EYEGROUND (fundus oculi) — the inner surface of an eyeglobe seen at an oftalmoskopiya: an optic disk, a retina with the central artery and the central vein and a choroid.
At oftalmoskopiya (see) with a usual light source (electrolamp) an eyeground (tsvetn. fig. 2) has red color which develops of a combination of three components: dark brown, caused by a retinal pigment, prevailing red (from blood in a choroid) and white (from raying of a sclera). Intensity of coloring of G. of generally depends on quantity of a retinal and choroidal pigment. At people with a large number retinal (in a retina) and choroidal (in a choroid) a pigment color G. of more dark and evenly red since more deeply the lying vessels of a choroid do not appear through. At insignificant quantity retinal and big a choroidal pigment of G. of has uneven coloring owing to raying on certain sites of a choroid; such G. carries the name parquet (fundus tabulatus; tsvetn. fig. 3). Pigmentation of a bottom of an eye to the periphery often decreases and G. has lighter coloring.
In the bottom the bottom is, as a rule, painted is lighter, than in upper.
Trace amount of a pigment in an epithelium of a retina and in a choroid causes a pale red background, sometimes with a yellow shade (tsvetn. fig. 4); vessels of a choroid well appear through in the form of the orange-red strips connecting in dense network. In the field of the equator of an eye the vortikozny (water portal) veins having an appearance of wide pink strips, ampoules in which narrower veins of a choroid connect are excreted. Vessels of a choroid are best of all visible at albinos.
On a red background of G. of are allocated an optic disk (discus n. optici), macula lutea (s. macula lutea) and vessels of a retina. Oftalmoskopiya does not give the chance at the same time to observe all G.'s picture of therefore in the beginning examine an optic disk, then the central part of a bottom with a macula lutea and, at last, the periphery of a retina.
The optic disk of light pink color in the form of clearly the outlined circle or an oval stands out on G. of clearly. Its coloring develops of three elements: blestyashcheserovaty color of fibrils of an optic nerve, white color of connective tissue fibers of a trellised plate of a sclera (lamina cribrosa) and red color of vessels. The combination of these elements also makes light pink coloring of a disk, can give edges depending on individual fluctuations of these elements insignificant fiziol, variations. Owing to uneven distribution of nerve fibrils and vessels color of a disk on various sites is not identical. In an outside half of a disk the nerve fiber layer is thinner also the number of vessels less in this connection it is represented to more pale in comparison with an internal pink half; often on a disk grayish points owing to raying of openings of a trellised plate are noted. The optic disk is flush with the retina surrounding it. In the center of a disk in the place of an exit of vessels deepening, a so-called vascular funnel is almost always noted, at the bottom the cut is illuminated by white fabric of a trellised plate. Sometimes in a temporal half of a disk there is a bowl-shaped deepening of white color — so-called physiological deepening of a disk (excavation). Unlike patol, deepenings it occupies only a part of a disk, without reaching its edge, and thus, between edge of a disk and fiziol, the strip of light pink color is always available deepening. Borders of a disk accurate, and the temporal party is allocated more sharply, than nasal since towards a macula lutea there is thinner and more translucent nerve fiber layer (a papillo-macular bunch). Quite often the disk is surrounded with a narrow white sickle or a ring (a scleral ring) that is caused by the sclera translucent here. To a scleral ring often prilezhit the thin black rim covering all disk or a part it — a choroidal ring. It represents the edge of an opening which is strongly pigmented and translucent through transparent tissue of a retina in a choroid.
Diameter of an optic disk is equal to about 1,5 mm (with fluctuations from 1,25 to 1,7 mm). Its visible sizes, as well as the sizes of other elements G. of, much more also depend on a method of an oftalmoskopiya, on a magnifying glass, about a cut the research, and also from a refraction of the studied eye is made. Diameter of an optic disk as size approximately constant, is used for measurement of the space relations on G. by.
