| drusen of the optic nerve head | Basophilic, laminated, calcareous acellular masses that resemble crystals within the nerve head, anterior to the lamina cribrosa, that may simulate papilledema and/or cause visual field defects. Synonym: intrapapillary drusen. (05 Mar 2000) |
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| optic nerve drusen | Basophilic, calcareous, laminated acellular bodies within the optic nerve anterior to the scleral lamina cribrosa. (05 Mar 2000) |
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| optic disk drusen | Hyaline bodies occurring in the intra-ocular portion of the optic nerve. They are distinguished from retinal drusen, which lie beneath the retinal pigment epithelium. This disorder is differentiated also from papilledema by the absence of dilated retinal vessels. (12 Dec 1998) |
| optic nerve head | The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve. Because the retina at the optic disk has no photoreceptors there is a corresponding blind spot in the visual field. (12 Dec 1998) |
| macular drusen | Excrescences of Bruch's membrane that produce a window in the retinal pigment epithelium and are a feature of age-related macular retinal degeneration. Synonym: macular drusen. (05 Mar 2000) |
| giant drusen | An obsolete term for a glial hamartoma of the optic nerve head or the peripapillary retina, seen in tuberous sclerosis. (05 Mar 2000) |
| retinal drusen | <ophthalmology> Colloid or hyaline bodies lying beneath the retinal pigment epithelium. They may occur either secondary to changes in the choroid that affect the pigment epithelium or as an autosomal dominant disorder of the retinal pigment epithelium. (12 Dec 1998) |
| drusen | Small bright structures seen in the retina and in the optic disc. Origin: Ger. Pl. Of druse, stony nodule, geode (05 Mar 2000) |
| drusen of the macula | Excrescences of Bruch's membrane that produce a window in the retinal pigment epithelium and are a feature of age-related macular retinal degeneration. Synonym: macular drusen. (05 Mar 2000) |
| intrapapillary drusen | Basophilic, laminated, calcareous acellular masses that resemble crystals within the nerve head, anterior to the lamina cribrosa, that may simulate papilledema and/or cause visual field defects. Synonym: intrapapillary drusen. (05 Mar 2000) |
| ganglionic layer of optic nerve | <anatomy, nerve> The inner layer of multipolar neurons in the retina consisting of the relatively large neurons that give rise to the fibres of the optic nerve. Synonym: stratum ganglionare nervi optici. (05 Mar 2000) |
| vascular circle of optic nerve | <anatomy, nerve> A network of branches of the short ciliary arteries on the sclera around the point of entrance of the optic nerve. Synonym: circulus vasculosus nervi optici, circulus arteriosus halleri, circulus zinnii, Haller's circle, Zinn's corona, Zinn's vascular circle. (05 Mar 2000) |
| coloboma of optic nerve | <anatomy, nerve> A congenital notch in the formation of the optic nerve, appearing as a craterlike excavation at the optic disk. (05 Mar 2000) |
| postlaminar part of optic nerve | <anatomy, nerve> The portion of the optic nerve posterior to the lamina cribrosa of the sclera. Synonym: pars postlaminaris nervi optici. (05 Mar 2000) |
| prelaminar part of optic nerve | <anatomy, nerve> The portion of the optic nerve anterior to the lamina cribrosa of the sclera. Synonym: pars prelaminaris nervi optici. (05 Mar 2000) |
| dural sheath of optic nerve | <anatomy, nerve> The outer sheath around the optic nerve, continuous with the dura mater. Synonym: vagina externa nervi optici, dural sheath of optic nerve. (05 Mar 2000) |