Methods for reducing or preventing transplant rejection in the eye and intraocular implants for use

1. An intraocular, bioerodible drug delivery system comprising a steroid effective in preventing or reducing neovascularization in an eye prone to neovascularization, and a bioerodible polymer selected from the group consisting of hydroxyaliphatic carboxylic acids, and polysaccharides, thereby forming an implant for placement in the interior of an eye prone to neovascularization, wherein: (a) the steroid is dexamethasone and comprises about 50% to 80% of the weight of the drug delivery system; (b) the drug delivery system is configured for placement in the vitreous, wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 8 weeks.

2. The drug delivery system of claim 1 , wherein the steroid is the sole active ingredient for preventing or reducing the neovascularization.

3. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of D-lactic acid.

4. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of L-lactic acid.

5. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of racemic lactic acid.

6. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of glycolic acid.

7. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of polycaprolactone.

8. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a calcium alginate.

9. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of carboxymethylcellulose esters.

10. The drug delivery system of claim 1 , wherein the bioerodible polymer comprises a polymer of hydroxypropyl methylcellulose.

11. An intraocular, bioerodible drug delivery system comprising particles of dexamethasone and a polylactic acid polyglycolic acid (PLGA) copolymer, wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 5 days, and wherein the intraocular, bioerodible drug delivery system is a single pellet or a single extruded filament, and wherein: (a) the dexamethasone comprises about 50% to 80% of the weight of the drug delivery system; and (b) the drug delivery system is configured for placement in the vitreous, wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 8 weeks.

12. The system of claim 11 , wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 9 weeks.

13. The system of claim 11 , wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 10 weeks.

14. The system of claim 11 , wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 12 weeks.

15. The system of claim 11 , wherein the system is effective in releasing the dexamethasone into the eye over a period of up to about 6 months.

16. The system of claim 11 , wherein the system is effective in releasing the dexamethasone into the eye over a period of up to about 1 year.

17. An intraocular, bioerodible drug delivery system comprising a drug effective in preventing or reducing edema in an eye prone to edema, and a bioerodible polymer, wherein: (a) the drug is dexamethasone and comprises about 50% to 80% of the weight of the drug delivery system; and (b) the drug delivery system is configured for placement in the vitreous, wherein the system is effective in releasing the dexamethasone into the eye over a period of at least about 8 weeks.

18. The drug delivery system of claim 17 , wherein the dexamethasone is the sole active ingredient for preventing or reducing the edema.

19. An intraocular, bioerodible drug delivery system comprising a steroid effective in preventing or reducing neovascularization in an eye prone to neovascularization, and a bioerodible polymer selected from the group consisting of hydroxyaliphatic carboxylic acids, and polysaccharides, thereby forming an implant for placement in the interior of an eye prone to neovascularization, wherein: (a) the steroid is dexamethasone and comprises about 50% to 80% of the weight of the drug delivery system; (b) the drug delivery system is configured for placement in the vitreous, and; (c) the drug delivery system is effective in releasing the drug into the eye over a period of at least about 8 weeks.

20. The drug delivery system of claim 19 , wherein the steroid is the sole active ingredient for preventing or reducing the neovascularization.

21. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a polymer of D-lactic acid, L-lactic acid, or racemic lactic acid.

22. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a polymer of glycolic acid.

23. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a polymer of polycaprolactone.

24. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a calcium alginate.

25. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a polymer of carboxymethylcellulose esters.

26. The drug delivery system of claim 19 , wherein the bioerodible polymer comprises a polymer of hydroxypropyl methylcellulose.