Glaucoma implant device
A surgical implant device for treating glaucoma includes an elongate duct structure formed from a material comprising polyisobutylene and a glassy segment. The material of the elongate duct structure preferably has a general block structure with a central elastomeric polyolefinic block and thermoplastic end blocks (e.g., a triblock polymer backbone comprising polystyrene-polyisobutylene-polystyrene). The elongate duct structure provides a fluid passageway for diverting aqueous humor from the anterior chamber of the eye. Preferably, the elongate duct structure defines a lumen channel having an inside diameter between 0.05 mm and 0.3 mm. The material of the elongate duct structure is biocompatible and biostable. Moreover, the material will not encapsulate in the eye and thus provides an unobstructed flowpath that diverts aqueous humor from the anterior chamber. Different embodiments of the implant device divert the aqueous humor to different parts of the eye (e.g., a space between the conjuctiva and sclera, Schlemm's canal, or a fluid reservoir formed on a posterior surface of the eye).
1. An aqueous humor drainage device comprising:
an elongate duct structure formed from a material, said material comprising polyisobutylene and a glassy segment, wherein said elongate duct structure provides a fluid passageway having a diameter less than 0.3 mm for diverting aqueous humor from the anterior chamber of the eye, and wherein said material resists obstruction of the elongate duct structure by cell encapsulation.
2. An aqueous humor drainage device according to claim 1 , wherein:
said elongate duct structure has a hardness with a range between Shore 10A and Shore 100D.
3. An aqueous humor drainage device according to claim 1 , wherein:
said glassy segment preferably does not contain any cleavable group which will release in the presence of body fluid inside the human eye and cause toxic side effects and cell encapsulation.
4. An aqueous humor drainage device according to claim 1 , wherein:
said glassy segment comprises a vinyl aromatic polymer.
5. An aqueous humor drainage device according to claim 4 , wherein:
said vinyl aromatic polymer comprises at least one of styrene and α-methylstyrene.
6. An aqueous humor drainage device according to claim 1 , wherein:
said glassy segment comprises a methacrylate polymer.
7. An aqueous humor drainage device according to claim 6 , wherein:
said methactylate polymer comprises at least one of methylmethacrylate, ethylmethacrylate, and hydroxymethalcrylate.
8. An aqueous humor drainage device according to claim 1 , wherein:
said material has a general block structure with a central elastomeric polyolefinic block and thermoplastic end blocks.
9. An aqueous humor drainage device according to claim 8 , wherein:
said material comprises a triblock polymer backbone comprising polystyrene-polyisobutylene-polystyrene.
10. An aqueous humor drainage device according to claim 8 , wherein:
said material has a general block structure selected from one of the following:
a) BAB or ABA,
b) B(AB)n or a(BA)n , and
c) X-(AB)n or X-(BA)n;
where A is an elastomeric polyolefinic block, B is a thermoplastic block, n is a positive whole number and X is a starting seed molecule.
11. An aqueous drainage device according to claim 10 , wherein:
wherein said material comprises one of a star-shaped block copolymer (where n=3 or more) and multi-dendrite-shaped block copolymer.
12. An aqueous humor drainage device according to claim 1 , wherein:
said fluid passageway has a diameter between 0.05 mm and 0.3 mm.
13. An aqueous humor drainage device according to claim 12 , wherein: said fluid passageway has a diameter between 0.05 mm and 0.10 mm.
14. An aqueous humor drainage device according to claim 13 , wherein:
the elongate duct structure has an outside diameter less than 0.50 mm.
15. An aqueous humor drainage device according to claim 1 , further comprising:
a disk-shaped element and a retention member that are integral to said elongate duct structure and that are spaced apart such that the sclera of the eye is held therebetween in a manner that fixates said elongate duct structure.
16. An aqueous humor drainage device according to claim 15 , wherein:
said disk-shaped element and said retention member are angled with respect to a longitudinal axis of said elongate duct structure.
17. An aqueous humor drainage device according to claim 1 , further comprising:
retention means, disposed on the outer surface of said elongate duct structure, for fixating said elongate duct structure to the sclera of the eye.
18. An aqueous humor drainage device according to claim 17 , wherein:
said retention means comprises at least one of the following:
a) at least one suture thread wrapped around said elongate duct structure;
b) a silicon sleeve or other material that promotes scarring;
c) a glue such as silastic adhesive; and
d) at least one mechanical feature that is adapted to butt up against the sclera of the eye in order to limit at least one of posterior movement and anterior movement of said elongate duct structure.
19. An aqueous humor drainage device according to claim 1 , wherein:
said elongate duct structure is treated with an agent that prevents the fluid passageway from sticking closed in the event that it is pinched.
20. An aqueous humor drainage device according to claim 19 , wherein:
said agent is selected from the group consisting of hyaluronic acid, phosphatidyl choline, and glycerin.