Monofixation syndrome is a particular form of eye alignment disorder in which the eyes are almost straight, a small degree of depth perception is present, but one eye shows mild reduced vision (amblyopia). It is a frequently encountered condition that can arise spontaneously or appear as the result of successful squint treatment.
In normal binocular vision both eyes fixate the same point simultaneously, and the brain fuses the two images into a single three-dimensional impression. In monofixation syndrome, by contrast, only one eye fixates the viewed point sharply, while the other eye looks in a similar direction but "sees" the point with a small deviation. The brain suppresses the central image of the weaker eye within a small area, but uses the peripheral fields of both eyes for a limited form of depth perception.
Diagnosis requires a careful orthoptic examination. Special tests such as the Worth four-dot test or the Bagolini striated glass test show that the brain suppresses the central image of one eye while the peripheral images are merged. A cover test can reveal a small eye deviation (microtropia).
Many of those affected need no treatment, since the eye position is cosmetically unremarkable and vision is sufficient for everyday life. In certain cases the following measures can be useful:
Monofixation syndrome is a stable condition and is often regarded in ophthalmology as a good functional result after squint treatment. Those affected have depth perception that serves them well in daily life and usually manage without restrictions. Regular ophthalmological check-ups, particularly during childhood, ensure that amblyopia is treated in good time.