferred hydrophilic materials have a contact angle of about 40 ° or less. This unexpected discovery is very important for a number of reasons, first, most polymeric materials have a specific gravity greater than about 1. This invention allows the use of said material is for a floating PRL design. Second, the current invention will lead engineers to design a PRL with a maximum surface area and a minimum weight, in order to maximize the characteristics of the floating design. Finally, the relationship of the different factors needs to be considered, in order to maximize the flotation characteristic. For example, when it is used For the design of floating PRL up material with a high specific gravity, its surface area can be increased, or its total weight can be decreased or both, in order to compensate the negative effect by the increase in specific gravity. In summary, the most critical factor for a floating PRL design is not the specific gravity, but the surface area of mass per unit (milligrams / mm2). Experiments indicate that materials with specific gravity greater than about 1.0 g / cm3 can be used for floating design., if its mass / area is minimized. For example, an acrylic material with a specific gravity of 1.2 grams / cm 3 can be used to achieve the characteristics of flotation (Example 5). In general, the materials useful in the present invention will have a specific gravity of from about 0.9 to about 1.2, preferably from about 1.0 to about 1.2 g / cm3, and even more preferably greater than about 1.0. at about 1.2 g / cm3. Finally, the materials used to manufacture the lenses of the present invention should be flexible, preferably having a hardness of about 20 to about 50 Shore A. This will allow the lenses to maintain their shape for proper operation, but also, it will give them enough flexibility to insert them into the eye and to avoid harmful interactions with the iris and the natural lens of the eye. In some cases, it may be possible to use materials that have a hardness greater than 50 Shore A, s that material (for example, poly (methyl methacrylate) can be made flexible by using it at very high thicknesses. small (see Examples 7 and 8), or (for example, poly (hydroxyethyl methacrylate) by hydrating them (see Example 6) A logical extension of the present invention is that if the surface area of the PRL is increased by roughness the surface of the non-optic portion of the lens, the value of the mass surface area per unit of the lens is decreased, thus forming a more effective floating PRL, even for len: it is with somewhat higher masses The preferred materials to be used in the formulation of the lenses of the present invention include silicones, poly (acrylates), poly (methacrylates), hydrogels, collagen-containing polymers and mixtures of said materials.The present invention also comprises an equipment , which comprises the refractory phakic lens described above, together with means for inserting the lenses into the posterior chamber of the eye, so that it floats on the aqueous lens of the eye between the iris and the lens. of the patient, with no permanent fixation point. Such means may include one or more of the following: an instrument for making the required incision in the cornea, an instrument for inserting the phakic lens into the eye, an instrument for correctly placing the phakic lens in the eye, means for closing the incision of the cornea and instructions for the implantation of the lens in the eye EXAMPLES The following examples are provided for purposes of illustration of the present invention, and are not intended to be limiting thereof.

