ObjectiveWork in this laboratory is devoted to researching facts and developing tools to help the rehabilitation of people with low vision, especially those with macular vision loss. ProjectsVision assessment after macular vision loss - The Macular Mapping Test Focal attention and letter recognition in the retinal periphery Sustained and transient attentional mechanisms in the retinal periphery Optimizing conditions for peripheral reading and letter recognition Analysis of behavior and eye movements in children with dyslexia Analysis of motion perception in two different contexts: Age-Related Maculopathy [ARM] and Attention How patients with low vision perform in a “search and identify” paradigm Self-exploration of the visual field by low vision patients Analysis of macular vision by Scanning Laser Ophthalmoscope (SLO) Self-Exploration of the Visual Field by the PatientProject Completed Patients with scotomas (spots of diminished or no vision) often do not realize the nature of their deficit. We developed a technique that patients can use to heighten their awareness of scotomas. In the process of learning eccentric viewing, several stages have to be passed. 1. Use hand movements to find the location of best vision in the visual field of one eye, while the other eye is closed and gaze is fixed. A. While examiner and patient confront each other, the patient is asked to look at the examiner’s nose. This allows the examiner to see the deviation of the patient’s gaze. Example: If the patient looks slightly up and right, the examiner can conclude that the patient is using a spot in the lower right of the visual field. B. Conduct a simple topographic test of the patient’s visual field like the Macular Mapping Test (see "Macular Mapping Test", this website) or a tangent screen test. The results will indicate where there is relatively intact vision is available. After this preliminary test, the screen or card (see below) should show free space in the quadrant indicated by the visual field test. Visual Field Exploration A. The scientific (“high-tech”) way: This is done with the help of a computer, a monitor and a light pen. The patient looks at the angle between two straight high contrast edges using the center of the retina. This is done even if the angle itself is seen blurred or disappears altogether due to a scotoma. Gaze should be held as stable as possible. B. The practical (“low tech”) way: This is done with the help of a cardboard sheet that again shows an angle between two straight high contrast edges. The preferred hand is used to move a small piece of cardboard with a letter printed on it through the visual field. Thus, the field can be explored in the same way described above for the “high tech” method. ![]() copyright by Manfred MacKeben 2010 |