Abstract:
An intraocular pressure compensating and regulating valve installed inside the eye&#39;s cornea includes: a valve body having a valve seat at an end; a mobile element connected to the valve seat under normal intraocular pressure conditions inside the eye, the mobile element being configured such that it can be separated from the valve seat when the intraocular pressure exceeds the intraocular pressure limit; and an element to keep the mobile element in contact with the valve seat.

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure refers to devices to use in glaucoma treatment, and specifically to a device to reduce intraocular pressure. 
     BACKGROUND OF THE DISCLOSURE 
     Glaucoma is an ocular disorder characterized in that it is a neuropathy in which several mechanisms causing damage and loss of retinal ganglion cells intervene, one of the main factors and to date a controllable factor is that of intraocular pressure, and an objective of the disclosure is to keep the intraocular pressure at a normal level. One of the theories is that cell damage is caused by the elevated intraocular pressure that by means of mechanical action causes compression of the nervous fibers and consequently damage to the optical nerve, which is expected to gradually lead to irreversible damage to ganglion cells, nervous fibers and atrophy of the optical nerve and consequently damage and visual field loss until eyesight is lost completely. 
     The frontal part of the eye is filled with a clear liquid called aqueous humor, which is primarily produced in the ciliary passages found behind the iris. This liquid exits or is removed from the eye through canals in the frontal part thereof, in an area called the anterior chamber angle, at times simply referred to as “angle.” 
     A normal eye has been generally considered as having a normally appropriate intraocular pressure of about 10 to about 20 mm Hg, through the circulation inside the aqueous humor of the eye, which is secreted from the ciliary body, goes through the pupil to the anterior chamber of the eyeball, and is filtered outside the eyeball through the trabecular meshwork and the Schlemm&#39;s canal. When the aqueous humor excreting passageway is blocked, the aqueous humor cannot leave the eyeball at a suitable speed, the intraocular pressure is increased, the eyeball hardens, and direct damage is produced, subsequently developing atrophy of the optical nerve, which is called glaucoma. A characteristic optical neuropathy is developed, resulting in progressive loss of ganglion cells of the retina, visual field restriction, and finally producing blindness. The advanced stages of the illness are also characterized by significant pain. 
     Treatment for glaucoma, if started early in the course of the illness, may avoid additional damage and preserve the most of the ocular functions. The object of glaucoma treatment is to reduce the intraocular pressure until reaching a level considered safe particularly for the sight, but which is not so low as to cause an ocular malfunction or retinal complications. 
     There are diverse and varied techniques for treating intraocular high pressure “deviating” the aqueous humor to adjacent tissues contained inside the eyeball, all beneath the sclera or conjunctiva, this technique being subject to the ability of absorbing each one of the tissues wherein the liquid causing the elevated intraocular pressure is canalized. 
     Typical ophthalmic implants have a valve mechanism to regulate the aqueous humor flow from the anterior chamber; defects in and/or failure of said valve mechanisms can lead to an excessive loss of aqueous humor from the eyeball and possible hypotony. The implants also tend to be obstructed as time goes by, whether from the interior by the tissue, such as the iris, being inhaled at the entrance, or from the exterior by cell proliferation, for example, by forming scars. Furthermore, typical operation of inserting the implant is complicated, highly traumatic and takes a long time. 
     U.S. Pat. No. 3,788,327 shows an implant from the state of the art using a valve mechanism for regulating the aqueous humor flow from the eyeball to its exterior. 
     The deficiency and main drawback of this device is the existence of a gap or cavity between the upper part of its liquid-releasing mechanism and the output hole located in the exterior of the eye that is directly connected to the environment and eyelids; since said cavity is highly inclined to organic and inorganic matter sedimentation that will restrict or impede free movement of the release mechanism and/or will generate an obstruction (clogging) in the aqueous humor exit channel, thus resulting in deficiency of its performance and draining capacity of aqueous humor and increasing the intraocular pressure. 
     The functioning of this device and draining capacity is unsafe since it is conditioned to free movement in its release mechanism, free fluid conduction and the lack of obstacles in the channel removing the aqueous humor towards the outside of the eye and does not have any mechanism nor measures to impede forming these restrictions and/or obstructions. 
