From Big Medical Encyclopedia

SLIT LAMP — the device for biomicroscopic examination of an eye allowing to reveal the smallest changes of its structures, to determine the size, character and localization of these changes, to find the foreign bodys of an eyeglobe available to survey.

A method of biomicroscopy of an eye (see) it is offered by A. Gulljspgrand in

1911, it designed for this purpose a slit lamp.

The research is conducted in the darkened room at illumination of the studied department of an eye by a narrow beam of light of high intensity. The form and size of a light bunch is defined by width of disclosure of a crack of a diaphragm in this connection the lamp received the name slot-hole. The image of a crack is projected on a cornea of an eye of the patient. At most opened diaphragm the diffusion lighting allowing to examine all sites of front department of an eye at a narrow crack is created — shining optical «section». At combination of a beam of light with the observed site the direct focal lighting which is most often applied at biomicroscopy of an eye to establishment of localization patol turns out. processes. At indirect lighting (a research in a dark field) observe the site lit by light reflected from deeper tissues of an eye. At the same time vessels, atrophic sites and ruptures of fabrics are well visible. For survey of transparent environments of an eye use lighting by a transmitted light and the method of the mirror field allowing to reveal microscopic roughnesses of a front surface of a cornea, fold of a descemete cover, the surface of the capsule of a crystalline lens.

Main parts Shch. l. — the binocular stereomicroscope (see), to-ry called corneal, with replaceable increases and the lighter with a slit diaphragm creating the image of the shining crack earlier. The distance from a microscope to the studied environment or tissue (working distance) usually makes 60 — 120 mm. The microscope and the lighter mount on a coordinate little table at an angle; they can turn on ±60 ° around the vertical axis passing through the middle of a head rest that gives the chance to consider optical «section» under various corners. The coordinate little table together with a support for a face of the patient (a front ustanov) is mounted on a tool little table with hydraulic or screw rise. In a set Shch. l. a tonometer (see Tonometers in ophthalmology) also other devices for a comprehensive investigation of an eye enter gonioskop (see Gonioskopiya) (prefixes for selection of contact lenses, laser devices for a research of retinal visual acuity, the photo and film device).

In the USSR are issued a stationary slit lamp (ShchLT) with a tonometer (fig.) and manual Shch. l. A light source in stationary Shch. l. the filament lamp of 6 in is, 25 W. The binocular microscope has 5 steps of increase: 5; 9; 18; 35; 60.

The measuring eyepiece allows

Fig. A slit lamp with a tonometer of ShchLT:

1 — a tool little table; 2 — a coordinate little table; z — the lighter; 4 — the handle of the mechanism of a crack; 5 — the binocular microscope; 6 — a flywheel of installation of increase in the binocular microscope; 7 — an applanation tonometer; 8 — the device for fixing of a look; 9 — a head rest; yu — an optical wedge of a tonometer;

11 — front ustan.

to determine depth of an anterior chamber of an eye. By means of the handle of a slit diaphragm smooth adjustment of the image of a crack from 0,04 to 8 mm across and from 0,04 to 15 mm down is provided. For a research of a retina, an optic disk and a horioidea the attachment replaceable oftalmoskopichesky lens by force + 60 dptr joins. The applanation tonometer allows to measure true intraocular pressure ranging from 10 to 120 mm of mercury. and tonometric pressure is from 5 to 60 mm of mercury. The weight (weight) of a lamp without tool little table of 13,7 kg, with a little table — 31 kg.

Manual Shch. l. it is more compact and convenient at inspection of patients in a prone position, and also children, but has smaller functionality. It consists of a magnifying glass with increase 4 — 7 and the lighter creating the image of a crack from 0,1 to 5 mm wide and not less than 6 mm long. Manual Shch. l. are included in the package of the universal manual ophtalmoscope with fiber light guides OVSR-01 and the manual electric OP-2 ophtalmoscope (see Oftalmoskopiya, devices). Release also operating rooms Shch. l., allowing to investigate the patient in a prone position.

The device should be stored in the dry heated room at f from 1 to 40 ° and relative humidity of air no more than 80%; air shall not contain reactive vapors, gases and dust. At operation shch. l. it is necessary to preserve it against blows, pushes, against contact with firm objects, not to touch with hands a surface of optical details, and in case of their pollution to wipe with a flannel or suede.

Bibliography: V. V. wolves, Gore -

ban A. I. and Dzhaliashvi-l and O. A. Clinical trial of an eye by means of devices, page 7, L., 1971; Shulpina N. B. Biomicroscopy of an eye, M., 1974. R. M. Tamarova.