Radial peripapillary capillary density in superior segmental optic hypoplasia measured with OCT angiography.

Abstract Background: To investigate the diagnostic power of radial peripapillary capillary (RPC) density, measured with optical coherence tomography angiography (OCT-A), in patients with superior segmental optic hypoplasia (SSOH), a disease which is important to differentiate from glaucoma. Methods: Forty subjects with SSOH and 40 age- and axial length-matched control subjects were retrospectively registered for this study. SSOH was defined as intraocular pressure (IOP) less than 21 mmHg with the presence of two of the following: superior rim thinning, superior entrance of the central retinal artery, scleral halo, and pale optic disc; as well as non-progressive visual field loss. RPC density was measured with swept-source OCT-A (Triton, Topcon) in the overall, quadrants, and 12 clock-wise sectors. RPC density was compared in normal and SSOH subjects with Welch’s t-test. Diagnostic power was assessed with the area under the receiver operating characteristics curve. Results: Overall cpRNFLT was significantly different in the normal (106.7 ± 9.5 μm) and SSOH (77.2 ± 13.7 μm, p < 0.001) subjects. RPC density in the overall area (p < 0.001) and superior (p < 0.001), nasal (p < 0.001), and inferior (p < 0.001) quadrants was significantly lower in the SSOH group, but not in the temporal (p = 0.756) quadrant. The diagnostic power of RPC density was highest in the superior quadrant (AUC = 0.928) and the 1 o’clock sector (0.896). Conclusions: Low RPC density was found in the three non-temporal quadrants of the optic nerve head. Measuring RPC density with OCT-A may help the diagnosis of SSOH and may improve the management of glaucoma.