Older Eyes Get New Lease on Life
May 22, 2000 -- Find yourself getting farsighted as you get older? A new
operation that reverses age-induced loss of close-up vision may offer patients
a "fountain of youth for the eye," according to Gene W. Zdenek, MD.
Approximately 80% of people over age 40 require glasses or contact lenses to
read comfortably, says Zdenek, an ophthalmologist in private practice in
Reseda, Calif. At age 10, children can see small objects or print from two
inches away. By age 30, they have to hold the same objects six inches away, and
by 40 to 45, "we can no longer read comfortably at 12-16 inches,"
Zdenek says. It is around this time that most people start wearing glasses for
reading and other close-up tasks.
This loss of close-up vision with age is called presbyopia. For many years,
it was thought that presbyopia resulted from progressive hardening of the lens
of the eye. However, in 1994, Texas researcher Ronald Schachar, MD, PhD,
advanced the theory that the lens keeps growing throughout life, something like
an onion that keeps adding new layers. This leads to crowding of the eye
chamber and creates slack in the tiny, thread-like structures that connect the
lens to the muscles that make it change shape to accommodate the visual demands
we place on it.
Zdenek likens the process to pulling a wagon with a rope: "The wagon is
the lens, your arm is the muscle, and the rope is [the thread]," he tells
WebMD. "If there's too much slack in the rope, the wagon won't move when
you move your arm."
Presbyopia differs from true far-sightedness, in which the eye or cornea is
The new procedure. known as scleral expansion band (SEB) surgery, involves
placing four small plastic segments in the white of the eye, or sclera, to
expand the space between the lens and the muscles that control it. This
tightens the threads that connect the two, allowing the lens to once more
respond to the muscles that make it move, as it did when the eye was
From February 1998 to January 2000, Zdenek implanted these segments in a
total of 45 eyes, with five later requiring re-operation due to minor problems.
The patients ranged in age from 43 to 72. The procedure lasted less than 30
minutes and patients required only numbing eye drops, no shots or general
anesthesia, says Zdenek. So far, the only complication has been slight
reddening in one eye. If complications do occur, "the procedure is fully
reversible," Zdenek says.
The SEB operation can reverse ocular aging by 20-40 years -- perhaps 30-50
years with the latest generation of segments, he says.
- About 80% of people over 40 require the use of reading glasses, a condition
known as presbyopia.
- A new surgical procedure, called scleral expansion band (SEB), can reverse
this loss of close-up vision with few side effects.
- SEB is still in the experimental phases, so it is only available to people
participating in clinical trials to test the surgery.