What can be used to heal a damaged optic nerve in glaucoma after surgery?

No repair: Unfortunately, vision loss due to damage to the optic nerve from glaucoma is not considered reversible. This is part of the reason that screening for glaucoma is an important public health issue -- treatment to prevent or decrease progression is well established, but there is not treatment to reverse vision loss from glaucoma.

Nothing: Damage to an optic nerve from glaucoma is irreversable. This is because it it part of the central nervous system and does not regenerate. This is why early diagnosis of glaucoma is essential to stop permanent nerve damage and vision loss.

Sorry, not much: Here is where an "ounce of prevention" is critical, but, at this point, the outcome is immutable, and the damage likely permanent. So sorry for the unfortunate outcome.

Unfortunately : Optic nerve damage from glaucoma and other diseases does not have reparative treatment. The damage is irreversible. Treatment rendered for managing glaucoma is to protect and hopefully prevent optic nerve damage to the point where visual function is impaired. Hopefully, with much research, a cure may be discovered to prevent the disease from occurring in the first place.