Patent Publication Number: US-11045665-B2

Title: Light-guided ophthalmic radiation device

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates generally to ophthalmic radiation device for directing a therapeutic dose of radiation to a portion of the eye to treat subretinal neovascularization associated with age-related macular degeneration (AMD) and other ophthalmic diseases responsive to irradiation. 
     Exudative macular degeneration is a pathologic process associated with subretinal neovascularization. The subretinal neovascularization allows fluid, blood, and lipids to leak beneath the surface of the retina. This leakage has detrimental effects on the health of the globe. For example, this leakage typically causes retinal detachment and destroys the macular retina resulting in severe damage including irreversible loss of central vision. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, in regards to its features, components and their configuration, operation, and advantages are best understood with reference to the following description and accompanying drawings in which: 
         FIG. 1  is a general, schematic perspective view of an ophthalmic radiation treatment device, according to an embodiment; 
         FIG. 1A  is a cutaway view of the handle of  FIG. 1 ; 
         FIG. 2  is schematic, perspective view of an embodiment of a radiation treatment device depicting a radioactive source holder integrally connected to a treatment wand in which both are configured to function as an integral light guide, according to an embodiment; 
         FIG. 2A  is schematic, perspective view of variant embodiment of the device depicted in  FIG. 2  in which the treatment wand forks into two wand branches,  FIG. 1 ; 
         FIG. 2B  is schematic, perspective view of another embodiment of the device depicted in  FIG. 1  in which the holder is non-integrally attached to the wand implemented as multiple light pipes, according to an embodiment; 
         FIGS. 3-3A  are schematic, perspective views of an embodiment of the radiation treatment device in which the holder is connected to distal portions of each of two wand branches, according to an embodiment; 
         FIGS. 3B, 3C, and 3D  are schematic cross-sectional views along section lines A-A, B-B, and C-C depicted in  FIGS. 3-3A , respectively; 
         FIG. 4  is schematic perspective view of a variant embodiment of the device depicted in  FIGS. 3-3D  in which the holder is releasably attachable to each of the wand branches, according to an embodiment; 
         FIG. 4A  is schematic perspective view of the treatment wand depicted in  FIG. 4  detached from the holder, according to an embodiment; 
         FIG. 4B  is schematic perspective view of the holder depicted in  FIG. 4  detached from the wand, according to an embodiment; 
         FIG. 4C  is schematic cross-sectional view of the device depicted in  FIG. 4  along section line A-A according to an embodiment; 
         FIG. 5  is schematic, front view of releasably attachable holder having notched connection configuration, according to an embodiment; 
         FIG. 5A  is schematic, front view of releasably attachable treatment wand having multiple wand branches (fingers) corresponding to the notched connection configuration of the holder depicted in  FIG. 5 , according to an embodiment; 
         FIG. 5B  is schematic, front view of releasably attachable treatment wand in which the holder depicted in  FIG. 5  and the wand depicted in  FIG. 5A  are in a connected state, according to an embodiment; 
         FIGS. 5C and 5D  are schematic, front views of a variant embodiment of the device depicted in  FIG. 5B  having an alternative branching configuration, according to an embodiment; 
         FIG. 6  is schematic, perspective view of an integral prismatic surface molded into the wand branch, according to an embodiment; 
         FIG. 6A  is schematic, perspective view of a wand branch having both integral prismatic light redirecting surfaces, and focusing lens according to an embodiment; 
         FIG. 6B  is schematic, perspective view of a variant embodiment of the wand branch of  FIG. 6A  having an opaque film selectively disposed on the surface to minimize unwanted light emission through the wand, according to an embodiment; 
         FIG. 7  is a schematic, front view of an alternative embodiment of a wand and holder arrangement in which the wand is implemented as a plurality of stiff hollow tubes configured to receive either fiber optics, or electrical wires when the illumination ports are implemented as light emitting diodes, according to an embodiment; 
         FIG. 8  is a schematic, perspective view of the ophthalmic radiation device disposed in a treatment position behind an eyeball in which the illumination ports surrounding the holder are visible through the pupil, according to an embodiment; 
         FIG. 8A  is a schematic, section view of the ophthalmic radiation device disposed in a treatment position behind an eyeball in which the radiation source is in proximity to the a macula, according to an embodiment; 
         FIG. 9  is a schematic, perspective view of a radioactive source-material holder having a holding cavity facing the eye, according to an embodiment; 
         FIG. 9A  is a schematic, cross-sectional view of the holder depicted in  FIG. 9  along section line A-A; according to an embodiment; 