     Another drawback or deficiency of this device results in its high feasibility of establishing bacterial colonies in the cavity existing between the upper part of its liquid release mechanism and the output hole located outside the eye, since this channel does not have any mechanism or measure to impede the formation and accumulation of bacteria as well as the eye&#39;s own secretions. 
     This device has a high endophtalmitis risk, since clogging the channel existing in the upper part of the release mechanism will cause an aqueous humor blockage in its inside, and thus bacteria will find here a favorable niche for its rapid development and entrance to the inside of the eye. 
     As previously mentioned, the defects and/or failure in the mechanism and drainage of the valve could lead to increasing the intraocular pressure. 
     The device of the present disclosure does not depend on the capacity of absorption of any tissue to remove the aqueous humor without obstructions between its spindle and the outside. Also, its implant process is the least traumatic possible, typically requiring only ambulatory or out-patient surgery, the device or valve of the disclosure being based on its design simplicity and components. The present valve comprises an interior part or chassis and a stem that is displaced outside in the corneal surface (over the epithelium), the valve stem is subject to a tension caused by a compression spring or the repulsion between two permanent magnets, this spring or the magnetic repulsion are calibrated to a given tension (about 10 to about 20 mm Hg), and when the eyeball reaches the tension value greater than the spring or the repulsion, it achieves displacement of the stem outside the cornea, such that the aqueous humor causing the elevated intraocular pressure can be drained outside the eye. Once the pressure is regulated, the stem returns to its initial position tightly closing the valve and thus avoiding any entrance of foreign objects, such as dust, microorganisms, etc., into the eye. 
     There are very clear and precise advantages between the device of the present disclosure and the devices from the state of the art. These include:
         Regulating pressure is always constant, and the aqueous humor flow is free of obstacles.   The smooth exterior upper surface of the device allows cleaning and constant lubrication through the natural movement of the eyelids impeding formation of sediments and bacteria build-up.   The lack of interior and exterior cavities impedes the formation of sediments and bacteria build-up.   The drainage mechanism is always free and lacks movement restrictions; thus its functioning does not have conditions.   This type of configuration allows a laminar flow of the aqueous humor through the device walls to achieve a sweeping effect and thus avoid adherence of bacterial strains.       

     The present disclosure provides an intraocular pressure compensating and regulating valve installed on the cornea of an eye, comprising: a valve body having a valve seat on one end; a mobile element in contact with the valve seat under normal intraocular pressure conditions in the eye; the mobile element is configured such that it can be separated from the valve seat when the intraocular pressure exceeds an intraocular pressure limit; and an element is provided to keep the mobile element in contact with the valve seat. The valve body has an exterior part with fastening elements to retain the valve to the cornea, and the intraocular pressure limit is from about 10 to about 20 mm Hg. 
     In a first embodiment, the element to keep the mobile element in contact with the valve seat is a spring placed on an interior part of the valve body, and the mobile element is a stem comprising a tubular body with an internal canal therein, the stem having on its upper part perforations for allowing the aqueous humor exit the valve. 
     In a second embodiment, the element to keep the mobile element in contact with the valve seat is constituted by two permanent magnets with the same polarity placed on an interior part of the valve part, and the mobile element is a stem comprising a tubular body with an internal canal therein, the stem having on its upper part perforations for allowing the aqueous humor exit the valve. 
     In a third embodiment, the mobile element is a stem comprising a tubular body with an internal canal therein, and the element for keeping the mobile element in contact with the valve seat is constituted by two springs placed in contact with one valve body end opposite the end where the valve seat is and a ring located in the stem, the stem having on its upper part perforations for allowing the aqueous humor exit the valve. 
