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The Most Probable Origin and Initial Global Spread of HIV
Published in James Chin, Jeffrey Koplan, The AIDS Pandemic, 2018
The history of Zaire as told and painted by Tshibumba Kanda Matulu in conversation with Johannes Fabian. Then Lumumba himself was now the Prime Minister. As Prime Minister in Kinshasa, in ’60, he issued an order: “All the Belgians living in Zaire – or rather the Congo – they all must leave. Within twenty-four hours they should be on their way. I don’t want to see whites any more,” he said. “I don’t want to see a white person in the Congo.”http://www2.fmg.uva.nl/lpca/aps/tshibumbaintro.html
Ocular Blood Flow and Metabolism
Published in Neil T. Choplin, Carlo E. Traverso, Atlas of Glaucoma, 2014
Alon Harris, Leslie Abrams Tobe, Brent Siesky
The innermost layer of the choroid, the choriocapillaris, is composed of richly anastomotic, fenestrated capillaries beginning at the optic disc margin (Figure 12.3). The capillaries of the choriocapillaris are separate and distinct from the capillary beds of the anterior optic nerve. The SPCAs supply most of the optic nerve head and the portion of the choriocapillaris posterior to the equator. The choriocapillaris anterior to the equator is supplied by the long posterior ciliary arteries (LPCAs) and the anterior ciliary arteries (ACAs), which are branches of the OA. The LPCAs pierce the sclera and course anteriorly through the suprachoroidal space to branch near the ora serrata. Each LPCA then sends three to five branches posteriorly to supply the choriocapillaris anterior to the equator. The ACAs accompany the rectus muscles anteriorly to supply the major circles of the iris (Figure 12.4). Before reaching the iris, 8–12 branches pass posteriorly through the ciliary muscle to supply the anterior choriocapillaris together with the LPCAs (Figure 12.5). Functional anastomoses between the choriocapillaris anterior and posterior to the equator have not been demonstrated, representing a peripheral choroidal watershed zone.
Biomechanics of suprachoroidal drug delivery: From benchtop to clinical investigation in ocular therapies
Published in Expert Opinion on Drug Delivery, 2021
Shelley E. Hancock, Chen-Rei Wan, Nathan E. Fisher, Rafael V. Andino, Thomas A. Ciulla
Lastly, the vasculature in the choroid may also play an important role in the clearance of fluids and molecules from the SCS [25]. Interactions between the choroid and the properties of the injectate, including particle charge and/or size, can significantly influence drug transport. The fenestrated choriocapillaris is estimated to have pore sizes between 6 and 12 nm with a negatively charged glycocalyx matrix [26]. Furthermore, the choriocapillaris also has been shown to impede suprachoroidal fluid patterns [27]. Chiang et al. found that the long posterior ciliary artery (LPCA), attached to the sclera at multiple points, serves as aphysical barrier for fluid and particle flow in the SCS as it can create localized restrictions in the opening of the SCS. Additional venous pathways within the SCS have also been documented with corrosion casting or fluorescent imaging of the space [28,29]. The presence of these pathways may impact both fluid distribution and clearance.
Risk of Anterior Segment Ischemia Following Simultaneous Three Rectus Muscle Surgery: Results from a Single Tertiary Care Centre
Published in Strabismus, 2018
Shailja Tibrewal, Ramesh Kekunnaya
The pathological basis of development of anterior segment ischemia following tenotomy of rectus muscles can be understood by studying the anterior segment circulation. The anterior segment of the eye derives its blood supply from two types of vessels; the long posterior ciliary arteries (LPCA) and the anterior ciliary arteries (ACA). The medial and lateral LPCA run in an intrascleral course beneath the medial and lateral rectus muscles respectively. The anterior ciliary vessels originate within the rectus muscles belly and are derived from the muscular branches of the ophthalmic artery. Barring a few anatomical variations, mostly there are two anterior ciliary arteries in all rectus muscles excepting the lateral rectus muscle which has one ACA.16,17 Primate studies have shown that the LPCA account for around 30% and ACA account for 70–80% of anterior segment circulation.18 Additionally there are three levels of anastomosis between the two sets of circulation; one between the adjacent ACA at the episcleral circle and two between the LPCA and ACA at the intramuscular circle and the major arterial circle. Experimental primate studies have shown that occlusion of the long posterior ciliary arteries in itself produces no changes in the anterior segment circulation.19 Similarly, when two or three rectus muscles are operated simultaneously it leads to transient mild to moderate ASI. However when all four muscles are tenotomised or when the posterior circulation is occluded along with the horizontal rectus muscle surgery, it leads to severe ASI in monkeys.19