VASCULAR PERFUSION DENSITY MAPPING USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY COMPARING NORMAL AND OPTIC DISK PIT EYES
Shangjun Jiang1, Bryen Turco2, Netan Choudhry3,4
1Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Purpose:
Optic disk pits (ODPs) are typically detected incidentally as small, gray, unilateral, oval-shaped excavation in the temporal optic disk on routine fundus examination. In this cross-sectional retrospective case series, we report optical coherence tomography angiography findings in patients with unilateral ODPs and describe changes in vessel perfusion associated with ODP.
Methods:
A total of eight eyes (four with ODP and four normal contralateral) were included in this study. Patients were excluded if any other optic disk abnormalities were present. Spectral-domain optical coherence tomography angiography (AngioVue; Optovue, Fremont, CA) imaging was conducted to map the vascularization of three layers in the optic nerve over a 4.5-mm × 4.5-mm region. The radial peripapillary capillaries, the nerve head capillaries, and the choriocapillaris were automatically segmented based on the OCT system software, and the capillary perfusion density (CPD) was quantified for each layer. Kruskal-Wallis one-way analysis of variance was used to compare CPD in normal and ODP eyes of four patients with monocular ODP.
Results:
Overall, CPD was lower in eyes with ODP compared with the contralateral normal eye in the radial peripapillary capillary (0.4521 ± 0.08 vs. 0.5505 ± 0.03, P = 0.08) and nerve head capillary layers (0.5461 ± 0.08 vs. 0.5989 ± 0.01, P = 0.08). Significantly lower CPD values were associated with ODP eyes in the radial peripapillary capillary layer within the disk (P = 0.04), inferior nasal (P = 0.04), and temporal (P = 0.02) regions and in the nerve head vessel layer within the disk region (P = 0.04). Significantly higher CPD values were associated with ODP eyes in the choriocapillaris layer within the nasal (P = 0.02), superior temporal (P = 0.02), and inferior temporal (P = 0.02) regions. Visual acuity was also decreased in ODP eyes at 0.4 ± 0.3 logarithm of the minimum angle of resolution units (20/50) compared with normal eyes at 0.1 ± 0.1 logarithm of the minimum angle of resolution units (20/25) (P = 0.12).
Conclusion:
This study demonstrated that the presence of an ODP is associated with decreased vascular density in some regions of the optic disk and reduced visual acuity.