         FIG. 9B  is a schematic, cross-sectional view along section line A-A of a variant embodiment of the holder of  FIG. 9  in which the holding cavity is enclosed with a cover; according to an embodiment; 
         FIG. 9C  is a schematic, perspective view of radioactive source-material holder having a holding cavity facing the skull orbit, according to an embodiment; 
         FIG. 9D  is a schematic, cross-sectional view of the holder depicted in  FIG. 9C  along section line B-B; according to an embodiment; 
         FIG. 9E  is a schematic, cross-sectional view along section line B-B of a variant embodiment of the holder of  FIG. 9C  in which the holding cavity is enclosed with a cover; according to an embodiment; 
         FIGS. 10 and 10A  are schematic, perspective views of an ophthalmic radiation device fitted with a radiation-shielding sleeve in shielded and non-shielded states, respectively, according to an embodiment; 
         FIG. 11  is a schematic, perspective view of ophthalmic radiation device configured to receive a radiation source into a lumen of a hollow wand, according to an embodiment; 
         FIG. 11A  is a schematic, cross-sectional-view of the lumen along section line D-D, according to an embodiment; 
         FIG. 11B  is a schematic, cross-sectional-view of the lumen along section line E-E depicting a lumen constriction, according to an embodiment; 
         FIG. 12  is a schematic, perspective view of a ophthalmic radiation device having labyrinthine holder configured to receive a liquid therapeutic radioisotope, according to an embodiment; 
         FIG. 12A  is a schematic, perspective view of ophthalmic radiation device depicted in  FIG. 12  in which the liquid therapeutic-radio isotope is disposed in the labyrinthine holder, according to an embodiment; 
         FIG. 12B  is a schematic side view of a double-sided piston pump configured to simultaneously inject liquid radioisotope and withdraw inert liquid from the labyrinthine holder depicted in  FIGS. 12 and 12A , according to an embodiment; and 
         FIG. 13  is a schematic, perspective view of the ophthalmic radiation device in which light is directed into the device from an external light source, according to an embodiment; 
         FIG. 13A  is a schematic, perspective view of a ophthalmic radiation device in that the light is directed into the handle in close proximity to a handle grip at an angle non-parallels to the longitudinal axis of the handle, according to an embodiment; 
         FIG. 13B  is a schematic, perspective view of the ophthalmic radiation device in which a light source is disposed in the device and powered from an external power source, according to an embodiment; and 
         FIG. 13C  is a schematic, perspective view of the ophthalmic radiation device in which both a light and power sources are self-contained inside the device, according to an embodiment. 
         FIG. 14  is a flow chart depicting a process for inserting the ophthalmic radiation device into a treatment position it; according to an embodiment; and 
         FIG. 15  is a flow chart depicting a process for advancing a radioactive-source-material into an ophthalmic radiation device after the device has been placed into a treatment position; according to an embodiment; 
         FIG. 15A  is a flow chart depicting a process for inserting a liquid radioactive isotope into the ophthalmic radiation device after placement into a treatment position; according to an embodiment; and 
         FIG. 15B  is a flow chart depicting a method for visually identifying a position of a concealed radioactive source material according to an embodiment; 
         FIG. 16  is a schematic, perspective view of a shielding cradle disposed in a treatment position on a patient&#39;s face, according to an embodiment. 
     
    
    
     It will be appreciated that for clarity elements shown in the figures may not be drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Furthermore, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION OF EMBODIMENTS THE PRESENT INVENTION 
     In the following detailed description, numerous details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details and that well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. 
     Embodiments of the present invention are generally directed to an ophthalmic radiation device and treatment method facilitating placement of a therapeutic radioisotope onto or near the eyeball and within its socket as noted above. Specifically, embodiments are directed at effectively directing light from a light source through the body of the wand to illumination ports by using the wand body itself as the lightguide. The illumination ports are used as reference points by a medical practitioner to facilitate placing the device into a correct treatment position. 
     The following terms will be used out through the document: 
     “Radioactive-source-material”, “source”, “source material”, or “radiation source” all refer to a radioactive material providing the therapeutic dose of radiation. Non-limiting examples of a therapeutic-radioisotope include, inter alias, Yttrium, and Strontium 
     “Holder” refers to a structure for supporting or containing a therapeutic quantity of a radioactive source material. The holder may be configured to contain the source material in either solid or liquid form as will be further discussed. 
