Doll’s Eye Reflexes: Principle, Cause, Procedure

This post on Doll’s Eye Reflexes topics are related to its causes, principle, positive and negative doll’s eye reflex or OCD reflex, and step by step procedure, and a case study.

This post has a FAQ section which further enriches your knowledge on doll’s eye reflexes. You can also check our MCQ section in various subfield in forensic science and our Higher Order Thinking Question (HOTs) Section

What are Doll’s Eye Reflexes?

It is an eye’s reflex movement test, to estimating the brain functioning in comatose or servery lethargic patients.

The word “doll’s eye” somehow can be correlated to toy dolls which have mechanical eye function i.e. even with the movement of their head, their eyes where fixed at a position and seems to move opposite to the direction of head movement.


Why doll’s eye is performed?

As stated earlier, the doll’s eye reflex test is performed to test the test brain stem function in comatose or servery lethargic patients.

Or in other words, it is the simple test to indicate brain death condition of a person.


What is the principle of Doll’s eye reflexes test?

Doll’s eye reflex test is based on the oculo-cephalic reflex phenomenon (OCR) comatose patients and young infants.

The OCR is controlled by the brainstem, which receives signals from the vestibular nerve and transmits signals to the oculomotor nerve.

Note 1: Oculo-Cephalic Reflex: It is a reflex that stabilizes the image on the retina during head movement by producing eye movement opposite to the head movement.

The nerves that responsible for these reflexes are oculomotor nerves and the 8th nerve. In conscious alert adults, the OCR is always present but are automatically suppressed.

So, if the patient has intact brain stem, it means that oculomotor nerves and 8th nerves are functioning which finally responsible for dolly’s eye reflexes generally termed as positive/ normal doll’s reflexes.

And if the mid-obits of eye stay fixed, then it is the indication of serve brain damage or brain death which called as a negative doll’s eye.

Note 2: There is another term called Vertibuloocular Reflex. Oculo- Cephalic Reflex is a form of Vertibuloocular Reflex (VOR), that is responsible to stabilize the vision during head movement.

The VOR does not depend on visual input. It can be elicited by caloric (hot or cold) stimulation of the inner ear, and works even in total darkness or when the eyes are closed.


What causes the Doll’s eye reflexes and its interpretation?

In order to stabilize the visual world on the retina, the eyes show dolly’s eye phenomenon in comatose person.

There are basically three types of reflexes arc involved in the maintenance of a stable visual field includes:
1. Extraretinal signals of head motion
2. Retinal signals
3. Neuro control of stabilization reflexes

1. Extraretinal signals of head motion:

It is a type of Non-visual signals used by the CNS to encode the position of the eyes in orbits.

2. Retinal Signals:

Due to the head rotation, retinal image motion of the visual field also tries to maintain the retinal point image.

3. Neuro control of stabilization reflexes:

The three semi-circular canals converting the head motion signals into a neural stimulus that trigger the doll’s eye reflex or vestibulo–ocular reflex.


What are Positive/ Normal and Negative doll’s eyes reflexes?

In a positive or normal doll’s eyes reflex, the eyes move in the counter direction to the head movement due to the presence of extraretinal signals of head motion, retinal signals and neuro control of stabilization reflexes.

While negative doll’s eye reflex means that the eyes don’t show any counter-measures to the head movement, and the motor functionality of oculomotor nerves and 8th nerves get disturbed, which indicates a brain dead person.


Causes for a Negative Doll’s Eye Reflex

In the case where the doll’s eye reflexes are absent then there may be due to one or more lesions in the following pathways:

  1. The vestibular nerve and labyrinth
  2. The neck proprioceptors
  3. Cranial nerves 3 and 6
  4. The external ocular muscles

Other regions that can cause difficulty in assessing Doll’s Eye Reflex:
1. Orbital Edema: Impairing ability of the examiner to open eyes
2. Conjunctival Edema: Impairing ability of the eyes to move appropriately.

Note 3: False-Positive Doll’s eye reflexes:
There might be a false-positive dolls eye reflexes. This majorly due to the influence of some medication like anesthesia.


How do you asses the doll’s eyes? Neuro Assessment (Procedure)

There are basically 6 steps involved in the doll’s eye neuro assessment test for obtaining maximum stimulation and result:

  1. Assess the conscious level of Patient:

    Before starting for manoeuvre the patient current position is thoroughly assessed.

