Nystagmus: Eye Tremors as a Symptom – Treatment for Eye Movement Disorders

Nystagmus is one of the most common conditions in ophthalmology. 

In medicine, nystagmus refers to a rhythmic movement of the eyes in which both eyes cannot remain steadily focused on a target. These involuntary eye movements cause the gaze to shift repeatedly. Typically, the eyes slowly drift in one direction and then quickly snap back.

In everyday language, this is often referred to as “eye tremor.” Nystagmus is a type of eye movement disorder and can impair eye fixation, pupil position, and visual acuity.

The eyes do not move randomly but follow a typical pattern. Nystagmus occurs in various forms. Horizontal nystagmus is particularly common, while vertical or rotatory forms are less frequent.

Types of nystagmus include jerky nystagmus and pendular nystagmus.

Medically, a distinction is also made between congenital forms of nystagmus and those acquired later in life.

Congenital nystagmus (also known as congenital nystagmus) often begins in the first year of life. In this context, it is also referred to as infantile nystagmus. In addition, there are forms that develop later in life, such as acquired nystagmus. Another type of nystagmus is latent nystagmus, or manifest-latent nystagmus, which can occur in connection with strabismus (crossed eyes), among other conditions.

Furthermore, doctors distinguish between physiological nystagmus—such as optokinetic nystagmus—and pathological forms, in which pathological nystagmus may indicate an underlying medical condition.

Optokinetic nystagmus

There are various possible causes of nystagmus. The cause may lie within the visual system, the vestibular system, or the brain. Accordingly, different factors can trigger or cause nystagmus.

Early-onset forms often have developmental or genetic causes. Congenital nystagmus, for example, may be associated with albinism. Early visual impairments can also sometimes contribute to the development of congenital nystagmus.

In many cases, nystagmus is often already visible in infancy or early childhood. If nystagmus does not appear until later in life, a neurological disorder must always be considered. Changes in the brainstem and cerebellum are particularly relevant because these structures control essential eye movements. Damage to the brainstem or cerebellum can therefore cause pathological nystagmus. Other central changes also play a role. In this context, the term “central eye movement disorders” is also used.

Another important group consists of disorders of the vestibular system. A vestibular-related condition can cause nystagmus if signals from the inner ear are processed incorrectly. Vestibular nystagmus is often accompanied by vertigo. Such processes can originate peripherally in the vestibular system or centrally. This distinction is particularly important for diagnosis. In addition, inflammatory diseases, circulatory disorders, medications, or intoxications can contribute to nystagmus. Multiple sclerosis is also a known cause. Overall, nystagmus can therefore result from a wide variety of neurological or ophthalmological triggers.

The primary symptom of nystagmus is visible or subjectively perceived eye tremors. Those affected often describe images as wobbling or appearing unstable. The eye movements occur uncontrollably. The eyes move rhythmically in a repetitive pattern, making it difficult to fixate on a single point.

The severity of the symptoms depends on the cause and type of nystagmus. In some patients, visual acuity is primarily reduced; others notice that their eyes have difficulty tracking objects or that the image lacks stability. Especially in cases of gaze-dependent nystagmus, those affected often seek a comfortable head and gaze position in which the tremor is less pronounced.

Nystagmus is often accompanied by additional symptoms. Other symptoms may include unsteadiness when walking, nausea, or difficulty with orientation. If nystagmus is caused by vestibular or neurological factors, it can affect balance and coordination. For people with nystagmus, this can make daily life significantly more difficult.

If nystagmus occurs, a thorough medical evaluation should be conducted. First, the doctor takes a detailed medical history. This involves determining how long the nystagmus has been present, whether it is congenital or acquired, whether there is a family history of the condition, and whether any comorbidities are known. It is also important to determine in which direction of gaze the tremor intensifies. During the examination, the findings are first assessed clinically.

The ophthalmologist or neurologist observes the eye movements, the direction of the jerks, the frequency, and the conditions under which the nystagmus occurs. This often allows for an initial assessment of whether the cause is more likely to be peripheral or central.

Examination using Frenzel goggles has proven effective; these goggles optically enlarge the eyes while simultaneously making it more difficult to fixate sharply, allowing for better observation of the nystagmus. In addition, electronystagmography can objectively record eye movements. These procedures help to classify the eye tremor more accurately.

If a central cause is suspected, further neurological examinations and imaging procedures are performed. Rapid evaluation is particularly important when there are indications of involvement of the brainstem or cerebellum. Specialized sources, such as the *Deutsches Ärzteblatt*, also point out that the evaluation should always be conducted within the overall clinical context. The findings must therefore be interpreted both clinically and in terms of their underlying cause.

As in any medical field, the doctor’s diagnosis is crucial. The treatment of nystagmus depends on the specific type, severity, and cause of the eye tremor, as well as the available compensatory strategies.

For example, the patient may be able to compensate for and reduce the eye tremor by changing the position of their head. The primary goal of treatment is to improve the patient’s visual acuity. There are numerous treatment methods available for this purpose.

• Medication for Nystagmus

When treating with medication, doctors typically prescribe memantine or gabapentin.

Doctors in Europe and the United States typically use memantine to treat dementia.

The drug is also used in the treatment of Parkinson’s disease. Side effects of memantine include headaches, nausea, dizziness, fatigue, vomiting, and confusion.

