Abstract
Purpose: :
SDOCT imaging generates high resolution images with retinal thickness reports which are used for diagnosis and guiding treatment in eyes with neovascular AMD (NAMD). We evaluated quality issues in SDOCT images of eyes with NAMD to detect artifacts that lead to center subfield thickness (CSFT) errors.
Methods: :
A retrospective consecutive series of 95 eyes with NAMD requiring SDOCT (Cirrus) imaging for routine clinical care were included in this study. The images were acquired by the 512X128 volume scan protocol. SDOCT scanning was performed by highly experienced technicians certified for obtaining images for multiple clinical trials. The data from each eye was evaluated for artifacts affecting CSFT such as boundary line errors (BLE), scan decentration (SDC), Z offset error, eye movement artifact, and other artifacts. BLE involving > 50% of retinal thickness in at least 5 contiguous B scans were considered significant. SDC was identified when the center of the macula was not located within the central subfield (decentered by at least 500 microns). Software tools were used to correct BLE and SDC to generate corrected CSFT.
Results: :
BLE were present in 76 (80%) of scans of which 18 (23%) were significant. SDC occurred in 9 scans (9.4%). Both SDC and significant BLE were seen in 3 (3%) scans. Mean CSFT change with BLE correction and/or grid re-centration was 66µ; BLE alone 86µ, SDC alone 28µ and both 85µ.
Conclusions: :
Artifacts are frequent in SDOCT scans in NAMD and may result in large variance from the correct measurement. Image quality evaluation is an important step in interpretation of the CSFT in NAMD.
Keywords: age-related macular degeneration • imaging/image analysis: clinical • retina