  2. Placing the patient in the supine position:

    The patient must be placed in a supine position. And head should be elevated at least 30° to minimize any intracranial pressure while assessing the eye’s movement of the patient.

  3. Hold the eyelids:

    Try to hold the eyelids with thumb and index finger of one hand.

  4. Rotate the head Head in a single direction and observe:

    Gently rotate the head to one direction. The eyes should move in the counter direction. This deviation should be smooth and conjugate.
    The head should be kept steady for a while and the eyes should slowly return to the midline.

  5. Rotate the head to another side:

    Again gently rotate the head to another direction and hold the position for few seconds. Again the counter-movement of eyes and slowly return to midline clarify that patient have intact brainstem.

  6. Switch to Up-side movement of the head:

    Tilting the head down results in the opening of eyelids and also counter-movement of eyes also seen, which generally termed as the doll’s head phenomenon.

Video by OPENPediatrics

Things to avoiding while performing doll’s eye reflex test

1. Never perform this test on a normal and alert person.
2. Never perform the doll’s eye reflex test if a patient has a cervical spine fracture or injury.


Doll’s Eye Reflexes in Newborns

Literature Review

The OCR can be seen only in comatose patients and in young normal infants. In the unconscious adult with a head injury, it serves as a measure to identify the integrity of the brain-stem or vestibular system.

And in case of the developing infant, the visible doll’s eye reflexes first develops a normal eye-righting phenomenon before the OCR suppressed.

As state earlier, the doll’s OCR reflexes are controlled by the brainstem, which receives and transmits signals from the vestibular to oculomotor nerve respectively. And in conscious alert adults, the OCR is always present but are automatically suppressed.

Two major outcomes of the study

  1. OCR Suppressed period: In the case of the growing infant, study show that these doll’s eye reflexes automatically get suppressed in a period of about 11.5–20 weeks.
  2. Growth Pathway: Another major part of this study is, in newborn baby, there is initially a considerable lag between the head and eye movements.
    But as the baby grows and matures, the eyes are able to adjust more rapidly to the action of head movement.

Note 4: What if OCR reflexes never suppressed?
If these reflexes never get suppressed then it may result in impaired movement of eyes to the head movement. Then the individuals would be unable to turn their head to see something located outside their center field of vision.

So, after the period of 20 weeks, an infant can properly look at the object that is out of central field of vision by turning the eyes towards the side of the head rotation while maintaining the alignment with the macula.

Note 5: Macula; It is the central area of the retina and it gives us the ability to see “20/20” and provides the best color vision.

The bottom line of the study on Doll’s eye reflexes in infants

The process of suppression of the OCR in healthy growing infants is longitudinal and is part of the normal maturation of the visual system.

In infants, the doll’s eye reflexes are commonly suppressed by age 11.5–20 week.


Frequently asked questions (FAQ)

Q1. Why doll’s eye reflexes are performed?

To test the test brain stem’s functionality in comatose or servery lethargic patients. It can be the indication of brain death condition of a person.

Q2. Which nerves are responsible for dolls reflexes?

Oculomotor nerves and the 8th nerve.

Q3. What if the doll’s eye reflex an infant doesn’t stop or suppressed?

If the doll’s reflexes or OCD doesn’t suppressed then the individuals would be unable to turn their head to see something located outside their center field of vision.

Q4. What is the doll’s head phenomenon?

When the head is tilted down results in the opening of eyelids in the counter direction which generally termed as the doll’s head phenomenon.

Q5. How a dolly’s eye reflex has a false-positive result?

In case of medication like anesthesia.


References:

  • S. Simakurthy, K. Tripathy. (updated 2019). Oculovestibular Reflex [PubMed]
  • Khan S, Chang R. Anatomy of the vestibular system: a review. NeuroRehabilitation. 2013; [PubMed]
  • Sole ML, et al. Introduction to Critical Care Nursing, 4th edition. W.B. Saunders Co., 2005
  • Checking for oculocephalic reflex: Nursing2019. (n.d.). Retrieved from [URL]
  • Snir, M., et.al. (2010). Suppression of the Oculocephalic Reflex (Doll’s Eyes Phenomenon) in Normal Full-Term Babies.[PubMed]