Non-arteritic ischemic optic neuropathy (NAION) is a neurological disease due to poor perfusion in optic disk. It causes severe visual function impairment, characterized by loss of vision and visual field defect. Optical coherence tomography (OCT) is vital for detecting anterior laminar depth, peripapillary nerve fiber layer thickness, ganglion cell complex thickness and peripapillary choroid thickness change in eyes with NAION at different course of the disease. In addition, OCT features are in accordance with visual function impairment. OCT angiography (OCTA) reveals retinal and choroidal vasculature networks in optic and macular area. OCTA revealed vasculature perfusion decline in eyes with NAION, even if their visual sensitivity and visual evoked potential were normal. Studying OCT and OCTA features is vital for exploring the pathogenesis and prognosis of NAION.
Objective To observe the optic disc perfusion in anterior ischemic optic neuropathy (AION) patients. Methods Forty eyes of 40 AION patients and 30 eyes of 30 normal subjects were included. The stage of the diseases was defined based on the course of the disease, including acute stage (less than 3 weeks) and recovery stage (more than 3 months). Optic disc blood flow area, outer vascular density and blood flow index were measured by optical coherence tomography angiography in all the subjects. Optic disc perfusion was observed in acute and recovery stage of disease. Results The optic disc blood flow area, outer vascular density and blood flow index were decreased of AION eyes in acute stage compared with the normal subjects, the difference was statistically significant (P < 0.05); while the optic disc blood flow area, outer vascular density and blood flow index of AION eyes in the recovery stage showed no significant difference compared with normal subjects (P > 0.05). ConclusionDisc perfusion is reduced in AION at the acute stage, but recovered at the recovery stage.
ObjectiveTo compare the fast blood flow density (FBFD) of intermediate choroid between endogenous Cushing syndrome (ECS) patients and healthy control subjects.MethodsThirteen eyes of 7 eligible ECS patients (ECS group) and 13 eyes of 7 gender, age, axial length matched healthy volunteers (control group) were enrolled in this study. For each subject, macular radial scan with swept source optical coherence tomography (SS-OCT) was performed and subfoveal choroidal thickness (SCT) was measured. Then 3.0 mm×3.0 mm macular scan with SS-OCT angiography was performed, and selected blood flow image at intermediate choroid level or 1/2 SCT beneath Bruch membrane. The grayscale images were then binarized for the analysis of FBFD.ResultsThe SCT in ECS group was (394.7±77.7) μm, which was significantly thicker than (332.1±68.1) μm in control group (t=2.923, P=0.008). The FBFD of intermediate choroid in ECS group were (76.35±14.46)%, which were significantly greater than (63.57±13.42)% in control group (t=2.775, P=0.01).ConclusionECS patients had increased FBFD at intermediate choroid level compared with healthy controls.
ObjectiveTo observe the blood perfusion of optic nerve and macular areas and investigate its relationship with visual field defect in nonarteritic anterior ischemic optic neuropathy (NAION).MethodsTwelve consecutive unilateral NAION patients (course of disease ＜3 months) and 12 healthy Chinese adults were enrolled in the study. The affected eyes and fellow eyes from 12 NAION patients were defined as group A and group B; 12 eyes from 12 healthy adults were defined as group C. Best corrected visual acuity (BCVA), intraocular pressure (IOP), indirect ophthalmoscope and computer optometry were performed on all of the three groups of patients. Visual field (VF) and optical coherence tomography (OCT) were performed on NAION patients. Logarithm of the minimum angle of resolution (logMAR) was used to calculate visual acuity. Compared to group B, logMAR BCVA, mean deviation (MD) and pattern standard deviation (PSD) in group A were significant decreased (t=3.278, −4.909, 4.130, P＜0.05). There was no significant difference in spherical equivalent, IOP, peripapillary retinal nerve fibre layer (pRNFL) between group A and group B (t=0.000, 0.890, 1.215; P＞0.05). OCT angiography (OCTA) was used to measure the flow area (FA) at optic disc, flow area at radial peripapillary capillaries (RCFA) and FA, non-perfusion area (NFA), parafoveal vessel density (PVD) and parafoveal vascular index (PVI) in macular area. Pearson correlations between the deficiency of optic blood flow and visual field were analyzed.ResultsThe differences of FA at optic disc and peripapillary RCFA among 3 groups were significant (F=4.162, 3.357; P＜0.050). Compared to group B (t=−5.822, −7.467; P＜0.001) and C (t=9.435, 4.615, P＜0.05), FA at optic disc and peripapillary RCFA in group A was significantly reduced. There is several NAION showed quadrantal FA decreased in optic nerve. However, there was no significant difference in optic disc FA and peripapillar RCFA between group B and C (F=0.004, 0.030; P＞0.050). There was no differences of FA, NFA, PVD and PVI among 3 groups (F=0.488, 1.107, 0.493, 1.086, 1.098, 0.093, 1.093, 1.221; P＞0.05). Positive correlation between optic disc FA, peripapillary RCFA and MD (r=0.542, 0.585; P＜0.05) were observed. However, there was no significant correlation between optic disc FA, peripapillary RCFA and PSD (r=−0.404, −0.430; P＞0.05), and negatively correlated to BCVA (r=−0.617, −0.596; P＜0.05). PRNFL was negatively correlated to optic disc FA (r=−0.643, P＜0.05), but not correlated to peripapillary RCFA (r=−0.377, P＞0.05).ConclusionsThe optic disc blood flow reduced in affected eyes of unilateral NAION whose disease course was less than 3 months, while the macular perfusion was normal. There was a positive correlation between optic disc flow and visual field.
