In early glaucoma what would be considered minimal optic nerve damage?

No loss of function : Minimal optic nerve damage seen in early glaucoma is a structural change with or without visual field loss, depending on how the nerve is structurally changed. A visual field defect therefore isn't necessary to have in early glaucoma. Minimal nerve damage may show up as asymmetry, cup elongation, nerve fiber layer thinning, focal notching or excavation, vessel deformation, and other.