The Degree of Anisocoria in Pediatric Patients With Horner Syndrome When Compared to Children Without Disease.

PURPOSE: To study the magnitude of anisocoria in pediatric patients using the plusoptiX A08 (plusoptiX GmbH, Nuremberg, Germany) photoscreener as compared to a literature review of pediatric patients with known Horner syndrome to determine if anisocoria alone should raise suspicion for the diagnosis.

METHODS: The medical records of 592 consecutive patients, neonates to 9 years old, were collected and analyzed. All patients had complete ophthalmic examinations that included photoscreening with the plusoptiX A08. Data included age, pupil sizes, and anisocoria. A complete literature search of documented pupillary size in pediatric patients with the diagnosis of Horner syndrome was performed. This was then compared to the normative pediatric pupil data from the study.

RESULTS: Of the 592 children without Horner syndrome, 372 had an anisocoria of 0.1 to 0.5 mm (62.84%), 167 had an anisocoria of 0.6 to 1.2 mm (28.16%), and 21 had an anisocoria of 1.3 mm or greater (3.70%). There was no correlation between increasing age and severity of anisocoria (P = .55). For pediatric patients with a diagnosis of Horner syndrome, the average level of anisocoria was 1.37 mm in room light and 2 mm in darkness. In room light, three children had anisocoria of 0.1 to 0.5 mm (9.4%), 14 had anisocoria of 0.6 to 1.2 mm (43.8%), and 15 had anisocoria of 1.3 mm or greater (46.9%). In darkness, the level of anisocoria increased in 19 patients, causing the first category, 0.1 to 0.5 mm, to include 1 patient (3.1%), the second group to include 5 patients (15.6%), and the last group to include 26 patients (81.3%). Other associated signs/symptoms included ptosis (100%), heterochromia (28.1%), anhidrosis (9.4%), straight hair on affected/curly on unaffected side (9.4%), and neck mass (6.3%). In 37.5% of cases, imaging results were negative and no specific etiology was determined.

CONCLUSIONS: In a study of 592 children without Horner syndrome, the average pupillary size increased with age, but the degree of anisocoria remained stable with increasing age. Over half of the children studied had anisocoria up to 0.5 mm (62.84%), but rarely had anisocoria greater than 1.3 mm (3.70%). In children with a diagnosis of Horner syndrome, the majority had anisocoria greater than 1.3 mm, with the discrepancy in pupil size becoming more apparent in low levels of light intensity. Anisocoria greater than 1.3 mm is unlikely to be physiologic in a child; therefore, he or she should be carefully evaluated for other localizing signs, such as ptosis, anhidrosis, and neck mass. [J Pediatr Ophthalmol Strabismus. 2016;53(3):186-189.].