Priority is claimed pursuant to 35 U.S.C. 119(e)(1) of U.S. provisional application Ser. No. 61/393,741, filed Oct. 15, 2010, which is incorporated by reference in its entirety for all purposes
- Top of Page
The suprachoroidal space is a potential space in the eye that is located between the choroid, which is the middle layer or vascular tunic of the eye, and the sclera, the outer (white) layer of the eye. The suprachoroidal space extends from the anterior portion of the eye near the ciliary body to the posterior end of the eye adjacent to the optic nerve. Normally the suprachoroidal space is not evident due to the close apposition of the choroid to the sclera from the intraocular pressure of the eye. Since there is no substantial attachment of the choroid to the sclera, the tissues can separate to form the suprachoroidal space when fluid accumulation or other conditions occur. The suprachoroidal space provides a potential route of access from the anterior region of the eye to the posterior region for the delivery of treatments for diseases of the eye. Standard surgical access to the suprachoroidal space is achieved through incisions in the conjunctiva and the sclera, and is primarily performed in an operating room. Surgical access is useful in draining choroidal effusions or hemorrhage, and in placing microcatheters and cannulas into the suprachoroidal space for delivery of agents to the back of the eye. Treatments for diseases such as age-related macular degeneration, macular edema, diabetic retinopathy and uveitis may be treated by the appropriate active agent administered in the suprachoroidal space.
The sub-retinal space is a potential space in the eye that is located between the sensory retina and the choroid. The sub-retinal space lies under all portions of the retina, from the macular region near the posterior pole to the ora serrata, the anterior border of the retina. Normally the sub-retinal space is not evident as the retina needs to be apposed to the underlying choroid for normal health and function. In some disease states or as a result of trauma, a retinal detachment may occur, forming a fluid filled region in the sub-retinal space. Such spaces normally require treatment to reattach the retina before retinal function is irreversibly lost. However, it has been found that some treatments such as gene therapy or cell therapeutics may be applied to the sub-retinal space to provide maximum exposure to the retina. In a normally functioning retina, small injections in the sub-retinal space create a small area of retinal detachment which resolves in a short period of time, allowing direct treatment of the retina.
The sub-retinal space may be accessed ab-interno by piercing a small gauge needle through the retina. This procedure involves penetration of the intraocular space of the eye and forming a small retinotomy by the needle. A therapeutic agent injected into the sub-retinal space may flow out through the retinotomy into the vitreous cavity causing exposure of the therapeutic to the lens, ciliary body and cornea as it exits through the anterior aqueous outflow pathway.
It is desired to have a method whereby the suprachoroidal space or the sub-retinal space may be accessed in a minimally invasive method via an ab-externo transconjunctival approach. Such a method would provide a method to limit, guide or guard the penetration of a needle device into the suprachoroidal space or sub-retinal space to prevent further penetration. The present invention provides an apparatus to allow minimally invasive, transconjunctival access to the suprachoroidal space or sub-retinal space in the eye for the delivery of therapeutic or diagnostic materials.
- Top of Page
OF THE DISCLOSURE
The present invention provides a device comprising an elongated body having a distal end and proximal end, said ends in communication through an internal pathway within the body wherein:
the distal end is configured with a sharp edge or point to penetrate into ocular tissues of the outer shell of the eye,
a moveable guarding element disposed in a first configuration to shield the ocular tissues from the sharp edge or point, and adapted to apply a distally directed force to the tissues at the distal end of the device to displace tissue away from the distal end of the device upon entry into the suprachoroidal space or subretinal space in an eye with the distal end; wherein the guarding element is moveable to a second configuration to expose said sharp edge or point to said tissues for penetration into the tissues,
and an access port to deliver materials and substances through the pathway in the elongated body after deployment of the guarding element within the suprachoroidal space or subretinal space.
In some embodiments the guarding element is attached to a spring or compressible element that upon compression thereof provides a distally directed force on the guarding element.
In some embodiments the guarding element comprises a flowable material selected from a fluid or gas that is directed to flow out of the distal end of the device to provide a distally directed force.
In some embodiments the device further comprises a sealing element attached at the distal end of the elongated body adapted to reduce or prevent leakage of fluid or gas through a tissue tract created by the device.
In some embodiments the device accommodates a spring to apply a distal force on the sealing element to provide a sealing force of the element against the eye tissue.
In some embodiments the device comprises a reservoir at the proximal end for receiving a material to be delivered at the target space and the sealing element is in mechanical communication with an activating element for releasing the material from the reservoir.
In some embodiments the device comprises an associated sealing element adapted for retention on the surface of the eye to receive the distal end of the device to locate and stabilize the device during penetration into the eye.
The invention further provides a device for placement in the sclera of an eye, comprising a body having a proximal end adapted for location at or near the scleral surface and a distal end adapted for location within the suprachoroidal or subretinal space, where the device comprises a lumen and a mechanical stop at the proximal end for retaining the proximal end at or near the scleral surface.
Methods of using the devices of the invention to access the suprachoroidal or subretinal spaces of the eye are also provided.
BRIEF DESCRIPTION OF THE DRAWINGS
- Top of Page
FIG. 1 is a schematic cross-section of the eye with a detail view of the layers of the eye.
FIG. 2 is a schematic of a device according to one embodiment of the invention comprising an angled tip.
FIG. 3 is a schematic of a device according to one embodiment of the invention comprising a guard element disposed in the lumen of the main shaft.
FIG. 4 is a schematic of a device according to one embodiment of the invention comprising a tubular guard element disposed about the outside of the main shaft.
FIG. 5 is a schematic of a device according to one embodiment of the invention comprising a reservoir element.
FIG. 6 is a schematic of a device according to one embodiment of the invention comprising a sealed reservoir activated by piercing said seal.
FIG. 7 is a schematic of a device according to one embodiment of the invention comprising a spring loaded distal element on a sliding shaft with a valve mechanism.
FIG. 8 is a schematic of a device according to one embodiment of the invention comprising a sliding distal element on a sliding shaft with a valve mechanism.
FIG. 9 is a schematic of a device according to one embodiment of the invention comprising a fixed shaft and a sliding outer element connected to a valve mechanism.