     In a fourth embodiment, the element to keep the mobile element in contact with the valve seat is a spring having a first end and a second end, the spring is located in an interior part of the valve body, and the mobile element is a pad having on its lower part a hoop to fasten a first end of the spring; and the second end of the spring is attached to a fastening element located on the inside part of the valve body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a better understanding of the present disclosure, a description thereof is provided below, along the attached drawings, wherein: 
         FIG. 1  is a sectional somewhat schematic view of an eye showing the location of a valve of the present disclosure; 
         FIG. 2  is a side elevational view of the valve of the disclosure in a first embodiment; 
         FIG. 3  is a longitudinal sectional view of the first embodiment of the valve of  FIG. 2 ; 
         FIG. 4  is a side elevational view of a valve of the disclosure in a second embodiment; 
         FIG. 5  is a longitudinal sectional view of the second embodiment of the valve of  FIG. 4 ; 
         FIG. 6  is a side elevational view of a valve of the disclosure in a third embodiment; 
         FIG. 7  is a longitudinal sectional view of the third embodiment of the valve of  FIG. 6 ; 
         FIG. 8  is a side elevational view of a valve of the disclosure in a fourth embodiment; and 
         FIG. 9  is a longitudinal sectional view of the fourth embodiment of the valve of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , an eye  10  is shown indicating the eyeball  11 , the optical nerve  12  and the cornea  13  in which the intraocular pressure compensating and regulating valve  14  is implanted. Said valve  14  allows release of aqueous humor outside the eye, when the threshold pressure is exceeded to which the valve  14  is calibrated. 
     A first embodiment of the intraocular pressure compensating and regulating valve  100  is illustrated in  FIGS. 2 and 3 , and comprises a valve body or sheath  110 , a stem  120  and a spring  130 . The valve body  110  has a hollow tubular body  111  and a flange  112  in a tubular body  111  end. The stem  120  comprises a tubular body  121  with an internal canal  122  having in one of its ends, a conical part  123  resting on a seat  113 , which is also conical at the location where the flange  112  is located in the valve body  110 . The tubular body  121  of the stem  120 , beneath the conical part  123 , has radial perforations  124  in communication with the internal canal  122  of the tubular body  111  of the stem  120 . 
     The valve body  110  includes the spring  130  in the internal part of the hollow tubular body  111 , to keep the stem  120  pressured such that the conical part  123  is seated on seat  113  of the valve body  110 . The hollow tubular body  111  includes fastening elements  114  to retain and fasten the valve  100  to the cornea. The spring  130  is tightened to the stem  120  and the other one of the ends of the spring is not tightened to the stem but there is a separation with the stem  120  from about 5 to about 10 microns, such that the stem  120  can be displaced outside the valve body  110 . 
     Under normal conditions of intraocular pressure (10-20 mm Hg), valve  100  remains closed and there is no aqueous humor flow outside. However, when the intraocular pressure exceeds the limit to which the spring  130  is calibrated, the stem  120  is displaced defeating the spring&#39;s  130  strength and thus the conical part  123  of the stem  120  is separated from the seat  113  of the valve body  110  allowing the aqueous humor to flow through the internal canal  122  and the radial perforations  124  of the stem  120  expelling the aqueous humor. Once the pressure is regulated, stem  120  returns to its initial position tightly closing valve  100  and thus avoiding any entrance of foreign objects to the eye (dust, microorganisms, etc.). 
     In a second embodiment, such as is illustrated in  FIGS. 4 and 5 , the intraocular pressure compensating and regulating valve  200  comprises one valve body  210  or sheath, a stem  220  and two circular magnets ( 230  and  231 ). The valve body  210  has a hollow tubular body  211  and a flange  212  at a tubular body  211  end. The stem  220  comprises a tubular body  221  with an internal canal  222  having on one of its ends, a conical part  223  resting upon a seat  213 , which is also conical in the part wherein the flange  212  is located in the valve body  210 . The stem  220  tubular body, beneath the conical part  223 , has radial perforations  224  in communication with the internal canal  222  of the tubular body  221  of the stem  220 . 
     The valve body  210  includes the first circular permanent magnet  230  placed on the internal part of the hollow tubular body  211  at the end where the flange  212  of the valve body  210  is located. The second circular permanent magnet  231  is placed on stem  220  at the other end level of the valve body  210 , such that magnets ( 230  and  231 ) are separated by a distance. The polarity of the first magnet is equal to that of the second magnet in order to obtain a repulsion strength between the magnets, and thus to keep the conical part  223  resting on seat  213  of the valve body  210 . The hollow tubular body  211  includes fastening elements  214  to retain and attach the valve  200  to the cornea. The second magnet  231  is tightened to stem  220  and the first magnet  230  is not tightened to the stem but there is a separation with the stem  220  from about 5 to about 10 microns, such that stem  220  can be displaced outside the valve body  210 . 