Doctors use gabapentin to treat pain in the peripheral nervous system or epilepsy. It is important that the patient avoid alcohol and morphine, as these can lead to severe side effects.

Expert opinion on the pharmacological treatment of nystagmus is rather controversial. Some researchers and doctors doubt the effectiveness of these medications in treating eye tremors.

Surgical treatment, on the other hand, is much more common and is used for certain forms of the condition.

• Procedure for Nystagmus Surgery

In about 50% of patients, doctors can reduce congenital nystagmus through surgical intervention. Experts determine the appropriate surgical approach through specialized preliminary examinations.

It must be determined whether the patient exhibits less eye tremor when holding their head in a certain position and whether they have a forced head posture.

In addition, doctors must determine whether the patient can see objects better up close or at a distance. Based on this information, the specialist can choose between two common surgical procedures.

• Reducing Eye Tremors

One approach involves reducing the severity of the nystagmus. This can be achieved, for example, through one or more eye muscle surgeries or an injection of botulinum toxin (Botox). Botulinum toxin is a highly potent neurotoxin that has been used in medicine since the 1980s. In addition to its use in cosmetic surgery for wrinkle reduction, Botox can also serve as an alternative to eye muscle surgery.

However, treatment with botulinum toxin has two fundamental drawbacks:

• First, the effect of the neurotoxin wears off after a certain period of time and does not lead to permanent results.
• Second, Botox is difficult to dose accurately, which is particularly dangerous when treating the sensitive eye area.

For this reason, doctors prefer to treat nystagmus with surgery.

Botox can reduce the uncontrolled eye movements associated with nystagmus, although the results do not last long @ Oleksandr /AdobeStock

• Strengthening Compensatory Mechanisms

The other surgical procedure aims to strengthen the patient’s compensatory mechanisms against eye tremors. The goal is to determine which compensatory measures (e.g., altered head posture) the patient uses to minimize their individual eye tremors.

Some patients experience less severe eye tremor when looking to the side. The surgeon takes advantage of this effect by repositioning the eyes during surgery so that the eye tremor stops when looking straight ahead. This method is also known as the Kestenbaum parallel shift.

Here is how the procedure is performed:

1. In the first step, the patient is anesthetized. This is usually general anesthesia. Local anesthesia is an alternative option if the patient requests it.
2. To prepare for this surgery, the doctor turns the patient’s head to the left and turns both eyes to the right.
3. The doctor stabilizes the eyeballs so that some of the external eye muscles retract.
4. The doctor surgically removes other extraocular muscles.

Some patients, however, report less severe eye tremors when looking at close objects—that is, when viewing objects at very close range. In this case, the doctor refers to what is known as convergence-induced nystagmus suppression.

Doctors are also particularly effective at treating this form of nystagmus surgically. The goal of this surgical procedure is to reduce the eye tremor—which is reduced during near vision—even during distance vision.

The preferred surgical procedure is the Cüppers artificial divergence technique. In this procedure, the doctor reposition the specific outer eye muscles backward.

The eyes are among the most important sensory organs in humans. Consequently, potential complications that arise during nystagmus surgery can significantly impact the patient’s quality of life.

If the surgery is performed on the oblique extraocular muscles, among others, more severe bleeding may occur. This is due to their close proximity to a venous blood vessel (known as the vortex vein).

The surgeon should avoid operating on too many lateral eye muscles at once in order to maintain as consistent a blood supply to the eye muscles as possible. For this reason, it is advisable to schedule multiple surgical appointments.

Severing multiple eye muscles can impair blood flow to the anterior segments of the eye.

An eye infection may occur as a side effect of the treatment.

However, surgical procedures to treat nystagmus are generally associated with low risks. In particular, permanent damage to the eyes is very rare.

Before the surgery, the patient should have a detailed consultation with the anesthesiologist to ensure that the anesthesia is administered safely.

If you are allergic to certain substances, you should inform the anesthesiologist. You should also have realistic expectations regarding the surgery.

You should not assume that your vision will improve significantly after nystagmus surgery. However, most patients find it easier to see after the surgery.

Patients typically remain in the hospital for a few days after surgery. This allows the hospital staff to properly care for the postoperative wounds.

This allows doctors to monitor the success of the treatment and quickly identify and treat any complications or side effects (e.g., inflammation).

Patients who opt for outpatient surgery may go home after the procedure. However, they must attend the follow-up appointments for postoperative checkups.

The course of the condition depends largely on the cause. In cases of early-onset nystagmus, the condition often persists permanently but can be partially compensated for through adaptation and effective gaze strategies. In cases of acquired nystagmus, the underlying condition is the primary factor determining the future course of the disease.

If the cause is detected and treated early, the condition may improve or at least stabilize. In other cases, the nystagmus remains permanent. It is precisely in these cases that those affected benefit from specialist care and individually tailored interventions. For many patients, while vision may not return to normal after effective treatment, it becomes significantly easier.

The appropriate specialists to consult for diagnosis and treatment are an ophthalmologist, a neurologist, or an ENT specialist. Interdisciplinary collaboration is particularly important when a central or vestibular cause is suspected.

Specialized centers can more accurately assess which form of the condition is present and determine the most appropriate treatment. This is particularly important if the condition is new, is accompanied by other symptoms, or severely impairs vision. An early consultation with a specialist improves the chances of an accurate diagnosis and appropriate treatment.