What would the nurse expect to observe in a patient who has anisocoria?

Anisocoria is a clinical condition characterized by a difference in pupillary diameter exceeding 0.4 mm. It results from an imbalance in the autonomic innervation between the sympathetic and parasympathetic pathways. While potentially physiological, it may signify life-threatening intracranial hypertension or oculomotor nerve compression. The nurse must assess light reactivity to differentiate etiology. A. Dilated pupils: Bilateral dilation, known as mydriasis, typically results from sympathomimetic drugs, anticholinergic toxicity, or brainstem death. While one pupil may be dilated in anisocoria, the term specifically refers to the inequality between the two pupils rather than the absolute state of dilation in both. B. Pupils of unequal size: This is the hallmark observation of anisocoria. The nurse observes that one pupil is visibly larger or smaller than the other under the same lighting conditions. This finding requires further investigation to determine if the inequality is constant or changes with varying ambient light levels. C. Excessive tearing: Known as epiphora, this usually indicates nasolacrimal duct obstruction, corneal irritation, or ocular surface inflammation. It is a secretory and drainage issue of the lacrimal system. It has no direct pathophysiological relationship to the neurological control of pupillary size or anisocoria. D. Uneven curvature of the lens: This describes astigmatism, a refractive error where light does not focus evenly on the retina. It is a structural defect of the crystalline lens or cornea. It affects visual acuity but does not alter the physical size or symmetry of the pupils.