Multimodality Imaging Approach for Combined Central Retinal Vein and Artery Occlusion: The Role of Optical Coherence Tomography Angiography

Quantitative Wide-Field Swept-Source Optical Coherence Tomography Angiography and Visual Outcomes in RAO

Purpose

Retinal artery occlusion (RAO) is an ophthalmic emergency that can lead to poor visual outcomes and is associated with an increased risk of stroke and cardiovascular events. Wide-field swept-source OCT-A (WF SS-OCTA) can provide quick and non-invasive angiographic information with a wide field of view. Here, we looked for associations between OCT-A vascular imaging metrics and vision in RAO patients.

Methods

Patients with diagnoses of central (CRAO) or branched retinal artery occlusion (BRAO) were included. 6mm × 6mm Angio and 15mm × 15mm AngioPlex Montage OCT-A images were obtained for both eyes in each patient using Zeiss Plex Elite 9000 WF SS-OCTA device. Each 6mm × 6mm image was divided into nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Non-perfusion area (NPA) was manually measured using 15mm × 15mm images. A linear regression model was utilized to identify correlation between imaging metrics and vision. P-values less than 0.05 were considered as statistically significant.

Results

Twenty-five subjects were included. For RAO eyes, there was a statistically significant inverse correlation between retinal thickness as well as superficial capillary plexus (SCP) vessel density (VD) and vision. An inverse correlation was found between deep capillary plexus (DCP) VD and vision without statistical significance. There was a positive correlation between choroidal thickness as well as choroidal volume and vision without statistical significance. No significant correlation was found between the metrics and vision in contralateral eyes. For NPA and vision, no significant correlation was identified.

Conclusion

This is the first study to investigate the utility of WF SS-OCTA in RAO and to demonstrate correlations between retinal vascular imaging metrics and visual outcomes. The results of this study provide a basis to understand the structural changes involved in vision in RAO and may guide management of RAO and prevention of cerebral stroke and cardiovascular accidents.

Evaluation of childhood developing via optical coherence tomography-angiography in Qamdo, Tibet, China: A prospective cross-sectional, school-based study

BACKGROUND

Optical coherence tomography angiography (OCTA) is a new and reliable machine used to evaluate retinal structure and macular perfusion in children. The use of OCTA under bad condition such as high altitude, low atmospheric oxygen, and low humidity, in children is rarely.

AIM

To quantify the macular micro-vasculature in healthy children of various ages using OCTA in Qamdo.

METHODS

Design: Prospective cross-sectional, school-based study. Three hundred and forty-seven normal students from 9 schools in 4 different areas in Qamdo were included. OCTA was performed on a 3 mm × 3 mm area centered on the macular region and macular cube 512 × 128 showed details in macular. Early treatment of diabetic retinopathy study Vessel Flow Density (VD) of the macular central vascular plexus density (CVD), inner vascular plexus density (IVD), full vascular plexus density (FVD), and the size of the foveal avascular zone (FAZ) were measured. All these results corrected by t/s = 3.382 × 0.01306 × (axial length-1.82). The differences were compared among various ages, sexes and living environments.

RESULTS

The mean FAZ area in all eyes was 0.27 mm2 ± 0.12 mm2. The mean foveal thickness (MFT) in the macular cube was 227.64 μm ± 23.51 μm. Compared with girls, boys had a lager FAZ (P = 0.0029). Among the different age groups, MFT (P < 0.001) and FVD (P < 0.0001), IVD (P < 0.0001), and CVD (P = 0.0050) increased with age. FAZ areas were not correlated with age (P = 0.8853) or others (MFT, area).

CONCLUSION

OCTA can use to evaluate macular perfusion in children. Our data bridge the gap between structural OCT and perfusion density in children in high altitude. Even though these were not a longitudinal study, it may provide us with hints about retina development during puberty and clinical implications of OCTA in children.

Choroidal changes in lens-induced myopia in guinea pigs

INTRODUCTION

This study aimed to determine the role of the choroid in lens-induced myopia (LIM) in guinea pigs.

METHODS

Guinea pigs were randomly divided into two groups: a normal control (NC) group and a LIM group. Refraction and axial length (AL) were measured by streak retinoscopy and A-scan ultrasonography. The choroidal thickness (ChT), vessel density of the choriocapillaris (VDCC) and vessel density of the choroidal layer (VDCL) were assessed by Spectral-domain Optical Coherence Tomography Angiography (SD-OCT). In addition, the choroidal expression of nitric oxide synthase (NOS) enzymes at the mRNA and protein levels was analyzed by real-time fluorescence quantitative PCR, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry.