     “Wand”, “treatment wand”, “body of the wand”, or “wand body” refer to an elongated ergonomic structure extending from a handle and supporting the holder at its distal end, according to an embodiment. The wand is contoured to provide the optimal access, visibility, and control, and fatigue-preventive ergonomics for the surgeon. The wand is light transmissive and has minimal surface features so as to minimize light dissipation through the body of wand. 
     “Medicinal agent” refers to therapeutic agents like, inter alia, a drug or a chemical, visible light, non-visible electromagnetic radiation, or particle radiation. 
     “Medical practitioner” refers to surgeons, doctor, nurse, or any other personnel applying or assisting in applying a radiation treatment. 
     “Distal” and “proximal” are relative terms of position measured in terms of positional relationship to the end of handle closest to the user holding the device. Accordingly, “distal” refers to the point or portion most distant from the end of the handle closest to the user holding the handle, whereas “proximal” refers to a point or portion nearest to the end of the handle closest to the user holding the handle 
     “Distal portion” refers to a position near the distant extremity; but, does not necessarily include the most distant point. 
     “Light guide” refers to substantially transparent solid body through which light propagation is directed in accordance with the surface geometry of the body. “Light pipe” refers to a specific type of light guide implemented as a fiber. “Illumination source light pipe” refers to an optic fiber. 
     “Opaque” refers to a state that is either non-transparent, non-translucent, or impenetrable by light. 
     “Catch element” refers to a structure securing the radiation-source-material in a single to location in lumen of a wand. Accordingly, a wall bulge constricting the cross-sectional area of the lumen is also deemed to be a catch element. 
     “Circumscribe” refers to surrounding even if the source is non-circular. 
     In addition to the administration of therapeutic doses of radiation in the treatment of AMD, melanoma, and other eye ailments responsive to radiation, the device may also be used to administer a drug or therapeutic substances released from body of the device into, through or onto the sclera or other associated tissues or attach specialized medicinal agents to the sclera itself, according to an embodiment. 
     Turning now to the figures,  FIG. 1  depicts an ophthalmologic radiation device, generally labeled  1 , enabling a medical practitioner to apply a therapeutic dose of radiation to the target tissue. In anon-limiting embodiment device  1  includes a radioactive-source-material holder  4 , a handle  2 , a light pipe in communication with a light source coupling  5  for connecting the light pipe  6  to handle  5 , and a treatment wand  3  for inserting the radioactive-source-material near the target tissue. 
     Wand  3  may be constructed of strong, substantially light transparent polymeric material such as polycarbonate or polysulfone, for example, or other material providing mechanical integrity and transparency enabling light to propagate through the wand  3 . In certain embodiments the wand  3  is releasably attachable to handle  2  while in other embodiments wand is permanently attached to handle  2 . 
     As shown in  FIG. 1A , wand  3  extends into the body of handle  2  and abuts light pipe  6  held inside handle  2  by coupling  5  to enable light to propagate through wand  3  from light pipe  6  to the distal end of the wand  3  near holder  4 , according to a certain embodiment. It should be appreciated that in certain embodiments non-abutment connection configurations between illuminations source  6  and wand  3  may be employed. 
       FIGS. 2-2B  depict various wand embodiments through which light is directed from the illuminations source to a series of illumination ports  7  circumscribing a radiation source disposed in holder  4 , according to certain embodiments. The emitted light beams advantageously provide a visual reference useful in identifying the position of a radioactive source material disposed in holder  4 . 
     Specifically,  FIG. 2  depicts a wand  3  integrally connected to holder  4  so as to enable light emission through illumination ports  7  and also holder floor,  4   c , holder wall  4   a , or both, according to an embodiment. It should be appreciated that in such embodiments both holder  4  and the wand  3  are constructed from similar or identical light transmissive material. 
       FIG. 2A  depicts a variant embodiment of the wand depicted in  FIG. 2  in which a wand  3  forks into two branches,  3   a  and  3   b , integrally connected to holder  4  so as to enable light emission through illumination ports  7  and also holder floor  4   c , holder wall  4   a , as described previously. In a certain embodiment, holder  4  is configured to prevent light emission through any part of the holder and so that substantially all light emission occurs at illumination ports  7 . 
       FIG. 2B  depicts another variant embodiment of the wand and holder depicted in  FIG. 2  in which wand  3  is implemented as four independent light pipes  3   c  enabling independent light propagation through each light pipe  3   c  to illumination ports  7  disposed in holder  4 . It should be appreciated that any plurality of light pipes  3   c  is included within the scope of the present invention. 
