Slit lamp

The slit lamp (also: slit lamp microscope) is one of the most important ophthalmic examination instruments with which the ophthalmologist or optometrist can inspect the eyes stereoscopically. It was introduced by the Swedish physician and Nobel laureate Allvar Gullstrand 1911 in ophthalmology.

History of slit lamp

For microscopic examination of the eye led Gullstrand 1910, powered by a Nernst lamp lighting a gap. The industrial production of such slit lamps, but with equally bright incandescent light, first performed at Carl Zeiss in Jena and Haag-Streit, Bern. The extensions developed there by Goldmann, hangman, Koeppe, Vogt and others made the slit lamp soon became the major investigation unit of ophthalmology. The coupling of the slit lamp with a laser light source enables since the mid 20th century and surgical actions and made the slit lamp the most versatile instrument of ophthalmology.

Function and application

This optical device offers the investigator the possibility of a sharply defined gap-shaped light beam whose width can be varied to direct the eye. At the same time he has the opportunity to look at this through a light microscope. The magnification of the microscope is variable with most devices and usually ranges from 6 - to 30- fold.

Through various exposure methods (diffuse, direct, focal, indirectly, regressed, side, etc. ) and variable light gap widths, it is possible to inspect almost all front, middle and rear portions of the eye to complex, located in the peripheral regions of the retina. For some investigations are additional tools, such as a three- mirror contact lens, necessary.

Most modern slit lamps are additionally equipped with a tonometer Goldmann, which is used to measure the intraocular pressure. A combination with digital cameras is possible to document findings on film or in photographs.

Production and quality of slit lamps in Germany regulates the standards committee Precision Mechanics and Optics ( NAFuO ) in the DIN EN ISO 10939:2007.