J Korean Ophthalmol Soc.  2019 Jul;60(7):676-684. 10.3341/jkos.2019.60.7.676.

Interocular Symmetry of Optical Coherence Tomography Angiography Parameters in Normal Eyes of Korean Adults

• Park HJ
• Lim HB
• Lee MW
• Jo YJ
• Kim JY

• KMID: 2453019
• DOI: http://doi.org/10.3341/jkos.2019.60.7.676

Abstract

PURPOSE
To evaluate the interocular symmetry of microvascular parameters measured by optical coherence tomography angiography (OCTA) in normal eyes of Korean adults.
METHODS
We retrospectively reviewed the retinal microvascular structure of 91 healthy Korean subjects (182 eyes). We used OCTA to measure the area of the foveal avascular zone (FAZ), vessel density (VD), and perfusion density (PD) in both eyes. Intraclass correlation coefficients (ICCs), coefficients of variation (CVs), and Pearson correlation coefficients were calculated to evaluate the extent of agreement and correlations between binocular OCTA measurements.
RESULTS
Both eyes had similar microvascular characteristics: FAZ area (right eye: 0.31 ± 0.11 mm², left eye: 0.30 ± 0.10 mm², p = 0.98), FAZ perimeter (right eye: 2.35 ± 0.45 mm, left eye: 2.36 ± 0.39 mm, p = 0.86). VD 1-mm center (right eye: 9.42 ± 2.75, left eye: 9.14 ± 2.96, p = 0.163), full area (right eye: 19.94 ± 1.65, left eye: 19.72 ± 1.76, p = 0.285), and PD 1-mm center (right eye: 0.16 ± 0.05, left eye: 0.16 ± 0.05, p = 0.151), full area (right eye: 0.36 ± 0.03, left eye: 0.36 ± 0.04, p = 0.716). All ICC values were above 0.8 and all CVs below 10%.
CONCLUSIONS
The microvascular structure, as represented by the VD, PD, and FAZ area measured via OCTA, was bilaterally symmetric in normal eyes of Korean adults.

Keyword

Foveal avascular zone; Interocular symmetry; Microvascular parameters; Optical coherence tomography angiography

MeSH Terms

Adult*
Angiography*
Humans
Perfusion
Retinaldehyde
Retrospective Studies
Telescopes
Tomography, Optical Coherence*
Retinaldehyde

Figure

• 

  Figure 1 3 × 3 mm optical coherence tomography angiography image centered on the fovea in normal subject. (A) A B-scan showing the superficial capillary plexus between dash lines, (B) a superficial capillary plexus image overlaid with the Early Treatment of Diabetic Retinopathy Study grid. Vessel density measurement in individual subfield is calculated by AngioPlex software ver. 10.0 (Carl Zeiss Meidtec AG, Jena, Germany). (C) Perfusion density measurement in individual subfield is calculated by AngioPlex software. (D) Foveal avascular zone is automatically selected in the superficial capillary plexus and highlighted and its area, perimeter and circularity are quantitatively calculated by AngioPlex software.

• 

  Figure 2 Scatter plots of the right and left eyes in optical coherence tomography angiography parameters. This plot shows interocular symmetry of foveal avascular zone area (A), foveal avascular zone perimeter (B), vessel density of full area (C) and 1 mm center (D), perfusion density of full area (E) and 1 mm center (F). OD = right eye, OS = left eye.

• 

  Figure 3 Histogram showing the distribution of interocular differences (right eye-left eye) in optical coherence tomography (OCT) and OCT angiography parameters. Foveal avascular zone (FAZ) area (A), FAZ perimeter (B), vessel density of full area (C) and 1 mm center (D), perfusion density of full area (E) and 1 mm center (F) of the interocular difference.

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