Cataract


Cataract is opacification or clouding of eye lens, which is normally clear and transparent. When a cataract develops, the lens becomes cloudy, similar to a frosted window. When a cataract forms, it blocks light passage into the eye, blurs vision and leads to subnormal or total loss of sight. If sight is not greatly impaired, there is no need to remove the cataract. Over a period of years, sight can be partially or completely lost until the cataract is removed.

Detection

Cataracts are typically detected through a medical eye examination. The usual test for visual acuity (the letter eye chart) may not reflect the true nature of visual loss. Other tests that measure glare sensitivity, contrast sensitivity, night vision, color vision, and side or central vision help to nail down the diagnosis.


Causes

Most cataracts are caused by a change in the chemical composition of the lens resulting in a loss of transparency. These changes can be caused by aging, injuries to the eye, certain diseases, conditions of the eye and body, and heredity or birth defects.


The normal process of aging may cause the lens to harden and turn cloudy. These are called senile cataracts and are the most common type. They can occur as early as age 40. Children, as well as adults of any age can develop cataracts. When cataracts appear in children, they are sometimes hereditary or can be caused by infection or inflammation, which affect the pregnant mother and the unborn baby. These are congenital cataracts and are present at birth.


Eye injuries can cause cataracts at any age. A hard blow, puncture, cut, intense heat or chemical burn can damage the lens, resulting in a traumatic cataract. Certain infections or diseases of the eye (such as diabetes) can also cause the lens to cloud and form a secondary cataract.

Symptoms

  • Blurring or dimness of vision
  • Glare from light bulbs
  • Feeling of film over eye
  • Frequent changes of spectacle lens
  • Difficulty in Reading & Driving
  • Change in color of the pupil

Treatment

Topical Anesthesia (No Injection, and No Patch)

One of the latest and most significant developments in cataract surgery has been in the use is Topical Anesthesia. In the past many people would say that the worst part of their cataract operation was getting an injection "in their eye" to numb it up. Now the entire surgery (which lasts only about 15 minutes) can be done without an injection, using only eye drops. After Topical Anesthesia, you go home without an eye patch.


Temporal Clear-Corneal Incision (No Stitch)

Even the most modern techniques in cataract surgery require that an incision (slit) be made in the eye. No, cataract surgery cannot be performed with lasers (a common misconception; so called "secondary cataract" can be treated with laser, but secondary cataract only occur in eyes that have already had cataract surgery). Because this type of incision is small, it does not require a stitch to close it.


Phacoemulsification

Phacoemulsification or phaco is the or removing cataracts modern method for removing cataracts utilizing high energy ultrasound. Using this technology, a cataract can be vacuumed through an incision. Basically, phaco uses a hollow needle which activated by the surgeon, vibrates at 40,000 times per second thereby emulsifying (dissolve) the cataract. Emulsified cataract is aspirated through the hollow center in the phaco needle, and fluid is simultaneously infused into the eye in order to keep it "inflated" during surgery.


Foldable Lens Implant

The final step in cataract surgery is lens implantation. Prior to the development of safe intraocular lens implants, anyone who had their cataracts removed was forced to wear incredibly thick and heavy glasses, or contact lenses to correct their vision to normal. A typical lens implant looks like a miniature, round magnifying glass with two wiry attachments called hap tics. The hap tics when slightly compressed, they suspend the lens implant inside the lens capsule.