Retinal vessel structure measurement using spectral-domain optical coherence tomography

Abstract

Purpose To assess the reliability and validity of spectral-domain optical coherence tomography (SD-OCT) measurements of retinal vessel lumen diameters and wall thicknesses. Methods SD-OCT was used to characterize the circular region around the optic disc of 40 eyes (20 subjects). The inner and outer sides (vitreal and choroidal sides) of the vessel wall and the luminal diameter were measured using intensity graphs. Results Mean arterial and venous luminal diameters were 95.1 ± 16.1 and 132.6 ± 17.8 μm, respectively. The wall thicknesses of inner and outer sides of the artery were 23.9 ± 4.9 and 21.2 ± 3.5 μm, respectively. The wall thicknesses of the inner and outer sides of the vein were 20.7 ± 4.2 and 16.3 ± 4.3 μm, respectively. There were significant differences between the inner and outer wall thicknesses in both the artery and vein (Po0.01). Intra-and interobserver intraclass correlation coefficients (ICCs) for lumen measurements were 40.95, and for wall thicknesses were 40.85, except for the outer wall thickness measurements. The mean value of outer and inner wall thicknesses showed good reproducibility, with ICCs of 40.85. Conclusion Intensity graph-assisted measurements using SD-OCT provided more objective information in finding boundaries of vessels. Luminal diameters and wall thicknesses obtained with OCT showed good overall reproducibility, with inner wall thicknesses being thicker, and with better reproducibility compared with outer wall thicknesses, where ICC values were the lowest among the inner wall thicknesses, mean thicknesses of inner and outer walls, and luminal diameters. When using SD-OCT measurements, caution is therefore advised when using only the outer wall as representative of the wall thicknesses.

Plane-Wave Ultrasound Doppler of the Eye in Preeclampsia

“…The lumens of the CRA, SPCA and CRV have been variously reported to range from about 0.1 to 0.2 mm. 36 , 37 Volumetric flow is determined by the pressure gradient between vessel input and outlet divided by resistance, which according to the Poiseuille equation, varies inversely with the fourth power of lumen diameter. Hence, a small change in diameter will result in a large change in flow.…”

Detection of retinal blood vessel changes in multiple sclerosis with optical coherence tomography

“…We discarded all automatically segmented blood vessels that were 2 pixels or less in size (less than 12 µm in diameter) from the analysis, which could erroneously have appeared due to image noise. Similar methodologies for measuring retinal blood vessels from OCT scans have been shown to be reliable and reproducible [28,34]. The inner and outer nerve fiber layer boundaries (INFL and ONFL, respectively) in the same OCT images were also segmented using the same software, initially automatically, and then occasionally corrected manually for any anomalies.…”

“…There is a single report of a decrease in relative blood flow to the optic nerve head in MS eyes, measured using OCT angiography [25]. However, this technique is not yet widely available in the clinical setting, compared to quantitative static retinal blood vessel metrics which can be extracted from OCT scans that are acquired using currently available clinical instrumentation [26][27][28]. We sought to investigate quantitative retinal blood vessel metrics as a marker of MS using a cross sectional study of retinal blood vessel diameters in individuals with and without MS, and with and without a history of ON.…”

Methods of evaluation of microvascular structure: state of the art

“…Intensity graph-assisted measurements using spectral-domain optical coherence tomography (OCT) may provide objective measurements of retinal vessels lumen diameters and wall thicknesses [60]. In a previous report, OCT has been proposed for the investigation of retinal vessels: Schuster et colleagues [61] have demonstrated a relationship between mean arterial blood pressure and OCT-based AVR.…”