cataracts

Cataracts:

A cataract is the lense in the eye that has lost it's clarity. As the lense becomes cloudy, vision grow steadily worse. At some point, the loss of vision becomes great enough the sufferer is willing to have surgery to have the problem fixed. In this procedure, the cloudy lense is removed and is replaced by an artificial lense, or lense implant

The crystalline lense inside the eye has several parts. The center of the lense is a hard core called the nucleus. The lense nucleus is made up of rings of cells, pushed together over time. Though soft in childhood, they become harder with age. Surrounding the nucleus is the cortex, a softer area. The entire lense is covered by a capsule similar to a clear bag. The lense is held in place by small fibers named the zonule

Cataract surgery is usually done under local anesthetic, and the patient is awake

There are several different techniques for removing cataracts. These are divided into two groups, being intra- and extracapsular. One common misconception is that cataract surgery can be performed with lasers. While lasers are common tools in eye surgeries, they cannot remove a cataract

With intracapsular surgery, the entire lense is removed with it's capsule. A large opening is made in the eyeball, and injected with a drug to make the zonular fibers dissolve. An instrument uses liquid nitrogen to freeze it to the lense. When the lense is frozen to the probe, it is gently pulled from the eye. The opening is then stitched up until it heals. Intracapsular cataract surgery is now considered archaic and is very rare

During extracapsular surgery, a much smaller opening is made in the eye. Then, an opening is created in the front of the capsule, just large enough for the nucleus of the lense to be removed. It is either removed whole or is more commonly dissolved into tiny pieces using phacoemulsification. The cortex is also removed, leaving only the back section of the capsule. Stitches may or may not be required

In either operation, after the natural lese has been removed, it is replaced with a rigid one of plastic. Recently, some newer types of material such as silicone and hydrogels have been used. In an inracapsular surgery, the lense implant is placed in front of the iris. In extracapsular, the lense implant is placed behind the iris, in it's natural resting place

After cataract removal, glasses are worn to fine-tune vision. With a lense implant in the eye, the vision is close to normal, even without glasses. If a lense implant is not used, much thicker glasses are needed. Even with the implant, however, the lense has lost flexibility and the patient loses some ability to focus well

Results are not guaranteed. It is possible to lose all vision if surgery is not correctly performed. Don't panic, about 95% of surgeries have good results :0)

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