Abstract:
A method for improving the draining of aqueous humor in an eye of a living being and a device for widening the Schlemm&#39;s canal is described wherein a first incision is made in a lamellar section of the sclera to form a first scleral flap which is then folded upwards in the direction of the cornea, thereby creating a recess in the sclera. A second scleral flap is formed by incising a second lamellar section in the area of the recess and lifted upwardly in the direction of the first sclera flap, thereby exposing two opposite openings into the Schlemm&#39;s canal into which an expanding medium is injected into the Schlemm&#39;s canal; formation of a slitlike passageway connecting the aqueous humor-permeable Descemet-membrane with the subscleral space is realized by detaching the Descemet-membrane on the area of the Schwalbe&#39;s line by means of a slight pressure force; and subsequently, the first scleral flap folded back, after severance of the second scleral flap, for placement upon a support surface formed as a consequence of the incision of the second lamellar section. Subsequently, a viscous medium is injected into a subscleral space formed behind the first scleral flap and the first scleral flap is rejoined to the sclera.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates, in general, to a method for improving a drainage of aqueous humor within the eye of a living being, and to a device for widening the circular canal of Schlemm to improve drainage of aqueous humor.  
           [0002]    If the trabecular meshwork is either partially or completely non-functional due to an obstruction or back-up, or pathological changes, natural flow of the aqueous humor becomes limited, thereby raising the pressure inside the eye which negatively impacts on the blood circulation and the function of the visual nerve. The resulting disease is commonly known under the name “glaucoma” which may lead to blindness in the eye.  
           [0003]    U.S. Pat. Nos. 5,360,399 and 5,486,165 describe a method and apparatus, by which the trabecular meshwork, which is located upstream of the canal of Schlemm and which due to pathological changes, may either partially or completely obstruct the outflow of aqueous humor, is essentially widened by the hydraulic pressure of a highly viscous aqueous solution, which when injected into the canal of Schlemm opens it at several location points, so that an outflow of the aqueous humor can be realized.  
           [0004]    Surgical methods are known for increasing the flow of aqueous humor within the eye, in particular, when the outflow of the aqueous humor is diminished. However, surgical methods which open the canal of Schlemm and the trabecular meshwork have not necessarily led to the required success in the long term because, for example, regeneration of the tissue closes the openings in the trabecular meshworks.  
         SUMMARY OF THE INVENTION  
         [0005]    It is thus an object of the present invention to provide an improved method for realizing an enhanced flow of aqueous humor within the eye, obviating the afore-stated drawbacks.  
           [0006]    In particular, it is an object of the present invention to provide an improved method by which the necessary drainage of the aqueous humor via the outflow pathways of the eye is realized and which thereby results in an improved circulation of the aqueous humor in the eye and thus regulating the pressure within the eye.  
           [0007]    These objects, and others which will become apparent hereinafter, are attained by a method in accordance with the present invention which includes the following steps: incising a first lamellar section of the sclera to form a first scleral flap; lifting the first scleral flap upwards in the direction of the cornea, thereby creating a recess in the sclera; incising a second lamellar section in the area of the recess to thereby form a second scleral flap and a support surface bounding the scleral flap; lifting the second scleral flap upwards in the direction of the first sclera flap, thereby exposing two opposite openings into the Schlemm&#39;s canal; injecting an expanding medium through the openings into the Schlemm&#39;s canal; folding the first scleral flap back, after severance of the second scleral flap, for placement upon the support surface, thereby confining a subscleral space adjacent the first scleral flap; injecting a viscous medium into the subscleral space; and rejoining the first scleral flap to the sclera.  
           [0008]    In accordance with a further feature of the present invention, a slit-like passageway is formed between the subscleral space and the anterior chamber by applying a pressure force against a peripheral edge of the aqueous humor-permeable Descemet&#39;s membrane to detach the Descemet&#39;s membrane from the cornea. In this manner, the aqueous humor, which normally flows into the canal of Schlemm via the trabecular meshwork, flows additionally by way of Descemet&#39;s membrane from the anterior chamber in fluid connection therewith, and the slit-like passageway, into the subscleral chamber.  
