Gulden's Opto-Kinetic Flag is used to produce Optokinetic Nystagmus (OKN) physiologic jerk in a patient's eyes. It is elicited when the patient attempts to fixate on moving, alternate, contrasting squares, moved in the field of vision.
The observer examines the patient's eyes as he/she counts the squares as they pass. The slow phase of the nystagmus is in the direction of the movement of the flag, while the fast phase is in the opposite direction. The nystagmus can be induced both horizontally, left or right, and vertically, up or down. The OKN response is difficult to inhibit. When exhibited, it usually means vision is at least 20/400.
Optokinetic Nystagmus can be useful in:
- Functional versus Organic Blindness
- Complete Homonyous Hemianopia
- Congenital Nystagmus
- Dorsal Midbrain Syndrome
- Abduction and Adduction Deficits
- Eye movement assessment in nuero-degenerative disorders.
The Flag is sold with a complete set of instructions.