Abstract
Purpose:
To determine the prevalence of different types of spectral domain optical coherence tomography (SD-OCT) scan artifacts for four different types of open angle glaucoma (OAG): primary OAG (POAG), normal tension glaucoma (NTG), pseudoexfoliation glaucoma (PXG), and pigmentary glaucoma (PDG), and compare with normal controls.
Methods:
SD-OCT (Heidelberg Engineering, Heidelberg, Germany) retinal nerve fiber layer (RNFL) scan printouts were evaluated for three patterns of artifacts: 1) algorithm failure: misidentification of the RNFL borders, 2) poor signal, or signal strength <15 dBm, 3) scan de-centration. The prevalence of each type of artifacts was determined for four subtypes of OAG and for normal patients.
Results:
The study population consisted of 256 eyes of 256 patients: 91 patients with OAG, 28 with NTG, 45 with PXG, 12 with PDG, and 80 without glaucoma. The prevalence of good scans was 49.21% (n=126), algorithm failure was 21.87% (n=56), de-centration was 7.03% (n=18), and poor signal was 13.28% (n=34). For scans with two types of artifacts, we could detect combined algorithm failure and poor signal in 7.03% (n=18), algorithm failure and de-centration in 0.39% (n=1), and poor signal and de-centration in 0.39% (n=1). Two eyes (0.78%) had three types of artifacts. There were no significant differences in the prevalence of artifacts between different subtypes of OAG and normal eyes. (p >0.05 )
Conclusions:
This study reveals that the prevalence of SD-OCT artifacts is high, with the algorithm failure being the most common artifact. There were no significant differences in the prevalence of artifacts among all studied subtypes of OAG.
Keywords: 550 imaging/image analysis: clinical