           [0009]    According to another feature of the present invention, severance of the second scleral flap can be executed at any time after lifting the second scleral flap and before folding back the first scleral flap, i.e. before or after injection of expanding medium into the canal of Schlemm or before or after detachment of the Descemet&#39;s membrane.  
           [0010]    It is a further object of the present invention to provide an improved device for expanding a surgically exposed Schlemm&#39;s canal in an eye to thereby realize an enhanced flow of aqueous humor.  
           [0011]    This object is attained in accordance with the present invention by providing a probe insertable into the Schlemm&#39;s canal for injecting a viscous medium to thereby generate a localized pressure buildup, with the probe having an outlet port which is defined by a diameter and an axial length, whereby the length is sized at least twice the diameter of the outlet port.  
           [0012]    The probe is suitably connected to a pressure source for supply of expanding medium via an adapter and includes a tube which is connected to the adapter and has a circular ring shaped or elliptic cross section. The adapter may have an arcuate configuration, and the tube may have an inner axial bore which forms the outlet port and is in fluid communication with an interior space of the adapter for conduction of the expanding medium to the Schlemm&#39;s canal. Alternatively, the tube may have an outer periphery formed with an axial groove which forms the outlet port and is in fluid communication with an interior space of the adapter for conduction of the expanding medium to the Schlemm&#39;s canal.  
           [0013]    According to another embodiment of the present invention, the adapter may have a T-shaped configuration and include a vertical portion and a horizontal portion formed integrally with the vertical portion for attachment of two of probes in opposite disposition, wherein each of the probes has an inner axial bore which forms part of the outlet port and is in fluid communication with an inlet port in the vertical portion of the adapter. The vertical portion is suitably connected to the pressure source via a feed conduit such that expanding medium is injected into the Schlemm&#39;s canal via the inner axial bore of both probes simultaneously or sequentially.  
           [0014]    According to still another feature of the present invention, the probe has a distal end and a proximal end and includes a transition piece which is secured to the proximal end of the probe for attachment to the adapter, with the transition piece having a conical configuration or a circular arc shaped configuration.  
           [0015]    The probe may be formed in one piece with the adapter, or the probe may be securely fixed in a complementary recess of the adapter. Suitably, the probe is made of flexible plastic material, e.g. transparent plastic, or may be made of a metal tube or, a flexible tube from metal, e.g. a nickel titanium alloy. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0016]    The above and other objects, features and advantages of the present invention will now be described in more detail with reference to the accompanying drawing in which:  
         [0017]    [0017]FIG. 1 is a schematic illustration of a portion of a eye, on an enlarged scale, showing a first parabolic incision in the sclera for forming a first scleral flap which is folded upwards;  
         [0018]    [0018]FIG. 2 is a schematic view of the portion of the eye of FIG. 1, taken along the line II-II in FIG. 1;  
         [0019]    [0019]FIG. 3 is a schematic illustration of the portion of the eye of FIG. 1, showing a second parabolic incision within the area of first incision for formation of a second scleral flap which is folded upwards;  
         [0020]    [0020]FIG. 4 is a schematic view of the portion of the eye of FIG. 3, illustrating both upwardly folded scleral flaps and taken along the line IV-IV in FIG. 3;  
         [0021]    [0021]FIG. 5 is a schematic illustration of the portion of the eye of FIG. 3, depicting a first embodiment of a probe according to the present invention for insertion into the exposed canal of Schlemm, with the probe being attached to an arcuate adapter;  
