Abstract
Purpose:
To investigate factors affecting visual acuity (VA) after long term anti-VEGF treatment in patients with neovascular age-related macular degeneration (AMD) and to determine the treatment benefit and outcome.
Methods:
This is a non comparative, retrospective case series of 109 eyes of 94 patients with neovascular AMD treated with bevacizumab or/and ranibizumab for at least 2 years (mean follw-up: 40.1±8.0 months). Patients were also grouped according to the total number of injections received within the first 2 years of treatment (High injection frequency group (HIFG): ≥ 18 injections/2 years; Low injection frequency group (LIFG): < 18 injections/2 years). Baseline VA, intravitreal injection history and AMD risk factors were recorded and analyzed for their influence on VA outcome using descriptive and inferential statistics.
Results:
The response to anti-VEGF treatment is characterized by an early phase of substantial improvement in VA (on average, 47% in logMAR units) followed by a late plateau and slow degradation phase. VA at baseline has a predominant influence on the VA gained in the initial improvement phase. In addition, the presence of hypertension or diabetes, as well as older age, lowers the VA gain during this phase. During the plateau phase from the second year of treatment on, the influence of these risk factors as well as initial VA diminishes, and only the injection frequency has a significant effect. Higher anti-VEGF injection frequency was associated with a better treatment response during the first 15 months of treatment with more prolonged sustained VA compared to the lower injection frequency group. However, at 4 years follow up both HIFG and LIFG showed substantial deterioration of VA.
Conclusions:
For most patients with neovascular AMD, anti-VEGF injections have a beneficial effect with many patients maintain driving vision. The most dramatic improvement in VA is seen during the early treatment months, followed by a plateau. In the long-term, slow degradation of VA is observed. This suggests that additional therapeutic strategies may be needed for improvement and maintenance of vision beyond current outcomes.
Keywords: 412 age-related macular degeneration •
748 vascular endothelial growth factor •
754 visual acuity