Glaucoma is the leading cause of irreversible blindness worldwide. The primary cause of glaucoma is not known, but several risk factors have been identified, including elevated intraocular pressure and age. Loss of vision in glaucoma is caused by the death of retinal ganglion cells (RGCs), the neurons that convey visual information from the retina to the brain. Therapeutic strategies aimed at delaying or halting RGC loss, known as neuroprotection, would be valuable to save vision in glaucoma. In this review, we discuss the significant progress that has been made in the use of gene therapy to understand mechanisms underlying RGC degeneration and to promote the survival of these neurons in experimental models of optic nerve injury.