Philadelphia, July 16, 2007 – New research suggests that an eyedrop used to diagnose a rare syndrome in infants can cause severe lethargy lasting up to 10 hours and requiring hospital admission and oxygen administration. In the article “Adverse Effects of Apraclonidine Used in the Diagnosis of Horner Syndrome in Infants”, published in the June issue of Journal of AAPOS (Journal of the American Association for Pediatric Ophthalmology and Strabismus), Dr. Patrick Watts and coauthors described five cases of extreme drowsiness or unresponsiveness after infants under 6 months of age were administered 1% apraclonidine eyedrops.