Visual field loss and its management

What are the different types of visual field tests?

• Electroretinography
• Amsler grid: A basic visual field test for central vision
• Confrontation visual field test
• Automated static perimetry test
• Kinetic or functional visual field test
• Frequency doubling perimetry

How can magnocellular deficits affect your life?

A magnocellular deficit is a disorder that impairs the ability to learn and read. It leads to difficulties such as reading comprehension and poor reading fluency. When trying to read small letters, patients complain that they move around and blur. Magnocellular deficits cause patients to be uncoordinated and clumsy, and they have trouble balancing.

How are constricted visual fields or visual field defects treated?

Neuro vision rehabilitation

Neuro vision rehabilitation addresses the peripheral system with the help of lenses, prisms and binasal occlusion. Lenses help to stabilize the vestibular ocular systems. Base in or yoked prisms may also be prescribed by our eye doctor. Binasal occlusion covers the nasal visual field to reduce the stress on your visual system. It helps with your gait and balance.

Filters

Filters may be incorporated into your eyeglasses to reduce glare and enhance contrast. Green filter combined with blue help with photosensitivity. Blue filter reduces ocular pain with eye movements. Yellow filter reduces blue light from passing through the lens and helps with computer and fluorescent lighting.

How can prisms help with visual field loss?

Prisms can change the spatial orientation of the patient. It can expand space or constrict space. They are used in vision therapy and/or a full time prescription in glasses. They are prescribed by an eye doctor after a thorough eye exam.

Peli prisms

They are primarily used to locate objects outside the visual field of patients with homonymous hemianopsia. They are placed on the lens of the temporal field defect. You do not actually view through the prisms but if an object is seen peripherally on the field loss side, they are used to detect the object. It is advised to practice walking and use of stairs while wearing the peli prism. They may be fit on the upper visual field first if you are having a hard time adapting to it.

Yoked Prisms

Yoked prisms can cause improvement in posture and gait when it is prescribed correctly. They also enhance the functional visual field. The key to effective treatment with prism lenses is how it's being prescribed. 

Peripheral visualization therapy program

In this exercise, you will be asked to scan into the side of the field loss and to remember as many objects there as possible. Then you will be asked to look straight ahead to visualize those objects. After that you will point to the area where you saw the objects. While you are still pointing, you will be asked to turn your head so that you could view the missing field.

Side vision awareness eyeglasses (SVAG)

These glasses have the widest viewing area, which enhances the visual field. If you're out shopping, these glasses can be very helpful. When crossing the street, these glasses can also be helpful because they allow you to see the cars more clearly. Depending on state law, patients with hemianopsia who wear side vision awareness glasses may be able to drive again.