Objective To observe the alterations of macular vascular density and the area of foveal avascular zone (FAZ) in branch retinal vein occlusion (BRVO) eyes. Methods A retrospective case-control study. Forty-five patients with unilateral BRVO and macular edema were enrolled in this study. Optical coherence tomography angiography (OCTA) was performed on the BRVO and fellow eyes. The scanning region in the macular area was 3 mm×3 mm. Macular vascular density and FAZ area in the superficial and deep retinal capillary plexi were measured in all eyes. The values of macular vascular density and FAZ area between BRVO eyes and fellow eyes, affected sector and unaffected sector were compared. Results The mean overall vascular density measured in the entire scan was lower in BRVO eyes compared with fellow eyes in both the superficial and deep capillary plexus (t=14.186, 9.468; P＜0.05). The reduce degree of vascular density in the deep capillary plexus (7.65%) was higher than that in the superficial plexus (7.27%). In the superficial plexus, the vascular density was lower in the affected sector and the unaffected sector of the BRVO eyes compared with the corresponding sector in the fellow eyes (t=15.386, 9.435; P＜0.05). The FAZ area enlarged in the BRVO eyes compared with the fellow eyes in the superficial capillary plexus and in the deep capillary plexus (t=3.216, 5.119; P＜0.05). The degree of enlargement of FAZ area in the deep capillary plexus (0.19 mm2) was higher than that in the superficial plexus (0.11 mm2). Conclusions In eyes with BRVO, quantitative OCTA measurements confirm that vascular density decreased and FAZ area enlarged in the superficial and deep capillary plexi. The reduce degree of vascular density and enlargement degree of FAZ area in the deep capillary plexus are higher than those in the superficial plexus.
Objective To observe the choroidal blood flow and morphological changes in patients with severe stenosis of internal carotid artery stenosis (ICAS). Methods A retrospective case-control study. Forty-six patients (46 eyes) with ICAS were enrolled in this study. There was severe stenosis in one side (the eyes in this side were set as case group) and mild or no stenosis in other side (the eyes in this side were set as control group). Color doppler ultrasound (CDI) was used to observe the changes of hemodynamic parameters of the ophthalmic artery (OA) and posterior ciliary artery (PCA), the main parameters of ultrasound Doppler imaging are peak systolic velocity (PSV), end diastolic velocity (EDV), resistance indices (RI) and the calculation of the pulsation indices (PI) through the use of a formula. Enhanced binarization of deep imaging coherence tomography (EDI-OCT) was used to measure the subfoveal choroidal thickness (SFCT). The total subfoveal choroidal area (TCA), luminal (LA), stromal (SA) and choroidal vascularity index (CVI) were obtained by modified image binarization technique. Results In the case group, the PSV in the OA and PCA was significantly lower than that of the control group (t=−2.200, −2.612; P=0.030, 0.011). There were no significant differences in EDV, RI, PI of OA (t=0.337, −1.810, −1.848; P=0.737, 0.074, 0.068) and PCA (t=−1.160, 1.400, 0.815; P=0.249, 0.165, 0.417). The SFCT (t=−3.711, P＜0.001), TCA (t=−2.736, P=0.007), LA (t=−3.188, P=0.002) and CVI (t=−2.096, P=0.039) of the case group was significantly lower than that of the control group. There were no significant differences in SA (t=−1.262, P=0.210) and LA/SA (t=−1.696, P=0.093). Conclusion In severe stenosis ICAS eyes, the PSV in the PCA and SFCT, TCA, LA, CVI are decreased.
Objective To observe the imaging features of the optical coherence tomography angiography (OCTA) of complex retinal arterial macroaneurysm (RAM). Methods Nineteen eyes of 19 patients with RAM were enrolled in this retrospective study. There were 1 male (1 eye) and 18 females (18 eyes). The patients aged from 62 to 85 years, with the mean age of 71.3 years. The fundus photography examination revealed the tumors were located in the 1 - 3 branch of the artery, which showed focal spindle-shaped or fusiform angiomatous dilatation. The fundus fluorescein angiography revealed the early uniform fluorescence of the tumor, and the tumor was a high-fluorescence leak in the late period. RAM was divided into exudative type and hemorrhagic type according to the literature and based on the ocular fundus appearance. In 19 eyes, 8 eyes were exudative RAM and 11 eyes were hemorrhagic RAM. All eyes were examined by OCTA, and the retinal blood flow images of 3 mm ×3 mm diameter were routinely collected to observe the OCTA imaging features. Results OCTA examination showed that the superficial RAM of all eyes had strong reflection signal connected with retinal artery. B-scan image showed smaller tumors in the lumen with strong reflection of expansion, or large tumor with peak-like uplift and the blood flow signals in the tumor body were abundant. The enface image clearly showed the three-dimensional shape of the tumor. Tumors with exudation or multi-level bleeding could be clearly documented for their bleeding range and boundary. The white signal co-localized with the superficial retinal blood vessels by the function of multi-color fluoroscopy. The pattern of blood flow density can also clearly show the three-dimensional shape of the tumor. Conclusion The complex RAM is a strong reflection signal in the superficial layer of retina, which is connected with the retinal vessels; B-scan images shows small tumors with a small piece of strong reflection and dilation, or large tumors with mountain-like elevation with abundant blood flow signals. En face image can clearly show the three-dimensional shape of the tumor.
Optical coherence tomography angiography (OCTA) base on OCT with an algorithm that can image a high-resolution picture of retinal circulation. OCTA has allowed quantifying the characteristic lesions of diabetic retinopathy (DR) in early stage, such as fovea avascular zone, retinal vascular density and the counts of retinal microaneurysm. In addition, OCTA can objectively evaluate the progression and prognosis of DR in late stage through imaging involved retinal neovascularization. Understanding OCT angiography features of DR lesions with different course of the disease may provide reference value for the diagnosis and treatment of DR.
ObjectiveTo observe the macular capillary morphology in diabetic patients.MethodsA total of 61 patients (104 eyes) with diabetes mellitus (DM group) and 31 healthy controls (41 eyes) were enrolled in the study. According to the degree of diabetic retinopathy (DR), the DM group was divided into non-DR (NDR) group, non-proliferative DR (NPDR) group, and proliferative DR (PDR) group. There were 13 patients (23 eyes), 21 patients (34 eyes) and 27 patients (47 eyes) in each group, respectively. According to whether there was diabetic macular edema (DME), the DM patients were divided into DME group and non-DME group, each had 20 patients (28 eyes) and 41 patients (76 eyes), respectively. The age (F=2.045) and sex (χ2=2.589) between the control group, the NDR group, the NPDR group and PDR group were not statistically significant (P=0.908, 0.374). The 3 mm × 3 mm region in macula was scanned by optical coherence tomography angiography (OCTA), and the retinal capillary morphological changes of superficial capillary layer (SCL) and deep capillary layer (DCL) were observed. Chi-square test and t test were used to compare data among different groups.ResultsThere was no abnormal change of retinal capillary morphology in control group. Microaneurysms and foveal avascular zone (FAZ) integrity erosion can be found in NDR group. There were microaneurysms, FAZ integrity erosion, vascular tortuosity bending, capillary non-perfusion and venous beading in NPDR and PDR groups. The microaneurysms of DCL were significantly more than that of the SCL (t=4.759, P＜0.001). The eyes with microaneurysms in NDR group, NPDR group, and PDR group showed significant differences (χ2=44.071, P＜0.001), and the eyes with FAZ integrity erosion among these three groups also showed significant differences (χ2=30.759, P＜0.001). Compared with NPDR group and PDR group, there were significant differences in vascular tortuosity bending and capillary non-perfusion (vascular tortuosity bending: OR=0.213, 95%CI 0.070−0.648, P=0.004; capillary non-perfusion: OR=0.073, 95%CI 0.022−0.251, P＜0.001), and there was no significant difference in venous beading (OR=0.415, 95%CI 0.143−1.208, P=0.102). SCL blood flow density in the 4 groups (control, NDR, NPDR and PDR group) was 49.233±1.694, 48.453±2.581, 45.020±4.685 and 40.667±4.516, respectively. While the difference between the control and NDR group was not significant, the differences between other pairs (control vs NPDR/PDR, NDR vs NPDR/PDR, NPDR vs PDR) were significant. The ratio of FAZ integrity erosion and non-perfusion of DME group was significantly higher than those of non-DME group (vascular tortuosity bending: OR=7.719, 95%CI 1.645−36.228, P=0.004; capillary non-perfusion: OR=14.560, 95%CI 3.134−67.646, P＜0.001).ConclusionsOCTA can distinctively detect the abnormal retinal capillary changes of SCL and DCL in diabetic patients. Even in DM patients without diabetic retinopathy, OCTA can detect abnormal blood vessels.