Sunday, September 6, 2009

Types of Cataracts

žAge-related cataract
Most cataracts are related to aging.
žWith aging, the composition of the lens undergoes changes and the
structure of the protein fibers breaks down. Some of the fibers begin to
clump together, clouding small areas of the lens
ž
Congenital cataract
žSome babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may not affect vision. If they do, they may need to be removed.
žMay be the result of the mother having contracted German measles (rubella) during pregnancy. They may also be due to metabolic disorders. PICTURES -
žSecondary cataract
žCataracts are more likely to develop in people who have certain medical problems, such as diabetes.
žThey can also be linked to use of medications; such as steroids.
žLong-term unprotected exposure to sunlight is also believed to contribute to the development of cataracts.
žTraumatic cataract
žEyes that have sustained an injury may develop a traumatic cataract either immediately following the incident, or several years later. carachteristic cataract due to head trauma takes on the shape of a rossete.
rossete -
Direct blow -
Location
žNuclear cataract
This is the most common type of cataract and associated with aging. Occurs in the center of the lens. In its early stages, as the lens changes the way it focuses light, you may become more nearsighted. Unfortunately, this so-called second sight disappears as the lens gradually turns more densely yellow and further clouds your vision. The lens may even turn brown. Seeing in dim light and driving at night may be especially troublesome. Advanced discoloration can lead to difficulty distinguishing between shades of
blue and purple.
lens with nuclear
Cortical cataract
This type of cataract initially develops as wedge-shaped spokes
n the cortex of the lens, with the spokes extending from the
outside of the lens to the center. When these spokes reach the
center of the lens they interfere with the transmission of light and
cause glare and loss of contrast. This type of cataract is frequently
developed in persons with diabetes, and while it usually develops
slowly, it may impair both distance and near vision so significantly
that surgery is often suggested at an early stage.
Subcapsular cataract
Starts as a small, opaque area just under the capsule of the
lens. It usually forms near the back of the lens, right in the
path of light on its way to the retina. A subcapsular cataract
often interferes with your reading vision, reduces your vision
in bright light and causes glare or halos around lights a
night.A subcapsular cataract is often found in persons with
diabetes, myopia, retinitis pigmentosa, and in those taking
steroids.
pic -

No comments:

Post a Comment