Glaucoma is characterized by the death of retinal ganglion cells (RGCs) and loss of vision. It is the second most frequent cause of irreversible blindness in the world and affects primarily the older population. 1 Projections of prevalence show that by 2020 there will be an estimated 79.6 million people worldwide with glaucoma, with a higher proportion of women than men. 1 Glaucoma can be treated but is not yet curable. Treatments currently available, such as the daily administration of eye drops, lead to high levels of noncompliance, especially in the aged population. In several laboratories, including ours, intense research is ongoing to search for alternative treatments of the disease. Using genes, we seek to develop gene drug therapies that can be many times more efficient than conventional drugs and allow less frequent administration—perhaps just once every 1 or 2 years. In cases of inherited glaucoma caused by either recessive or dominant genes, we seek gene replacement and gene knockdown strategies that could reverse the undesired outcome of the mutation. Technology for this new state-of-the-art treatment is currently available and has been successfully applied in other diseases, including conditions in the eye. 2 Most glaucomas are induced by dysfunction of the trabecular meshwork (TM) tissue, which in turn leads to increased resistance to aqueous humor outflow and elevated intraocular pressure (IOP). The mechanism by which elevated IOP damages the posterior RGCs is not fully understood. Whether the elevated IOP first damages the RGC axons and then causes the cell body to die or it damages the cell body first, which then causes the axons to die is a subject of intense deliberation. Although elevated IOP is not the only factor causing RGC death, it is the most common. All currently available drugs that lower IOP slow the progression of all glaucomas, even the form referred to as normal-tension glaucoma. Because of this particular physiology, there are two main avenues to follow in approaching research in gene therapy for glaucoma. The first entails targeting the RGCs with the goal of promoting their survival and protecting them against glaucomatous insults (neuroprotection). The second entails targeting the TM with the goal of lowering IOP. Gene therapy vectors deliver the genetic material to the inside of the cells. Because viruses have been selected during evolution to cleanly and efficiently enter living cells, they have emerged as excellent carriers of any desired genetic material. Given the tools of molecular biology and recombinant DNA that are now available, a virus can be specially engineered both to remove the potentially deleterious sequences from its genome and to insert the beneficial foreign sequences to be delivered to the target cell.