The contact angle is a measure of the hydrophobicity (or hydrophilicity) of the surface. In the present invention, the Sessile Dr? P method and a Rame-Hart Goniometer method are used for the measurement. In a typical test, the average of 1 2 readings is used for reporting purposes. A typical rofobic material such as silicone generally has a contact angle in the range of about 80 ° or greater, whereas a typical hydrophilic material such as poly-H EMA has a contact angle in the range of approximately 40 ° or less. Example 1 - PRL Silicone Float SI SI 1 .46 is a silicone material with a refractive index of 1.46 and a specific gravity of 1 (which is available on the market at SI EL Ltd., A supplier of silicone specialty in Russia). A small amount of the material (3 part A: Part B = 1 0: 1 by weight) (approximately 30 mg or less) is placed on a metal mold of PRL. The mold is fastened and placed in a preheated oven at a temperature of 1 20 ° C for 70 minutes. Subsequently, the mold is cooled to approximately room temperature. The mold is opened and the PRL is carefully removed from the mold. The PRL has a configuration and dimensions as illustrated in Figure 2. The PRL is placed in deionized water and observed to float on the surface of the water. A spatula or tweezers can be used to gently push the PRL into the water. However, as soon as the force of the impulse is released, the PRL will again hover over the water surface. Even when all the PRL is pulled into the water, it returns to the surface of the water, as soon as the pulling force is released. The contact angle of the PRL is 80 °. The Urea Shore A of the PRL material is in a range of 20 to 25. The PRLs with the configurations shown in Figure 2 generally weigh 1 5 millig ram. s or less. The surface area of the PRL is approximately 1 32 mm2. Therefore, the surface area of mass per unit is approximately 0.1 1 milligram / mm2 or less. Example 2 - Silicone floating PRL A Silicone material Med 6820, manufactured by NuSil Silicone Technology, was used to prepare the PRLs according to the following conditions. Equal amounts of Part A and Part B were m for 10 minutes. The mixture is transferred to a syringe, and degassed in vacuo until all visible bubbles disappear. A very small amount of the mixture is poured into a metal alloy mold and cured at a temperature of 1 20 ° C for 70 minutes. The PRL is moved from the mold and placed in deionized water while facing its back side.; r down. It is observed that the PRL floats on the surface of the water, when a spatula or tweezers are used to push the PRL lightly into the water, the PRL floats on the surface of the water again, as soon as the spatula of the water is removed. PRL. Other physical and mechanical properties of the Med 6820 silicone material are as follows: tensile strength = 750 psi; elongation = 1 25%; refractive index = 1 .43; Specific gravity = 1.05 g / cm3 at ambient temperature. The specific gravity measurement is based on a method of Specific Gravity and Plastics Density by Displacement ASTM D792 using a Dynamic Contact Angle Analyzer Cahn DCA312. The contact angle, measured by the Sessile Drop method, using a Rame-Hart Goniometer is 95 °. The d ureza is in a range of 40 to 50 Shore A. The shape and dimensions of the PRL are the same as those of Example 1. The surface area of mass per unit in this case is approximately 0.1 2 m iligrams / mm Example 3 (Comparative) - Intraocular lenses for Cataracts of Non-Floating Silicone (IOL) By way of comparison, non-floating lenses are made in the following manner. Using a silicone material identical to that of Example 2, ie Med 6820 of Nil Silicone Technology, a regular intraocular lens (IOL) was cast for cataract surgery, instead of an LRP. The IOL for cataracts has a shape and dimensions illustrated in Figure 3. The IOL for cataracts is placed in deionized water and it is observed that the IOL for cataracts does not float on the surface of the water or in the water, and attach to the bottom of the container. A much larger force is required to disturb the water in order to allow the IOL floats temporarily in the water. This is because the mass of this cataract lens is much larger than that of the floating force. In this case, the surface area of the I OL for cataracts is approximately 64 mm2. The I O, L for cataract weighs 20 mg. Therefore, the surface area of mass per unit for this IOL for cataracts is approximately 0.31 mg / mm2, more than twice the amount of the lenses of the present invention illustrated in Examples 1 and 2. Example 4 - PRL Floating Acrylic A mixture of 1 5.2 grams of hexylmethacrylate was purged with argon, 4. 8 grams of methylmethacrylate 0.07 grams of ethylene glycol dimethacrylate, and 0.02 grams of benzoyl peroxide and then heated to a temperature of 1000 ° C to prepare a viscous syrup. This syrup can still float when it is turned to one side only. The syrup is then transferred to a glass mold for lenses and placed in an oven at a temperature of 100 ° C overnight (approximately 16 hours). The mold is cooled to room temperature and opened to obtain positive sprayed lenses. The configuration of the lenses is illustrated in Figure 4. And their overall diameter is about 1 0.05 mm and the optical diameter is about 5 mm. When the lens is placed in deionized water with the back side facing down, it floats on the surface of the water. The PRL can be forced into the water. However, the PRL can float in the water when it is slightly disturbed. The specific gravity of the lens material is measured to be 1.09 g / cm3. The contact angle of this hexylmethacrylate-methacrylate copolymer is measured to be 76 °. The lens weight of 21 mg and its surface area is approximately 1 74mm2.