     In a certain embodiment, illumination of each light pipe  3   c  is implemented with light of different wavelengths while in another embodiment light pipes  3   c  are illuminated non-simultaneously. 
     It should also be appreciated that various combinations of illumination wavelengths and timing are included in the scope of the present invention. 
       FIGS. 3-3D  depict a third variant embodiment having the forked wand described above permanently attached at only distal and proximal portion  3   d  of holder  4 , to minimize light dissipation during propagation though wand  4  and holder  4 . This structure is most clearly depicted in the cross-sectional views along section lines A-A, B-B and C-C depicted in  FIGS. 3B-3D , respectively. 
     Specifically, along section line A-A wand branches  3   a  and  3   b  are permanently attached to holder  4 , whereas along section line B-B wand branches  3   a  and  3   b  are separate from holder  4 , and along section line C-C each of the wand branches  3   a  and  3   b  are connected to the proximal portion of holder  4  via a web connection  3   k . The reduced thickness of web connection  3   k  advantageously reduces light dissipation into holder  4 . 
     It should be appreciated that in certain embodiments, wand  3  may have a non-transparent component, or opaque surface layer or film applied to the surface to minimize light dissipation. 
       FIGS. 4-4B  depict an embodiment of the forked wand that is releasable attachable to holder  4 , according to a certain embodiment. The connection is accomplished by way of two set of cooperating flex tabs  8 , each set disposed on opposite sides of holder  4 . 
       FIG. 4C  depicts a cross-section along section lines A-A and depicts wand branches  3   a  and  3   b  clamped in between flex tabs  8 . 
     Such a connection configuration also reduces light dissipation through structures connected to wand branches  3   a  and  3   b , thereby preserving available light intensity for illumination ports  7 , according to an embodiment. 
       FIGS. 5-5D  depict additional embodiments of releasably attachable connection configuration for wand  3  and holder  4 . Specifically, as shown in  FIGS. 5A and 5C  wand  3  branches into several wand fingers  9  configured to clip into corresponding notches  11  disposed in holder wall  4   a  in  FIGS. 5B and 5D , respectively. 
     In certain embodiments wand fingers  9  are implemented with non-circular cross-sections with illumination ports disposed at each distal end  12 . 
     As shown in  FIGS. 5A and 5C , light rays  10  are directed along the length of wand  3  and internally reflected through wand fingers  9  until they exit through illumination ports  12  at the distal end of each of wand finger  9 . 
     It should be appreciated that any feature disclosed in a particular embodiment may be applied to other embodiments. 
       FIGS. 6 and 6A  depict non-limiting embodiments of wand branches having integral light-directing-structures for directing light propagating through the wand branches. Light rays  14  depict schematically a general propagation direction through the light guide. 
     Specifically,  FIG. 6  depicts an embodiment of wand branch  9  having an illumination or emission point  12  at the distal end of branch  9 . Reflective surfaces  13  are implemented integrally in branch body  9  so that each reflective surface  13  forms a substantially 45.degree. angle relative to the axis of propagation of the incident light, according to an embodiment. As shown, light propagation is redirected from its incident propagation direction by an angle of about 90.degree. thereby minimizing light dissipation prior to exiting the branch body  9  at distal end  12 , according to an embodiment. 
       FIG. 6A  depicts the non-limiting embodiment of wand branch  3   a  depicted in  FIG. 3 . Illumination ports  7  are disposed in wand branch  3   a  directly opposite reflective surfaces  13  so that the propagation direction is redirected through illumination point  7 , according to this embodiment. 
     Embodiments in which reflective surface  13  deviates from the 45.degree. angle relative to the axis of propagation of the incident light, illumination ports are accordingly displaced from a position directly opposite the reflective surface  13  so as to ensure there directed light passes through illumination port  7 . 
     In a certain non-limiting embodiment, each illumination point  7  is implemented as an integrally connected, protruding focusing lens  7  having a substantially convex surface geometry with a radius of curvature focusing light  14  on or near the retina when the device is inserted behind the eyeball. 
     In certain embodiments, the central of axis  19  of each lens or protruding illumination port is orientated roughly perpendicularly to the sclera so as to minimize the travel path to the retinal to minimize light diffusion through the sclera and the retina and maximize light intensity. 
     It should be appreciated, however, that embodiments in which the central axis of respective lenses are not disposed at substantially right angles relative to the sclera are also included within the scope of the present invention. 
