13.
Anti-VEGF Therapy for Diabetic Macular Edema
Nicole Eter (Bonn)
Inhibition of vascular endothelial growth factor (VEGF) has become the standard of care in neovascular
age-related macular degeneration. The effect of VEGF in other proliferative diseases
such as diabetes also suggests a role for this approach in the management of diabetic macular
edema (DME). Chronic hyperglycemia leads to oxidative damage to retinal endothelial cells,
which in turn leads to ischemia and subsequent overexpression of a number of growth factors
including VEGF.
Pegaptanib sodium (Macugen™) has recently been studied in a phase II trial for DME. In that
study, 172 subjects with DME were randomized to receive a series of 3 intravitreal injections
of pegaptanib (at entry and every 6 weeks) in 1 of 3 doses, or sham injections, and were followed
for 36 weeks. Mean visual acuity had improved to 20/50 in the pegaptanib 0.3-mg group
versus only 20/63 in the sham group. Mean central retinal thickness decreased by 68 μm in the 0.3-mg group, whereas it
increased by 4 μm in the sham group.
Ranibizumab (Lucentis™) is currently investigated in a Phase II trial (RESOLVE study). 150 patients with DME have been
randomized to receive either 1 of 2 doses of ranibizumab, or sham treatment. Three uploading injections are given in monthly
intervals, followed by on-demand-treatment until month 12. First interim analysis after 6 months showed a reduction in
macular edema and an increase in visual acuity in both treatment groups as opposed to the control group.
Bevacizumab (Avastin™) has been investigated in smaller case series so far, where it also demonstrated potentials for
edema reduction. Thus, anti-VEGF therapy for DME shows promising results in preliminary studies. Larger studies are ongoing.
VEGF inhibition may represent an important component of DME therapy in the future.