| Doyne's honeycomb choroidopathy | An obsolete term for macular drusen. (05 Mar 2000) |
|---|---|
| Doyne, Robert Walter | <person> English ophthalmologist, 1857-1916. See: Doyne's honeycomb choroidopathy. (05 Mar 2000) |
| honeycomb | 1. A mass of hexagonal waxen cells, formed by bees, and used by them to hold their honey and their eggs. 2. Any substance, as a easting of iron, a piece of worm-eaten wood, or of triple, etc, perforated with cells like a honeycomb. <anatomy> Honeycomb moth See Reticulum. Origin: AS. Hunigcamb. See Honey, and 1st Comb. Source: Websters Dictionary (01 Mar 1998) |
| honeycomb lung | <radiology> Mnemonic: honey and SPICE, sarcoid, pneumoconiosis, interstitial fibrosis, collagen-vascular disease, eosinophilic granuloma, ** see also: interstitial lung disease, honeycombing (12 Dec 1998) |
| honeycomb macula | Oedema of the macular region of the retina. (05 Mar 2000) |
| honeycomb pattern | Dense, slightly irregular circular shadows, most common next to the pleura at the lung base, on chest radiographs or CT; caused by chronic interstitial fibrosis of diverse causes. (05 Mar 2000) |
| honeycomb ringworm | 1. <dermatology> A disease of the scalp, produced by a vegetable parasite. 2. A tile or flagstone cut into an hexagonal shape to produce a honeycomb pattern, as in a pavement. Synonym: favas and sectila. Origin: L, honeycomb. Source: Websters Dictionary (01 Mar 1998) |
| all-trans-retinal | The orange retinaldehyde resulting from the action of light on the rhodopsin of the retina, which converts the 11-cis-retinal component of the rhodopsin to all-trans-retinal plus opsin. Synonym: trans-retinal, visual yellow. (05 Mar 2000) |
| blood-retinal barrier | Specialised nonfenestrated tightly-joined endothelial cells that form a transport barrier for certain substances between the retinal capillaries and the retinal tissue. (12 Dec 1998) |
| central retinal artery occlusion | <ophthalmology> The sudden blockage of the retinal artery with a blood clot that commonly leads to a painless but irreversible blindness in that eye. (12 Jan 1998) |
| central retinal fovea | A depression in the centre of the macula retinae containing only cones and lacking blood vessels. Synonym: fovea centralis retinae, central pit. (05 Mar 2000) |
| central retinal vein occlusion | <ophthalmology> The sudden blockage of the retinal vein with blood clot that commonly leads to a painless irreversible blindness in that eye. (12 Jan 1998) |
| retinal | 1. <anatomy> Pertaining to the retina. 2. <biochemistry> The aldehyde of retinol, derived by the oxidative enzymatic splitting of absorbed dietary carotene and having vitamin A activity. In the retina, retinal combines with opsins to form visual pigments. One isomer, 11 cis retinal combines with opsin in the rods (scotopsin) to form rhodopsin or visual purple. Another, all trans retinal (trans r.), visual yellow, xanthopsin) results from the bleaching of rhodopsin by light, in which the 11 cis form is converted to the all trans form. Retinal also combines with opsins in the cones (photopsins) to form the three pigments responsible for colour vision. (18 Nov 1997) |
| retinal adaptation | Adjustment to degree of illumination. (05 Mar 2000) |
| retinal anlage tumour | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |