Patent Publication Number: US-8974511-B2

Title: Methods for treating closed angle glaucoma

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to methods for treating closed angle glaucoma. 
     BACKGROUND 
     Glaucoma is a disease of the eye that affects millions of people. Glaucoma is associated with an increase in intraocular pressure resulting either from a failure of a drainage system of an eye to adequately remove aqueous humor from an anterior chamber of the eye or overproduction of aqueous humor by a ciliary body in the eye. Build-up of aqueous humor and resulting intraocular pressure may result in irreversible damage to the optic nerve and the retina, which may lead to irreversible retinal damage and blindness. 
     There are two main types of glaucoma, “open angle” and “closed angle” glaucoma. Open angle glaucoma refers to glaucoma cases in which intraocular pressure increases but an anterior chamber angle (drainage angle) of an eye remains open. A common cause of open angle glaucoma is blockage in the trabecular meshwork, the fluid flow pathways that normally drain aqueous humor from the anterior chamber of the eye. Closed angle glaucoma refers to glaucoma cases in which intraocular pressure increases due to partial or complete closure of the anterior chamber angle. In closed angle glaucoma, swelling or movement of the iris closes the anterior chamber angle and blocks fluid from accessing to the trabecular meshwork, which in turn obstructs outflow of the aqueous humor from the eye. 
     Generally, glaucoma may be treated by surgical intervention that involves placing a shunt in the eye to result in production of fluid flow pathways between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm&#39;s canal or the subconjunctival space). Such fluid flow pathways allow for aqueous humor to exit the anterior chamber. Generally, the surgical intervention to implant the shunt involves inserting into the eye a deployment device that holds an intraocular shunt, and deploying the shunt from the device and into the eye. A deployment device holding the shunt enters the eye through a cornea (ab interno approach), and is advanced across the anterior chamber. The deployment device is advanced into the anterior chamber angle and through the sclera until a distal portion of the device is in proximity to a drainage structure of the eye. The shunt is then deployed from the deployment device, producing a conduit between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm&#39;s canal, the sclera, or the subconjunctival space). See for example, Yu et al. (U.S. Pat. No. 6,544,249 and U.S. patent application number 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511). 
     SUMMARY 
     A problem with treating closed angle glaucoma with surgical intervention is that the closed anterior chamber angle prevents an operator from advancing the deployment device into the anterior chamber angle, and thus the device cannot be properly positioned to deploy an intraocular shunt. 
     The present invention generally relates to methods for treating closed angle glaucoma that involve using a deployment device that is configured to both re-open a partially or completely closed anterior chamber angle and deploy an intraocular shunt. By re-opening the anterior chamber angle, the deployment device is provided access to the anterior chamber angle so that an operator may properly position the device to deploy the intraocular shunt, thereby generating a fluid flow pathway for outflow of aqueous humor from an anterior chamber of an eye. 
     In certain aspects, methods of the invention involve inserting into an eye a deployment device configured to hold an intraocular shunt, using the device to re-open an at least partially closed anterior chamber angle of an eye, and deploying the shunt from the device. Deploying the shunt results in a flow path from an anterior chamber of the eye to an area of lower pressure. Exemplary areas of lower pressure include intra-Tenon&#39;s space, the subconjunctival space, the episcleral vein, the suprachoroidal space, and Schlemm&#39;s canal. In certain embodiments, the area of lower pressure is the subarachnoid space. 
     In other aspects, methods of the invention involve inserting into an eye a deployment device configured to hold an intraocular shunt, advancing the device such that a protrusion on a distal end of the device advances into an at least partially closed anterior chamber angle of the eye, thereby re-opening the closed angle, and deploying the shunt from the device. In certain embodiments, a distal portion of the device includes a sleeve and a hollow shaft that is movable within the sleeve. In certain embodiments, the protrusion may be formed integrally with the distal end of the sleeve or may be connected to a distal end of the sleeve. In certain embodiments, the protrusion may surround the distal end of the sleeve, or the protrusion may extend around only a portion of the sleeve. In certain embodiments, the protrusion is a collar that surrounds the distal end of the sleeve. In other embodiments, the protrusion includes a flat bottom portion and an angled top portion. In particular embodiments, the angle of the top portion is substantially identical to an anterior chamber angle of an eye. 
     Methods of the invention are typically conducted using an ab interno approach. Such an approach is contrasted with an ab externo approach, which involves inserting a deployment device through the conjunctiva of the eye. Although, methods of the invention may be conducted using an ab externo approach. 
