Abstract
Purpose:
To examine the morphologic features of parapapillary atrophy by using enhanced depth imaging optical coherence tomography (EDI-OCT) and color fundus photographs.
Methods:
The clinical observational comparative study included 80 normal eyes of 46 subjects and 80 eyes of 46 patients with primary open-angle glaucoma. Both groups did not vary significantly in axial length (P=0.19) and refractive error (P=0.22). Color fundus photographs and horizontal cross-sectional B-scan images obtained by EDI-OCT were examined. On the EDI-OCT images, we measured a gamma zone defined as the region between the temporal disc margin to the beginning of Bruch's membrane, and a beta zone defined as Bruch's membrane without retinal pigment epithelium.
Results:
Gamma zone (mean area: 1.09±1.83 mm2) was significantly associated with longer axial length (P<0.001; standardized coefficient beta: 0.59), longer vertical disc diameter (P<0.001; beta: 0.32), older age (P<0.001; beta: 0.22), and absence of glaucoma (P=0.003; beta: -0.20). Beta zone (mean area: 0.83±0.59 mm2) was associated with longer axial length (P<0.001; beta: 0.29), longer vertical disc diameter (P=0.002; beta: 0.24), older age (P=0.01; beta: 0.19), and presence of glaucoma (P<0.001; beta: 0.34).
Conclusions:
In addition to associations with older age, increasing myopia and larger disc size, EDI-OCT defined gamma zone of parapapillary atrophy was associated with absence of glaucoma, while EDI-OCT defined beta zone was associated with the presence of glaucoma. Differentiation between both beta zone and gamma zone may clinically be useful.
Keywords: 550 imaging/image analysis: clinical •
627 optic disc