Everything about The Macula totally explained
The
macula or
macula lutea (from
Latin macula, "spot" +
lutea, "yellow") is an oval
yellow spot near the center of the
retina of the human
eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of
ganglion cells. Near its center is the
fovea, a small pit that contains the largest concentration of
cone cells in the eye and is responsible for central vision.
It is specialized for high
acuity vision. Within the macula are the
fovea and
foveola which contain a high density of
cones (photoreceptors with high acuity). In contrast to the rest of the retina, which is supplied by the
retinal artery, the macula receives its blood supply from the
choroid.
Clinical significance
Whereas loss of
peripheral vision may go unnoticed for some time, damage to the macula will result in loss of central vision, which is usually immediately obvious.
The progressive destruction of the macula is a
disease known as
macular degeneration and leads to the creation of a macular hole. Macular holes are rarely caused by trauma, but if a severe blow is delivered perfectly it can burst the blood vessels going to the macula, destroying it.
Visual input to the macula occupies a substantial portion of the brain's visual capacity. As a result, some forms of
visual field loss can occur without involving the macula; this is termed
macular sparing. (For example,
visual field testing might demonstrate
homonymous hemianopsia with macular sparing.) This finding can be very informative for the
ophthalmologist.
Further Information
Get more info on 'Macula'.
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