Macular pigment

Reference: PVM-PI

This program performs an evaluation of the density of macular pigments. These pigments have antioxydant properties and may play a protective role on ARMD development (HADDAD & al, 2006, WHITEHEAD & al, 2006). It has been shown that dietary modification or the use of nutritional supplements can change the macular pigments density (HAMMOND & al, 1997).

Photographs of a cross section of the central retina in primate retina under green (top) and blue (bottom) illumination. Dark areas correspnd to absorption of light by pigment. (SNODDERLY & al, 1984)

One of the macular pigments properties is to absorb blue light, especially on the fovea. The principle of the Vision Monitor program is to measure the sensitivity thresholds to red and blue light for retinal, foveolar and perifoveolar zones. The pigment density is obtained by comparing the differential threshold measured in the fovea to the threshold measured in the perifoveolar zone.

Sensitivity threshold of red (620 nm) and blue (460 nm) stimuli are measured in the foveolar and peri foveolar areas.
In normal subjects, blue thresholds present a relative attenuation of about 0.6 log units in the fovea location, indicating the presence of macular pigment which absorbs blue light.

Note: this technique is much easier for patients than the heterochromatic flicker technique.

The program subtracts the global alteration of blue thresholds resulting from mild lens opacities.
It compares the resulting measurements to a normal data base and gives a score with a probability of abnormality.

The program searches all the results from the same patient and plot the evolution of the score over the last exams.

The fundus program allows the comparison of the visual field with the eye fundus. The image of the eye fundus is imported as an image file either through the computer network or by USB key, CDROM etc.
The operator identifies by simple clicks the position of the fovea and papilla and the program automatically performs the scaling and repositioning of the eye fundus image.

Vision Monitor systems compatible with this program:

• MonCV3: multifunction perimeter
• MonPack: universal stimulator for visual electrophysiology

Additional information:

• download the PDF brochure
• request additional information