     The protruding, convex surface geometry provides certain physiological benefit by advantageously minimizing irritation when the illumination ports  7  contact the sclera during treatment and enhances illumination through coupled light transmittance. 
     In other non-limiting embodiments, illumination ports  7  are implemented with flat or concave surface geometries having a radius of curvature substantially corresponding to the curvature of the eyeball. 
       FIG. 6B  depicts an variant embodiment of the branch wand of  FIG. 6A  having an opaque film  3   h  on selected surfaces of wand body  3   m  so as to reduce or eliminate light emission from wand body  3   m  and to allow emission from the illumination ports  7 . This configuration advantageously renders illumination ports  7  visually obtrusive to facilitate identification of the radiation-source-material relative to illumination ports  7 . 
     Such opaque films may be applied through dipping the wand into a material like urethane, for example, and then removing the resulting film from designated illumination ports. Alternatively, the desired opaque film may be formed on the wand surface through secondary injection molding as is known to those skilled in the art. It should be noted that the terms “coating” and “film” are used interchangeably in this document. 
       FIG. 7  depicts an alternative embodiment in which wand  3  is implemented as multiple, hollow branches  3   e . In certain embodiments, a concentric fiber optic is disposed in each branch whose distal end is disposed in holder  4  forming the illumination ports  7 . In other embodiments, the lumen of each wand branch  3   e  contains electrical wiring for miniature light emitting diodes (LED) or other light producing electronic devices disposed in holder  4  to generate light beams emanating from illumination ports  7 . 
     It should be appreciated that in some embodiments, a single device may employ any combination of the illumination means like LED&#39;s, fiber optics, light pipes, or integral light guide to generate the illumination for the points or ports. Furthermore, it should be understood that in certain embodiments the wand  3  may contain two or more illumination points disposed equidistantly on opposing sides of the holder wall itself or adjacent to the wall in other non-limiting embodiments. 
       FIGS. 8 and 8A  are schematic, transparent perspective and side cross-sectional views, respectively, depicting wand  3  disposed behind eyeball  17  in abutment with optical nerve  17   a , to administer a therapeutic dose of radiation into macula  17   b  from radioactive material  4   f  contained in holder  4 , according to an embodiment. 
     As noted above, in certain embodiments, wand branches  3   a  and  3   b  include illumination ports  7  having convex focusing lenses configured to focus light either on or near the retina. Such lens orientation may be achieved largely through a general concavity of wand branches  3   a  and  3   b  that substantially conforms to the contour of eye  17 . 
     The illumination ports  7  may be viewed along lines of vision  19   a  by way of transpupillary ophthalmoscopy. 
     As most clearly shown in  FIG. 8A , holder  4  is implemented as a disc having a distal surface concavity or notch  20  to receive optic nerve  17   a  when wand  3  is disposed in a treatment position, according to an embodiment. This configuration provides further guidance to the medical practitioner positioning holder  4  into the proper treatment position by providing tactile feedback upon abutment of holder  4  and optic nerve  17   a.    
     A non-limiting example of such a concavity is one having radius of curvature of about 2.5 mm to 3 mm. Furthermore, concavity  20  advantageously enables radioactive-source material  4   f  to be placed in maximal proximity to the macula for optimal therapy. 
     It should be appreciated that notches or slots of a wide variety of geometries suited to the needs and anatomical requirements of the individual patient are also included within the scope of the present invention. 
     In certain embodiments, holder  4  is implemented without distal notch  20 , but rather, with a rounded distal end for application in treatment of intraocular tumors, for example. 
     In some embodiments, visual support may be further augmented by attaching a sub-miniature video camera and lighting element (such as a fiber optic or an LED) to the distal end of holder  4 . This configuration advantageously allows the surgeon to directly view and avoid obstructions in the wand&#39;s path during insertion and placement against optic nerves heath  17   a.    
     As noted above, the portion of wand  3  configured for insertion behind eyeball  17  within the orbit of the skull has acceptable ergonomics to minimize patient trauma and surgeon fatigue. Specifically, the insertion portion has a rounded contour, an overall curvature substantially corresponding to the curvature of the eyeball, and is thin; having a maximum thickness of less than about 5.0 mm and width ranging from about 10.0 mm to about 6 mm at the narrowest point in non-limiting examples. 
     Specifically,  FIGS. 9 and 9C  depict non-limiting embodiments of holder  4  having a holding cavity  4   b  facing the eyeball or facing the skull orbit when the wand is disposed in a treatment position respectively. 
