How Pupil Evaluation Can Help the Diagnosis of Brain Injuries?

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Many people underestimate the intelligence of the human brain. According to common perception, the only part of a person's brain visible from the outside is their eyes. Non-medical people often overlook pupil diagnosis in critical care nursing since it may help cure brain injury or other neurological conditions. Neurological treatment may benefit from four distinct forms of diagnosis covered in this article.

1. Pupillary response in traumatic brain injury

Adverse effects on daily activities, such as changes in cognition, attention, and movement, are common in patients with traumatic brain injury. 

Researchers used an anti-saccade task to examine whether a traumatic brain injury (TBI) affects the time to pay attention to a stimulus. An anti-saccade will be performed to measure pupillary reaction latencies after a visual cue is displayed (i.e., the time necessary for pupils to dilate in response to the allocation of attention).

2. Pupil diameter measurement

The pupil diameter measurement is essential because it may provide crucial diagnostic information in severely ill patients because of variations in pupil size and equality. Each pupil should be the same size and shape. The Glasgow Coma Scale has to be supplemented by examining the patient's pupils, especially if the patient is unconscious.

3. Pupillary light reflex

The pupillary light reflex (PLR), which controls the pupil's diameter in response to the amount of light falling on the retinal ganglion cells at the back of the eye, is one process that enhances the eye's capacity to adapt its vision to changing light and dark circumstances. 

When the light intensity increases, the pupil contracts (constriction velocity), allowing less light in, and when the intensity decreases, the pupil dilates (mydriasis or expansion), allowing more light in. The pupillary light reflex, as a result, controls the quantity of light that penetrates the eye's retina. If the light is just shining in one of your eyes, the patient will see a contraction in both of their pupils.

4. Pupil reactivity

An adult's pupil may be between 2 and 8 millimeters in diameter, even under bright light. As a general rule, the size of the pupil is the same. The eyes constrict to focus on the light and light coming from a different direction (consensual response). During the night, one's pupils dilate. Pupils dilate when one's gaze is fixed on a close object (accommodative response). When it's dark, the pupil should widen; when it's light, it should constrict.