         [0022]    [0022]FIG. 6 is a schematic illustration of the portion of the eye of FIG. 3, depicting a second embodiment of a probe according to the present invention for insertion into the exposed canal of Schlemm, with the probe being attached to an adapter of T-shaped configuration;  
         [0023]    [0023]FIG. 7 is a schematic view of the portion of the eye of FIG. 4, illustrating the application of a swab for applying a small pressure force against the Schwalbe&#39;s Line in the area of the two upwardly folded scleral flaps;  
         [0024]    [0024]FIG. 8 is a schematic view of the portion of the eye of FIG. 7, illustrating a detachment of the Descemet&#39;s membrane from the cornea and severed second scleral flap;  
         [0025]    [0025]FIG. 9 is a schematic view of the portion of the eye of FIG. 8, illustrating the first scleral flap being folded downwards;  
         [0026]    [0026]FIG. 10 is a partially sectional view, on an enlarged scale, of a first embodiment of a united adapter-probe arrangement according to the invention;  
         [0027]    [0027]FIG. 10A is a partially sectional cutaway view of a variation of the adapter-probe arrangement of FIG. 10;  
         [0028]    [0028]FIG. 10B is a partially sectional cutaway view of another variation of the adapter-probe arrangement of FIG. 10;  
         [0029]    [0029]FIG. 11 is a partially sectional cutaway view of still another embodiment of a united adapter-probe arrangement according to the present invention;  
         [0030]    [0030]FIG. 11A is a partially sectional view of the adapter-probe arrangement, taken along the line XI-XI in FIG. 11;  
         [0031]    [0031]FIG. 11B is a partially sectional view of an adapter-probe arrangement, showing a first variation of the probe;  
         [0032]    [0032]FIG. 11C is a partially sectional view of an adapter-probe arrangement, showing a second variation of the probe;  
         [0033]    [0033]FIG. 11D is a partially sectional view of an adapter-probe arrangement, showing a third variation of the probe;  
         [0034]    [0034]FIG. 12 is a partially sectional cutaway view of yet an other embodiment of a united adapter-probe arrangement according to the present invention;  
         [0035]    [0035]FIG. 12A is a partially sectional view of the adapter-probe arrangement, taken along the line XII-XII in FIG. 12;  
         [0036]    [0036]FIG. 12B is a partially sectional view of the adapter-probe arrangement of FIG. 12, showing a variation of the probe;  
         [0037]    [0037]FIG. 13 is a schematic illustration of the T-shaped adapter of FIG. 6 with two probes in opposite disposition formed to the adapter. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0038]    Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.  
         [0039]    Turning now to the drawing, and in particular to FIG. 1, there is shown a first process step for improving a drainage of aqueous humor in an eye  15  which is shown only schematically by way of a portion of an iris  2 , a cornea  4 , a sclera  3 , a partial section of the circular Schlemm&#39;s canal  5  (sinus venosus sclerae) and outflow pathways  3 ′ which is comprised of a multitude of collector channels for conducting the aqueous humor. In the initial phase of the process according to the invention, a first incision of approximately parabolic shape is made in the sclera  3  to form a scleral flap  10  which is lifted upwards in the direction towards the cornea  4  to thereby expose a corresponding recess  11  which is bounded by a circumferentially extending side wall  11 ′. The scleral flap  10  is held in upwardly folded position by a tool or other means which are not shown for the sake of simplicity but are generally known by the artisan.  
         [0040]    [0040]FIG. 2, which is a sectional view of the portion of the eye  15 , taken along the line II-II in FIG. 1, shows a portion of the sclera  3 , a portion of the cornea  4  with the Descemet membrane  6  and the Schwalbe&#39;s line  7 , a portion of the iris  2  and a portion of the lens  9  connected to the sclera  3  by means of the zonular fibers  9 ′. Further shown is the first scleral flap  10  which has been lifted upwards in the direction of arrow  16  and the corresponding recess  11 , in addition to the canal of Schlemm  5  with the trabecular meshwork  8  (trabecular meshwork) disposed anteriorly thereof.  
         [0041]    Arrows  1  and  1 ′ in FIG. 2 designate essentially the circulation of aqueous humor and the natural drainage thereof. The aqueous humor, which in a healthy eye, regenerates continually, flows according to arrow  1  from the posterior chamber H to the anterior chamber V and is conducted at the iridocomeal angle V′ in the direction of arrow  1 ′ via the trabecular meshwork  8  into the Schlemm&#39;s canal  5  and from there, via outflow pathways  3 ′ (FIG. 1) into the natural venous system (not shown). When the trabecular meshwork  8  is partially or completely non-functional due to back-up or like blockage, the natural drainage of aqueous humor is limited to such an extent that the pressure inside the eye  15  rises to thereby restrict the blood circulation and thus the functionality of the optic nerve (not shown). The resulting disease is commonly known under the name “glaucoma” and may lead to blindness of the affected eye.  
         [0042]    Before incising the sclera  3  in a manner shown in FIG. 1, a micro-surgical procedure is carried by which the conjunctiva (not shown) is retracted with a suitable tool for exposing a sufficient portion of the sclera  3 . After the first incision, the formed scleral flap  10  is folded upwards in the direction towards the cornea  4 , thereby exposing the first recess  11  with its circumferential side wall  11 ′. The first incision may cover an area of, for example, 3 mm×3 mm with a depth which is so selected that the thickness  10 ′ of the first sclera flap  10  is approximately ⅓ of the natural thickness of the sclera  3  in this zone, as depicted in FIG. 2. In this first phase, the Schlemm&#39;s canal  5  is not yet exposed.  
         [0043]    In the next process step, as shown in FIG. 3, a second incision is made within the area of the first incision to form a second parabolic scleral flap  12  which is then lifted upwards in the direction of the cornea  4 , so that a second recess  13  is defined in correspondence with the second scleral flap  12  and bounded by a support surface  14 . The depth of the second incision is selected such that the Schlemm&#39;s canal  5  is now exposed over the entire width of the second recess  13 . In this phase, two openings  17  and  17 ′ of the Schlemm&#39;s canal  5  in opposite disposition in the recess  13  are accessible for injection of an expanding medium.  
         [0044]    [0044]FIG. 4 shows the portion of eye  15 , taken along the line IV-IV in FIG. 3, with the two scleral flaps  10 ,  12  folded upwards in the direction of arrow  16  and held in place by suitable means (not shown). The second incision results in a thickness  12 ′ of the second scleral flap  12  that allows sufficient exposure and accessibility of the Schlemm&#39;s canal  5 . This is essentially realized by selecting the depth of second incision in such a manner that a portion  5 ′ of the Schlemm&#39;s canal  5  remains at the inside of the second scleral flap  12 . As shown in FIG. 3, the attached portion  5 ′ extends over the entire width of the second sclera flap  12  and has a substantially grooved configuration.  
         [0045]    Turning now to FIG. 5, which is an enlarged illustration of the eye  15  of FIG. 3 and shows a portion of the sclera  3  and the two upwardly folded sclera flaps  10 ,  12  as well as the second recess  13  and the lateral support surface  14  of the sclera  3 , to show a third phase of the novel and inventive process, in which a suitable medium, preferably a high viscosity sodium-hyaluronate solution (high viscosity hyaluronate) is injected into the two lateral openings  17  and  17 ′ of the Schlemm&#39;s canal  5  by an injection unit, generally designated by reference numeral  25  to expand the lumen of the Schlemm&#39;s canal  5 . The injection unit  25  includes a probe  35  which is attached to an arcuate adapter  30  and inserted into the exposed opening  17  of the Schlemm&#39;s canal  5  for injecting the high viscosity sodium hyaluronate solution. After expanding the lumen of the Schlemm&#39;s canal  5  at least along the entire length of the inserted probe  35 , the injection unit  25  with the probe  35  is withdrawn from the opening  17  and turned for insertion in the opposite opening  17 ′ of the Schlemm&#39;s canal for injection of the expanding medium and expansion of the lumen. The injection unit  25  is connected via a supply conduit  28  to pressure source  26  in the form of a single-chamber syringe or similar. The injected medium is forced into the lumen of Schlemm&#39;s canal in the direction of arrow  27 , by means of the manually or electrically operated pressure source  26  for expansion of the lumen.  