       FIGS. 9A and 9B  are cross-sectional views along section line A-A and depict two variant embodiments of the embodiment of  FIG. 9 . 
     As shown in  FIG. 9A , holding cavity  4   b  is defined by holder floor  4   c  and holder wall  4   a . Diameter and depth dimensions are defined in accordance with required dimensions of the radioactive source material to be disposed in holder cavity  4   b  during treatment, according to a certain embodiment. In such lidless embodiments, the radioactive source-material is affixed to holder floor  4   c.    
       FIG. 9B  depicts a generally analogous embodiment of  FIG. 9A  with the addition of holder cover  4   e  so as to entirely encapsulate a radioactive source material disposed in holder cavity  4   b . Sealed holder configurations advantageously enable the radioactive source-material to be implemented as a solid, a powder or even as a liquid, in some embodiments. 
     Holder cover or lid  4   e  may be attached to holder walls  4   a  by glue, ultrasonic welding, or mechanical means like, inter alias, threading or flex tabs. 
     Holder  4  and holder cover  4   e , in some embodiments, are constructed from polymeric materials such as polycarbonate or polysulfone or even metallic materials. Holder cover  4   e  may have a relatively thickness ranging from 0.1 mm to 1 mm according to certain non-limiting examples. 
     As noted above,  FIG. 9C  and the associated cross-sectional views,  FIGS. 9C and 9D  depict generally analogous embodiments with the exception of the direction of the holder cavity opening. In these embodiments holder walls  4   a  and floor  4   c  define a holder cavity  4   b  opening towards the skull orbit and are otherwise analogous to the embodiments described in  FIGS. 9A and 9B . 
     The holder floor  4   c  is implemented as a relatively thin polymeric material like polycarbonate or polysulfone having a minimal thickness ranging from 0.2 mm to 1 mm to enable the radiation to effectively penetrate through holder floor  4   c  into the target tissue, according to non-limiting embodiments. 
     It should be appreciated that the holder cavity may be implemented in a wide variety of shapes in accordance to the required shape of the radioactive source material. 
       FIGS. 10A-10B  depict a radiation-shielding sleeve  22  slideably mounted on wand  3  to enable a user to slide sleeve along wand  3  into and out of a shielding mode, according to an embodiment. Such functionality advantageously protects a medical practitioners and the patient from radiation during insertion and removal of the radiation device if such protection is deemed necessary. 
     Specifically,  FIGS. 10 and 10A  depict shielding sleeve  22  disposed in a shielding, and a non-shielding modes, respectively. When disposed in the shielding mode, sleeve  22  covers radioactive-source-material  4   f  disposed in holder  4 , and, when slid into a non-shielding mode upwards along wand  3 , the radioactive source  4   a  is revealed for treatment. 
     It should be noted that shielding sleeve  22  is typically constructed of a shielding material like high molecular weight polymer with additives or other materials exhibiting similar functionality, according to non-limiting embodiments. 
     Typically, the distal area of the shielding sleeve  22  is implemented as thinly as possible to facilitate sliding of sleeve  22  while wand  3  is disposed in a treatment position before and after administration of the therapeutic radiation. It should be appreciated that in certain embodiments, the shielding sleeve remains stationary while the wand and holder  4  slide into and out of treatment position. 
       FIG. 11  depicts a wand embodiment configured to facilitate insertion of radioactive source material  4   f  into the distal end of the wand  3  after it is disposed in a treatment position. As shown, wand  3  is implemented as a relatively flat, hollow tube having lumen  3   f  (most clearly seen in  FIGS. 11A and 11B ) through which a solid form of the source material  4   f  advances when pushed by a semi-flexible inserter  23 , according to an embodiment. 
       FIGS. 11A and 11B  are cross-sectional views respectively depicting lumen cross-sectional lumen geometries at section lines D-D and E-E, respectively. As shown in  FIG. 11A , lumen has a cross-sectional area sufficient for the passage of source material  4   f  whereas, at the distal end of wand  3 , at section line E-E, the cross-sectional area  3   f  is constricted by wall bulge  3   j . The lumen constriction engages source material  4   f  in between the lumen walls at the distal end of wand  3 , thereby holding it in a treatment position. It should be appreciated that lumen wall bulges or other means of securing source material  4   f  into a treatment position inside lumen  3   f  are included within the scope of this invention. 
     Illumination ports  7  are disposed in a distal portion of the wand and at least partially circumscribe the radiation source material to assist the practitioner in positioning wand  3  into a treatment position as described above. 
       FIGS. 12-12A  depict an alternative embodiment of the wand depicted in  FIG. 11  in which liquid radioisotope is injected through passageways leading to either a reservoir or a labyrinthine network disposed in the distal portion of wand  3 . It should be appreciated that liquid radioisotopes include, inter alia, suspensions of various types of particulate radioisotopes in a carrier liquid. Examples of carrier liquid include, inter alia, glycerin and water. 
     Examples of particulate radioisotopes include, inter alia neutron-activated, glass micro-spheres like yttrium aluminosilicate magnesium aluminosilicate, holmium-166, erbium-169, dysprosium-165, rhenium-186, rhenium-188, yttrium-90, or other elements on the periodic table. 
     In a certain embodiment, the particulate radioisotope is implemented as non-radioactive glass mixed with a radioactive material like, inter alia, iodine-125, palladium-103, and strontium-90 to emit low energy gamma rays. 
     In another embodiment, the particulate radioisotope is selected from Auger emitters like, inter alia, 67Ga, 99mTc, 111In, 123I, 125I, and 201Tl or from alpha-emitters like, inter alia, uranium, thorium, actinium, and radium, and other transuranic elements. 
     In yet another embodiment, the particulate radioisotope is implemented as any one or a combination of inter alia  89 Sr,  90 Sr,  169 Yb,  32 P,  33 P,  90 Y,  192 Ir,  25 I,  131 I,  103 Pd,  177 Lu,  149 Pm,  140 La,  153 Sm,  186 Re,  166 Ho,  166 Dy,  137 Cs,  57 Co,  369 Er, 
       165 Dy,  97 Ru,  193m Pt,  195m Pt,  105 Rh,  68 Ni,  67 Cu,  64 Cu,  109 Cd,  11 Ag, 
       198 Au,  199 Au,  201 Tl,  175 Yb,  47 Sc,  159 Gd,  212 Bi, and  77 As. 
     As shown in  FIG. 12 , labyrinthine network  26  is disposed at the distal end of wand  3  in liquid communication with pump  28  of  FIG. 12B  via passageways  25  and  24 . In certain embodiments, the entire liquid delivery system, i.e. pump  28 , labyrinthine network  26 , and passageways  25  and  24 , are implemented as a closed system containing two different liquids; an inert fluid  30  and liquid radioisotope  4   g.    
     As shown in  FIG. 12  the inert fluid is initially held in the labyrinthine network  26 , and passageways  25  and  24  while the liquid radioisotope  29  is held in a holding chamber  32  associated with pump  28 , according to a certain embodiment. When treatment commences, the liquid radioisotope  29  is injected into a passageway  25 , designated source material feed line and displaces inert liquid  30  disposed in labyrinthine network  26  which feeds into a secondary holding chamber  31 . 
     Upon completion of the treatment, double piston  33  is driven in the reverse direction to expel the inert liquid  30  from the secondary holding chamber  31  and injects it though passageway  24  into the labyrinthine network  26  where the liquid radioisotope  29  is displaced and returned to holding chamber  33  until the next treatment, according to certain embodiments. 
     The labyrinthine network  26  advantageously maximizes the quantity of the liquid radioisotope  4   g  to which the target tissue may be exposed. In certain embodiments pump  28  is disposed at the proximal end of wand  3 . A non-limiting example of liquid radioisotope is a Ytterbium suspension and examples of suitable inert liquids include, inter alias, water and glycerin. 
       FIG. 13-13D  all depict light weight handles  2  affording comfortable complete wand control during insertion, removal, and administration of the therapeutic radiation. Regarding illumination sources,  FIGS. 13-13C  depict various embodiments of illumination or light sources. 
     Specifically,  FIG. 13  depicts a non-limiting handle embodiment in which illumination from an external light source (not shown) is piped into handle  2  through light pipe  6  and coupling  5  disposed at a proximal end of handle  2 . 
       FIG. 13A  depicts a non-limiting handle embodiment in which illumination from an external light source (not shown) is coupled in close proximity to the hand grip at an angle non-parallel to the longitudinal axis of handle  2  to advantageously reduce torque 
       FIG. 13B  depicts a non-limiting handle embodiment in which illumination is provided from an internal light source disposed inside illumination housing  5   a  and powered from an external power source (not shown) through electrical cable  6   a.    
       FIG. 13C  depicts a non-limiting handle embodiment in which illumination is provided from an internal light and power source disposed inside illumination housing  5   a.    
     It should be appreciated that light control features may also be provided for controlling brightness, color and time responsive audio and video feedback mechanisms configured to alert medical personnel as needed. Such functionality may be provided with the associated hardware known to those skilled in the art, embedded in handle  2  according to certain embodiments or built into the cradle in communication with the handle, according to other embodiments. 
     It should be further appreciated that in some embodiments respective illumination ports may have light emissions differing in color or frequency from emissions of other illumination ports, and light emission frequencies at each illumination port may be individually variably controlled. 
       FIG. 14  depicts a method for facilitating placement of the radiation source material into a treatment position using visual reference points produced from illumination ports disposed near the radiation source material; according to an embodiment. 
     Specifically, in step  35 , an ophthalmic radiation device having a treatment wand with the above-described light transmitting configuration is provided. In step  36 , light is propagated through the wand from an illumination source in the handle to the illuminations ports. In step  37 , a medical practitioner placing the device into a treatment position directs the radiation-source holder in accordance with the reference points created from the illumination ports. In step  38 , the practitioner employs additional guidance from the tactile feedback resulting from contact of the distal end of the holder with the optical nerve. In step  39 , a radiation shielding sleeve is slid towards the handle to uncover and expose the radiation source material in the holder for administration of the therapeutic radiation. In step  40 , the device is removed from the treatment position after the source material is covered by the shielding device. 
       FIGS. 15 and 15A  are flow charts depicting treatment steps for devices configured to receive the radioactive-source-material after placement in a treatment position. 
     Specifically, in step  41  of  FIG. 15  in view of  FIGS. 11-11B  an embodiment of the radiation device having wand lumen is provided. In step  42 , wand  3  is positioned into a treatment position. In step  43 , the radioactive source material  4   f  is pushed through the lumen  3   f  into its treatment position at the distal end of the wand lumen. In step  44 , the source material is lodged into place by way of a catch element  3   j  constricting lumen  3   f.    
     In  FIG. 15A , in reference to  FIGS. 12-12B , an embodiment of the radiation device including labyrinthine network  26  is provided. In step  46 , the wand is inserted into a treatment position. In step  47 , a liquid radioisotope is injected into the labyrinthine network  26  through passageways  25  and  24 . In step  48  an inert liquid injected into labyrinthine network  26  displaces the liquid radioisotope back into its dedicated storage chamber. 
     In the next usage, liquid radioisotope  4   g  is retrieved from the holding chamber and injected into labyrinthine network  26  and inert liquid  30  is displaced into its dedicated storage chamber, according to an embodiment. It should be noted that the injection is accomplished through a driven piston, as noted above. 
       FIG. 15B  is a flow chart depicting a method for facilitating visual identification of a position of a concealed radioactive-source-material based on a visually identifiable reference, according to an embodiment of radiation device. 
     It should be appreciated that the method may be applied in a wide variety of situations in which radioactive-source-material is concealed and the light beams provide visually identifiable reference. 
     Specifically, in step  51  a concealed radioactive-source-material disposed in a holder is provided. 
     In step  52 , light is propagated through a substantially light transparent wand. 
     In step  53 , a light beam emanating from the light propagating through the substantially light transparent wand is emitted from each of a series of illumination ports at least partially circumscribing the concealed radioactive-source-material disposed in the holder. 
       FIG. 16  is a schematic, perspective view of a shielding cradle, generally labeled  60 , disposed in a treatment position on a patient&#39;s face  62  for minimizing radiation exposure to the patients and the medical practitioner, and to provide stability to the device during treatment. 
     Shielding cradle is constructed of high molecular weight polymers for example, and has a semi-flexible bottom surface configured to substantially form to the contour of the patient&#39;s face  62  in certain embodiments. Support element  63  is traversed by a bore  61  configured to receive the handle of the ophthalmic radiation device and to provide a basic direction from which the device will be inserted into a treatment position. 
     During treatment the cradle is positioned on the patient&#39;s face and the wand is inserted through bore  61  and partially supported by support element  63  as the medical practitioner maintains the wand in the treatment position, according to an embodiment. 
     It should be noted that cradle embodiments lacking radiation shielding capacity are also enclosed within the scope of the present invention. 
     It should be further appreciated that in some embodiments respective illumination ports may have light emissions differing in color or frequency from emissions of other illumination ports, and light emission frequencies at each illumination port may be individually variably controlled. 
     It should be appreciated that various combinations of features disclosed in different embodiments are also included within the scope of the present invention. 
     While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.