Fundus (eye)

For other uses, see Fundus (disambiguation).
Fundus

Fundus of human eye

Anatomical terminology

Fundus photographs of the right eye (left image) and left eye (right image), as seen from the front (so that left in each image is to the person's right and the person's nose would be between the two images).

Each fundus has no sign of disease or pathology. The gaze is into the camera, so in each picture the macula is in the center of the image, and the optic disk is located towards the nose. Both optic disks have some pigmentation at the perimeter of the lateral side, which is considered non-pathological.

The left image (right eye) shows lighter areas close to larger vessels, which has been regarded as a normal finding in younger people.
A fundus photo, showing the optic disc as a bright area on the right where blood vessels converge. The spot to the left of the centre is the macula. The grey, more diffuse spot in the centre is a shadow artifact.

Structure

The fundus of the eye is the interior surface of the eye opposite the lens and includes the retina, optic disc, macula, fovea, and posterior pole.[1] The fundus can be examined by ophthalmoscopy[1] and/or fundus photography. The term fundus may also be inclusive of Bruch's membrane and the choroid.

Variation

The color of the fundus varies both between and within species. In one study[2] of primates the retina is blue, green, yellow, orange, and red; only the human fundus (from a lightly pigmented blond person) is red. The major differences noted among the "higher" primate species were size and regularity of the border of macular area, size and shape of the optic disc, apparent 'texturing' of retina, and pigmentation of retina.

Clinical significance

Medical signs that can be detected from observation of eye fundus (generally by funduscopy) include hemorrhages, exudates, cotton wool spots, blood vessel abnormalities (tortuosity, pulsation and new vessels) and pigmentation.[3] Arteriolar constriction, seen as "silver wiring", and vascular tortuosities are seen in hypertensive retinopathy.

The eye's fundus is the only part of the human body where the microcirculation can be observed directly.[4] The diameter of the blood vessels around the optic disc are about 150 μm, and an ophthalmoscope allows observation of blood vessels with diameters as small as 10 μm.[4]

References

  1. 1 2 Cassin, B. and Solomon, S. Dictionary of Eye Terminology. Gainesville, Florida: Triad Publishing Company, 1990.
  2. Wolin LR, Massopust LC (September 1967). "Characteristics of the ocular fundus in primates". J. Anat. 101 (Pt 4): 693–9. PMC 1270903. PMID 6059819.Free full text in PubMed Central
  3. Imran Akram, Adrian Rubinstein "Common retinal signs. An overview", "Optometry Today", 28/01/05,
  4. 1 2 Ronald Pitts Crick, Peng Tee Khaw, "A Textbook of Clinical Ophthalmology: A Practical Guide to Disorders of the Eyes and Their Management", 3rd edition, World Scientific, 2003, ISBN 981-238-128-7

See also

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