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 vascular density and the area of foveal avascular zone (FAZ) in the follow eyes of monocular retinal vein occlusion (RVO) patients.MethodsRetrospective case-control study. From May to November 2018, 78 follow eyes of 78 monocular RVO patients who were clinically diagnosed in Changsha Aier Eye Hospital were included in the study. Among them, 44 were male and 34 were female. The average age was 53.17±10.12 years. There were 42 patients with central retinal vein occlusion (CRVO group) and 36 patients with branch retinal vein occlusion (BRVO group). Forty-two eyes of 33 gender and age matched healthy volunteers were selected as the control group. Among them, 17 were male (22 eyes) and 16 were female (20 eyes), with the mean age of 53.48±10.84 years. OCT angiography was performed on all eyes in CRVO group, BRVO group and control group. The scanning region in the macular area was 6 mm×6 mm. Macular vascular density and FAZ area in the superficial and deep retinal capillary plexi were measured.ResultsThe mean overall vascular density measured in the entire scan was lower in the CRVO group (t=－4.26, －4.93) and BRVO group (t=－4.79, －4.74) compared with the control group in both the superficial and deep capillary plexus (P＜0.05). The reduce degree of vascular density in the deep capillary plexus (CRVO group:5.51%, BRVO group:4.58%) was higher than that in the superficial plexus (CRVO group:4.13%, BRVO group:3.50%). In the CRVO group, the FAZ area decreased compared with the control group (t=－3.43, P＜0.05). There was no statistically significant difference in the area of FAZ between the BRVO group and the control group (t=－0.10, P＞0.05).ConclusionsThe macular vascular density in the follow eyes of monocular RVO patients is lower than that of normal healthy eyes. The reduce degree of vascular density in the deep capillary plexus is higher than that in the superficial plexus. Compared with normal healthy eyes, the FAZ area in the follow eyes of monocular CRVO patients decreased, while it did not change significantly in the follow eyes of monocular BRVO patients.
ObjectiveTo observe the changes of blood flow density in the macular area of normal eyes, and to analyze its correlation with age. MethodsA cross-sectional study. Two hundred and fifty normal healthy subjects (125 males and 125 females, aged 44.76±14.77) in routine ophthalmologic examination at the Department of Ophtalmology of Guangdong Provincial People’s Hospital during June 2017 to June 2018 were enrolled. Among them, 20 to 29, 30 to 39, 40 to 49, 50 to 59, and ≥ 60 years old were 50 subjects (50 eyes) in each. BCVA, slit lamp microscope, indirect ophthalmoscope, OCT angiography (OCTA) examinations were conducted for all eyes. The subjects were examined by both eyes, and the data of 1 eye was selected by EXCEL to generate random numbers, including 126 right eyes and 124 left eyes. The range of 6 mm × 6 mm in the macular area was scanned using a frequency domain OCTA instrument. The software automatically divides it into three concentric circles centered on the macular fovea, which were foveal area with a diameter of 1 mm, parafoveal area of 1 to 3 mm, and foveal peripheral area of 3 to 6 mm. The blood flow density of superficial capillary vessel, deep capillary vessel and foveal avascular area (FAZ) within a 300 μm width (FD-300), FAZ area, perimeter (PERIM), non-circularity index, center retinal thickness (CRT) were measured. The relationship between the blood flow density in macula, CRT, FAZ and age was analyzed by Pearson correlation analysis. ResultsThe mean blood flow density of superficial capillary vessel and deep capillary vessel were (51.61±2.54)% and (54.04±5.46)%, respectively. The average FD-300, CRT, PERIM and non-circularity index were (285.55±12.13) μm, (2.150±0.367) mm, 1.10±0.04, respectively. The relevance of the results showed that the age was negatively correlated with the blood flow density of whole area (r=−0.335, −0.279; P＜0.01), parafoveal area (r=−0.255, −0.368; P＜0.01), foveal peripheral area (r=−0.330, −0.269; P＜0.01) in superficial capillary vessel and deep capillary vessel as well as FD-300 (r=−0.311, P＜0.01), but not correlated with the blood flow density of foveal area (r=−0.071, −0.118; P=0.264, 0.064). There was no relationship between the age and the FAZ area, PERIM, non-circularity index (r=−0.070, −0.055, 0.074; P=0.267, 0.385, 0.142). The age was negatively correlated with the average CRT (r=−0.217, P＜0.01), but not correlated with the CRT in foveal area (r=0.115, P=0.068). The CRT was positively correlated with the blood flow density of superficial capillary vessel and deep capillary vessel in foveal area (r=0.715, 0.653; P＜0.01), but negatively correlated with the FAZ area (r=−0.669, P＜0.01). ConclusionThe capillary blood flow density of macular area in the normal eyes decreases with age.
