Optical coherence tomography angiography (OCTA) is an noninvasive, rapid and reproducible technology which can provide high resolution view of the vascular structures and quantifies the vessel densities in retina and choroid. Myopia can be divided into simple myopia and pathologic myopia. The mechanism of myopia is not clear while it is closely related to the vessel density. For simple myopia, OCTA can monitor the course and deepen the understanding of myopia by quantifying the vessel densities in each layers and sectors and the foveal avascular zone. For pathologic myopia, OCTA has an advantage of observing the choroidal neovascularization, chorioretinal atrophy and Zinn-Haller arterial circle which can contribute to the early diagnosis and management and follow-up to estimate the prognosis. However, there are several limitations of OCTA which need to be improved, including in the process of acquiring high-quality images, accurate layering and dynamic observation.
Through the different image technologies, peripapillary atrophy can be classified into four types: α zone, β zone, γ zone and δ zone. Each type of them has different imaging and histological features. Peripapillary atrophy is a common structure in peoples’ eyes and it is correlated with many factors and diseases such as age, myopia, glaucoma, non-arteritic anterior ischemic optic neuropathy and age-related macular degeneration which bring difficulties to our diagnosis and antidiastole. Classifying and qualifying peripapillary atrophy properly, which can evaluate the changes and degrees, can benefit our studies about their mechanism and offer the clinical biological indictors and research basis.
ObjectiveTo observe the morphological characteristics of internal carotid artery (ICA) siphon and ophthalmic artery (OA) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) based on CT angiography (CTA) three-dimensional reconstruction of ICA siphon and OA models. MethodsA retrospective cohort study. From January 2017 to January 2019, 26 patients with 31 eyes (NAION group) who were diagnosed with NAION by ophthalmic examination at Beijing Friendship Hospital, Capital Medical Universitywere included in the study. Among them, there were 11 males with 13 eyes, and 15 females with 18 eyes; the age was 67.52±6.30 years old. Nineteen eyes of 19 non-affected contralateral eyes were selected as the contralateral eye group. Among them, there were 9 males with 9 eyes and 10 females with 10 eyes; the age was 65.95±5.66 years old. Twenty-six eyes of 26 age- and sex-matched subjects with normal fundus examination during the same period were selected as the normal control group. All subjects underwent best corrected visual acuity (BCVA), intraocular pressure, fundus photography and CTA examination. The data obtained from CT scans were reconstructed by 3D model, and the anatomical morphology of ICA siphon was divided into U-shape, V-shape, C-shape and S-shape; the diameter of ICA siphon portion and the diameter at the beginning of OA were measured. One-way analysis of variance was used to compare the diameter of the OA at the beginning of the OA and the diameter of the ICA siphon between the three groups of eyes. ResultsThe diameters at the beginning of OA in the NAION group, the contralateral eye group, and the normal control group were 1.17±0.20, 1.34±0.17, and 1.39±0.15 mm, respectively, and the differences among the three groups were statistically significant (F=12.325, P<0.05); there was no significant difference between the contralateral eye group and the normal control group (P=0.310). In the NAION group, the anatomical morphology of the ICA siphon was U-shaped and V-shaped in 20 (64.52%) and 8 (25.81%) eyes respectively, and S and C-shaped in 3 eyes (9.67%); in the contralateral eye group, in the control group, the ICA siphon shape of the eyes examined was U-shaped and V-shaped, and S-shaped and C-shaped were rare. The diameters of the ICA siphons in the NAION group, the contralateral eye group, and the normal control group were 3.50±0.69, 3.22±0.59, and 3.55±0.54 mm, respectively. There was no significant difference between the three groups (F=1.860, P=0.163). ConclusionU-shaped and V-shaped ICA siphons are more common in NAION-affected eyes; the diameter of the starting point of OA is significantly reduced.
Acute coronary syndromes (ACS) are clinical syndromes caused by the instability or rupture of coronary atheromatous plaques. The development and treatment of ACS are closely related to some ocular manifestations. Hypertensive retinopathy, retinal arteriovenous occlusion, diabetes retinopathy, and age-related macular degeneration are associated with a high risk of ACS. Retinal vascular occlusion may be a potential postoperative complication of the percutaneous coronary intervention for ACS. Ocular parameters such as the retinal vascular diameter and density, the blood flow velocity of the ophthalmic artery, and the choroidal thickness are expected to be markers for assessing or predicting the risk of ACS, which are of important value for the prevention of cardiovascular events such as ACS.