Or a little knutra from it leaves the central artery of a retina (a. centralis retinae) accompanied by the corresponding vein (v. centralis retinae), the located knaruzha from an artery the center of an optic disk. The artery and a vein are divided into two leading branchs going up and down and dividing a disk into internal and outside half. Quite often the artery shares in a trunk of an optic nerve, behind an eyeglobe, and in these cases top and bottom its branches appear on G. of separately. In turn top and bottom arteries and veins on a disk or near it are divided into arterioles and venules from which one go in top and bottom parts of the temporal (outside) party of G. of (arteriola et venula temporales sup. et inf.), and others — in top and bottom parts of the nasal (internal) party (arteriola et venula nasales sup. et inf.). Further vessels it is treelike branch, extending according to all G. The separate vessels leaving from an artery on an optic disk and the small lateral branches going from larger temporal top and bottom arterioles and venules approach a macula lutea; they terminate, without reaching a macula lutea. Occasionally between a disk and a macula lutea branches of vessels (so-called tsilioretinalny vessels) which leave at temporal border of a disk are visible; they originate not from the central artery of a retina, and from back short ciliary arteries, from a vascular circle of an optic nerve (a ring the Wood reed), and go to a macula lutea.
Arterioles and venules of a retina easily differ from each other: arteries — thinner and lighter-red stipitates, veins thicker, more dark and are more twisting. Arterioles among themselves do not cross; decussation is observed only between arterioles and venules. On site decussation if the arteriole is ahead of a venule, the last appears through through a transparent wall of an arteriole. The ratio of caliber of arterioles and venules of a retina is defined as 2:3. On vessels of a retina silver-white strips of a light reflex (the brilliant narrow lines arising owing to reflection of light from a column of the blood proceeding in a vessel) are visible. On arterioles they wider also have continuous character, on venules — discontinuous. On an optic disk of a healthy eye the pulsation of a vein is quite often noted. In an artery the pulsation is observed only as patol, the phenomenon at insufficiency of aortal valves or at glaucoma when diastolic pressure in the central artery of a retina is lower than intraocular. The pulsation of an artery can be caused artificially, pressing on an eyeglobe (see. Oftalmodinamometriya ).
Extremely important site of a retina having function of the central sight (the highest sight in a retina), is the macula lutea (s. macula lutea) with the central pole (fovea centralis). The macula lutea is located knaruzh approximately on 2 diameters of a disk from its temporal border; the center is a little lower than it the horizontal line passing through the middle of a disk. The macula lutea is allocated in more dark color; it has the form of horizontally located oval, on edge to-rogo often, especially at young age, the silver-white arch or a ring — a macular reflex is noted. This light reflex arises thanks to a thickening of a retina in the form of the roller around a macula lutea. In the center of a macula lutea more dark round speck — a dimple (foveola) with a brilliant point in the middle is looked through. At people of advanced age the macula lutea stands out less clearly, at the same time light reflexes are usually poorly expressed or absolutely are absent; situation he is judged in this case on more dark coloring and lack of vessels.
At a usual oftalmoskopiya yellow color of a spot is indiscernible on a red background of G. of; it is possible to see it only at the oftalmoskopiya in redless light offered by Vogt (A. Vogt, 1913). This method is used for a research of a retina and an optic disk. At a research with the light source deprived by means of the blue-green light filter of red beams is represented to G. painted in green-blue color, vessels of a retina seem almost black, a macula lutea citreous and in it it is possible to find the thin vascular branches invisible at a usual oftalmoskopiya (tsvetn. fig. 5) since short-wave beams are reflected generally from the surface of a retina. F. Dimmer established that yellow color depends on the pigment which is in a retina in the field of a macula lutea. Except redless, light which is variously painted by means of light filters is applied to an oftalmoskopiya.
In 1960 the complex method of a research G. of light of various spectral structure including a comparative oftalmoskopiya in blue, yellow, red, redless, flavovirent and purple light is developed (see. Oftalmoskopiya ).
