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 -

http://www.sriramanaeyecentre.org/Pediatric.html

http://www.bendeyes.com/guat_gallery/content/guat_baby_large.html

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 -

http://www.opt.indiana.edu/NewHorizons/Rosette.html

Direct blow -

http://arapaho.nsuok.edu/~fulk/Images/Img0067.JPG

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.

Normal lens - http://www.drhlis.net/faq/Normal%20Lens.JPG

lens with nuclear

http://www.uku.fi/silmat/verkkokurssi/cataract.htm

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.

pic - dro.hs.columbia.edu/corticalcat.htm

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 -

www.drhlis.net/faq/Normal%20Lens.JPG