slitlamppua

Slitlamppu, or slit lamp in English, is a biomicroscope combined with a high-intensity, adjustable light source used for detailed examination of the eye. It provides a magnified, stereoscopic view of the anterior segment and, with appropriate lenses and techniques, can also facilitate examination of the posterior segment. In Finnish, the instrument is commonly referred to as slitlamppu, with grammatical forms such as slitlamppua appearing in running text.

The device consists of a binocular microscope mounted on a stable stand, with an adjustable chin and forehead rest for patient comfort. The illumination system can project a narrow, adjustable slit of light across the eye, enabling precise control of light intensity, slit width, angle, and height. Additional features include filters (for fluorescein and blue-light viewing), as well as attachments for applanation tonometry and various lenses to examine deeper ocular structures.

During an examination, the clinician positions the patient and selects magnification appropriate to the task. Direct, diffuse, and retroillumination techniques illuminate different layers of the cornea, iris, lens, and sclera. Fluorescein staining under cobalt blue light highlights corneal defects. The slit beam can be rotated and shaped to reveal subtle surface and stromal changes, and scleral indentation can aid peripheral evaluation, including the vitreous to some extent when combined with lenses.

Common applications include assessment of corneal ulcers and dystrophies, eyelid and conjunctival disease, cataracts, lens subluxation, iris abnormalities, and signs of glaucoma in the angle. With specialized lenses, slit lamps enable examination of the posterior segment. The instrument remains a central tool in eye care, evolving through improved optics, illumination (often LED), and digital imaging.