     Methods of the invention may be performed such that the distal portion of the deployment device is inserted above or below the corneal limbus. Methods of the invention may be performed such that the distal portion of the deployment device is inserted into the eye without removing an anatomical feature of the eye, such as the trabecular meshwork, the iris, the cornea, and the aqueous humor. In certain embodiments, methods of the invention may be conducted without substantial subconjunctival blebbing. In particular embodiments, methods of the invention are performed without the use of an optical apparatus that contacts the eye, such as a goniolens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic showing an embodiment of a shunt deployment device according to the invention.  FIG. 1B  shows a cross sectional view of the device of  FIG. 1 . In this figure, the distal portion of the housing is extended from the proximal portion of the housing.  FIG. 1C  shows a cross sectional view of the device of  FIG. 1 . In this figure, the distal portion of the housing is retracted within the proximal portion of the housing.  FIG. 1D  is a schematic showing an enlarged view of a protrusion on a distal end of a distal portion of a housing of the device of  FIG. 1A . In this figure, a bottom portion of the protrusion is flat and a top portion of the protrusion is angled. 
         FIGS. 2A-2C  are schematics showing an enlarged view of a protrusion on a distal end of a distal portion of a housing of devices of the invention.  FIG. 2B  is a side view of the protrusion shown in  FIG. 2A .  FIG. 2C  is a top view of the protrusion shown in  FIG. 2A . 
         FIG. 3  shows an exploded view of the device shown in  FIG. 1 . 
         FIGS. 4A to 4D  are schematics showing different enlarged views of the deployment mechanism of the deployment device. 
         FIGS. 5A to 5C  are schematics showing interaction of the deployment mechanism with a portion of the housing of the deployment device. 
         FIG. 6  depicts a schematic of an exemplary intraocular shunt. 
         FIG. 7  shows a cross sectional view of the deployment mechanism of the deployment device. 
         FIG. 8A  is a schematic showing deployment devices of the invention in a pre-deployment or insertion configuration.  FIG. 8B  shows an enlarged view of the distal portion of the deployment device of  FIG. 8A . This figure shows an intraocular shunt loaded within a hollow shaft of the deployment device and that the shaft is completely disposed within the sleeve of the housing.  FIG. 8C  show a schematic of the deployment mechanism in a pre-deployment or insertion configuration.  FIG. 8D  is another schematic showing deployment devices of the invention in a pre-deployment or insertion configuration. 
         FIG. 9  is a schematic showing insertion of a device of the invention into an anterior chamber of the eye. This figure also shows the sleeve and protrusion fitted within an anterior chamber angle of the eye. 
         FIG. 10  is a schematic showing extension of the shaft from within the sleeve, which is accomplished by partial retraction of the distal portion of housing to within the proximal portion of housing. 
         FIGS. 11A and 11B  show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device.  FIG. 11C  shows an enlarged view of the distal portion of the deployment device of  FIG. 11A . This figure shows an intraocular shunt partially deployed from within a hollow shaft of the deployment device. 
         FIG. 12  is a schematic showing the deployment device after completion of the first stage of deployment of the shunt from the device and in to the eye. 
         FIG. 13A  show a schematic of the deployment mechanism at the end of the second stage of deployment.  FIG. 13B  shows a schematic of the deployment device at the end of the second stage of deployment.  FIG. 13C  shows another view of the deployment device at the end of the second stage of deployment. 
         FIG. 14  is a schematic showing the deployment device after completion of deployment of the shunt from the device and in to the eye. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention generally relates to methods for treating closed angle glaucoma that involve using a deployment device that is configured to both re-open a partially or completely closed anterior chamber angle and deploy an intraocular shunt. In certain aspects, methods of the invention involve inserting into an eye a deployment device configured to hold an intraocular shunt, using the device to re-open an at least partially closed anterior chamber angle of an eye, and deploying the shunt from the device. 
     Reference is now made to  FIG. 1A  which shows an embodiment of a shunt deployment device  100  that may be used to re-open a partially or completely closed anterior chamber angle and deploy an intraocular shunt. While  FIG. 1  shows a handheld manually operated shunt deployment device, it will be appreciated that devices of the invention may be coupled with robotic systems and may be completely or partially automated. As shown in  FIG. 1A  deployment device  100  includes a generally cylindrical body or housing  101 , however, the body shape of housing  101  could be other than cylindrical. Housing  101  may have an ergonomical shape, allowing for comfortable grasping by an operator. Housing  101  is shown with optional grooves  102  to allow for easier gripping by a surgeon. 
