[Atrophy of the macula in the context of its wet, age-related degeneration : An inescapable consequence of anti-VEGF therapy?]

BACKGROUND: Current understanding of the mechanisms that underlie the long-term consequences of anti-VEGF therapy in wet, age-related macular degeneration (AMD) is poor. Here, the impact of this treatment on the development of macular atrophy (MA) is discussed based on our current pathophysiological understanding.
METHODS: This review is based on a PubMed literature survey using the MeSH terms "wet AMD" and "macular atrophy" (151 hits) and limited to publications since 2013 (n = 90). Publications focussing on diagnostics and clinical course not in the context of therapy were excluded. Macular atrophy is defined herein as atrophy affecting the functionally relevant complex of photoreceptors, retinal pigmented epithelium (RPE), Bruch's membrane and choriocapillaris.
RESULTS: Experimentally, a primary complete suppression of local VEGF leads to evident changes in the choriocapillaris, whereas its incomplete suppression exacerbates cell death of RPE and photoreceptors. Since pre-existing atrophic changes are already present at diagnosis, the role of anti-VEGF treatment cannot be separated from the spontaneous progression of AMD. The progression of MA appears to be faster under ranibizumab than bevacizumab, and likewise on a monthly rather than as-needed basis. Although MA progresses more rapidly under consequent therapy, visual function remains better. Hence, a functionally relevant progression of atrophy during the first five years of treatment would only be expected in pre-existing advanced MA.
CONCLUSIONS: Despite doubts regarding the long-term safety of anti-VEGF therapy, it is the author's view that this is the only option to stabilise visual function. The impact of therapy-induced damage on the spontaneous progression of AMD and the biological status of the aging individual cannot be unequivocally assessed.