J Korean Ophthalmol Soc.  2019 Apr;60(4):355-361. 10.3341/jkos.2019.60.4.355.

Measurement of Vessel Density Using Optical Coherence Tomography-angiography in Normal Subjects: Difference by Analysis Area

• Im JC

• KMID: 2443152
• DOI: http://doi.org/10.3341/jkos.2019.60.4.355

Abstract

PURPOSE
To evaluate the vessel density of macula according to analysis area in health subjects using optical coherence tomography angiography (OCTA).
METHODS
We retrospectively analyzed 30 eyes of 20 healthy people who underwent OCTA. We measured vessel density (VD) according to analysis area and foveal avascular zone (FAZ) size of superficial capillary plexus (SCP) and deep capillary plexus (DCP). The analysis areas were classified as 3 × 3 mm scan area (Box), Box area excluding FAZ (Box-FAZ), fovea centered 3 mm circle area (Circle), Circle area excluding FAZ (Circle-FAZ) and area between fovea centered 1 mm circle and 3 mm circle (Ring).
RESULTS
The SCP VDs were Box 34.00 ± 3.97, Box-FAZ 35.37 ± 4.09, Circle 31.70 ± 4.56, Circle-FAZ 33.34 ± 4.72, and Ring 35.22 ± 5.09. The DCP VDs were Box 30.04 ± 3.51, Circle 29.49 ± 3.57, Box-FAZ 31.59 ± 3.65, Circle-FAZ 31.46 ± 3.72, and Ring 32.60 ± 4.00. There was a significant difference according to analysis area from both SCP and DCP (p < 0.001 and p < 0.001, respectively). Comparison of the vessel density between SCP and DCP in the same analysis area were different in all areas (p < 0.001, p = 0.001, p < 0.001, p = 0.005, p = 0.001, respectively).
CONCLUSIONS
This study shows different results according to analysis area when measuring VD using OCTA. Therefore, when comparing studies related to VD, it is necessary to pay attention to the analysis area in the interpretation of the results.

Keyword

Analysis area; Foveal avascular zone; Healthy subjects; Optical coherence tomography angiography; Vessel density

MeSH Terms

Angiography
Capillaries
Healthy Volunteers
Retrospective Studies
Tomography, Optical Coherence

Figure

• 

  Figure 1 Optical coherence tomography angiography analysis areas. (A) Manual drawing of the foveal avascular zone (FAZ) area (gray) and boundary (white dot line). (B) Fovea centered 3 × 3 mm scan (Box). (C) Box area excluding FAZ (Box-FAZ). (D) Fovea centered 3 mm circle area (Circle). (E) Circle area excluding FAZ (Circle-FAZ). (F) Area between foveal centered 1 mm circle and 3 mm circle (Ring).

• 

  Figure 2 Zones divided by distance from the fovea. (A) Fovea centered 1 mm circle area (zone A). (B) Area between fovea centered 1 mm circle and 3 mm circle (zone B). (C) 3 × 3 mm scan area excluding foveal centered 3 mm circle (zone C).

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