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.
ObjectiveTo observe the changes of macular vascular density of hypertensive patients without obvious hypertensive retinopathy (HRP).MethodsTwenty-three patients (hypertension group) diagnosed as grade 2 or grade 3 essential hypertension in Cardiology Department of Renmin Hospital of Wuhan University from January to April 2019 were enrolled in the study. Among them, there were 13 males and 10 females. The mean age was 61.6 ± 5.6 years, and the mean BCVA was 0.74 ± 0.16. The course of hypertension was more than 7 years; Keith Wagener (K-W) grade was 0 or 1. Fifteen age-matched people without hypertension were selected as the control group, among which included 8 males and 7 females. Their average age was 59.7 ± 4.4 years and the average BCVA was 0.79 ± 0.17, the K-W grades were 0. There was no significant difference (P=0.265, 1.000, 0.563) between the two groups in age (t=1.739), sex ratio (χ2=0.036) or BCVA (t=0.585). All subjects were examined by BCVA, fundus photography and OCTA. OCTA scanned the macular area in the range of 3 mm × 3 mm. The software automatically divided the image into two concentric circles with the macular fovea as the center, which are the inner ring with a diameter of 1 mm (foveal area) and the outer ring with a diameter of 1-3 mm. The blood flow density of the whole, temporal, upper, nasal and lower capillary layers within 3 mm of the macular area, and foveal avascular zone (FAZ) area, central foveal retinal thickness (CFT) were measured.ResultsSignificant differences were observed in the vascular densities of total, temporal, nasal and inferior area of maculas (t=2.188, 2.472, 5.105, 2.734; P=0.037, 0.020, 0.000, 0.010) between the two groups, while no significant differences were evidenced in foveal vascular densities and superior vascular densities (t=0.575, 0.140; P=0.570, 0.889). There was no significant difference in FAZ area or CFT between the two groups (t=0.367, 0.753; P=0.714, 0.457). Macular arches were intact in all hypertension patients.ConclusionsThe vascular densities of total, temporal, nasal and inferior area of maculas in the hypertension patients without HRP decreased. The area of FAZ did not expand, and the structures of macular arch ring were normal.
ObjectiveTo observe the OCT angiography (OCTA) features of adult-onset foveomacular vitelliform dystrophy (AFVD).MethodsRetrospective clinical observational study. Twelve patients (22 eyes) diagnosed as AFVD by multi-modal imaging in Ophthalmology Department of Yunnan Second People’s Hospital from March 2018 to May 2019 were included in this study. There were 8 males (16 eyes) and 4 females (6 eyes). The patients aged from 33 to 62 years, with the mean age of 48.7±8.9 years. Ten patients were binocular, 2 patients were monocular. The visual acuity was 0.08-0.6. In 22 eyes, the vitelloid-like substance was relatively complete in 8 eyes, the vitelloid-like substance had different degrees of rupture in 14 eyes, secondary choroidal neovascularization (CNV) was observed in 10 eyes. The Heidelberg OCTA instrument was used for OCTA examination. The central wavelength was 840 nm, the acquisition speed was 85,000 times/s. A 3 mm × 3 mm scan was obtained. In the scanning process, eye-tracking technology was adopted to select images with better image quality and position for marking and saving. The image characteristics of vitelloid-like substance, fundus vascular changes and secondary CNV in OCTA were analyzed.ResultsIn 8 eyes with a relatively complete vitelloid-like substance, B-scan images showed dense vitelloid-like substance under the retinal neurocortical layer, which was located between the RPE layer and the ellipsoid zone and had a uniform density. Blood flow signals at the vitelloid-like substance can be seen in the en-face image, which was the artifact of the vitelloid-like substance reflecting the blood vessels above. In the 14 eyes with different degrees of vitellin-like material rupture, the signal of vitellin-like substance between the ellipsoid zone and the RPE layer in the B-scan image was not uniform, and some weak reflected signal lacunae could be seen. In the image of en-face, the relatively intact areas of vitelloid-like substance still showed the artifact of the blood vessels above the reflection, while there was no blood flow signal at the rupture of vitelloid-like substance. In 22 eyes, the morphology of retinal small blood vessels in the superficial and deep capillary arch ring region of retina was abnormal in 10 eyes. Some small blood vessels could be seen to have branch and shape changes, and the anastomosis failed to show a complete arch ring structure.No significant structural changes in retinal capillaries were observed in 12 eyes. Among the 10 eyes with secondary CNV, 8 eyes showed the non-active CNV which was as thick as "wild branches", and 2 eyes showed the active CNV which was composed of dense and small vascular branches.ConclusionAFVD in OCTA can be manifested as abnormal retinal vascular morphology caused by the vitelliform material pushing, vascular artifacts reflected by the vitelliform material itself, and the presence of CNV under the vitelliform material.
As a neurodegenerative disease of the retina, glaucoma can cause irreversible vision loss in patients. More and more evidences indicate that systemic blood flow abnormalities, decreased optic nerve blood flow, and retinal microcirculation disorders are related to the mechanism of glaucoma ganglion injury. Optical coherence tomography (OCTA) has the advantages of non-invasive, high resolution, quick inspection, three-dimensional imaging, and quantitative blood flow perfusion. Compared with other blood flow detection methods such as color ultrasound Doppler, laser speckle blood flow imaging, etc. it has higher performance and accuracy, and is easier to be applied in clinical practice. OCTA can not only be used for the early diagnosis and follow-up of glaucoma, but has a strong correlation with retinal nerve fiber layer thickness and visual field parameters; it can also provide objective data for the follow-up of patients with advanced glaucoma to assess the progress of the disease. In the future, OCTA is expected to become a routine detection method and follow-up method for the diagnosis of glaucoma.
ObjectiveTo observe the changes of macular blood flow density in patients of macular telangiectasis type 1 (Mac-Tel type 1) with macular edema before and after the treatment of anti-VEGF.MethodsA retrospective clinical study. From January 2016 to December 2017, 14 Mac-Tel type 1 patients (14 eyes) diagnosed in Nanjing Medical University Eye Hospital were included in the study. There were 6 males (6 eyes) and 8 females (8 eyes), with the mean age of 35.3±9.3 years. All patients underwent BCVA and OCT angiography examinations. The BCVA examination was performed using the Snellen visual acuity chart, which was converted into logMAR visual acuity. All the patients were received anti-VEGF injection treatment once a month for 3 consecutive months. The OCTA scanning region in the macular area was 3 mm × 3 mm. Macular blood flow density in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), the vessel density within a 300 μm width ring surrounding the foveal avascular area (FD-300) and central macular thickness (CMT) were measured in all eyes. Paired samples t-test and Pearson correlation analysis were used in this study.ResultsAt the baseline, logMAR BCVA was 0.69±0.07, CMT was 468.43±26.59 μm, SCP blood flow density was (50.99±1.19)%, DCP blood flow density was (43.79±1.44)%, FD-300 was (50.73±1.16)%. Compared with the baseline, there were significant differences between logMAR BCVA, CMT, DCP blood flow density and FD-300 in 1 week, 1 month, 3 months after treatment and 2 months after cessation of treatment (logMAR BCVA: t=6.77, 13.30, 16.99, 9.51; P=0.00, 0.01, 0.00, 0.01. CMT: t=6.99, 15.88, 26.10, 6.50; P=0.00, 0.01, 0.01, 0.00. DCP: t=6.75, 8.61, 15.12, 7.63; P=0.00, 0.01, 0.01, 0.00. FD-300: t=11.86, 13.08, 14.36, 4.41; P=0.00, 0.01, 0.01, 0.03). There was no significant difference in blood flow density of SCP between baseline and 2 months after cessation of treatment (t=1.36, P=0.19), but there was significant difference at the other time points after treatment (t=5.50, 6.84, 6.27; P=0.00, 0.01, 0.01). The Pearson's correlation analysis showed that there was a significant positive correlation between FD-300 and CMT (r2=0.54, P=0.04).ConclusionsThere is no significant change in the SCP blood flow density in the patients of Mac-Tel type 1 with macular edema, while the DCP blood flow density decreased and FD-300 increased. After anti-VEGF treatment, DCP blood flow density increased and FD-300 decreased. FD-300 is positively correlated with CMT.
ObjectiveTo observe the clinical and multimodel imaging characteristics of paracentral acute middle maculopathy (PAMM).MethodsRetrospective case series study. From January 2014 to August 2018, 12 eyes of 12 patients with PAMM diagnosed in Department of Ophthalmology, Peking University People’s Hospital, were included in this study. There were 9 males and 3 females, with the mean age of 57 years. All patients were referred for sudden impaired vision, with or without paracentral scotoma. The patients underwent BCVA, slit lamp examination, fundus photography, FFA and OCT. Simultaneously, OCT angiography (OCTA) was performed in 10 eyes, visual field was performed in 5 eyes, near infrared fundus photography was performed in 1 eye. Clinical and multimodal imaging findings were reviewed and analyzed.ResultsAmong 12 eyes, there were 5 eyes with BCVA 0.05-≤0.1, 4 eyes with BCVA 0.3-0.5, 3 eyes with BCVA 0.6-1.0. There were 1 eye with central rentinal artery obstruction (CRAO), 7 eyes with branch retinal artery obstruction (BRAO). Among them, BRAO with central retinal vein occlusion (CRVO) in 1 eye, with non-arteritic anterior ischemic optic neuropathy in 1 eye, with diabetic retinopathy in 1 eye; old BRAO in 3 eyes; pure BRAO in 1 eye. There were 4 eyes with pure CRVO, including 3 eyes with ischemic CRVO. All eyes demonstrated hyperreflective lesions at the level of the inner nuclear layer and/or outer plexus layer on OCT. En face OCT highlighted the areas with hyperreflectivity corresponding to these lesions. OCTA demonstrated significant deep capillary dropout, abnormal morphology and enlargement of foveal avascular zone.ConclusionHyperreflective band-like lesions at the level of the inner nuclear layer on OCT and middle retinal perivascular hyperreflectivity on en face scan are characteristic in PAMM.
ObjectiveTo observe the changes of choroidal capillary flow area (CBFA) and density in patients with idiopathic macular hole (IMH) before and after surgery.MethodsA prospective clinical study. Thirty patients (60 eyes) with unilateral IMH diagnosed in Department of Ophthalmology of The Second Hospital of Hebei Medical University from February 2017 to March 2018 and 30 age-and sex- matched normal controls were included in this study. All eyes were divided into group A (30 affected eyes), group B (30 fellow eyes) and group C (30 normal eyes of controls). Among 30 eyes in group A, there were 5, 14, 11 eyes with hole in stage Ⅱ, Ⅲ, Ⅳ, respecitvely. The eyes in group A were divided into two subgroups according to the diameter of the holes: group D: hole diameter less than or equal to 500 μm (11 eyes), group E: hole diameter over than 500 μm (19 eyes). All eyes in group A underwent vitrectomy. Spectral-domain OCT was used to observe the diameter size of macular hole and the closure of the hole after vitrectomy in eyes of group A. The CBFA and blood flow density of superficial choroidal capillaries were measured by OCT angiography before and 3 months after vitrectomy in groups A, B and C. Univariate analysis of variance and t test were used for statistical analysis.ResultsBefore surgery, in group A, B and C, the CBFA were 2.84±0.35, 3.19±0.23, 3.26±0.24 mm2, the blood flow density were (20.74±8.26)%, (35.18±5.20)%, (35.20±6.49)%, respectively. The CBFA and blood flow density in group A were significantly lower than those in group B and C (F=19.768, 45.583; P = 0.000, 0.000), but there was no significant difference between group B and C (F=19.768, 45.583; P=0.332, 0.994). The CBFA and blood flow density in group D were higher than those in group E (t=2.230, 2.202; P=0.034, 0.036). The diameter of macular hole was negatively correlated with CBFA and blood flow density (r=－0.377, －0.477; P=0.044, 0.009). Three months after surgery, the macular holes in group A were closed; CBFA and blood flow density in macular area were significantly higher than before surgery (t=－4.126, －4.912; P=0.000, 0.000).ConclusionsCBFA and blood flow density decreased in the macular area of IMH. CBFA and blood flow density can be recovered after vitrectomy.