| IOA | inner optic anlage; International Osteopathic Association |
|---|---|
| ION | ischemic optic neuropathy |
| IOT | intraocular tension; intraocular transfer; ipsilateral optic tectum |
| LHON | Leber hereditary optic neuropathy |
| LOA | leave of absence; Leber optic atrophy; left occipitoanterior [fetal position] |
| fleck retina of Kandori | An autosomal-recessive disorder of the retinal pigment epithelium occurring among Japanese. (05 Mar 2000) |
|---|---|
| layers of retina | Light sensitive layer of the eye. In vertebrates, looking from outside, there are four major cell layers: (i) the outer neural retina, which contains neurons (ganglion cells, amacrine cells, bipolar cells) as well as blood vessels, (ii) the photoreceptor layer, a single layer of rods and cones, (iii) the pigmented retinal epithelium (PRE or RPE), (iv) the choroid, composed of connective tissue, fibroblasts and including a well vascularised layer, the chorio capillaris, underlying the basal lamina of the PRE. Behind the choroid is the sclera, a thick organ capsule. In molluscs (especially cephalopods such as the squid) the retina has the light sensitive cells as the outer layer with the neural and supporting tissues below. See: retinal rods, retinal cones, rhodopsin. (18 Nov 1997) |
| leopard retina | A normal fundus to which a deeply pigmented choroid gives the appearance of dark polygonal areas between the choroidal vessels, especially in the periphery. Synonym: fundus tigre, leopard fundus, leopard retina, mosaic fundus, tigroid fundus, tigroid retina. (05 Mar 2000) |
| limiting membrane of retina | One of two layers of the retina: (05 Mar 2000) |
| axis, optic | <microscopy> The direction, or directions in an anisotropic crystal along which light is not doubly refracted. (05 Aug 1998) |
| 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) |
| glioma of optic chiasm | A slow-growing tumour, usually an astrocytoma, of the optic chiasm in children. (05 Mar 2000) |
| medial root of optic tract | The smaller division of the posterior end of the optic tract that disappears under the medial geniculate body. Synonym: radix medialis tractus optici. (05 Mar 2000) |
| Graves' optic neuropathy | Visual dysfunction due to optic nerve compression in Graves' orbitopathy. (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) |
| principal optic axis | A line passing through the centre of the lens of a refracting system at right angles to its surface. (05 Mar 2000) |
| septo-optic dysplasia | <radiology> Blindness, hypopituitarism, hypoplastic optic nerves, optic chiasm rotated 90 degrees, bulbous 3rd ventricle, CT findings: absent septum pellucidum, small optic nerves (12 Dec 1998) |
| neuroma, optic | A benign tumour of the optic nerve. (12 Dec 1998) |
| depression of optic disk | The normally occurring depression or pit in the centre of the optic disc. Synonym: excavatio disci, depression of optic disk, excavatio papillae, physiologic cup, physiologic excavation. (05 Mar 2000) |