pupillary reactions. Although anesthetic agents and psychiatric drugs have also been found to affect pupillary reaction, 9, 13 these treatments did not affect the results in our previous report 9. Debra Rose Wilson, Ph.D., MSN, R.N., IBCLC, AHN-BC, CHT, What You Should Know About Diabetes and Eye Exams, Everything You Should Know About Cholesterol Deposits in Your Eye, an overactive ciliary muscle, located in the middle layer of your eye. Some examples of conditions that cause differently sized pupils include: If your pupils aren’t responding to light or moving objects, it could indicate: Keep in mind that the results of a pupil exam usually aren’t enough to diagnose any condition. When we are assessing the patient’s pupils, we are gaining information regarding the brain and also if there has been an increase in intracranial pressure. Each eye should be checked sepa-rately. There are 25% of normal people born with uneven pupils. The diagnosis can be easily made on slit-lamp examination: an acute episode will show ciliary injection, endothelial dusting, aqueous cells, anterior vitreous cells and in severe cases hypopyon and posterior synechiae. Horner’s syndrome can be confirmed with the cocaine test. 1. When light reaches a pupil there should be a normal direct and consensual response. Pupil size is a result of the interplay between the sympathetic and parasympathetic nervous system supplying the intrinsic muscles within the iris, the dilator and sphincter pupillae respectively. Reactivity is assessed by shining a low-beam flashlight inward from the outer canthus of each eye. The iris may be transiently compressed against the anterior surface of the lens by severe anteroposterior force, with resultant imprinting of the pigment from the pupillary margin. Clinical Assessment. sierra_ruiz9. They’ll move it toward you, away from you, and from side to side. 9 Gayfield Square, Edinburgh EH1 3NT, UK. Thus the largest pupil in the light or the smallest pupil in the dark should be the prime suspect in determining which is the abnormal pupil. You can confirm that the lesion is in the efferent pathway by shining light into that eye and noting that the pupil does not constrict but the consensual light reflex in the contralateral pupil is intact. Any kind of trauma causing damage to the iris sphincter may result in traumatic mydriasis, which can be temporary or permanent – the pupil will react sluggishly or not at all to light or accommodation but the consensual reflex in the other eye will be present. Repeat action noting the reaction of pupil the light is . First, the range of “normal” pupil sizes, or, more accurately, what the average is. The pre-ganglionic neuron emerges from the first thoracic ventral nerve root to enter the paravetebral sympathetic chain, which runs up to the superior cervical ganglion. A patient with this condition will need to be referred immediately to the ophthalmologist. Examination of the pupils and pupillary reflexes are crucial in obtaining an accurate diagnosis of an ophthalmological problem and many other systemic conditions. In evaluating pupil size, the clinician shines a handheld light obliquely from below the nose for indirect illumination and a clear view of the pupils in both darkness and room light. A complete third nerve palsy is evidenced by a fully dilated pupil, fully abducted ‘down and out’ eye, complete ptosis and no constriction to either light or accommodation. In practice it is near impossible to get hold of cocaine so a handy alternative is the ‘iopidine test’ using apraclonidine, a weak adrenergic agonist that reverses the anisocoria caused by Horner syndrome through denervation hypersensitivity . Assessing pupillary response. Anisocoria is an inequality in the size of the pupils. Pupil light reactivity is evaluated by shining a light into a patient's eye to make the pupil constrict in … Normal pupils are of the same size bilaterally, about 2 to 6 mm and round (see Visualizing pupil size). The pupils are assessed for their size and shape, as well as how they react to the presence of light. PERRLA is an acronym used to document a common pupillary response test. The efferent limb passes from the occipital lobe to the midbrain, where some fibres activate the Edinger-Westphal nucleus as well as the vergence cells in the reticular formation. the reaction of one pupil to light Testing of the consensual light response in healthy eyes is possible because: if one pupil reacts to light, the other reacts with it. This assessment is part of the nursing head-to-toe- assessment you have to perform in nursing school and on the job. Most pupils in brain death are nonreactive and midposition. It is due to damage of the post-ganglionic fibres of the parasympathetic pathway. Ocular effects of apraclonidine in Horner syndrome. See also separate Examination of the Eye article. The sympathetic pathway starts with the central neuron in the posterior hypothalamus which as it descends is joined in the pons and medulla by the ipsilateral fibres descending from the reticular formation. In Horner’s syndrome, there is a deficiency of norepinephrine at the synapse resulting in a poor dilation of the affected pupil. Morales J, Brown SM, Abdul-Rahim AS, Crosson CE. How to check the pupil reflexes response for direct and consensual responses and accommodation using a pen light. Flashcards. You may have heard your eye doctor mention “PERRLA” when discussing testing your pupils. The Pupillary Pupil Size Normal and Assessment In pupil response test, it is important to know the size of your pupil and what it reveals according to the size. All rights reserved. A post-cocaine anisocoria of greater than 0.8mm confirms a Horner’s pupil on the side of the smaller pupil. This pathway results in the direct and indirect light reflex as the input to one optic nerve reaches both Edinger-Westphal nuclei.