         [0046]    [0046]FIG. 6 shows a variation of an injection unit, generally designated by reference numeral  25 ′ and including an adapter  60  having a T-shaped configuration and provided with two probes  65 ,  65 ′ in opposite disposition for injection of expanding medium through both openings  17 ,  17 ′ of the Schlemm&#39;s canal. The adapter  60  is connected to a pressure source  26 ′ via a supply conduit  28 ′ which has two separate passageways in respective fluid communication with the probes  65 ,  65 ′. The injection unit  25 ′ offers the option to insert the probe  65  in a first phase through movement in the direction of arrow Z into the opening  17  for injection of expanding medium. After expansion of the Schlemm&#39;s canal  5 , the adapter  60  with the probe  65  is withdrawn from the Schlemm&#39;s canal  5  and slightly moved to the left in the direction of arrow Z′ for inserting the probe  65 ′ into the other opening  17 ′ of the Schlemm&#39;s canal  5  for injection of expanding medium. This injection unit  25 ′ is thus designed for successive injection of expanding medium through the openings  17  and  17 ′.  
         [0047]    Persons skilled in the art will understand however that the T-shaped adapter  60  may certainly be designed in such a manner that simultaneous supply of expanding medium through the openings  17 ,  17 ′ is also possible. In this case, the adapter  60  is handled such that initially the probe  65  is inserted through the opening  17  and then moved slightly to the left for insertion of the other probe  65 ′ through the opposite opening  17 ′.  
         [0048]    The injection unit  25 ′ is connected via the supply conduit  28 ′ to the manually or electrically actuated pressure source  26 ′ which is formed as a dual chamber syringe. This allows operation of the injection unit  25 ′ such that expanding medium can be injected sequentially or simultaneously via the probes  65 ,  65 ′ into the lumen of the Schlemm&#39;s canal  5 .  
         [0049]    Turning now to FIG. 7, there is shown the next process step, after expansion of the Schlemm&#39;s canal  5  and withdrawal of the injection unit  25 ,  25 ′, for detachment the Descemet&#39;s membrane  6  from the inner surface of the cornea in the area of the Schwalbe&#39;s line. The detachment of the Descemet&#39;s membrane  6  is realized by using a swab  20  for applying a slight force against the Schwalbe&#39;s line so as to create a passageway  21  between the cornea  4  and Descemet&#39;s membrane  6  as shown schematically enlarged in FIG. 8. The passageway  21  is approximately slit-shaped and extends in a manner not shown here across the entire width of the second recess  13 . The passageway  21  provides a further connection between the anterior chamber V and the second recess  13  so that aqueous humor can drain apart from the natural outflow via the trabecular tissue  8  in the direction of arrow  1 ′ also via the substantially transparent Descemet&#39;s membrane  6 , which is partly permeable for aqueous humor in the direction of arrow  1 ″, as indicated in FIGS. 8 and 9, and via the passageway  21  to the recess  13  which is fluidly connected with the Schlemm&#39;s canal  5 . The second recess  13  which corresponds to the scleral flap  12  essentially forms a reservoir for aqueous humor for drainage into the Schlemm&#39;s canal  5 .  
         [0050]    In a next phase, the second scleral flap  12 , save for a small remaining portion  12 . 1 , is then severed with a suitable surgical instrument (not shown), as shown in FIG. 8. It will be appreciated by persons skilled in the art, that the separation of the second sclera flap  12  may be carried out also before detachment of the Descemet&#39;s membrane  6  with the swab  20  to form the passageway  21 .  