At a research G. of in redless and flavovirent light it is possible to see the course and distribution of nerve fibrils of a retina. These fibers in the form of white strips begin from a disk, are bent through its edge and disperse fanlikely. About a disk of fiber are more rough and more clearly expressed, than on the periphery. Part of them follows the direction of large vessels and reaches the periphery, a part goes to a macula lutea, forming a papillomakulyarny bunch. At a macula lutea some fibers are abruptly bent, accept the vertical direction and, bordering a macula lutea from the temporal party, are lost in it. The fibers going from a disk up and down do not participate in formation of a papillomakulyarny bunch; they are bent and cross at an obtuse angle, and partly, without crossing, go to the periphery. Fluorescent allows to define the blood circulating in vessels of a retina and a choroid angiography (see). With its help it is possible to specify the reasons of a circulatory unefficiency in vessels of a retina (obturation, a spasm), to reveal indiscernible at an oftalmoskopiya patol, processes in a macula lutea and an optic nerve, to differentiate tumoral and inflammatory processes, early changes of vessels at diabetes.
The peripheral border of G. of corresponds to the gear line (ora serrata); it has more dark coloring and is visible at a mydriatic pupil and maximum deviation of an eye in the relevant party. G.'s periphery of is better visible at use of a special method of the research consisting in local impression of an eyeglobe and observation with the help slit lamp (see) through gonioskop with the corresponding mirror (see. Gonioskopiya ).
Pathological changes of G. of are caused by damage of an optic nerve, mesh and vascular covers of an eye, and also a boundary membrane of a vitreous.
Oftalmoskopicheski at damage of an optic nerve is distinguished by the changes which are followed by a hyperemia and a papilledema — a congestive nipple, ischemic hypostasis of a disk, a pseudo-congestive nipple (see. Congestive nipple ), neuritis; atrophic changes (primary and secondary atrophy of an optic nerve), tumors of an optic disk and anomaly of development (see. Optic nerve ). In some cases changes come to light oftalmoskopichesk only when process, having begun somewhere in an optic nerve behind an eye, reaches a disk (retrobulbar neuritis, the descending atrophy).
Patol, changes in a retina of an oftalmoskopicheska are characterized by emergence in it diffusion opacifications or the limited white centers, hemorrhages and dispigmentation, change of vessels. Are the cornerstone of these changes inflammatory (see. Retinitis ), circulator and exchange (see. Retinopathy ), dystrophic processes, disturbances of blood circulation and anomaly of development (see. Retina ).
The changes of a choroid seen at an oftalmoskopiya are a consequence of inflammatory, dystrophic, sclerous processes, new growths and anomalies of development. In most cases inflammatory processes of a choroid have focal character (see. Choroiditis ). At the same time the pigmental epithelium of a retina is involved in process owing to what in the area patol, changes accumulation glybok a pigment appears. Gradually on site the inflammatory centers there are atrophic changes which are the main oftalmoskopichesky sign of defeat of a choroid. Some changes of G. of, napr, you - standing of a disk at a congestive nipple, a speckled reflex on arteries at a diabetic angiopatiya of a retina, come to light at an oftalmokhromoskopiya better. Microaneurysms at a diabetic angiopatiya of a retina well come to light at a fluorescent angiography.
Clinicodiagnostic characteristic of changes of an eyeground
Bibliography Arkhangelsk V. N. Morphological bases of ophthalmologic diagnosis, M., 1960; Berezinskaya D. I. Bases of oftalmoskopichesky diagnosis, M., 1960; A. M. Oftalmokhromoskopiya's Water carriers, Atlas, M., 1969, bibliogr.; V. V. wolves, Gore of baths of A. I. and Dzhaliashvili O. A. Clinical trial of an eye by means of devices, L., 1971; The Multivolume guide to eye diseases, under the editorship of V. N. Arkhangelsky, t. 1, book 2, page 16, M., 1962, bibliogr.; P l and t and with P. S. Oftalmoskopichesky the atlas, M., 1960; Radzikhovsky B. A. Oftalmoskopicheskaya diagnosis (with the oftalmoskopichesky atlas), Chernovitsa, 1957; P and d N about t of M. The atlas of eye diseases, the lane with Wenger., t. 2, Budapest, 1963; Shulpina N. B. Biomikrosko-piya of an eye, M., 1974, bibliogr.; Der Augenarzt, hrsg. at. To. Velhagen, Bd 1, S. 559, Lpz., 1969, Bibliogr.; System of ophthalmology, ed. by S. Duke-Elder, v. 5, L., 1970; Trevor-Roper P.D. The eye and its disorders, Oxford, 1974.
H. K. Ivanov; originator of table. A. M. Vodovozov.