Therefore, the surface area of mass per unit, in this case, is approximately 0.1 2 mg / mm2. Other properties of this acrylic material are the following: refractive index: 1.482; glass transition temperature = 23 ° C, d ureza = 47 Shore A. Example 5 - PRL Floating Acrylic A mixture of 48 grams of phenyl ether ethylene glycol acrylate, 2 grams of bisphenol A of diarylto propoxylate, 0.65 grams of 2- (4-benzoyl-3-h-idroxyphenoxy) ethyl acrylate, and 50 milligrams of azobisisobutyronitrile are deaerated with an ultra pure nitrogen gas for about 15 minutes. This mixture can be used to make the PRL directly or it can be previously gelled. In any case, the mixture is transferred to a mold. The cure conditions are: temperature from 90 to 1 0 ° C; time = 1 1 to 1 6 hours. Other properties of this acrylic material are: refractive index = 1 .558; glass transition temperature = 7 ° C; Shore A hardness 36; % tensile strength = 280; % elongation = 1 60%. The specific gravity of this material is 1.2 grams / cm3. The contact angle of this polymer is 81 °. The PRL weighs 23.2 m iligrams. The shape and dimensions of the PRL are the same as in Example 4 (Figure 4). The surface area is approximately 1 73 mm2. Therefore, the surface area of mass per unit for this PRL is approximately 0. 1 3 mg / mm2. When this PRL is placed in deionized water with its back side facing down, f ote on the surface of the water. The PRL It can be forced into the water. However, PRL can float in water when moved lightly. Example 6 - Hydrophilic Lens Fl ota nte A procedure similar to that of Example 4 is safe except that a different composition is used. nte. The new composition comprises a mixture of 5 grams of 2-hydroxyethyl methacrylate (H EMA), 0.25 grams of ethylene glycol dimethacrylate, 5 mg of benzoyl peroxide. The lenses made of this composition do not float on the surface of the water. However, they can float or add a few seconds in the water, when the water solution is lightly agitated. Said temporary flotation may also cover the requirements of a floating PRL design.

Within the eye, the aqueous tumor flows from the posterior chamber to the anterior chamber. When the flow of said aqueous humor occurs, a floating PRL is given to the aqueous flow, thus conserving the dynamics of the eye. The unhydrated poly (hydroxyethyl methacrylate) has a specific gravity of 1.5 g / cm 3. It is solid, hard material, and its hardness exceeds the Shore A scale. The mass surface area per unit for the dry lens of poly (hydroxyethyl methacrylate) is about 0.1 2 mg / mm2. However, when hydrated, poly (hydroxyethyl methacrylate) absorbs approximately 40% of the agus and becomes mild. The contact angle of the fully hydrated lens is 34 °. Eiem plo 7 A very thin disc is cut by means of a lathe from the material of poly (methyl methacrylate) (PMMA). PM MA has a specific gravity of 1.1 g / cm3 and is a hard solid polymer with a hardness Rockwell of M-93. Its hardness exceeds the Shore A hardness scale and, therefore, it can not be measured by a Shore A method. The disk has a radius of 6 mm and a thickness of ap approximately 0.07 mm. Its weight is approximately 9 mg. Therefore, the surface area of mass per unit is approximately 0) L04 mg / mm2. It has been discovered that the disk can float on a water surface. Without an external force applied to the disk, it always floats on the surface of the water. However, it can be forced into the water. When the water is moved slightly, the disk can float in the water. Furthermore, although the PMMA material is a hard solid, when machined in the form of a disk with a thickness of approximately 0.07 mm, it becomes much more flexible, for example, it can be rolled without breaking the disk. Example 8 A similar disc of the PMMA material was cut with a radius of approximately 5mm and one is 0.28mm in weight. The weight of the disc is approximately 26 mg. Therefore, the surface area of mass per unit is 0.1 7 mg / mm2. It was found that the disk can float on the surface of the water. Without an external force applied to the disk, it always floats on the surface of the water. However, the disc can be forced into the water. When the water is slightly disturbed the disk can also float in the water.

