Pathogenesis of visual field defects. Role of the ciliary circulation.
TL;DR: The present study demonstrates such a sectoral blood supply in the optic nerve head and choroid and is of considerable significance in explaining the site of the lesion and the pathogenesis of these defects.
Abstract: Clinically the presence of nerve fibre bundle defects in glaucoma and non-glaucomatous lesions, and altitudinal or vertical hemianopias in pre-chiasmal lesions has been known for a long time. These suggest a sectoral lesion in the optic nerve or retina. In the majority of such cases, no retinal lesion is seen to account for these visual field defects. It has been presumed that the lesion lies in the optic nerve. Such a visual field defect can be produced only by a sectoral lesion. Most of these field defects are considered to be vascular in origin, but studies of the blood supply of the optic nerve have so far failed to demonstrate any segmental blood supply to the nerve which could explain them. The present study demonstrates such a sectoral blood supply in the optic nerve head and choroid and is of considerable significance in explaining the site of the lesion and the pathogenesis of these defects.
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TL;DR: Emerging information on the various factors that influence the optic nerve circulation, and also the various systemic and local risk factors which play important roles in the development of various types of ischemic optic neuropathy have given a better understanding of their pathogeneses, clinical features and management.
493 citations
TL;DR: An enhanced understanding of the nature of the optic nerve damage in POAG and improved methods of study may result in earlier diagnosis or allow us to distinguish among different pathological processes all currently grouped under the diagnosis of POAG.
395 citations
Journal Article•
TL;DR: Serial reconstructions of radioautographs and peroxidase-reacted sections of the optic nerve heads demonstrated that the orthograde and retrograde transport obstructions were coincidental anatomically by light microscopy in the LS and occurred most prominently in the temporal quadrants of the nerve head.
Abstract: Orthograde and retrograde axoplasmic transport have been studied in the optic nerve heads of 37 Macaca fascicularis eyes with normal or elevated intraocular pressure (IOP) produced by cannulation of the anterior chamber Orthograde transport was labeled by 3H-amino acids injected intravitreally and incorporated into retinal ganglion cell proteins Retrograde transport was studied in the same eyes by injecting horseradish peroxidase (HRP) into one or both optic tracts and dorsal lateral geniculate nuclei (dLGN) Both tracers accumulated in the lamina scleralis (LS) of eyes maintained at pressures of 25 to 150 mm Hg for 12 to 28 hours (pressure in normal controls = 10 to 14 mm Hg) but the HRP technique was markedly more sensitive The degree of retrograde transport obstruction in the LS appeared to be directly proportional to both the height and the duration of elevated IOP In one experiment, the blockades of orthograde and retrograde transport induced at 50 mm Hg were demonstrated to be reversible Serial reconstructions of radioautographs and peroxidase-reacted sections of the optic nerve heads demonstrated that the orthograde and retrograde transport obstructions were coincidental anatomically by light microscopy in the LS and occurred most prominently in the temporal quadrants of the nerve head These transport obstructions occurred at moderate elevations of IOP (25 TO 50 mm Hg) despite (1) elevated arterial PO2 levels during inhalation of 100 percent oxygen and (2) intact nerve head capillary circulation, as demonstrated by perfusion with nucleated avian erythrocytes
370 citations
TL;DR: The objective of this paper is to differentiate myths and misconceptions from reality about the OnH blood supply; to elucidate the reasons for disagreement on the blood supply of the ONH; and to evaluate the reliability and validity of various methods currently used to measure ONH blood flow.
337 citations
TL;DR: In this article, the authors investigate systematically the natural history of visual outcome in central retinal artery occlusion (CRAO), and classify CRAO eyes into four categories: non-arteritic (NA) CRAO, arteritic (AR), NA-CARO with cilioretinal artery sparing (35), transient NA-CRO (41), and arteritic CRAO (13).
326 citations
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1,072 citations
TL;DR: The 418 pages devoted to these and other structures portray the system as a whole in an orderly fashion and with considerable new material, including a detailed account of the blood supply and drainage.
Abstract: There are four outstanding features of this work which the reviewer believes will stand as a monumental classic. These are the historic, anatomic, pathologic, and biologic aspects of the vertebrate visual system. The author’s approach was primarily anatomic. Therefore, this section describes in minute detail the gross and microscopic structures concerned with the visual pathways which center chiefly on man, apes, and monkeys. Naturally, there is some repetition concerning the retina and optic radiation from the author’s previous works. However, the 418 pages devoted to these and other structures portray the system as a whole in an orderly fashion and with considerable new material, including a detailed account of the blood supply and drainage. The most helpful part of the anatomic portion deals with the general theory of the organization of the nervous systems and visual functions. Here one finds in review an interpretation of neuronal patterns, especially retinal elements. Biographic sketches with photographs of those who have made significant contributions to this phase of the subject are scattered throughout this section. The first section of this book deals historically with the study of the visual system. In dealing with the pathologic and biologic sections, the historical aspect is also stressed as each topic of discussion is brought into focus.
254 citations
01 Jan 1930
TL;DR: An important chapter deals with workmen's compensation, a subject that is rapidly becoming of practical importance in all countries, and a best exponent than Thiel could not have been found, as his researches have covered many parts of this field.
Abstract: One of the outstanding features of this remarkable "Handbuch" is the promptness with which its volumes are appearing. The new volume is the fourth and contains : "The Diseases of the Conjunctiva, Cornea and Sclera," which are described by Professor Schieck, of W\l=u"\rzburg Dr. Cramer, of Kottbus, contributes the part on the "Injuries and Occupational Diseases of the Eye," including the subject of "Compensation." "Sympathetic Diseases of the Eye" are treated by Professor Reis, of Bonn. "The Physiology and Pathology of Intra-Ocular Pressure and Glaucoma" are discussed by Professor Thiel, of Berlin. The part on the conjunctiva, cornea and sclera occupies one half of the volume. Professor Schieck has treated this important part in a masterly way, presenting the essentials and omitting nothing of importance, with many new and excellent illustrations, often in colors, pertinent slit-lamp findings and a brief bibliography. The second part on injuries and occupational diseases as they pertain to the eye was written by Dr. E. Cramer, of Kottbus, who unfortunately died in 1929; his nearly completed manuscript had to be revised and brought up to date by Dr. O. Thies, of Dessau. The subject is systematically treated and adequately illustrated, and a useful bibliography is appended. Burns and injuries by caustics are particularly well described and are evidence of the large experience gained by Dr. Thies in Dessau. An important chapter deals with workmen's compensation, a subject that is rapidly becoming of practical importance in all countries. That important and still obscure condition, sympathetic disease, is handled by Prof. W. Reis, of Bonn. After a description of sympathetic irritation, sympathetic ophthalmia is considered under the following headings : the conditions that lead to sympathetic inflammation, the clinical picture of sympathetic uveitis, sympathetic serous iritis, sympathetic papilloretinitis, retinal periphlebitis, retrobulbar neuritis, sympathetic chorioretinitis, detachment of the retina and secondary glaucoma. Pathology, etiology, diagnosis and treatment complete this unusually well written chapter. Professor Thiel, writing on the physiology and pathology of ocular pressure, first speaks of the normal height and variations of intra\x=req-\ ocular pressure; then he takes up the relation of ocular pressure to intracranial pressure, local blood pressure, general blood pressure, the constitution of the blood, internal secretion and the vegetative nervous system. This is a most timely exposition of a subject that at present is arousing a great deal of interest, and a better exponent than Thiel could not have been found, as his researches have covered many parts of this field. An excellent bibliography will be of great use to those working in this subject.
235 citations