Post Traumatic Vision Syndrome (PTVS)
Patients who suffer a traumatic brain injury can develop a syndrome called Post Traumatic Vision Syndrome. The syndrome is characterized by inability to move the eyes smoothly together as a team, problems focussing, balance issues, prescription changes, double vision, blurred vision, perceived movement of objects, headaches, hallucinations and light sensitivity.
Focal and Ambient Visual Systems
The visual system is composed of two components, the focal and the ambient systems. The focal system allows us to pay attention to detail in our environment. The ambient visual System allows us to orient ourselves in space. It provides a peripheral framework that allows our focal system to anticipate our movements in space. The ambient system is susceptible to damage during a TBI.
Visual Midline Shift Syndrome (VMSS)
Damage to the ambient system can cause the patient’s world to become a mass of detail, causing perceptual tunnel vision. Visual Midline Shift Syndrome (VMSS) can also occur.
Visual Midline Shift Syndrome is a displacement of the midline of the body after a TBI which results in the world appearing ‘tilted’ to a patient so that they develop abnormal postures and gait as an adaptation response.
Neuro optometric Rehabilitation
Bedford Eye Care is pleased to be able to offer assessment and treatment services for patients who have suffered a traumatic brain injury. (TBI)
Dr. Mandelman has spent a considerable amount of time becoming certified in the treatment of TBI patients by attending courses offered by N.O.R.A. (Neuro Optometric Rehabilitation Association) and also by Dr. William Padula at the Padula Institute of Vision.
Neuro optometric rehabilitation involves a comprehensive evaluation of the patient’s oculo-visual system including a careful case history, determination of prescription, saccades, pursuits, vergences, accommodation (including dynamic testing), response to binasal occlusion, depth perception, phorias, visual field loss &/or neglect, etc in order to determine if the patient suffers from Post Traumatic Vision Syndrome. The patient also undergoes extensive gait and posture analysis to determine if a Visual Midline Shift Syndrome (VMSS) exists. Many patients require some type of prism therapy to help stabilize the ambient vision system and allow it to ground the focal visual system so that perceptual reorientation can occur. Extensive assessment is required to determine the amount of either yoked prism or base in prism that will correct the VMSS &/or issues with the ambient visual system.
Patients with visual field neglect also require specialized testing procedures to determine the extent and direction of the neglect. This initial assessment takes almost 2 hours to complete. The fee is $983.00*.
Neuro Visual Postural Therapy
When the evaluation is completed, patients are prescribed specialized glasses to help stabilize the ambient visual system and relieve the symptoms of PTVS. Dr. Mandelman then contacts the patient’s physiotherapist to create a program of Neuro Visual Postural Therapy (NVPT) to help correct the visual imbalances and bring the oculo-visual system back to a more normal state. NVPT is a program of movement exercises, combined with ocular exercises that re-establish the damaged ambient visual system so that the focal system can once again be grounded by a working ambient system. NVPT should be performed with the correct specialty spectacles (usually involving prism) so that the visual world is correctly perceived by the patient. Patient’s symptoms reduce and many can return to a more normal life.
After the physiotherapist determines that the patient has successfully completed the program of NVPT, the optometrist re-examines the patient and reviews the entire oculo-visual system to determine the progress that has been made. In many cases, the prescription in the glasses can be modified (usually reduced). The cost of the glasses redo is at no charge to the patient. (with 6 months of picking up the glasses) The follow-up appointment takes about an hour. The fee is $489.00*
* Many insurance companies will cover the cost of our assessments and follow-up visits.
Check out Dr. Merrill Bowan's Binocular Dissonance Grate on his Simply Brainy website.
Click here for the grate.
(Warning: May cause visual distress. Hit the 'Back' button immediately, if it does.)
Many patients with Post Traumatic Vision Syndrome experience difficulty with visually 'noisy' environments.
This grate pattern of black and white stripes has been chosen to be the most disturbing to people with PTVS.
If you find it difficult or nauseating to look at the stripes, or they appear to move or swim, then you might have PTVS.