       FIG. 1B  shows a cross sectional view of device  100 . This figure shows that housing  101  includes a proximal portion  101   a  and a distal portion  101   b . The distal portion  101   b  is movable within proximal portion  101   a . In this figure, spring mechanism  120  includes a spring  121  that controls movement of distal portion  101   b . Spring mechanism  120  further includes a member  122  that acts as a stopper and limits axial retraction of distal portion  101   b  within proximal portion  101   a . Spring mechanism  120  further includes members  123  and  124  that run the length of spring  121 . The ends of members  123  and  124  include flanges  125  and  126  that project inward from members  123  and  124 . An end of distal portion  101   b  includes flanges  127  and  128  that project outward from distal portion  101   b . Flanges  125  and  126  interact with flanges  127  and  128  to prevent release of distal portion  101   b  from proximal portion  101   a . The flanges  125  and  126  and  127  and  128  hold the distal portion  101   b  in an extended position until a compressive force acts upon distal portion  101   b , thereby causing distal portion  101   b  to partially retract within proximal portion  101   a.    
     Distal portion  101   b  includes a capsule  129  and a hollow sleeve  130 . Capsule  129  and sleeve  130  may be formed integrally or may be separate components that are coupled or connected to each other. The hollow sleeve  130  is configured for insertion into an eye and to extend into an anterior chamber of an eye.  FIG. 1B  shows distal portion  101   b  of housing  101  extended from proximal portion  101   a  of housing  101 . In this configuration, hollow shaft  104  (not shown in this figure) is completely disposed within sleeve  130 .  FIG. 1C  shows distal portion  101   b  of housing  101  retracted within proximal portion  101   a  of housing  101 . Retraction of distal portion  101   b  of housing  101  within proximal portion  101   a  of housing  101  exposes hollow shaft  104 , which is discussed in greater detail below. 
     A distal end of sleeve  130  includes a protrusion  131  ( FIG. 1D ). Protrusion  131  is of a shape and size that it is capable of re-opening a partially or completely closed anterior chamber angle of an eye as an operator is advancing the device  100  through an anterior chamber of an eye. In a standard ab interno approach (see for example Yu et al. U.S. Pat. No. 6,544,249 and U.S. patent application number. 2008/0108933) a deployment device holding a shunt enters an eye through a cornea. The deployment device is advanced across the anterior chamber in what is referred to as a transpupil implant insertion. The deployment device is advanced into the anterior chamber angle on the opposite side of the eye from which the device entered the eye. With devices of the invention, upon advancement of the device  100  across an anterior chamber of the eye, the protrusion  131  at the distal end of the hollow sleeve  130  will contact a partially or completely closed anterior chamber angle, and continued advancement of the device  100  will result in the protrusion  131  re-opening the partially or completely closed anterior chamber angle. Once re-opened by the protrusion  131 , the device  100  can be moved into proper position for exposure of the hollow shaft  104 , which will advance through the sclera for deployment of an intraocular shunt. The protrusion  131 , provides adequate surface area at the distal end of sleeve  130 , thus preventing sleeve  130  from entering the tissue of the eye that is blocking access the trabecular meshwork (e.g., the iris). 
     In certain embodiments, protrusion  131  has a substantially flat bottom portion and an angled top portion ( FIG. 1D ). In other embodiments, protrusion  131  has a slightly tapered top and a slightly tapered bottom with a rounded distal portion ( FIGS. 2A-2C ). Referring back to  FIG. 1D , the angle of the top portion is substantially identical to an anterior chamber angle of an eye. Such a shape of the protrusion ensures that the device of the invention will conform and easily slide into the anterior chamber angle of the eye, the place for proper deployment of an intraocular shunt. 
     Referring back to  FIG. 1A , the proximal portion  101   a  of the housing  101  is open at its proximal end, such that a portion of a deployment mechanism  103  may extend from the proximal end of the proximal portion  101   a  of the housing  101 . The sleeve  130  of the distal portion  101   b  of the housing  101  is also open such that at least a portion of a hollow shaft  104  may extend inside the housing, into sleeve  130  of the distal portion  101   b  of the housing  101 , and extend beyond the distal end of the sleeve  130  in certain configurations (such as the deployment configuration). Housing  101  further includes a slot  106  through which an operator, such as a surgeon, using the device  100  may view an indicator  107  on the deployment mechanism  103 . 
     Housing  101  and protrusion  131  may be made of any material that is suitable for use in medical devices. For example, housing  101  and protrusion  131  may be made of a lightweight aluminum or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments, housing  101  and protrusion  131  are made of a material that may be autoclaved, and thus allow for housing  101  and protrusion  131  to be re-usable. Alternatively, device  100 , may be sold as a one-time-use device, and thus the material of the housing and the protrusion does not need to be a material that is autoclavable. 