     When the intraocular pressure exceeds the limit to which the repulsion strength is calibrated (e.g., about 10 to about 20 mm Kg), the stem  220  is displaced defeating the repulsion strength and thus the conical part  223  of stem  220  is separated from the seat  213  of the valve body  210  allowing the aqueous humor to flow through the internal canal  222  at the radial perforations  224  of stem  220  expelling the aqueous humor. Once the pressure is regulated, stem  220  returns to its initial position tightly closing valve  200  and thus avoiding entrance of foreign objects such as dust, microorganisms, etc. to the eye. 
     A third embodiment of the intraocular pressure compensating and regulating valve  300  is illustrated in  FIGS. 6 and 7 , and comprises a valve body  310 , a stem  320  and elastic laminates or springs  330  and  331 . The valve body  310  has a hollow tubular body  311  and a flange  312  in a tubular body  311  end. The stem  320  comprises a tubular body  321  with an internal canal  322  having in one of its ends, a conical part  323  resting on a seat  313 , which is also conical in the part where the flange  312  is found in the valve body  310 . The tubular body  321  of the stem  320 , beneath the conical part  323 , has radial perforations  324  in communication with the internal canal  322  of the tubular body  321  of the stem  320 . 
     Between the valve body  310  in the end opposite flange  312  and a ring or disk  325  located on stem  320  there is a spring  330  to keep the stem  320  pressured, such that the conical part  323  is seated on seat  313  of the valve body  310 . The hollow tubular body  311  includes fastening elements  314  to retain and attach the valve  300  to the cornea. Between the hollow tubular body  311  of the valve body  310  and stem  320 , there is a separation from about 0.5 microns to about 3 microns, such that the stem  320  can be displaced outside the valve body  310 . 
     Under normal conditions of intraocular pressure (about 10 to about 20 mm Hg), valve  300  remains closed and there is no aqueous humor flow outside. However, when the intraocular pressure exceeds the limit to which the spring  330  is calibrated, the stem  320  is displaced defeating the strength of spring  330 , resulting in the conical part  323  of the stem  320  becoming separated from the seat  313  of the valve body  310 , allowing the aqueous humor to flow through the internal canal  322  and the radial perforations  324  of the stem  320  expelling the aqueous humor. Once the pressure is regulated, stem  320  returns to its initial position tightly closing valve  300  and thus avoiding any entrance of foreign objects such as dust, microorganisms, etc. to the eye. 
     A fourth embodiment, such as is illustrated in  FIGS. 8 and 9 , of the intraocular pressure compensating and regulating valve  400  comprises a main body  410 , a magnetic head  420 , spring  430 . The main body  410  is tubular body with an internal canal  411  and a spring fastening element  412  in a flange  413 . The main body  410  includes a fastening element  414  to retain and attach valve  400  to the cornea. 
     The magnetic head  420  comprises a conical part  421  resting upon seat  415  also conical on an end of the main body  410 . One rear part of the magnetic head  420  includes a hoop  423  wherein the first end  431  of the spring  430  is attached, and a second end  432  of spring  430  is attached to the fastening element  412 . The spring is located inside the internal canal  411  of the main body  410 . 
     Under normal conditions of intraocular pressure about 10 to about 20 mm Hg), valve  400  remains closed and there is no aqueous humor flow outside. However, when the intraocular pressure exceeds the limit to which the spring  430  is calibrated, the magnetic head  420  is displaced defeating the strength of spring  430  and thus forming a separation between the magnetic head  420  and seat  415  of the main body  410  allowing the aqueous humor to flow through the internal canal  411  and thus the separation formed expels the aqueous humor. Once the pressure is regulated, the magnetic head returns to its initial position tightly closing the valve and thus avoiding any entrance of foreign objects such as dust, microorganisms, etc. to the eye. 
     The present disclosure has been described and illustrated in multiple embodiments; however, modifications can be made, for example, geometrical modifications of the valve&#39;s parts can be made, thus comprised within the scope of the following claims.