Ophthalmic Drugs

OPHTHALMIC DRUGS

Drugs Used in Glaucoma

Glaucoma is more common in the elderly, but its treatment does not differ from that of glaucoma of earlier onset.

Macular Degeneration

Age-related macular degeneration (AMD) is the most common cause of blindness in the elderly in the developed world. Two forms of advanced AMD are recognized: the neovascular “wet” form, which is associated with intrusion of new blood vessels in the subretinal space, and a more common “dry” form, which is not associated with abnormal vascularization. Although the cause of AMD is not known, smoking is a documented risk factor, and oxidative stress has long been thought to play a role. On this premise, antioxidants have been used to prevent or delay the onset of AMD. Proprietary oral formulations of vitamins C and E, β-carotene, zinc oxide, and cupric oxide are available. Evidence forthe efficacy of these antioxidants is modest or absent. Oral drugs in clinical trials include the carotenoids lutein and zeaxanthin, and n-3 long-chain polyunsaturated fatty acids. In advanced AMD, treatment has been moderately successful but only for the neovascular form. Neovascular AMD can now be treated with laser phototherapy or with antibodies against vascular endothelial growth factor (VEGF). Two antibodies are available:bevacizumab (Avastin, used off-label) and ranibizumab (Lucentis), as well as the oligopeptide pegaptanib (Macugen). The latter two are approved for neovascular AMD. These agents are injected into the vitreous for local effect. Ranibizumab is extremely expensive. Fusion proteins and RNA agents that bind VEGF are under study.