         [0051]    Next, while retaining the passageway  21 , the first sclera flap  10  is folded downwards in the direction of arrow  16 ″ (FIG.8) and placed upon the parabolic support surface  14 , as shown in FIG. 9. Then, the first sclera flap  10  is sutured partially to the sclera  3 . As the second sclera flap  12  has been separated, a subscleral space  13 ′ is formed behind the first scleral flap  10  and filled by means of a syringe (not shown) with high viscosity medium, such as sodium hyaluronate, before completely rejoining the first scleral flap  10 . This prevents an inside surface  10 ″ of the first scleral flap  10  to come into contact with the inside surface  13 ″ of the recess  13 , as shown in FIG. 9.  
         [0052]    Referring now to FIG. 10, there is shown a detailed illustration of the arcuate adapter  30  with attached probe  35 . The adapter  30  has a first leg  36  terminating in an inlet port  31 , and a second leg  36 ′ which defines an interior space  31 ′ in fluid communication with the inlet port  31  and bounded by a wall  32 . Formed integrally with the second leg  36 ′ of the adapter  30  is the tube-like probe  35  which has interiorly a continuous axial bore  33  forming an outlet channel and fluidly communicating with the interior space  31 ′ of the arcuate-shaped adapter  30 . For ease of insertion into the Schlemm&#39;s canal, the probe  35  has an adapter-distal end  34  of rounded configuration. At its other end, the probe  35  is connected to adapter  30  via a transition piece  37  which flares outwardly toward the second leg  36 ′ of the adapter  30 . The conical or circular arc shaped transition piece  37  ensures a sealing contact when the probe  35  is inserted through the openings  17 ,  17 ′ of the Schlemm&#39;s canal  5 , so as to substantially prevent leakage of injected fluid in case of back-up in the lumen of the Schlemm&#39;s canal  5 .  
         [0053]    As shown in FIG. 10, the probe  35  is formed as an elongate, flexible tube which is made of transparent, flexible plastic material, e. g. polymide or polytetrafluoro-ethylene, or may be made of flexible metal tube or a flexible metal, e.g. stainless steel or a nickel-titanium alloy to thereby impart the probe  35  with sufficient flexibility that permits free movement with respect to the longitudinal axis X, as indicated in dash-dot lines, while preventing a breakage when the probe  35  is of a longer configuration. Suitably, the probe  35  further includes a plurality of apertures  38  which are spaced from one another in axial direction and fluidly connected with the bore  33  for additionally providing an exit for injection of medium into the Schlemm&#39;s canal  5 . Although not shown, it is certainly possible to so configure the probe  35  as to flare outwardly between the end  34  and the transition piece  37 . In view of its flexibility, the tubular probe  35  can conform its orientation and disposition to the respective inner configuration of the Schlemm&#39;s canal  5  when being inserted into the Schlemm&#39;s canal  5 .  
         [0054]    [0054]FIG. 10A shows another embodiment of a combined adapter-probe arrangement which includes an adapter  30 ′ for attachment of a probe  35 ′. The second leg  36 ′ of the adapter  30 ′ is formed with a terminal recess  36 ″ for receiving the confronting end of the probe  35 ′ which is secured therein e.g. by gluing. The tube-like probe  35 ′ is connected with the interior space  31 ′ via an axial bore  33 ′ which forms an outlet port and a plurality of exit apertures  38 ′ spaced from one another in axial direction and fluidly connected with the bore  33 ′ for injection of medium into the Schlemm&#39;s canal. Suitably, the probe  35 ′ has an end face  34 ′ of back-slanted configuration. The adapter  30 ′ terminates in a circular arc shaped end face  37 ′ which has a greater outer diameter that the outer diameter of the probe  35 ′ to thereby form a shoulder. This ensures a substantial sealing contact upon the opening  17 ,  17 ′ when the probe  35 ′ is inserted into the Schlemm&#39;s canal  5 , thereby preventing leakage of injected medium upon a possible backup in the lumen of the Schlemm&#39;s canal  5 .  
