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PubMed1989

Investigation of the source of the blue field entoptic phenomenon.

The cellular source of the blue field entoptic phenomenon was investigated in two microvascular preparations using video-microscopy with lighting conditions similar to those under which the entoptic phenomenon is visualized within the human eye. In the wing of the hibernating bat, microvascular flow was simultaneously videotaped under transmission illumination at 430 nm and under unfiltered illumination. In the rat cremaster alternating observations were made using transmission illumination at 430 nm and epi-illumination fluorescence microscopy with leukocytes rendered fluorescent by intravenous Quinacrine. In both preparations, low magnification video-microscopy using 430 nm illumination produced a field of particles, which were brighter than the background, flowing within a network of dark vessels. The appearance of the particles and their movement simulated the blue field entoptic particle motion. Under higher magnification, the particles appeared brighter than the plasma gaps between red blood cells and were demonstrated to be leukocytes by morphology, by specific staining and by typical behavioral movement. The particles were observed in terminal arteriols capillaries, and post-capillary venules where they were not obscured by red blood cells. The results of this study of two microvascular preparations strongly suggest that in the human eye the blue field entoptic phenomenon is produced by leukocytes flowing within the macular retinal microvasculature.

Animals↗
PubMed1979

Blue field entoptic phenomenon in cataract patients.

The blue field entoptic phenomenon (BFE), which allows the observation of one's own leukocytes flowing in macular retinal capillaries, was used to predict postoperative macular function in 136 consecutive patients undergoing uncomplicated cataract operation. The results were compared to those obtained with three commonly used tests: two-light discrimination, color perception, and the Purkinje vascular entoptic phenomenon. All four tests identified a nearly equal number of the good maculae (visual acuity 20/40 of better) ranging from 87% for the two-light discrimination test to 94% for the BFE test. However, the tests varied greatly in predicting poor macular function (visual acuity 20/50 or worse). The BFE test identified more than 75% of the poor maculae; the Purkinje vascular entoptic test and the two-light discrimination test, only 22%; and the color perception test, 11%. A positive response to the BFE test indicated a .98 probability of good macular function; a negative response indicated a .82 probability of poor macular function, predictions that were better than the other three tests or their combination.

Cataract↗
PubMed1978

Macular circulation and the flying corpuscles phenomenon.

The entoptic phenomenon of the flying corpuscles (FLC) consists of the perception of one's own leukocytes flowing in the perifoveal capillaries. A method has been developed to investigate the type of motion of the FLC, their relative number and speed, and their distribution over the central visual field. The results in 38 patients with disease affecting the macula correlated well with the clinical findings obtained by ophthalmoscopy, visual field tests, and fluorescein angiography. The test is noninvasive, inexpensive, easy to perform, and provides information on the perifoveal retinal circulation and on macular function.

Adolescent↗
PubMed1982

Dichroism of the macular pigment and Haidinger's brushes.

It seems quite certain that the visual entoptic phenomenon called Haidinger's brushes is a consequence of dichroism of the macular pigment; this dichroism is usually ascribed to orientation of the pigment molecules. An alternative explanation of the dichroism, an explanation that requires no orientation of pigment molecules, investigated and shown to be feasible. Specifically, it is shown that form dichroism that is due to the structure of the Henle fiber layer can account for Haidinger's brushes if the macular pigment is almost entirely confined to the Henle layer, if individual fibers have an index about 5% higher than that of the interfiber medium, and if the fibers form a tightly packed array.

Color Perception↗
PubMed1983

The blue field entoptic test with normal patients.

One hundred normal patients were evaluated with the Blue Field Entoptoscope test. Of those one hundred patients, ninety-nine were able to describe the appearance of their own leukocytes. The methodology did not permit encouraging or coaching patients to see their leukocytes. Of the ninety-nine who could perceive their own leukocytes, nineteen 19.19%) were unable to perceive an approximately equal number in each of the four quadrants of the blue field of light which is divided by a reticle. These patients who did not see an equal number of leukocytes in all four quadrants were generally older than those who saw an equal number of leukocytes. The results indicate that if the Blue Field Entoptoscope is to be used in clinical practice or research, it is useful to standardize the instrument for the population studied. In particular, the instrument should be standardized for age.

Adolescent↗
PubMed1989

Entoptic [corrected] phenomena in pregeniculate and postgeniculate hemianopsia with splitting of macula by perimetry.

With splitting of macula by perimetry, the entopic phenomena (the perception of one's own foveal xanthophilic pigment and macular vessel leukocytes) were utilized to study the character of macular sparing or splitting in patients with pregeniculate or postgeniculate hemianopsia. In the pregeniculate group, 11 of 14 eyes perceived the Haidinger brushes figure as a half circle corresponding to the perimetric macular splitting, whereas flying corpuscles were not perceived at all or were less numerous on the hemianoptic side than on the normal field side. In contrast, six of seven patients with postgeniculate lesions perceived the Haidinger brushes figure as a complete circle, four of six perceived fewer flying corpuscles on the hemianoptic side than on the normal field side, and two patients reported perceiving an equal number in all quadrants. This study indicated that in pregeniculate hemianopsia there is usually a true splitting of the macula, whereas in postgeniculate hemianopsia, there is some macular sparing even when perimetry shows macular splitting.

Adolescent↗
PubMed1981

Blue field entoptic phenomenon in amblyopia.

The blue field entoptic phenomenon allows the perception of leukocytes moving in the retinal capillaries of one's own retina. This phenomenon is not affected by media opacities provided that enough blue light reaches the retina. The phenomenon was investigated in 63 amblyopic patients to determine if the perception of the leukocytes in the amblyopic eye differs from that in the good eye. A difference in perception would provide a means of assessing amblyopic in eyes with opaque media. Ninety-four percent of the amblyopic eyes perceived less sharp particles, 83% perceived fewer particles and 60% perceived slower particles than in the good eyes. In 86% of the amblyopic eyes, the tails were shorter than in the good eyes or absent entirely. The degree of amblyopia correlated with the difference in the number of leukocytes observed in each eye. No differences in the perception of leukocytes were reported by 20 normal subjects.

Adolescent↗
PubMed1981

Macular sparing investigated by means of Haidinger brushes.

Haidinger brushes, an entoptic phenomenon perceived only through the most central macular retina, have been used in addition to kinetic and static perimetry with the Tubingen perimeter for determining macular sparing and splitting in hemianopic patients. Seven patients were examined: 2 with a bitemporal hemianopia resulting from traumatic damage to the optic chiasma, and 5 with a homonymous hemianopia resulting from extensive lesions of the optic radiations and/or the occipital cortex (including 2 cases of hemidecortication). On perimetric examination some exceptions could be observed in the correspondence of macular splitting and sparing respectively with pre- and postgeniculate lesions, but this was not the case when Haidinger brushes were used. Half of the figure was then perceived by the patients with lesions of the chiasma and the entire figure by all the patients with geniculostriate lesions. We consider that results obtained by this simple method are more reliable than those obtained by perimetry and that Haidinger brushes should be used for macular field examination in neuro-ophthalmic practice.

Adolescent↗