الفهرس 
Principle and Technology of PentacamOnly 14 pages are availabe for public view
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Abstract
The Pentacam is the first instrument to use a rotating Scheimpflug camera to take multiple images of the anterior segment and use these to generate three-dimensional images and calculate measurements of the eye. It provides:
• Detailed Scheimpflug images of the anterior segment from the posterior surface of the crystalline lens to the anterior corneal surface.
• Three-dimensional visualization and animation of the anterior segment.
• Measurements of anterior chamber angle, chamber volume, chamber depth, pupil diameter and corneal characteristics such as eccentricity, central radius and astigmatism.
• Pachymetry (limbus to limbus, accurate to ±5 μm). We can locate any point on the cornea manually, onscreen, and see the thickness at that point. The map notes the thinnest region.
• Densitometry data for the cornea and the crystalline lens, including the subcapsular layer, shown both graphically and quantitatively. The quantitative data make it easy to identify a developing cataract, categorize existing cataracts, and document their development.
• Topographic maps of the anterior and posterior corneal surfaces, based on measurement of 25,000 elevation points (when using the two-second scan), including tangential and sagittal (axial) curvature and limbus-to-limbus elevation, with freely selectable reference bodies.
• A “true net power map” that shows the refractive power of the cornea at any given point. (The instrument calculates the refractive power of both surfaces and adds them together.)
Because the Pentacam only measures to the posterior capsule of the crystalline lens, it can’t provide a measure of axial length. Also, because it’s optically based, it can’t measure from sulcus to sulcus. However, it can usually capture data behind an opacity because the camera images the eye from so many angles.
The key advantages of the rotating imaging process are the precise measurement of the central cornea, the correction of eye movements, the easy fixation for the patients and the extremely short examination time.
The high reliability of the rotating Scheimpflug system is a result of the measuring principle in which highly precise measurements are obtained through many repeated, mostly central, corneal measurements.
While summing up all the features of the Pentacam is the optimum analyzer for:
• Corneal refractive surgeons.
• Cataract refractive surgeons.
• Glaucoma screening.
• General screening.