Automated Detection of Optic Disc Margin in HRT II– Images

Abstract

 

Abstract:

 

To evaluate HRT II– parameters calculated upon a manual and automated contour line drawing in HRT II–reflectivity images.

 

108 optic disc images were acquired with the scanning laser tomography (HRT II, Heidelberg Engineering). Four experienced HRT II specialists and an automated algorithm defined in each image the contour line of the optic disc margin. The automated algorithm was based on a pattern recognition algorithm performing morphological operations and detection of anatomical structures (Chrastek et al., Methods Inf. Med. 2004; 43: 336–42). All morphological optic disc parameters were calculated (HRT II, version 1.4.1.0). The mean of each HRT II–parameter defined by the 4 glaucoma experts served as control. Correlations between the manually and automatically found HRT II–parameters were calculated. Statistical analysis was performed by the paired T–Test (SPSS 11.0 version).

 

All major HRT II– parameters defined by glaucoma experts correlated significantly with the HRT II parameters found by the automated procedure. The table depicts the R– and p–values. The 3^rd moment showed the strongest correlation.

 

 

^{An automated procedure to find the disc margin in HRT II– images gave similar morphological values as the mean of 4 experienced glaucoma specialists.}

 

 

Keywords: imaging/image analysis: clinical • optic disc • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)