     The proximal portion  101   a  of housing  101  may be made of multiple components that connect together to form the housing.  FIG. 4  shows an exploded view of deployment device  100 . In this figure, proximal portion  101   a  of housing  101 , is shown having two components  101   a   1  and  101   a   2 . The components are designed to screw together to form proximal portion  101   a  of housing  101 .  FIG. 4  also shows deployment mechanism  103 . The housing  101  is designed such that deployment mechanism  103  fits within assembled housing  101 . Housing  101  is designed such that components of deployment mechanism  103  are movable within housing  101 . 
       FIGS. 4A to 4D  show different enlarged views of the deployment mechanism  103 . Deployment mechanism  103  may be made of any material that is suitable for use in medical devices. For example, deployment mechanism  103  may be made of a lightweight aluminum or a biocompatible plastic material. Examples of such suitable plastic materials include polycarbonate and other polymeric resins such as DELRIN and ULTEM. In certain embodiments, deployment mechanism  103  is made of a material that may be autoclaved, and thus allow for deployment mechanism  103  to be re-usable. Alternatively, device  100  may be sold as a one-time-use device, and thus the material of the deployment mechanism does not need to be a material that is autoclavable. 
     Deployment mechanism  103  includes a proximal portion  109  and a distal portion  110 . The deployment mechanism  103  is configured such that proximal portion  109  is movable within distal portion  110 . More particularly, proximal portion  109  is capable of partially retracting to within distal portion  110 . 
     In this embodiment, the proximal portion  109  is shown to taper to a connection with a hollow shaft  104 . This embodiment is illustrated such that the connection between the hollow shaft  104  and the proximal portion  109  of the deployment mechanism  103  occurs inside the housing  101 . Hollow shaft  104  may be removable from the proximal portion  109  of the deployment mechanism  103 . Alternatively, the hollow shaft  104  may be permanently coupled to the proximal portion  109  of the deployment mechanism  103 . 
     Generally, hollow shaft  104  is configured to hold an intraocular shunt  115 . An exemplary intraocular shunt  115  in shown in  FIG. 6 . Other exemplary intraocular shunts are shown in Yu et al. (U.S. patent application number 2008/0108933). Generally, in one embodiment, intraocular shunts are of a cylindrical shape and have an outside cylindrical wall and a hollow interior. The shunt may have an inner diameter of approximately 50 μm to approximately 250 μm, an outside diameter of approximately 190 μm to approximately 300 μm, and a length of approximately 0.5 mm to about 20 mm. Thus, hollow shaft  104  is configured to at least hold a shunt of such shape and such dimensions. However, hollow shaft  104  may be configured to hold shunts of different shapes and different dimensions than those described above, and the invention encompasses a shaft  104  that may be configured to hold any shaped or dimensioned intraocular shunt. In particular embodiments, the shaft has an inner diameter of approximately 200 μm to approximately 400 μm. 
     The shaft  104  may be any length. A usable length of the shaft may be anywhere from about 5 mm to about 40 mm, and is 15 mm in certain embodiments. In certain embodiments, the shaft is straight. In other embodiments, shaft  104  is of a shape other than straight, for example a shaft having a bend along its length or a shaft having an arcuate portion. Exemplary shaped shafts are shown for example in Yu et al. (U.S. patent application number 2008/0108933). In particular embodiments, the shaft includes a bend at a distal portion of the shaft. In other embodiments, a distal end of the shaft is beveled or is sharpened to a point. 
     The shaft  104  may hold the shunt at least partially within the hollow interior of the shaft  104 . In other embodiments, the shunt is held completely within the hollow interior of the shaft  104 . Alternatively, the hollow shaft may hold the shunt on an outer surface of the shaft  104 . In particular embodiments, the shunt is held within the hollow interior of the shaft  104 . In certain embodiments, the hollow shaft is a needle having a hollow interior. Needles that are configured to hold an intraocular shunt are commercially available from Terumo Medical Corp. (Elkington, Md.). 
     A distal portion of the deployment mechanism  103  includes optional grooves  116  to allow for easier gripping by an operator for easier rotation of the deployment mechanism, which will be discussed in more detail below. The distal portion  110  of the deployment mechanism also includes at least one indicator that provides feedback to an operator as to the state of the deployment mechanism. The indicator may be any type of indicator know in the art, for example a visual indicator, an audio indicator, or a tactile indicator.  FIG. 4  shows a deployment mechanism having two indicators, a ready indicator  111  and a deployed indicator  119 . Ready indicator  111  provides feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from the deployment device  100 . The indicator  111  is shown in this embodiment as a green oval having a triangle within the oval. Deployed indicator  119  provides feedback to the operator that the deployment mechanism has been fully engaged and has deployed the shunt from the deployment device  100 . The deployed indicator  119  is shown in this embodiment as a yellow oval having a black square within the oval. The indicators are located on the deployment mechanism such that when assembled, the indicators  111  and  119  may be seen through slot  106  in housing  101 . 
