This is a distortion test whereby a distorted image is presented to one eye to a level were fusion cannot occur. This distortion is produced by grooves (plano-convex cylinders) ground onto a disc of coloured glass – red glass used for distance and green glass used for near. A spotlight seen through the disc is distorted into a streak of light at right angles to axis of grooves. The Maddox rod is commonly performed at distance (red glass).
The Maddox wing is designed to work at 30cm. The patient looks through two slit holes and the presence of a septa means that separate views are seen by each eye i.e. different targets are presented to each eye so fusion cannot occur. The right eye sees arrows while the left eye sees tangent scale...
People present to optometrists complaining of headache, eye ache, tired and sore eyes, poor concentration and poor performance at school or work. With this clinical scenario many optometrists test for the presence of fixation disparity. The amount of prism required to remove fixation disparity ha...
When evaluating the anterior segment the direct ophthalmoscope is used to assess the external structures, iris and lens, and to identify abnormalities or the need for further investigation. Abnormalities picked up in the anterior segment can be more thoroughly examined using slit-lamp biomicroscopy.