         [0055]    [0055]FIG. 10B shows a another variation of a combined adapter-probe arrangement which is illustrated here only by way of a tube-like probe  35 ″ which has interiorly an axial bore  33 ″ and a plurality of side-by-side exit apertures  38 ″ for injection of expanding medium into the Schlemm&#39;s canal. At its adapter-distal end face  34 ″, the probe  35 ″ is formed with a circular bead  39 .  
         [0056]    It will be understood that attachment of the probe  35 ′ to the adapter  30 ′ according to FIG. 10A and attachment of the probe  35 ″ to the adapter  30 ″ according to FIG. 10B is realized in a same manner as previously described in connection with the probe  35  in FIG. 10, and connected at the arcuate adapter  30 , are made from a flexible plastic tube or from a flexible metal tube having limited flexibility, for example, stainless steel or a nickel/titanium alloy.  
         [0057]    [0057]FIG. 11 shows a partially sectional front view of another embodiment of a combined adapter-probe arrangement, with an arcuate adapter  40  having an inlet port  41 . The adapter  40  has a first leg  46  and a second leg  46 ′ and is essentially configured in correspondence to the adapter  30  of FIG. 10. Attached to the second leg  46 ′ is a relatively short probe  45  which defines a longitudinal axis X and has formed interiorly therein an axial bore  43  to form an outlet channel in fluid communication with an interior space  41 ′ of the adapter  40  in the form of an outlet port. The probe  45  is further provided with a plurality of axially spaced apart apertures  48  which are in fluid connection with the bore  43 . For ease of insertion into the Schlemm&#39;s canal  5 , the probe  45  has an end face  44  of rounded configuration.  
         [0058]    At its other end, the probe  45  is formed to the second leg  46 ′ via an outwardly flared transition piece  47 . This conical or circular arc-shaped transition piece  47  ensures a sealing contact when inserting the probe  45  into the opening  17 ,  17 ′ of the Schlemm&#39;s canal  5  so that escape of injected medium due to a backup in the lumen of Schlemm&#39;s canal  5  is substantially prevented. It is certainly also possible to configure the probe  45  such as to flare outwardly from the end face  44  in the direction of the transition piece  47 .  
         [0059]    The interior space  41 ′ in the second leg  46 ′ of the adapter  40  has a funnel-shaped inner wall  42  which, starting from the inner diameter of the interior space  41 ′ tapers in the direction of the bore  43 . The thus nozzle-shaped tapered inner wall  42  effects a compressed and pressure-accelerated discharge of medium injected into the lumen of Schlemm&#39;s canal  5 . FIG. 11A shows a cross-sectional view, taken along the line XI-XI, of the adapter  40  with the first leg  46  and the probe  45  with the circular arc shaped bore  43 .  
         [0060]    Although not shown in the drawings, it will be appreciated by persons skilled in the art that the probe  45  may also be designed in correspondence with the probe  35 ′ of FIG. 10A, or the probe  35 ″ of FIG. 10B.  
         [0061]    [0061]FIG. 11B shows a first variation of the probe  45  in the form of a tube having a substantially elliptical shape and formed interiorly with a bore  43 ′ as outlet channel of elliptic configuration. In FIG. 11C, the probe  45  is in a disposition rotated by a right angle α with respect to the longitudinal axis X for ease of handling and better insertion into the Schlemm&#39;s canal  5 , whereas in FIG. 11D, the probe  45  is arranged at an obtuse angle α′ to the second leg  46 ′.  