     The distal portion  110  includes a stationary portion  110   b  and a rotating portion  110   a . The distal portion  110  includes a channel  112  that runs part of the length of stationary portion  110   b  and the entire length of rotating portion  110   a . The channel  112  is configured to interact with a protrusion  117  on an interior portion of housing component  101   a  ( FIGS. 5A and 5B ). During assembly, the protrusion  117  on housing component  101   a   1  is aligned with channel  112  on the stationary portion  110   b  and rotating portion  110   a  of the deployment mechanism  103 . The distal portion  110  of deployment mechanism  103  is slid within housing component  101   a   1  until the protrusion  117  sits within stationary portion  110   b  ( FIG. 5C ). Assembled, the protrusion  117  interacts with the stationary portion  110   b  of the deployment mechanism  103  and prevents rotation of stationary portion  110   b . In this configuration, rotating portion  110   a  is free to rotate within housing component  101   a   1 . 
     Referring back to  FIG. 4 , the rotating portion  110   a  of distal portion  110  of deployment mechanism  103  also includes channels  113   a ,  113   b , and  113   c . Channel  113   a  includes a first portion  113   a   1  that is straight and runs perpendicular to the length of the rotating portion  110   a , and a second portion  113   a   2  that runs diagonally along the length of rotating portion  110   a , downwardly toward a distal end of the deployment mechanism  103 . Channel  113   b  includes a first portion  113   b   1  that runs diagonally along the length of the rotating portion  110   a , upwardly toward a proximal end of the deployment mechanism  103 , and a second portion that is straight and runs perpendicular to the length of the rotating portion  110   a . The point at which first portion  113   a   1  transitions to second portion  113   a   2  along channel  113   a , is the same as the point at which first portion  113   b   1  transitions to second portion  113   b   2  along channel  113   b . Channel  113   c  is straight and runs perpendicular to the length of the rotating portion  110   a . Within each of channels  113   a ,  113   b , and  113   c , sit members  114   a ,  114   b , and  114   c  respectively. Members  114   a ,  114   b , and  114   c  are movable within channels  113   a ,  113   b , and  113   c . Members  114   a ,  114   b , and  114   c  also act as stoppers that limit movement of rotating portion  110   a , which thereby limits axial movement of the shaft  104 . 
       FIG. 7  shows a cross-sectional view of deployment mechanism  103 . Member  114   a  is connected to the proximal portion  109  of the deployment mechanism  103 . Movement of member  114   a  results in retraction of the proximal portion  109  of the deployment mechanism  103  to within the distal portion  110  of the deployment mechanism  103 . Member  114   b  is connected to a pusher component  118 . The pusher component  118  extends through the proximal portion  109  of the deployment mechanism  103  and extends into a portion of hollow shaft  104 . The pusher component is involved in deployment of a shunt from the hollow shaft  104 . An exemplary pusher component is a plunger. Movement of member  114   b  engages pusher  118  and results in pusher  118  advancing within hollow shaft  104 . 
     Reference is now made to  FIGS. 8-14 , which accompany the following discussion regarding deployment of a shunt  115  from deployment device  100 .  FIG. 8A  shows deployment device  100  is a pre-deployment or insertion configuration. In this configuration, shunt  115  is loaded within hollow shaft  104  ( FIG. 8B ). As shown in  FIG. 8B , shunt  115  is only partially within shaft  104 , such that a portion of the shunt is exposed. However, the shunt  115  does not extend beyond the end of the shaft  104 . In other embodiments, the shunt  115  is completely disposed within hollow shaft  104 . The shunt  115  is loaded into hollow shaft  104  such that the shunt abuts pusher component  118  within hollow shaft  104 . 
     In the pre-deployment or insertion configuration, the distal portion  101   b  of the housing  101  is in an extended position, with spring  121  in a relaxed state ( FIG. 8A ). Additionally, in the pre-deployment configuration, the shaft  104  is fully disposed within the sleeve  130  of the distal portion  101   b  of the housing  101  ( FIG. 8B ). Pusher  118  abuts shunt  115  ( FIG. 8B ). 
