Predicting visual outcomes in patients treated with aflibercept for neovascular age-related macular degeneration: Data from a real-world clinical setting

Background/objectives: There is a significant variation in the way neovascular age-related macular degeneration patients respond to anti-vascular endothelial growth factor treatment. Both the financial and time cost of treatment are significant. As such, being able to predict patient response to treatment is valuable. Subjects/methods: 72 eyes treated with intravitreal aflibercept were retrospectively included in analysis. For each subject, visual acuity (letters) and central retinal thickness (mu m) at baseline, second, third and fourth visits, as well as 12-month visits, were collated; a plot of visual acuity versus time was generated and a slope of the first three (slope3) and first four (slope4) visits was calculated. Differences in visual acuity at each visit compared to baseline were determined, as well as percentage differences in central retinal thickness at each visit compared to baseline. Lesion sub-type and the presence of fluid and haemorrhage were also recorded. Results: The average change in visual acuity over 12 months was +3.2 +/- 13.4 letters with 91.2% of patients losing <15 letters. Slope4 was the only significant predictive factor for 'visual acuity change over 12 months' (p < 0.001). Change in central retinal thickness, lesion sub-type, haemorrhage at baseline and the location of fluid at baseline were not useful predictive factors in long-term outcome. Conclusion: Aflibercept is an effective treatment option for neovascular age-related macular degeneration; however, the long-term response should not be predicted until at least three loading dose injections have been given. Visual acuity measures at each visit should be examined, as it is the trend in visual acuity across the first four visits (slope4) rather than the difference in visual acuity between two visits that is the predictive factor.