         [0062]    [0062]FIG. 12 shows still another embodiment of a combined adapter-probe arrangement with an arcuate adapter  50  having an inlet port  51 . The adapter  50  includes a first leg  56  and a second leg  56 ′ and is essentially designed in correspondence to adapter  30  of FIG. 10, or FIG. 10A, or FIG. 10B, or in correspondence to adapter  40  of FIG. 11, or FIG. 11A to FIG. 11D. Attached to the second leg  56 ′ is an elongate probe  55  having an elliptical or circular ring shaped cross section. Departing from the embodiment according to FIG. 10 and FIG. 11, the probe  55  is provided at its outer circumference with axial grooves  53  to form an outlet channel. Each of the grooves  53  is in fluid connection with an interior space  51 ′ of the second leg  56 ′, with the interior space  51 ′ being bounded by a wall  52  of the second leg  56 ′. Suitably, the probe  55  has an end face  54  of rounded configuration.  
         [0063]    At its other end, the probe  55  is formed to the second leg  56 ′ of the adapter  50  via an outwardly flared transition piece  57 . The conical or circular arc shaped transition piece  57  provides a sealing contact when the probe  55  is inserted into the opening  17 ,  17 ′ of the Schlemm&#39;s canal  5  so that leakage of injected medium, due to possible back-up in the lumen of Schlemm&#39;s canal  5 , is substantially prevented.  
         [0064]    The probe  55  may also be made, like the probe  35 , as a flexible plastic tube having limited flexibility so as to be freely movable with respect to the longitudinal axis X.  
         [0065]    [0065]FIG. 12A shows a sectional view of the adapter-probe arrangement, taken along the line XII-XII in FIG. 12, and depicts the circular configuration of the probe  55  which is formed with, for example, four grooves  53  evenly spaced about its circumference and fluidly connected with the interior space  51 ′ of the adapter  50 . FIG. 12B shows a variation of the probe  55  which has an elliptic cross section and is formed with four grooves  53  evenly spaced about its circumference and fluidly connected with the interior space  51 ′ of the adapter  50 .  
         [0066]    The adapters  30 ,  40 , or  50  as depicted in FIGS.  10  to  12  and the respectively attached probes  35 ,  45 , or  55  are so configured that medium is injected into the lumen of the surgically exposed Schlemm&#39;s canal  5  successively through either in the one or the other opposite opening.  
         [0067]    Turning now to FIG. 13, there is shown another embodiment of a combined adapter-probe arrangement including an adapter  60  for use with the injection unit  25 ′ schematically shown in FIG. 6. The approximately T-shaped adapter  60  has an upper portion  66 ′ for connection of two probes  65  and  65 ′ arranged in opposite disposition and having interiorly an axial bore  63 . Formed integrally with the upper portion  66 ′ is a leg  66  which extends perpendicular to the leg  66 ′ and has two separate entry ports  61  and  61 ′ in fluid communication with the bores  63  of probes  65  and  65 ′. It will be appreciated that the probes  65  may have different lengths, as schematically shown in FIG. 6. Probe  65  may be designed, analogous to probe  35 , as a flexible tube which is freely movable in its disposition and orientation with respect to the longitudinal axis X to conform to the inner configuration of the lumen of the Schlemm&#39;s canal  5  when inserted therein. Both probes  65  and  65 ′ may also have a cross section in correspondence to the probes of FIG. 11A or FIG. 11B or according to the probes shown in FIGS. 12A and 12B.  
         [0068]    Each probe  65  has an end face  64  of rounded configuration. Its other end is connected to the upper portion  66 ′ of the adapter  60  via an outwardly flared transition piece  67 . The conical or circular arc shaped transition piece  67  ensures a sealing contact when the probe  65  is inserted in the Schlemm&#39;s canal  5  so that leakage of the medium due to a possible back-up in the lumen of Schlemm&#39;s canal  5  is substantially prevented.  
         [0069]    While the invention has been illustrated and described as embodied in a method of and device for improving the flow of aqueous humor within the eye, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.  
         [0070]    What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims: