ABSTRACT
Optical coherence tomography angiography (OCTA) can be used to obtain retinal and choroidal blood flow images of optic disc and macular area, and evaluate the vascular morphology and blood perfusion of different layers in different areas of optic disc and macular area.It provides rich possibilities for the description and quantification of optic nerve diseases, the exploration of disease pathogenesis, and the development and evaluation of new treatments.In recent years, OCTA has played an important role in the diagnosis and treatment of optic nerve diseases.It is helpful in the diagnosis of optic neuritis, ischemic optic neuropathy, papilledema secondary to idiopathic intracranial hypertension, and to some extent to evaluate the visual function of affected eyes.The vascular morphology and quantitative analysis of the optic disc and macular area by OCTA may be of value in discriminating optic disc swelling from various etiologies and different types of anterior ischemic optic neuropathy, and facilitate further exploration of the pathogenesis of optic nerve diseases.This article reviewed the application status, recent progress and limitations of OCTA in the diagnosis, differential diagnosis and pathogenesis of optic nerve diseases.OCTA is still not in the stage of meaningful clinical use in neuro-ophthalmology, but its application can be wider as there are more meaningful researches and findings.
ABSTRACT
Objective:To observe the characteristics of macular telangiectasia (MacTel) in multi-color and multi-mode fundus images.Methods:An abservational case series study was conducted.Sixteen eyes of 12 patients diagnosed with MacTel by fluorescein fundus angiography (FFA) from January to November 2019 in Shandong Eye Hospital were analyzed.There were 8 cases (8 eyes) with MacTel type Ⅰ, among which 4 cases were male and 4 cases were female, with an average age of (62.3±12.5) years.The other 4 cases (8 eyes) had MacTel type Ⅱ, all of which were female, with an average age of (58.7±10.5) years.Best corrected visual acuity, slit lamp microscopy, color fundus photography, multicolor scanning laser imaging, FFA, optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) were carried out in all the patients.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Shandong Eye Institute (No.2019S003).Results:In color fundus images of MacTel type Ⅰ eyes, annular macular exudation with macular edema occurred in 6 eyes, macular edema without hard exudates in 1 eye, and hard macular exudates without macular edema in 1 eye.However, the transparency of retina in temporal fovea in MacTel type Ⅱ eyes decreased, showing a gray color.In multi-color fundus images of MacTel type Ⅰ eyes, punctate granular yellow macular exudation and yellow-green macular edema were observed, which were clearer than those in color fundus images.Punctate exudation was seen in both the blue and green reflectance images, which was clearest in green reflectance image, followed by blue reflectance image and then the infrared reflectance image.In OCT images of MacTel type Ⅰ eyes, cystoid edema of inner retina or uneven reflection signal of outer plexiform retina were observed.Loss of inner and outer retinal structures and cavities were observable in MacTel type Ⅱ eyes, and outer retinal atrophy appeared in 2 eyes.In OCTA images, the destruction of superficial and deep capillary plexus in macular area were observed in both MacTel typeⅠand type Ⅱ eyes, and the destruction of deep capillary plexus was more obvious.In addition, more obviously increased vascular space, decreased vessel density, and increased foveal avascular zone were found in MacTel type Ⅱ eyes.In early stage of FFA, delayed capillary filling near fovea was seen in MacTel typeⅠeyes, and dilated temporal vessels in fovea, some of which showed tumor-like dilation, and the limited tumor-like dilation was enhanced in the later stage.Different degrees of dilated parafoveal blood vessels in the early stage, and the capillary in the temporal side of the macula showing diffuse strong fluorescence in the late stage of FFA was observed in MacTel type Ⅱ eyes.Conclusions:Multi-color scanning laser imaging can be used to observe the morphological characteristics of MacTel, and the imaging features of different types of MacTel are significantly different.
ABSTRACT
Objective:To explore the microvasculature changes in macular area of central retinal vein occlusion (CRVO) patients with macular edema (ME).Methods:A cross-sectional study was conducted.Fifteen patients with monocular ME secondary to CRVO (30 eyes) and 15 age- and gender-matched normal subjects (15 eyes) were enrolled in The Second Affiliated Hospital of Chongqing Medical University from November 2017 to March 2019.Best corrected visual acuity (BCVA), intraocular pressure, slit lamp microscope with pre-set lens, color fundus photography and optical coherence tomography (OCT) were performed in all subjects.The central macular thickness (CMT), foveal avascular zone (FAZ) area, FAZ perimeter, acircularity index (AI), vessel density of superficial retinal capillary plexus (SCP) and deep retinal capillary plexus (DCP) in 3 mm×3 mm macular area were measured by optical coherence tomography angiography instrument and compared between different groups.The correlation between BCVA, CMT and microvascular structural parrameters in ME eyes of CRVO patients was analyzed by Pearson linear correlation test.This study protocol adhered to the Declaration of Helsinki and was approved by the Ethics Committee of The Second Affiliated Hospital of Chongqing Medical University (No.2018-211).Written informed consent was obtained from each subject before any medical examination.Results:Compared with contralateral eyes, the FAZ area and FAZ perimeter of ME eyes were significantly increased, and AI, the vessel density of SCP and DCP were significantly decreased (all at P<0.01).Compared with normal control eyes, the FAZ area and FAZ perimeter of contralateral eyes of CRVO patients were significantly increased, and AI, the vessel density of DCP were significantly decreased (all at P<0.05).In ME eyes, the BCVA LogMAR was positively correlated with FAZ area and FAZ perimeter ( r=0.614, 0.609; both at P<0.05), and was negatively correlated with AI and vessel density of SCP ( r=-0.517, -0.593; both at P<0.058).In ME eyes, CMT was positively correlated with FAZ area and FAZ perimeter ( r=0.523, 0.610; both at P<0.05), and was negatively correlated with AI and the vessel density of SCP ( r=-0.537, -0.608; both at P<0.05). Conclusions:The characteristic microvascular change in ME secondary to CRVO eyes is the decrease of blood flow caused by the decrease of capillaries in fovea, and the same change in blood flow also exists in their contralateral eyes.The degree of ME and visual function damage are correlated with the degree of foveal damage and the blood flow in fovea.
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Objective:To compare the change of macular microvasculature in early primary open-angle glaucoma (POAG) patients with central visual field defects (CVFDs) and peripheral visual field defects (PVFDs).Methods:A cross-sectional study was performed.Sixty-six eyes of 66 consecutive patients with early POAG were enrolled in Beijing Tongren Hospital from June to December 2020.The patients were divided into CVFDs group (25 eyes) and PVFDs group (41 eyes) according to their visual field defect.Another 55 eyes of 55 age-, gender- and spherical equivalent-matched healthy people were set as a normal control group.All subjects underwent routine ophthalmic examination.Humphrey 24-2 visual field test was carried out.Macular vessel density (VD) and perfusion density (PD) of an area of 6 mm×6 mm were measured by optical coherence tomography angiography (OCTA), and the area was divided into 3 rings and 9 zones, including center, inner ring (superior, inferior, temporal and nasal sectors), and outer ring (superior, inferior, temporal and nasal sectors) according to ETDRS ring.The relationship among VD, PD, and visual field defect was analyzed.This study adhered to the Declaration of Helsinki.The research protocol was approved by an Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.TRECKY2020-103). Written informed consent was obtained from each subject before any examination.Results:The total macular VD of normal control group, CVFDs group and PVFDs group was 18.20 (17.50, 18.50), 17.10 (16.30, 17.85), and 17.20 (16.25, 17.90)mm/mm 2, respectively, and there was a significant difference ( H=20.84; P<0.001). The total macular PD of normal control group, CVFDs group and PVFDs group was 0.45 (0.43, 0.46), 0.42 (0.40, 0.44), and 0.43 (0.40, 0.44)mm 2/mm 2, respectively, with a significant difference ( H=16.15; P<0.001). The total macular VD and PD of CVFDs and PVFDs groups were significantly lower than those of normal control group, with statistically significant differences (all at P<0.05). Significant differences were found in VD and PD of superior, inferior, temporal, and nasal sectors of the outer ring among three groups (all at P<0.05). VD of the outer ring and PD of superior, inferior, and nasal sectors of the outer ring were reduced in CVFDs group than normal control group, showing significant differences (all at P<0.05). VD and PD of the superior, inferior, and temporal sectors of the outer ring were reduced in PVFDs group compared with normal control group, with significant differences (all at P<0.05). A significant difference was found in macular PD of the outer-nasal sector between CVFDs and PVFDs groups ( P=0.035). Conclusions:Macular VD and PD are reduced in early POAG.Compared with POAG patients with CVFDs, the macular PD of the outer-nasal sector of POAG patients with CVFDs is lower.