Abstract
Purpose: :
To investigate irregularities in OCT imaging due to eye movements during the scanning process.
Methods: :
A fundus enhancement system (FES) was established to improve retinal image quality in a conventional OCT device (Zeiss Stratus OCT) and to record the scanning process. The specially designed software allows slow motion replay of a fundus image video, recorded during OCT–scan acquisition. A horizontal and a vertical single line scan of 5mm length through the center of fixation were obtained in 40 eyes of 20 normal healthy subjects, all with a visual acuity of 20/20. Scans were investigated for motion during the scanning process.
Outcome measures: Presence/absence of eye movements during scanning process. Mean deviation from intended scan position in millimeter.
Results: :
7 of 20 patients showed no eye movements in both eyes. 4 of the remaining 13 patients showed eye movements only in one eye. In the eyes with detectable movements, the mean deviation from the intended scan position was 0,2 mm in the horizontal and 0,28 mm in the vertical scans.
Conclusions: :
Minimal eye movements during OCT scanning are undetectable by conventional OCT systems but can be made visible by the use of an enhancement system. Minimal eye movements appear in a majority of eyes with normal visual acuity and seemingly stable fixation. The artifacts produced by these eye movements are probably neglectible in eyes with normal VA, but their presence warrants further investigation of the phenomenon in eyes with retinal pathologies.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • eye movements: recording techniques • imaging/image analysis: clinical