you're reading...

Cataract Treatment: Shifting Focus in a Long Search

Cataract, the clouding or discoloration of the lens in human eyes, cannot be prevented or cured. It remains the leading cause of blindness worldwide. The search for treatment has gone on since the dawn of time and continues to this moment.

The problem remains the same from ancient Babylon to Lexington. Normally absolutely clear, a human lens is convex on both sides and somewhat smaller than an M&M candy. It sits in a capsule between the iris (the colored part of the eye) and the retina at the back of the eye. It helps focus the light entering our eyes, forming an image on the retina. Many things, including injury or disease, may produce a cloudy lens, but by far the most common cause is aging. As we get older, the lens becomes more opaque until finally, if we live long enough, we are blind. Fifty percent of people over age 60 have some degree of cataract formation. That figure rises to 100 percent by age 80.

Archeologists have found bronze instruments thought to have been used for cataract treatment in excavations in Babylonia, Greece, and Egypt. The Babylonian Code of Hammurabi, dating from 1750 B.C., refers to cataract surgery. Susruta, a famous Indian surgeon, wrote treatises about 600 B.C. concerning cataract removal. The first references to treatment of cataract in the West are in 29 A.D. in De Medicinae by Roman medical writer Aulus Cornelius Celsus. Early treatment consisted of the surgeon using a lance to push the clouded lens backward into the jelly-like vitreous that normally fills the back of the eye where it remained, hopefully out of the field of vision. The procedure was called couching, depression of the lens rather than its removal from the eye.

From earliest times until the mid-eighteenth century couching was the standard operation for cataract. Couching is still used by traditional healers in Africa and parts of Asia. It did not restore good vision, but it was better than seeing nothing. Until the late 1840s when general anesthesia was introduced for surgical procedures, and 1884, when cocaine eye drops for anesthesia of the eye came into use, one very necessary member of the surgical team for couching was a strong man whose job was to hold the patient’s head still during the surgery.

The ailment was called “cataract,” meaning “waterfall,” from medieval Latin translations of Arabic writings concerning the supposed cause of the condition. A thickened humor, that is, some condensed bodily fluid, was thought to flow down into the eye collecting between the pupil and the lens. By clearing this space in couching, vision could be restored.

In the middle of the seventeenth century, observers began to think cataract might be a dysfunction of the lens itself. In 1656, Werner Rolfinck, German physician, scientist, and botanist, demonstrated an actual opaque lens in cataract.

Extracapsular cataract extraction (ECCE), removing the lens from the eye instead of pushing it aside, was first performed by a French surgeon, Jacques Daviel, in 1747. It was the first significant advance in cataract surgery since couching was invented.

In 1865 the German ophthalmologist, Albrecht von Graefe, improved the operation by removing the lens through a much smaller incision in the sclera (the white) of the eye. An older method is the intracapsular cataract extraction (ICCE) in which the surgeon removes the lens, capsule and all. In order to have good vision after these procedures it was necessary for the patient to wear extremely thick eyeglasses, sometimes referred to jokingly as “coke bottle glasses.” When contact lenses came into wide acceptance in the 1950s and 1960s, patients were sometimes fitted with contact lenses instead of the glasses. In those decades of the twentieth century, patients routinely spent ten days in the hospital recovering from cataract surgery.

Two vast breakthroughs were the invention of the operating microscope and of the implantable intraocular lens (IOL). Both were first used in 1948. The operating microscope is a low power microscope with special lighting so that the surgeon, looking down through the pupil of the patient’s eye, can see the lens and other eye structures accurately. In 1948 British ophthalmologist Dr. Harold Ridley, over the objection of the medical community, implanted the first IOL in the eye of a cataract patient.

In 1967 American ophthalmologist Dr. Charles D. Kelman developed phacoemulsification for cataract removal. It makes possible a smaller incision and is now the most common technique of cataract extraction used in developed countries. Folded IOLs are routinely installed through the smaller incision. Once inside the eye, they are unfolded and attached to the surviving capsule tissue with tiny spring-like hooks called haptics.

The treatment trail now includes Lexington where ophthalmologist Dr. Lance S. Ferguson, M.D. of Commonwealth Eyes and current president of the American College of Eye Surgeons, is the first in central Kentucky to use a laser in cataract removal.

Will the next advance be a way to restore accommodation? Loss of the ability of the ciliary muscles to change the shape of the lens (accommodation) as we age is the reason most middle-aged people need reading glasses. One eye surgeon suggests that if a reliable way to reestablish accommodation could be developed, people would have lenses removed in their forties rather than their seventies, bypassing both reading glasses and cataracts. Stay tuned.

By Martha Evans Sparks, Staff Writer



No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: