They found that injecting AAV2-BDNF into the vitreous 6 h post IOP elevation was ineffective at protecting RGC cells in the acute phase of retinal artery occlusion due to the slow onset of transgene expression, but did provide protection in later phases, which more closely resemble the gradual RGC loss observed from chronic IOP elevation in glaucoma. The gene discussed is BDNF; the disease is glaucoma.