| Blue Field Entoptic Phenomenon |
Article Index for Blue |
Website Links For Blue |
Information AboutBlue Field Entoptic Phenomenon |
| CATEGORIES ABOUT BLUE FIELD ENTOPTIC PHENOMENON | |
| ophthalmology | |
| vision | |
|
Scheerer R., "Die entoptische Sichtbarkeit der Blutbewegungen im Auge und ihre klinische Bedeutung." ''Klinisches Monatsblatt Augenheilkunde'' 1924;73:67-107 (German) These dots are due to the White Blood Cell s that move in the Capillaries in front of the Retina of the Eye , near the Macula . Sinclair et al. "Investigation of the source of the blue field entoptic phenomenon." ''Investigative Ophthalmology & Visual Science''. April 1989;30(4):668-673. PMID 2703307 The dots move somewhat in sync with the Heart Beat . Blue light (optimal ) is well absorbed by the Red Blood Cell s that fill the capillaries. The brain "edits out" the dark lines that would result from this absorption. The white blood cells, which are much rarer than the red ones and do not absorb the blue light well, create gaps in the blood column, and these gaps appear as bright dots. In a technique known as blue field entoptoscopy, the effect is used to measure the blood flow in the retinal capillaries, which is important in diseases such as Diabetes . The patient is alternatingly shown blue light and a computer generated picture of moving dots; by adjusting the speed and density of the computer generated dots, the patient tries to match the computer generated picture as best as possible to the perceived entoptic dots. This then allows calculation of the blood flow in the capillaries. Scheerer's phenomenon should not be confused with " Floater s" or ''muscae volitantes.'' Scheerer's phenomenon is distinguished by the appearance of ''multiple,'' ''identical-looking'' bright dots that follow each other ''rapidly'' along the ''same path.'' Floaters are variable in appearance; although they sometimes are dots, they often have the appearance of threads or shreds of crumpled cellophane. Floaters remain almost stationary or drift slowly and do not follow well-defined paths. They are due to debris floating in the Vitreous Humor of the eye. REFERENCES |
|
|