Cross-sectional anatomic configurations of peripapillary atrophy evaluated with spectral domain-optical coherence tomography

Abstract

Purpose: To evaluate the cross-sectional configurations of peripapillary atrophy (PPA)-alpha and -beta in ophthalmologically normal subjects using spectral domain-optical coherence tomography (SD-OCT).

Methods: One hundred twenty normal subjects had a complete ophthalmic examination including axial length measurement, standard automated perimetry, fundus imaging with photography, and SD-OCT (3D OCT-1000; Topcon Inc., Tokyo, Japan). PPA-alpha and -beta were identified in color photographs of the optic disc. Cross-sectional B-mode images of the peripapillary retina and sclera, including PPA-alpha and -beta obtained with SD-OCT, were analyzed.

Results: Of 120 normal eyes, 120 (100%) had PPA-alpha and 90 (75%) had PPA-beta. In OCT images of the peripapillary retina, the ganglion cell layer and the inner and outer plexiform layers were observed to end in a tapering fashion at the edge of the optic disc, whereas the retinal nerve fiber layer continued into the optic cup. The external limiting membrane (ELM), inner-outer segments (IS-OS), and retinal pigment epithelium(RPE)/Bruch's membrane complex were significantly more commonly absent before the optic disc edge within the PPA-beta compared with areas outside the PPA-beta (P < 0.0001). Specific findings in the peripapillary area including slope and step configurations of the scleral bed and hump- and wedge-shaped appearances of the RPE-Bruch's membrane complex were identified in 63 (52.5%), 6 (5.0%), 19 (15.8%), and 6 (5.0%) of 120 eyes, respectively. The presence of the step configuration was associated with myopia and longer axial length (P = 0.0014 and 0.0105, respectively).

Conclusions: The cross-sectional anatomic configurations of the peripapillary atrophy were evaluated by using SD-OCT. The termination of the retinal layers and configurations of the scleral bed in the peripapillary area varied among normal subjects.