Age-related macular degeneration (AMD) is the leading cause of vision loss in the industrialized world. In the last few decades, the mainstay of treatment for
choroidal neovascularization (CNV) due to AMD has been thermal
laser photocoagulation. In the last decade,
photodynamic therapy with
verteporfin extended treatment for more patients. While both of these treatments have prevented further vision loss in a subset of patients, improvement in visual acuity is rare. Anti-
vascular endothelial growth factor A (
VEGF)
therapy has revolutionized the treatment of AMD-related CNV.
Pegaptanib, an anti-
VEGF aptamer prevents vision loss in CNV, although the performance is similar to that of
photodynamic therapy.
Ranibizumab, an
antibody fragment and
bevacizumab, a full-length humanized
monoclonal antibody against
VEGF have both shown promising results with improvements in visual acuity with either agent.
VEGF trap, a modified soluble
VEGF receptor analogue, binds
VEGF more tightly than all other anti-
VEGF agents and has also shown promising results in early trials. Other treatment strategies to decrease the effect of
VEGF have used small interfering
ribonucleic acid (
RNA) to inhibit
VEGF production and
VEGF receptor production.
Steroids, including
anecortave acetate in the treatment and prevention of CNV, have shown promise in controlled trials.
Receptor tyrosine kinase inhibitors, such as
vatalanib, inhibit downstream effects of
VEGF, and have been effective in the treatment of CNV in early studies.
Squalamine lactate inhibits plasma membrane
ion channels with downstream effects on
VEGF, and has shown promising results with systemic administration. Other
growth factors, including pigment epithelium-derived
growth factor that has been administered via an adenoviral vector has shown promising initial results. In some patients
ciliary neurotrophic factor is currently being studied for the inhibition of progression of
geographic atrophy. Combination
therapy has been investigated, and may prove to be more effective in the management of AMD-associated CNV. Ongoing and future studies will be crucial for optimizing the treatment of patients with AMD.