Some aspects of the invention provide for a method of treating a patient having glaucoma, a non-hereditary optic neuropathy, steroid-induced oxidative stress, or steroid-induced oxidation-related disorders, comprising identifying a patient having a non-hereditary optic neuropathy or steroid-induced oxidative stress or steroid-induced oxidation-related disorders and in need of treatment repeatedly administering a polyunsaturated substance to the patient or the patients tissue, wherein the polyunsaturated substance is chemically modified such that one or more bonds is stabilized against oxidation wherein following said administration, the polyunsaturated substance or a polyunsaturated metabolite thereof comprising said one or more chemical modifications is incorporated into the patients body or the patients tissue.