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Careful use of anti-vascular endothelial growth factor agents for the treatment of age-related macular degeneration is acceptable, but physicians should be alert for exceptions to the expected outcome.
Philadelphia-Careful use of anti-vascular endothelial growth factor (VEGF) agents for the treatment of age-related macular degeneration (AMD) is acceptable, but physicians should be alert for exceptions to the expected outcome, said Elias Reichel, MD, here at the Macula 2011 and Atlantic Coast Retina Club meeting of the Wills Eye Institute.
"Judicious use of anti-VEGF agents is reasonable, considering [their] biological, clinical, and disease-subtype responses. [Patients with 'robust' responses] exist and likely represent genotypic/phenotypic disease response heterogeneity," said Dr. Reichel, vice chairman for research and education, Department of Ophthalmology and director, Vitreoretinal Diseases and Surgery Service, New England Eye Center, Boston.
Biological rationale for the judicious use of anti-VEGF agents for AMD includes the knowledge that VEGF is produced and expressed by Müller and photoreceptor cells, and that chronic VEGF blockade can lead to apoptosis of these cells.1
In treating AMD, however, there always will be exceptions to the expected treatment outcome. Patient responses can range from non-response, or "masquerade," syndromes to robust response.
"We have patients [whose condition masquerades] as possible wet AMD, cases that [show a robust response], cases that we would think [would show poor response] but [that] actually respond very well," Dr. Reichel said.
"It is important to understand that some patients may [have an early response] to anti-VEGF agents, but then they may not [have a response] over time," he added.
One possible "masquerade" syndrome is adult-onset foveomacular membrane dystrophy (AOFMD). Patients with AOFMD typically do not have a response to treatment with anti-VEGF injections, and proper diagnosis before treatment is the key to successful management, Dr. Reichel said.
Patients with robust responses usually present with small, classic, or occult choroidal neovascularization (<1 mm).
These patients have very good vision (20/50 or better), and are usually older (greater than 80 years old).
Patients with poor responses usually present with large pigment epithelial detachments, and disease is typically associated with retinal angiomatous proliferation or polypoidal choroidal vasculopathy.
It is difficult in these patients to predict response to anti-VEGF treatment, according to Dr. Reichel.
"In conclusion, VEGF suppression has biological ramifications both good and bad," Dr. Reichel said. "Anti-VEGF injections can be associated with elevated IOP, tachyphylaxis, and reduced [ocular perfusion pressure]."