Assessment of Sleep Apnea in NAION Patients

Abstract

Purpose: : To measure and compare parameters of obstructive sleep apnea (OSA) in NAION patients and in controls (non-NAION) using in-home sleep studies.

Methods: : 9 NAION patients (7 males, 2 females, mean age 59) and 4 controls (4 females, mean age 51) were recruited, given a history form and sleep log, instructed on the usage of the Apnea Risk Evaluation System Unicorder (Advanced Brain Monitoring, Inc, Carlsbad, CA), and sent home to acquire 2-3 nights of sleep study data. Each night, the Unicorder provided continuous 7 hour recordings of oxyhemoglobin saturation and pulse rate (reflectance pulse oximeter), snoring (microphone), head movement and position (accelerometers), nasal airflow (nasal pressure transducer), and respiratory effort by forehead venous pressure. Questionnaire and Unicorder data were masked and submitted for automated analysis with quality control review. An apnea hypopnea index with 4% desaturation (AHI-4%) and AHI with 1% desaturation (AHI-1%) were calculated.

Results: : Using AHI-4%, 4/9 NAION patients (44%) had AHI > 5 and 2/9 (22%) had AHI > 15. Using AHI-1%, all NAION patients (100%) had AHI > 5, and 6/9 (67%) had AHI > 15. Of the non-NAION controls, three had AHI-4% ≤ 5 and 1 had AHI-4% = 6. Applying the AHI-1% criteria, three had AHI > 5, however none had AHI-1% > 15. Using either the 4% desaturation or 1% desaturation criteria, the distribution of AHI values were greater in the NAION patients as compared to the non-NAION controls.

Conclusions: : The results support previous reports of an increased prevalence of OSA in NAION patients. The Unicorder may be used in the home setting to measure parameters of OSA in NAION patients.

Keywords: neuro-ophthalmology: optic nerve • clinical (human) or epidemiologic studies: prevalence/incidence