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Basic method for slit-lamp microscopy and photography


Light travels, due to differences in density, refractive index, light absorption, refraction, reflection, reflections, Nathan shot, phenomena such as diffraction and its intensity, hue, polarizer, phase changes. Human eye cannot distinguish between optical polarization and phase changes, but I can identify the amplitude of light (intensity) and wavelength (hue) changes. Slit-lamp microscopy is the use of light in the eyes of the various differences to discover the disease spread in your organization, and in accordance with their respective characteristics to provide qualitative, so application of slit-lamp technology, is in fact a way of light, can be divided into the following categories:

(A) the diffuse lighting Mons method is used to check the cornea and conjunctiva, tears, tears, eyelid skin, blepharitis, eyelashes, but on the entire surface of the eye has a rough, but a more comprehensive impression. Spots open to its maximum, the frosted-glass under the lamp reflector is moved into the optical path, more even illumination softer. Observation on effect in order to avoid corneal reflex points on, to move the slit lamp lights around. At the time of photography, when used at low magnification viewfinder, note that reflective patches on leaves the observation area of the cornea. Due to the restricted range after microscope mirror, preferably by ring and side mirrors directly by the camera lens and the body, results both in terms of depth of field, resolution, tolerance and perspective, a microscope objective lens to shoot with satisfaction.

(B) the fractured by direct focus lighting light source light beam after imaging lens, mirrors, the fractured blade, forged at the microscope objective lenses working distance. Depending on your needs, may adjust the aperture, forming a diameter of 8, 5, 3, 2, 0. 2mm rounded spots, or adjust the fractured blade spacing, formation O~8mm wide optical-gap. To keep the microscope objective lenses working distance coincides with the fracture focus, the factory has been set, but observers have refractive eye, or viewer for confronting the eyepiece is not zero, it cracked when the objects seen most clearly the focus is different, and should therefore be adjusted the eyepiece before use.

Slit width for 1.0~1.5mm called a wide band of light, it is reflected in the angular mausoleum can form a six interface fishing three-dimensional space. <O.2mm known as a narrow band of light, reflected in the play on the cornea, lens, vitreous of which formed a "optical slices", slit lamp and the larger the angle between the optical axis of the microscope, hierarchical relationships this section show more clearly. In looking at section of the cornea, fractured light axial alignment, to the rotation to 45 ° angle on either side of the microscope, so light that still retain their original curvature of the cornea and level display is better. Due to limitations in fissures of focal depth and shadow depth of field of a microscope, when in optical section, adjustable to get crystals, glass, and so you want a certain thickness of the Organization's overall concept. Scope of the narrow band of light shine is extremely small, need to move up and down about, to optical scanning to be part of, to see the picture. The same reasons, if there is only a narrow band of light when the camera lights, more often than not, showing lesions and surrounding tissues, should be combined with the background illumination. But too bright background light will inevitably reduce the contrast of the slit illumination parts and should select the appropriate background light through hole.

Darkroom in black, with a O.2mm beam irradiation on anterior chamber diameter, in the context of the black of the pupil, protein composition in aqueous, or wandering cells appears light gray due to Ding Duo, known as aqueous flare phenomenon. Since the beam focus into conical, tapered light is also called.

Narrow band of light on transparency can be displayed in the organizational hierarchy, projected onto the IRIS, retina, optic disc, or anterior chamber angle when the opaque organization, outlined the contours of the surface, have special significance for diagnosis.

(C) the method of indirect lighting in or near-side lighting. Light projection on the target tissue of the proximal to observe, take advantage of these organizations section of light to indirect lighting to observe targets. Commonly used to check for atrophy of IRIS tissue, rate the Protuberance is substantive or cystic, reflected embedded falls on limbal endoscopic foreign body, through the home angle after trabeculectomy
NET surface of the sclera, retina or membrane formation.

Application of this method of lighting, you should loosen the screws fractured after the lamp, lamp post rotation to make light projection not coincide with the optical axis of the microscope.

Attention indirect lighting brightness of the photo to be much lower than that of direct lighting, exposure should be chosen by indirect lighting brightness, otherwise will lead to underexposed results.

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