Optical coherence tomography (OCT) continues to advance our understanding of the various diseases characterized by optic disc edema. In acute papilledema or nonarteritic anterior ischemic optic neuropathy, OCT has demonstrated subretinal fluid extending from the optic disc towards the subfoveal region, assisting in our understanding of the pathophysiology of vision loss in these cases. In evolving cases of optic disc edema, OCT of the peripapillary retinal nerve fiber layer (pRNFL) can thus be an objective measurement of nerve swelling. By analyzing the macular ganglion cell-inner plexiform layer complex (mGCIPL), OCT can now help detect early axonal damage in optic nerve disease, even when the RNFL is edematous, which may be helpful in predicting visual outcomes. Finally, OCT of the optic nerve head has proven to be a reliable tool in assisting clinicians in differentiating between cases of frank papilledema and pseudopapilledema, including that which occurs in optic disc drusen, vitreopapillary traction, Bergmeister papilla and myelinated nerve fiber layer.