?What is Nystagmus An involuntary back-and-forth, up-and- down, or oscillatory rhythmical movement of the eyeballs. Many people with this condition suffer from partial sightedness and some are considered legally blind. There are approximately 45 different types of nystagmus.
Types Nystagmus can be classified into two general types: Physiological- Pathological- It can also be classified into according eye movement patterns: - pendular -jerky -rotatory
General Types Physiological- A normal response that is induced because of excessive demand or imbalance in the vestibular or ocular motor system. Pathological- An abnormal response that occurs spontaneously or appears in an individual looking at a stationary object. Congenital (early infancy-6 months)- )-Acquired (after 6 months
Eye Movement Patterns Pendular Jerk (physiological (congenital or or pathological) acquired) -characterized by an -thought to be a FEM in one direction result of a delay in and a slower messages to the movement in the brainstem opposite direction -characterized by -thought to result eye movements that from extra input to are equally paced in the oculomotor each direction system from the brainstem.
Causes 1- Ocular nystagmusA. nystagmus due to defective central visionB. Nystagmus due to blindnessC. Congenital idiopathic nystagmusD. Spasmus nutansE. Miners disease
2- vestibular nystagmus :A. Lesion of labyrinthB. Lesion of vestibular nerve 3- central nystagmus due to lesion of :A. Brain stemB. CerebellumC. Spinal cord
Effects of Nystagmus Nystagmus affects people in different ways. The most significant effect is the reduced visual acuity and binocular vision. Factors such as stress, tiredness, and nervousness can cause changes in ability to focus. Distance visual acuity is poorer than near vision. Balance may be affected due to poor depth perception or due to vestibular problems. Head nodding is common. Also, most sufferers have a null point where eye movement decreases and vision improves
Social Impact One major difficulty individuals suffering from nystagmus face is the lack of knowledge about the disorder, from the outside community. In conversation, sufferers with involuntary head movement may cause people to think they are disagreeing with what they are saying. Reading speed is likely to be affected because of the extra time and effort it takes to scan words. Some people are unable to get their driver’s license. “alcohol” People with the disorder find it difficult to play sports, especially those involving good hand to eye coordination.
Treatment At the moment, there is no cure for nystagmus. Many treatments have been tried, but the success varies from person to person. Some of the treatments include eye muscle surgery, anti parkinsonian drugs , Baclofen , Gabapentin , optical and acupuncture. In a medical journal, it was recorded that tenotomy of the horizontal muscles in horizontal nystagmus with no null point was very effective in improving or eliminating horizontal eye movement.