The role of trancranial Doppler in nonarteritic ichemic optic neuropathy Original Reearch Article

PURPOE: To invetigate through the ue of cerebral Doppler technology whether emboli are a more common caue of nonarteritic anterior ichemic optic neuropathy (NAION) than previouly recognized. METHOD: Eleven patient with a recent (<121 day) hitory of nonarteritic anterior ichemic optic neuropathy and 10 age-matched control (event >121 day) were examined uing a Nicolet Pioneer 2020 trancranial Doppler (TCD) unit with a 2-MHz bilateral continuou monitoring capability. The right and left middle cerebral arterie were evaluated imultaneouly for 30 minute at a depth of 50 to 55 mm, and the number of emboli, blood flow velocitie, and pulatility indice were recorded. Data were tored by computer, and hard-copy color recording were made. REULT: None of 11 patient with a recent hitory of NAION demontrated microemboli by TCD examination. One patient in the control group who had a remote hitory of NAION had a microembolic event rate of 12 per hour (ix over 30 minute). Thi patient had a hitory of prothetic cardiac valve replacement and wa taking anticoagulation medication at the time of the examination. CONCLUION: Our tudy did not reveal an increaed incidence of embolic event in patient with NAION when they were examined in a trancranial Doppler tudy of the middle cerebral arterie. Thi tudy doe not upport embolim a a frequent caue of NAION.