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Non-DR Retinal Vascular Diseases
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Sobha Sivaprasad, Luke Nicholson, Shruti Chandra
Cilioretinal artery occlusion (CLRAO) is often included under the umbrella of BRAOs. However, this is anatomically incorrect as the cilioretinal artery is a branch of the posterior ciliary artery, unlike branch retinal arteries that are branches of the central retinal artery (68). The natural history studies have defined the course of this particular form of retinal arterial occlusion and classified CLRAOs as a distinct entity. Etiologically CLRAO can be of three types: (1) non-arteritic CLRAO alone; (2) arteritic CLRAO associated with giant cell arteritis; and (3) non-arteritic CLRAO associated with CRVO or hemi-central vein occlusion (hemi-CRVO) (69–73).
Uveitis
Published in Mostafa Khalil, Omar Kouli, The Duke Elder Exam of Ophthalmology, 2019
Mostafa Khalil, Omar Kouli, Obaid Kousha
The choroid is the posterior component of the uveal tract. It lies between the sclera externally and retinal pigmented epithelium (RPE) internally. Its function is to provide nutrients to the outer third of the retina. It consists of Bruch's membrane and a vascular layer. Bruch's membrane: The innermost layer before the RPE. It is a highly homogenous structure consisting of five layers measuring less than 4 micrometres. The function is not clear; however, it may play a role in fluid transport from the choroid to the retina and is permeable to small molecules (e.g. fluorescein).Vascular layer: Consists of three layers: choriocapillaries which are external to the Bruch membrane, a medium-sized vessel layer and a large vessel layer. The choroid is perfused via two long posterior ciliary arteries, the short posterior ciliary artery and anterior ciliary artery.
How to master MCQs
Published in Chung Nen Chua, Li Wern Voon, Siddhartha Goel, Ophthalmology Fact Fixer, 2017
Branches of posterior ciliary artery supply the optic nerve head. Ischaemia causes optic nerve head swelling. Compared with the non-arteritic form, the visual loss in giant cell arteritis is usually profound and more often bilateral, unless steroid treatment is carried out early. C-reactive protein is a better indicator of response to treatment because its concentration changes more quickly with the amount of inflammation. The temporal artery lies on the temporalis fascia. Skip lesion may give a negative temporal artery biopsy but does not correlate with the severity of the disease.
Imaging-based Assessment of Choriocapillaris: A Comprehensive Review
Published in Seminars in Ophthalmology, 2023
Rohan Bir Singh, Tatiana Perepelkina, Ilaria Testi, Benjamin K. Young, Tuba Mirza, Alessandro Invernizzi, Jyotirmay Biswas, Aniruddha Agarwal
The arterial blood supply to the choroid predominantly arises from the ophthalmic artery branches from the internal carotid artery.19 The ophthalmic artery branches into two posterior ciliary arteries (in 48% of eyes) or three posterior ciliary arteries (in 38% of eyes). The posterior ciliary branches into the medial and lateral posterior ciliary arteries, showing different anatomical variations. The long posterior ciliary arteries arise from the medial and lateral posterior ciliary arteries, whereas the short posterior ciliary arteries arise from other branches of the posterior ciliary arteries. These branches are further divided into choroidal arterioles, which ultimately branch and segmentally feed into the choriocapillaris lobule.17 The recurrent branches of the long posterior and anterior ciliary artery supply the anterior choriocapillaris, and the short posterior ciliary arteries primarily supply the posterior choriocapillaris.
Comparison of Choroidal Vascularity Index in Patients with Pseudoexfoliation Glaucoma, Pseudoexfoliation Syndrome, and Healthy Controls
Published in Current Eye Research, 2022
Alev Ozcelik Kose, Serhat Imamoglu, Sevcan Balci, Nursal Melda Yenerel
The choroid is a dynamic structure, and its thickness varies depending on many factors such as age, axial length, high myopia, and high IOP.33,34 Choroidal blood flow is supplied by the posterior ciliary artery, a branch of the ophthalmic artery. Branches of the posterior ciliary arteries run along the choroid to supply the prelaminar and retrolaminar region.10 Of note, the prelaminar region also receives blood support directly from the posterior ciliary artery and the Zinn-Haller circle.35 The role of choroidal blood flow in glaucoma development has been shown in numerous studies.19,36–41 Considering the reduction in blood flow due to the accumulation of PEX material in the arterial and vein walls, recently, studies have examined blood flow in the ophthalmic artery in both PEG and PEX syndromes, with results demonstrating that hemodynamic parameters were altered in both cases.14,18 Glassi et al. showed that there was a deterioration in retrobulbar hemodynamics in eyes with PEG compared with primary open-angle glaucoma and healthy eyes.42 Detorakis et al. found that the end-diastolic volume was lower, and the resistance index score was higher in the short posterior ciliary artery in eyes with PEG compared to eyes with PEX syndrome.18
Structural Characterization of Glaucoma Patients with Low Ocular Blood Flow
Published in Current Eye Research, 2020
Kazuko Omodaka, Shunsuke Fujioka, Guangzhou An, Takuma Udagawa, Satoru Tsuda, Yukihiro Shiga, Soichiro Morishita, Tsutomu Kikawa, Kyongsun Pak, Masahiro Akiba, Hideo Yokota, Toru Nakazawa
The blood supply of the optic nerve originates in a branch of the posterior ciliary artery (PCA) and the circle of Zinn-Haller.22,23 Therefore, disturbances in these vessels may play a causative role in glaucomatous optic neuropathy. Additionally, the loss of retinal peripapillary capillaries (RPCs),24 measurable with OCTA, occurs in glaucoma, which is consistent with retinal nerve fiber loss. Moreover, the reduction of blood flow in the ONH, detectable with LSFG25 OCTA,26 and color Doppler imaging,27 is correlated to both nerve fiber loss in glaucoma and future glaucoma progression.17,18,28 Thus, it is an important question whether decreased OBF in the ONH is a cause or a result in glaucoma. As an initial strategy to answer this question, we set out in this study to adjust OBF measurements for confounding factors with a multi-regression analysis. We then investigated OBF-dependent phenotypes, and we hope to soon perform a prospective study. In the current study, we succeeded in creating an OBF index adjusted for confounding factors, proceeded to divide the patients into quartiles based on the adjusted OBF index, and then compared ONH structural characteristics between the high-OBF and low-OBF groups. Due to the accessibility of the ONH to fundus photography, our findings may be helpful for clinical glaucoma care.