     The deployment mechanism  103  is configured such that member  114   a  abuts a proximal end of the first portion  113   a   1  of channel  113   a , and member  114   b  abut a proximal end of the first portion  113   b   1  of channel  113   b  ( FIG. 8C ). In this configuration, the ready indicator  111  is visible through slot  106  of the housing  101 , providing feedback to an operator that the deployment mechanism is in a configuration for deployment of an intraocular shunt from the deployment device  100  ( FIG. 8D ). In this configuration, the device  100  is ready for insertion into an eye (insertion configuration or pre-deployment configuration). 
       FIG. 9  shows device  100  in the insertion configuration and inserted into an eye  140 . Any of a variety of methods known in the art may be used to insert devices of the invention into an eye. In certain embodiments, devices of the invention may be inserted into the eye using an ab externo approach (entering through the conjunctiva) or an ab interno approach (entering through the cornea). In particular embodiment, the approach is an ab interno approach as shown Yu et al. (U.S. Pat. No. 6,544,249 and U.S. patent application number 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511), the content of each of which is incorporated by reference herein in its entirety. 
       FIG. 9  shows an ab interno approach for insertion of device  100  into the eye  140 . In this figure, protrusion  131  at the distal end of the sleeve  130  has been advanced across the anterior chamber  141  to the anterior chamber angle  143  on the opposite side of the eye  140  from which the device entered the eye  140 .  FIG. 9  shows protrusion  131  and sleeve  130  fitted within the anterior chamber angle  143  of the eye  140 , thus re-opening the partially or completely closed anterior chamber angle  143 . 
     In certain embodiments, such insertion and placement is accomplished without the use of an optical apparatus that contacts the eye, such as a goniolens. In certain embodiments this insertion is accomplished without the use of any optical apparatus. Insertion without the use of an optical apparatus that contacts the eye, or any optical apparatus, is possible because of various features of the device described discussed herein. The shape of the protrusion  131  is such that it corrects for an insertion angle that is too steep or too shallow, ensuring that the sleeve  130  is fitted into the anterior chamber angle of the eye, the place for proper deployment of an intraocular shunt. Further, the shape of the protrusion provides adequate surface area at the distal end of sleeve  130  to prevent enough force from being generated at the distal end of sleeve  130  that would result in sleeve  130  entering an improper portion of the sclera  142  (if the insertion angle is too shallow) or entering an improper portion of the iris  144  (if the insertion angle is too steep). Additionally, since the shaft  104  is fully disposed within the sleeve  130 , it cannot piece tissue of the eye until it is extended from the sleeve  130 . Thus, if the insertion angle is too shallow or too steep, the protrusion  131  can cause movement and repositioning of the sleeve  130  so that the sleeve  130  is properly positioned to fit in the anterior chamber angle of the eye for proper deployment of the shunt. Due to these features of device  100 , devices of the invention provide for deploying intraocular shunts without use of an optical apparatus that contacts the eye, preferably without use of any optical apparatus. 
     Once the device has been inserted into the eye and the protrusion  131  and the sleeve  130  are fitted within the anterior chamber angle of the eye, the hollow shaft  104  may be extended from within the sleeve  130 . Referring now to  FIG. 10  which shows extension of the shaft  104  from within the sleeve  130 , which is accomplished by partial retraction of distal portion  101   b  of housing  101  to within proximal portion  101   a  of housing  101 . 
     Retraction of the distal portion  101   b  of housing  101  to within proximal portion  101   a  of housing  101  is accomplished by an operator continuing to apply force to advance device  100  after the protrusion  131  and the sleeve  130  are fitted within the anterior chamber angle of the eye. The surface area of protrusion  131  prevents the application of the additional force by the operator from advancing sleeve  130  into the sclera  134 . Rather, the additional force applied by the operator results in engagement of spring mechanism  120  and compression of spring  121  within spring mechanism  120 . Compression of spring  120  results in retraction of distal portion  101   b  of housing  101  to within proximal portion  101   a  of housing  101 . The amount of retraction of distal portion  101   b  of housing  101  to within proximal portion  101   a  of housing  101  is limited by member  122  that acts as a stopper and limits axial retraction of distal portion  101   b  within proximal portion  101   a.    
     Retraction of distal portion  101   b  of housing  101  to within proximal portion  101   a  of housing  101  results in extension of hollow shaft  104 , which now extends beyond the distal end of sleeve  130  and advances through the sclera  142  to an area of lower pressure than the anterior chamber. Exemplary areas of lower pressure include Schlemm&#39;s canal, the subconjunctival space, the episcleral vein, the suprachoroidal space, or the intra-Tenon&#39;s space. 
