What Causes Anisocoria?

Discussion Anisocoria is a common physical finding caused by the mechanical imbalance of the iris dilator (sympathetic innervation causing dilation) and sphincter muscles (parasympathetic innervation causes miosis). Which pupil is abnormal is important to determine. “Anisocoria greater in the light signifies an abnormal large pupil, whereas anisocoria in the dark indicates an abnormal small pupil.” The pupillary size should be noted along with any changes with accommodation, extra ocular movements and lighting. The time it takes to revert to the baseline pupillary size can also be helpful. Any ptosis, lacrimation and pain should be noted. Evidence of papilledema should be looked for. Additionally, a thorough head and neck examination and neurological examination are important to look for additional diagnostic clues. While a generalist may not be able to interpret all of these signs and symptoms, gathering this information and discussion with an ophthalmologist and/or neurologist can be helpful. Physiologic anisocoria is common with approximately 15-30% of the normal population having this physical finding. “Physiologic anisocoria should be longstanding, neurologically isolated, less than 1 mm in size discrepancy, and stable in light and dark conditions.” Old photographs may be helpful and reassuring. Evaluation for anisocoria may include pharmacologic testing, and imaging of the head and/or neck and potentially other body areas. Learning Point The diff...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news