RESULTS

In the LIM group, refraction and AL were increased significantly compared with those in the NC group at 2 weeks (refraction: LIM vs. NC, -4.23 ± 0.43 D vs. 2.20 ± 0.48 D; AL: LIM vs. NC, 8.36 ± 0.05 mm vs. 8.22 ± 0.03 mm) and 4 weeks (refraction: LIM vs. NC, -5.88 ± 0.49 D vs. 1.63 ± 0.41 D; AL: 8.57 ± 0.06 mm vs. 8.40 ± 0.04 mm). The ChT and VDCC were decreased significantly compared with those in the NC group at 2 weeks (ChT: LIM vs. NC, 60.92 ± 8.15 μm vs. 79.11 ± 7.47 μm; VDCC: LIM vs. NC, 23.43 ± 3.85% vs. 28.74 ± 4.11%) and 4 weeks (ChT: LIM vs. NC, 48.43 ± 6.85 μm vs. 76.38 ± 7.84 μm; VDCC: LIM vs. NC, 21.29 ± 2.17% vs. 27.64 ± 2.91%). The VDCL was also decreased compared with that in the NC group at 2 weeks and 4 weeks (NC vs. LIM, 24.87 ± 5.16% vs. 22.45 ± 3.26%; 23.37 ± 5.85% vs. 21.39 ± 2.62%; all P > 0.05). Moreover, the ChT was positively correlated with the VDCC and VDCL. The mRNA and protein expression of NOS enzymes (eNOS and nNOS) was increased.

CONCLUSIONS

During the development of myopia, the ChT, VDCC and VDCL were decreased, while NOS expression in the choroid was increased. The expression of NOS was negatively correlated with the ChT, VDCC and VDCL. NO may play an important role in regulating the choroid during myopia development.

Thickness, vessel density of retina and choroid on OCTA in young adults (18-24 years old)

PURPOSE

The purpose of this study was to quantify thickness, vessel density (VD) of retina and choroid in young adults (18-24 years old) using OCTA.

METHODS

This observational, cross-sectional study included 154 eyes from 77 young myopic adults. En-face angiogram OCTA was performed on a 3.00 × 3.00 mm region centered on the macula. Automated thickness calculations and macular maps were measured. Spherical equivalent refraction (SER) and AL were examined to determine associations with thickness, vessel density (VD) of retina and choroid.

RESULTS

A total of 148 healthy eyes from 77 young myopic adults (29 males and 48 females) with a mean age of 21.80 ± 1.32 years (range: 18-24 years) were included. The mean SER and AL were - 4.06 ± 2.26D and 25.25 ± 1.28 mm, respectively. The mean retinal thickness (RT, ILM-RPE layer) was 240.91 ± 13.36 μm, the retinal superficial (SVD) and deep vessel density (DVD) in fovea region were 18.35 ± 4.77% and 32.99 ± 6.01%, respectively. The foveal avascular zone (FAZ) area was 0.31 ± 0.10 mm². The mean subfoveal choroidal thickness (SFCT) and choriocapillaris (CC) perfusion area were 232.16 ± 56.65 μm and 2.17 ± 0.10 mm², respectively. By Pearson's correlation analysis, SER was revealed to be negatively correlated with RT (r = -0.180, p = 0.028) and DVD (r = -0.185, p = 0.025) in fovea region. SER was revealed to be positively correlated with RT in nasal (r = 0.224, p = 0.006) and inferior (r = 0.217, p = 0.008) regions. AL was revealed to be positively correlated with RT (r = 0.250, p = 0.002) and DVD (r = 0.284, p < 0.001) in fovea region. SER was revealed to be positively correlated with SFCT (r = 0.486, p < 0.001). AL was revealed to be negatively correlated with FAZ area (r = -0.232, p = 0.005) and SFCT (r = -0.407). RT was revealed to be negatively correlated with FAZ area (r = -0.645, p < 0.001). SER (r = -0.079), AL (r = 0.071) and SFCT (r = 0.089) did not correlate significantly with the CC perfusion area (all p > 0.05).

CONCLUSION

Myopic eyes present increased RT, DVD and thinned SFCT in fovea, while no significant correlation could be found between SER, AL, SFCT and CC perfusion area. It may indicate that the SFCT thinning may be secondary to ocular elongation, while the CC perfusion area may be a factor independent of AL growth.