     In this figure, a distal end of the shaft is shown to be located within the intra-Tenon&#39;s space. Within an eye, there is a membrane known as the conjunctiva, and the region below the conjunctiva is known as the subconjunctival space. Within the subconjunctival space is a membrane known as Tenon&#39;s capsule. Below Tenon&#39;s capsule there are Tenon&#39;s adhesions that connect the Tenon&#39;s capsule to the sclera. The space between Tenon&#39;s capsule and the sclera where the Tenon&#39;s adhesions connect the Tenon&#39;s capsule to the sclera is known as the intra-Tenon&#39;s space. This figure is exemplary and depicts only one embodiment for a location of lower pressure. It will be appreciated that devices of the invention may deploy shunts to various different locations of the eye and are not limited to deploying shunts to the intra-Tenon&#39;s space is shown by way of example in this figure. In this configuration, the shunt  115  is still completely disposed within the shaft  104 . 
     The distal end of shaft  104  may be beveled to assist in piercing the sclera and advancing the distal end of the shaft  104  through the sclera. In this figure, the distal end of the shaft  104  is shown to have a double bevel (See also  FIG. 8B ). The double bevel provides an angle at the distal end of the shaft  104  such that upon entry of the shaft into intra-Tenon&#39;s space, the distal end of shaft  104  will by parallel with Tenon&#39;s capsule and will thus not pierce Tenon&#39;s capsule and enter the subconjunctival space. This ensures proper deployment of the shunt such that a distal end of the shunt  115  is deployed within the intra-Tenon&#39;s space, rather than deployment of the distal end of the shunt  115  within the subconjunctival space. Changing the angle of the bevel allows for placement of shunt  115  within other areas of lower pressure than the anterior chamber, such as the subconjunctival space. It will be understood that  FIG. 11  is merely one embodiment of where shunt  115  may be placed within the eye, and that devices of the invention are not limited to placing shunts within intra-Tenon&#39;s space and may be used to place shunts into many other areas of the eye, such as Schlemm&#39;s canal, the subconjunctival space, the episcleral vein, or the suprachoroidal space. 
     Reference is now made to  FIGS. 11A to 11C . After extension of hollow shaft  104  from sleeve  130 , the shunt  115  may be deployed from the device  100 . The deployment mechanism  103  is a two-stage system. The first stage is engagement of the pusher component  118  and the second stage is retraction of the proximal portion  109  of deployment mechanism  103  to within the distal portion  110  of the deployment mechanism  103 . Rotation of the rotating portion  110 a of the distal portion  110  of the deployment mechanism  103  sequentially engages the pusher component and then the retraction component. 
     In the first stage of shunt deployment, the pusher component is engaged and the pusher partially deploys the shunt from the deployment device. During the first stage, rotating portion  110   a  of the distal portion  110  of the deployment mechanism  103  is rotated, resulting in movement of members  114   a  and  114   b  along first portions  113   a   1  and  113   b   1  in channels  113   a  and  113   b . Since the first portion  113   a   1  of channel  113   a  is straight and runs perpendicular to the length of the rotating portion  110   a , rotation of rotating portion  110   a  does not cause axial movement of member  114   a . Without axial movement of member  114   a , there is no retraction of the proximal portion  109  to within the distal portion  110  of the deployment mechanism  103 . Since the first portion  113   b   1  of channel  113   b  runs diagonally along the length of the rotating portion  110   a , upwardly toward a proximal end of the deployment mechanism  103 , rotation of rotating portion  110   a  causes axial movement of member  114   b  toward a proximal end of the device. Axial movement of member  114   b  toward a proximal end of the device results in forward advancement of the pusher component  118  within the hollow shaft  104 . Such movement of pusher component  118  results in partially deployment of the shunt  115  from the shaft  104 . 
       FIGS. 11A to 11C  show schematics of the deployment mechanism at the end of the first stage of deployment of the shunt from the deployment device. As is shown  FIG. 11A , members  114   a  and  114   b  have finished traversing along first portions  113   a   1  and  113   b   1  of channels  113   a  and  113   b . Additionally, pusher component  118  has advanced within hollow shaft  104  ( FIG. 11B ), and shunt  115  has been partially deployed from the hollow shaft  104  ( FIG. 11C ). As is shown in  FIG. 11C , a portion of the shunt  115  extends beyond an end of the shaft  104 . 
       FIG. 12  shows device  100  at the end of the first stage of deployment of the shunt  115  from device  100  and into the eye  140 . This figure shows that the distal portion  101   b  of the housing  101  remains retracted within the proximal portion  101   a  of the housing  101 , and that the shaft  104  remains extended from the sleeve  130 . As is shown in this figure, pusher  118  has been engaged and has partially deployed shunt  115  from shaft  104 . As is shown in this figure, a portion of the shunt  115  extends beyond an end of the shaft  104  and is located in the intra-Tenon&#39;s space. 
