Abstract
Purpose: :
To determine the ability of ganglion cell-internal plexiform (GCIP) layer thickness measured with Cirrus HD-OCT to differentiate normal and glaucomatous eyes.
Methods: :
Fifty glaucomatous patients and 95 age-matched normal subjects were included in this study. For each patient, one randomly selected eye was scanned using the Macular Cube 200x200 protocol. The Cirrus OCT ganglion cell segmentation algorithm was used to detect the GCIP layer and measure automatically the thickness of the overall GCIP average, the minimum GCIP, and the average thicknesses of GCIP in supero-temporal, superior, supero-nasal, infero-nasal, inferior, infero-temporal sectors. Unlike the ganglion cell complex algorithm, this GCIP algorithm only includes the RGCs and the IPL into the measurements. Receiver operating characteristics (ROC) curves were used to assess the ability of each parameter to discriminate between normal eyes and glaucomatous eyes irrespective of disease severity, between normal eyes and eyes with mild glaucoma, and between normal eyes and eyes with moderate to severe glaucoma. The diagnostic performance of each parameter was assessed by reporting the area under receiver operating characteristics (AUC).
Results: :
The best discriminants between normal eyes and glaucomatous eyes irrespective of disease severity were GCIP thickness of the infero-temporal sector (AUC = 0.975), minimum GCIP thickness (0.961), GCIP thickness of the inferior sector (0.956), overall average GCIP thickness (0.937), and GCIP thickness of the supero-temporal sector (0.935). To differentiate normal eyes and those with mild glaucoma, GCIP thickness of the infero-temporal (AUC = 0.976) sector was the best parameter, followed by GCIP thickness of the inferior sector (0.952), minimum GCIP thickness (0.948), and overall average GCIP thickness (0.916). All parameters had excellent ability to differentiate normal eyes from eyes with moderate to severe glaucoma (range: 0.916-0.975), except for GCIP thickness for the supero-nasal sector (0.851).
Conclusions: :
GCIP layer thickness measurements obtained with Cirrus HD-OCT showed excellent ability to discriminate between normal and glaucomatous eyes.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • ganglion cells