Claims (9)

1. CLAIMS 1 .- A refractive phakic lens, the lens being structurally adapted for implantation in the posterior chamber of the eye, to float in the aqueous humor between the iris and the natural lens, the lens having covered the following properties: a) the mass area by one lens unit is from about 0.03 to about 0.30 mg / m2-b) the lens is flexible; and c) the specific gravity of the materials forming the lens is from about 0.9 to about 1.2 g / cm3.
2. 2. The refractory phakic lens as described in claim 1, wherein the materials that They form the lens having a hardness of about 20 to about 50 Shore A. 3. The refractory phakic lens as described in claim 1, which floats on or within deionized water. 4. The refractory phakic lens as described in claim 2, having a mass area per unit of about 0.05 to about 0.30 mg / mm2. 5. The refractory phakic lens as described in claim 4, wherein the specific gravity of the materials forming the lens is greater than 1.0 to about 1.2 g / cm3. refractory as described in claim 5, which has a mass area per unit of about 0.05 to about 0.1 3 mg / mm2. 7. - The refractory phakic lens as described in claim 6, made of a hydrophobic material. 8. The refractory phakic lens as described in claim 6, made of an idrophilic material. 9. The refractory phakic lens as described in claim 6, made of a material selected from the group consisting of silicone, poly (acrylates), poly (methacrylates), hydrogels, collagen-containing polymers, and mixtures thereof. same. 1 0.- A method to correct the vision of a patient suffering from myopia or hyperopia who understands the implantation of a refractory phakic lens in the eye of said patient, floating the lens in the aqueous humor between the iris and the eye. The patient's natural lens without a permanent fixation point, the refractory phakic lens having the following properties: a) the area of mass per lens unit is from approximately 0.03 to approximately 0.30 mg / mm2; b) the lens is flexible; and c) the specific gravity of the materials forming the lens is from about 0.9 to about 1.2 g / cm3. 1. The method as described in claim 10, wherein the refractory phakic lens floats on or in deionized water. 12. The method as described in claim 10, wherein the materials that form the refractory phakic lens have a hardness of about 20 to about 50 Shore A.
3. 3. The method as described in claim 12, wherein the refractory phakic lens has a mass area per unit of about 0.05 to about 0.30 mg / mm2. 1
4. 4. The method as described in claim 1 3, wherein the specific gravity of the materials forming the refractive optical lens is greater than about 1.0 to about 1.2 mg / cm3.
5. 5. The method as described in claim 14, wherein the refractive phakic lens has a mass area per unit of about 0.05 to about 0.1 0.1 mg / cm2. 1
6. 6. The method as described in claim 1, wherein the refractory phakic lens is made of a material selected from the group consisting of silicone, poly (acrylate), poly (methacrylate), hydrogels, polymers that it contains n collagen and mixtures thereof. 1
7. 7.- An equipment that comprises: (1) a refractive phakic lens, the lens being structurally adapted for implantation in the posterior chamber of the eye, the lens having the following properties: a) an area of surface po of the lens unit from about 0.03 to about 0.30 mg / mm² 2;. b) the lens is flexible; and c) the specific gravity of the materials forming the lens is from about 0.9 to about 1.2 g / cm3; (2) means for implanting the refractory phakic lens in a patient's eye so that the lens is floating in the aqueous humor of the patient; eye between the iris and the patient's natural lens without a permanent fixation point. 1
8. 8. The equipment as described in claim 17, wherein the materials comprising the refractory phakic lens have a hardness of about 20 to about 50 Shore A.