     Reference is now made to  FIGS. 13A to 13C . In the second stage of shunt deployment, the retraction component of deployment mechanism is engaged and the proximal portion of the deployment mechanism is retracted to within the distal portion of the deployment mechanism, thereby completing deployment of the shunt from the deployment device. During the second stage, rotating portion  110   a  of the distal portion  110  of the deployment mechanism  103  is further rotated, resulting in movement of members  114   a  and  114   b  along second portions  113   a   2  and  113   b   2  in channels  113   a  and  113   b . Since the second portion  113   b   2  of channel  113   b  is straight and runs perpendicular to the length of the rotating portion  110   a , rotation of rotating portion  110   a  does not cause axial movement of member  114   b . Without axial movement of member  114   b , there is no further advancement of pusher  118 . Since the second portion  113   a   2  of channel  113   a  runs diagonally along the length of the rotating portion  110   a , downwardly toward a distal end of the deployment mechanism  103 , rotation of rotating portion  110   a  causes axial movement of member  114   a  toward a distal end of the device. Axial movement of member  114   a  toward a distal end of the device results in retraction of the proximal portion  109  to within the distal portion  110  of the deployment mechanism  103 . Retraction of the proximal portion  109 , results in retraction of the hollow shaft  104 . Since the shunt  115  abuts the pusher component  118 , the shunt remains stationary at the hollow shaft  104  retracts from around the shunt  115 . The shaft  104 , retracts completely to within the sleeve  130  of the distal portion  101 b of the housing  101 . During both stages of the deployment process, the housing  101  remains stationary and in a fixed position. 
     Referring to  FIG. 13A , which shows a schematic of the deployment mechanism at the end of the second stage of deployment of the shunt from the deployment device. As is shown in  FIG. 13A , members  114   a  and  114   b  have finished traversing along second portions  113   a   1  and  113   b   1  of channels  113   a  and  113   b . Additionally, proximal portion  109  has retracted to within distal portion  110 , thus resulting in retraction of the hollow shaft  104  to within the housing  101 . 
       FIG. 13B  shows a schematic of the device  100  in the eye  130  after the second stage of deployment has been completed.  FIG. 13B  shows that the distal portion  101   b  of the housing  101  remains retracted within the proximal portion  101   a  of the housing  101 . As is shown in these  FIGS. 13B and 13C , shaft  104  has withdrawn through the sclera  134  and has fully retracted to within sleeve  130 . At completion of the second stage of deployment, a distal portion of the shunt  115  has been deployed and resides in the intra-Tenon&#39;s space, a middle portion of the shunt  115  spans the sclera, and a proximal portion of shunt  115  has been deployed from shaft  104  yet still resides within sleeve  130 . The proximal portion of the shunt  115  still abuts pusher  118 . 
     Referring to  FIG. 13C , in the post-deployment configuration, the deployed indicator  119  is visible through slot  106  of the housing  101 , providing feedback to the operator that the deployment mechanism  103  has been fully engaged and that the deployment mechanism  103  has completed its second stage of deployment. 
     Referring to  FIG. 14 , which shows a schematic of the device  100  after completion of deployment of the shunt  115  from the device  100  and in to the eye  140 . After completion of the second stage of the deployment by the deployment mechanism  103 , as indicated to the operator by visualization of deployed indicator  119  through slot  106  of the housing  101 , the operator may pull the device  100  from the eye  140 . Backward force by the operator reengages spring mechanism  120  and results in uncoiling of spring  121 . Uncoiling of spring  121  proceeds as the proximal portion  101   a  of housing  101  is pulled from the eye  140 . Such action causes distal portion  101   b  to return to its extended state within proximal portion  101   a  of housing  101 . Continued backward force by the operator continues to pull the device  100  from the eye  140 . As the device  100  is continued to be pulled from the eye, the sleeve  130  is also pulled backward and the proximal portion of the shunt  115  is exposed from within the sleeve  130  and resides within the anterior chamber  141  of the eye  140 . The operator continues to apply backward force until the device  100  is completely withdrawn from the eye  140 . 
     COMBINATIONS OF EMBODIMENTS 
     As will be appreciated by one skilled in the art, individual features of the invention may be used separately or in any combination. Particularly, it is contemplated that one or more features of the individually described above embodiments may be combined into a single shunt. 
     INCORPORATION BY REFERENCE 
     References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes. 
     EQUIVALENTS 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein.