Visual Psychophysics and Rehabilitation : Investigation of low vision
Age-related Macular Degeneration (AMD) – Reading – Low vision
The general purpose of my studies is to investigate reading processes in patients with central field loss (CFL) using psychophysical tools, fMRI technique and mixed effects models analysis. One potential goal of these studies is to find some ways to enhance text display and improve visual readaptation.
Since April 2011, I have been working as a Research Assistant in the Department of Psychology at the University of Minnesota. I am actually doing this post-doc under the supervision of Dr. Gordon Legge at the Minnesota Laboratory for Low Vision Research, in Minneapolis.
From November 2007 to February 2011, I have been a PhD candidate under the supervision of Dr. Eric Castet, at the Mediterranean Institute for Cognitive Neuroscience (INCM-CNRS) and collaborated with the low-vision clinic of the hospital La Timone in Marseilles, France.
What is AMD?
Age-related Macular Degeneration (AMD) is the most common cause of vision loss in the industrialized country in those 50 or older. The macula (central retina) degenerates and becomes useless, in consequence, the patient percieve a black spot at the center of his visual field. For more information on AMD: http://www.allaboutvision.com/conditions/amd.htm
Reading & AMD…
To compensate this impairment, patients have to use parts of their peripheral vision to substitute their missing central vision. But such readaptative strategies are not perfect and leads to a dissociation between oculomotor and attentional behaviours. Patients report difficulties in faces recognition, orientation and mobility, but their major complaint is that reading is either impossible or very slow. Indeed, even with the best optical correction and an appropriate magnification, AMD patients still read significantly slower than healthy readers. My thesis work focuses on understanding the difficulties encountered by AMD patients during reading tasks. Final purpose is to find some ways to enhance or customize text display to improve their comfort and reading performances.
MP1 – Microperimeter
To understand the functionnal impairment, the first step is to examine the anatomical one. The Microperimeter MP1 (Nidek Technologies) is used to assess characteristics of each scotoma, such as its position, size and shape, or the position of the preferred retinal location(s) (PRL) used to fixate. All those informations are usefull to analyse reading performances.
In addition with reading performances recordings, the eye-tracker EyeLink II (SR Research) allows to record in real time oculomotor patterns of patients. Such dataset is crucial to investigate reading strategies.