Jurre den Haan1, Lisanne J Balk2, Frank D Verbraak3. 1. Alzheimer Center, Neurology, VU University Medical Center, Amsterdam, The Netherlands. 2. Department of Neurology, Neuroscience Amsterdam, VUmc MS Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. 3. Ophthalmology Department, VU University Medical Center, Amsterdam, The Netherlands.