Protection of undamaged but
at-risk retinal ganglion cells and axons from noxious stimuli released
by proximate damaged tissue and/or prevention of initiation of the
apoptosis program |
N-Methyl-d-aspartate
(NMDA)/other excitatory amino acid mantagonists (block
excitotoxicity) |
Anti-oxidants/free radical scavengers
(decrease levels of toxic moxygen radicals) |
NO synthase
inhibitors (block formation of reactive peroxynitrite from NO and
superoxide) |
Neurotrophins/growth
factors |
Ca2+ channel blockers (prevent entry of
toxic levels of calcium into the cell body or
axon) |
Rescue of marginally damaged retinal ganglion cells
and axons |
Lazaroids/21-aminosteroids (block lipid
peroxidation) |
Up-regulation of anti-death genes (bcl-2,
bcl-xL) |
Anti-oxidants/free radical
scavengers |
Ca2+ channel blockers |
NO synthase
inhibitors |
Neurotrophins/growth
factors |
Regeneration/regrowth/replacement of
axons |
Spanner neural grafts |
Growth
factors |
Transglutaminases/interleukin-2
dimerizers/oligodendrocytotoxins |
Neuroimmunomodulation—appropriately
activated macrophages, T cells |
Gene therapy (e.g.,
using viral vectors) vs. small molecule (drug) therapy to modulate the
various pathways listed |
Difficult and risks of gene and drug
delivery to the posterior ocular segment |
Duration and
specificity of gene expression and drug effects whether delivery
is local or systemic |