The condition where there is no strabismus or deviation in the eyes, yet it is perceived as if strabismus exists, is referred to as pseudostrabismus. This can occur due to an optical illusion caused by certain structural characteristics of the face. The most commonly observed type of pseudostrabismus is the perception of the eyes being crossed, known as pseudo-esotropia. Less common situations include the illusion that the eyes are deviating outward or not vertically aligned.
What is Pseudostrabismus?
Pseudostrabismus is a condition where the eyes do not actually deviate, yet it appears as if they do, and it can occur in infants and young children.
Since the facial anatomy of infants is not fully developed, the nasal bridge is flat and the skin around the eyes is folded, creating the impression of inward eye deviation. This appearance may diminish as children grow and their facial features mature. Additionally, structural differences in the eyeballs or the position of the visual axis relative to the geometric axis can also lead to symptoms of strabismus in children.
What Causes Pseudostrabismus in Infants and Children?
Pseudostrabismus in infants and young children typically stems from anatomical features of the face. It is more commonly observed in the following situations:
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A wide and flat nasal bridge: This makes the distance between the eyes appear closer, creating the impression of eye deviation.
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Epicanthus fold: The fold of skin at the inner corner of the upper eyelid partially covers the inner part of the eye.
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Eyelid structure: The reduced visibility of the sclera can create the impression that the child’s gaze is deviating. This anatomical appearance is usually more pronounced in infancy and early childhood.
As children grow, their facial proportions change. The nasal bridge becomes more pronounced, the area around the eyes takes on a more mature shape, and this developmental process usually reduces or completely eliminates the appearance of pseudostrabismus. Over time, with changes in the anatomical features of the face, such optical illusions naturally disappear.
Does Pseudostrabismus Cause Amblyopia?
Pseudostrabismus, being only related to appearance, may not lead to amblyopia. However, in the case of true strabismus, amblyopia can develop. Therefore, even in cases thought to be pseudostrabismus, periodic eye examinations should be performed.
If eye deviation is observed in infants, a doctor’s evaluation should not be delayed. Since infants' eyes are still in the developmental stage, failure to intervene early in such cases can lead to permanent problems or complications. Parents should regularly monitor their children's eye movements and consult a specialist if they notice any abnormalities.
How to Differentiate Between Pseudostrabismus and True Strabismus?
Differentiating between true strabismus and pseudostrabismus can sometimes be challenging. Eye doctors can clarify the diagnosis through light reflex tests and eye movement examinations. The following signs indicate true strabismus:
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One eye consistently looking in a different direction
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Tilted head posture
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One of the eyelids being lower
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Signs of amblyopia
How is Pseudostrabismus Examined?
Routine Eye Examinations
For individuals presenting with complaints of pseudostrabismus, routine tests such as visual and retinal examinations may be conducted. This type of complaint is among frequently encountered conditions, and standard eye examination procedures are applied when evaluating patients.
Hirschberg Test
The Hirschberg test examines light reflections in the eyes. Analysis of eye movements involves examining each eye in 9 different gaze directions.
Three-Dimensional Vision Test
A three-dimensional vision test can be applied when infants' speech skills are developing. This test can detect the presence of strabismus. For the test, glasses with red-green lenses and special cards are used.
Cover Test
Changes that occur if vision with one eye is disrupted by covering it are examined. Subsequently, the covered eye is uncovered, and if there is movement in this eye, an assessment is made.
Frequently Asked Questions
When does pseudostrabismus in infants completely resolve?
Pseudostrabismus may improve as infants' facial structure develops. It begins to lose its prominence between 6 to 12 months and most children experience complete resolution around the age of 2–3 years. However, if the deviation becomes more pronounced or appears permanent, an eye examination is definitely necessary.
Does pseudostrabismus cause amblyopia?
No, pseudostrabismus is purely an appearance and does not cause amblyopia by itself. However, in true strabismus, the risk of developing amblyopia is higher. Therefore, a doctor's examination is crucial in every situation.
What causes pseudostrabismus in adults?
Pseudostrabismus is rarely seen in adults. It can mostly occur due to the width of the nasal bridge or the shape of the eyelids, creating an impression of eye deviation. If there is suspicion of deviation in adults, the possibility of true strabismus should definitely be investigated.
When does pseudostrabismus resolve?
As the infant grows, the facial structure settles, and the appearance of pseudodeviation resolves. However, specialist evaluation for differential diagnosis is essential.