PURPOSE Visual impairment and intracranial pressure (VIIP) syndrome is a health concern for long-duration spaceflight, and a proposed risk factor is elevation of intracranial pressure (ICP). Our goal was to use finite element modeling to simulate how elevated ICP and interindividual differences affect tissue deformation within the optic nerve head (ONH). METHODS We considered three ICP condit...

BACKGROUND Research into retinal ganglion cell (RGC) degeneration and neuroprotection after optic nerve injury has received considerable attention and the establishment of simple and effective animal models is of critical importance for future progress. METHODOLOGY/PRINCIPAL FINDINGS In the present study, the optic nerves of Wistar rats were semi-transected selectively with a novel optic nerv...

To the Editor: We applaud Hamilton et al 1 for their recent contribution to the study of the retrobulbar optic nerve sheath diameter as a noninvasive surrogate for intracranial pressure. However, although its science appears sound, this article brings to light what we believe is an important limitation to the study of this topic in general: the lack of uniformity in how exactly the optic nerve ...

Secondary degeneration occurs commonly in the central nervous system after traumatic injuries and following acute and chronic diseases, including glaucoma. A constellation of mechanisms have been shown to be associated with secondary degeneration including apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, derangements in ionic homeostasis and calcium influx. Glial cells, such as...

Glaucoma is a result of increased intraocular pressure leading to damage to retinal ganglion cells and optic nerve axons. The aim of this study was to evaluate HIF-1 expression in optic nerve axons and retinal ganglion cells in 42 eyes enucleated because of complete glaucoma compared to eyes removed because of injury.The immunohistochemical reaction was done and specimens were examined under a ...

Aim: To evaluate the utility of measuring the optic nerve sheath diameter in children with shunted hydrocephalus, suspected of having raised intracranial pressure. Methods: 23 children with shunted hydrocephalus were examined, six had well controlled ICP, 17 however manifested symptoms suggestive of intracranial hypertension. A clinical history was taken from all patients and their parents or c...

AIM To evaluate the utility of measuring the optic nerve sheath diameter in children with shunted hydrocephalus, suspected of having raised intracranial pressure. METHODS 23 children with shunted hydrocephalus were examined, six had well controlled ICP, 17 however manifested symptoms suggestive of intracranial hypertension. A clinical history was taken from all patients and their parents or c...

Congenital absence of the optic nerve in man is a very rare anomaly (Duke-Elder, I963, I964). In true cases the optic disc, optic nerve fibres, and central retinal blood vessels are absent on ophthalmoscopic examination. Hypoplasia of the optic nerve, which is also rare, occurs when some or all of the nerve fibres fail to develop and reach the disc. The condition may be unilateral or bilateral,...

We studied the time of origin, development and location of glial elements in the developing optic nerve of Xenopus with light and electron microscopy. The first cells acting as a primitive glia are ependymal cells lying dorsal to the chiasmatic optic nerve (CON) at Nieuwkoop & Faber (1956) NF stage 39. Later (stage 47/48), immature astrocyte cell bodies migrate from the periphery of the middle ...