Michael Finley
"Dealing with Vision Loss"
Reprinted from his "What Ails You?" columns for Twin Cities Business Monthly
© 2003 by Michael Finley
The eyes are
the prize
At
the vet’s the other day, I beheld a little drama in the waiting room.
The doctor sat with a blind old man telling him his dog had cataracts and
would soon go blind itself. Watching from the next bank of chairs, I
thought this was the absolute zenith of poignancy, until the blind man,
patting his old friend, said, “I hate to break a new one in. This is my
fifth dog already.”
There
is a mythology to blindness, and I got my main ideas about it – that it
is impossibly tragic, and that all blind people are great musicians –
from silent movies and Motown. To understand eye problems for middle-aged
people, it’s best to set the mythology aside. Vision problems today do
not typically lead to dark glasses, tin cups, and a long parade of guide
dogs. Today we go to the doctor, we count on early diagnoses, and when
problems rise, we do what we have gotten so good at: we cope.
When
vision fades
Just as hair turns gray and feet recede from view as we age,
our eyes get older, too. Eyelids weaken and become thinner. The tissues of
the eyes become more brittle, and the lens loses flexibility. Given time,
we all would go blind. There are scads of things that can go wrong with
our vision, but the main culprits are:
Presbyopia.
When we reach our forties, we suddenly aren’t as good at reading
things up close. Presbyopia can cause major adaptation problems,
especially if we have always enjoyed perfect vision. One is obliged to
either get reading glasses or bifocals, or have one’s arms
lengthened.
Cataracts
are the clouding of the lens of the eye. Almost all of us get
cataracts to some degree as we age. Vision then becomes like a windshield
that keeps getting blearier. Surgery, replacing the clouded real lens with
an unclouded artificial one, is often necessary.
Macular
degeneration. When the macula, the talented part of your retina that
allows us to do things like thread needles and read legal documents,
deteriorates. It is the leading cause of blindness over age 65, macular
degeneration has no treatment in the “dry” form. The other form,
called “wet” macular degeneration, can sometimes be treated
surgically.
Glaucoma
is what Kirby Puckett has. Its reputation is as the silent thief of
vision, stealing it bit by bit before you even know you’ve got it. First
it steals your peripheral or side vision, then it attacks the middle.
Glaucoma is caused by too much pressure inside the eyeball. Eye drops are
the treatment of choice.
“The
Golden Age of Glaucoma”
Each
of these afflictions, and the treatment thereof, is a complex world unto
itself. Consider how ophthalmologist Lauren Baker of Health Partners in
Arden Hills approaches patients with glaucoma.
“I
tell patients this is the Golden Age of Glaucoma,” Baker says,
“because unless it’s an incredibly aggressive form of the disease, you
are not going to go blind. Diagnosed early, it is usually very possible to
stop it in its tracks.” Most people have mild symptoms that can be
controlled with a single eye drop per day.
No
one is sure what causes glaucoma, but it tends to strike people after age
40, and it especially likes people with a family history of the condition.
It frequently attacks African-Americans, and to a lesser extent, people of
Irish, Scandinavian, and Russian extraction. Curiously, the disease has a
high cross-correlation with obstructive sleep apnea.
But
the biggest indicator of glaucoma, according to the Mayo Clinic on Vision and Eye Health, is high intraocular pressure (IOP), which allows the eye to hold its
shape and function properly. Doctors use applanation tonometry, that hard
cone they push up against your eye to gauge the pressure; or, less often
today, they measure the eye’s resistance to a puff of air.
The
second assessment is the condition of the optic
nerve, to see how damaged it is. The optic nerve is exquisitely
detailed, a second brain we use just for seeing. Doctors use an
ophthalmoscope to examine the back of the eye. This is the test that they
dilate your eyes for, and why you bring someone to drive you home from
your appointment.. Doctors are on the lookout for a “cupping”
indentation of the optic disk, an early indication of the disease.
The
third assessment is of one’s field
of vision. In her practice Baker relies on the Humphrey Visual Field
Analyzer, a machine that tests for diminished sensitivity to light,
especially in the side vision where glaucoma usually starts.
None
of these tests is conclusive by itself, according to Baker. Having above
normal IOP isn’t the end of the world. You can be above normal and not
have glaucoma, or you can be normal and still have it. But if you have
high IOP and peripheral vision and your optic disk is “cupped up,” as
ophthalmologists say, you need to begin treatment, or it’s lights out
for you.
The
primary treatment for glaucoma is drops. Baker often starts patients with
a beta blocker, a single drop in the morning, and the reason is economics.
“A beta blocker is available in generic form, and costs only $20 to $30
per month. Other drugs can run from $50 to $80. Eye problems are a big
financial problem for many people. Someone without insurance who needs
three medications can spend $120 to $150 per month out of pocket.”
Beyond
drops, there are laser procedures for glaucoma, and some surgery
interventions. Beyond the realm of rational medicine, there is always
shark cartilege, which proponents claim cures not just glaucoma but
cancer, and marijuana, which supposedly decreases IOP, but has been linked
to sloth and overeating.
What
you can do
Tim
Olsen, associate professor at the University of Minnesota Medical School
and director of retina, likens light and oxygen’s effect on our eyes to
rust’s effect on our cars. “Without light, there is no vision. But too
much light, over too long a period, takes a toll of the tissue of the eye.
It’s especially destructive to the delicate structures inside.”
No
one has ever proven that exposure to light is the cause of macular
degeneration, Olsen said. But a famous “Watermen’s Study” of
cataracts conducted among fishermen on Chesapeake Bay, who are exposed to
more bright reflective than the average person experiences, showed a
strong correlation with cataracts.
Think
of it this way: you know that staring directly into the sun for twenty
minutes is a bad idea. So is spending 50 years in normal bright light. For
the bulk of human history, people didn’t live long enough, on average,
to go blind from glaucoma, cataracts, or macular degeneration. It’s a
paradoxical measure of our success as a species that so many of us are now
squinting.
And the cosmos has become even more dangerous with reports that ultraviolet light from the sun is pouring through our atmosphere unobstructed by a uniform ozone shield around the earth. Sheila West, an ophthalmologist at John Hopkins Wilmer Eye Institute in Maryland who took part in the “watermen’s study,” says there is no safe level of exposure to ultraviolet rays.
"Every time you go out into the sun, your eyes can take a hit from UV rays," says West. "The good news is it's never too late to start protecting your eyes, because the lens change is probably from an accumulated dose over the years. That's why everyone needs to get into the habit of protecting their eyes."
So
if you want to go easy on your eyes:
-
Wear sunglasses, not just when it’s bright outside but even when it’s cloudy, because clouds don’t stop ultraviolet rays.
-
Have great genetics. A lucky few of us have normal healthy vision into our 90s. Those with normal genes and merely human proteins, are fading by our 50s.
-
Fight the rust. If oxygen is wearing you out, fight back with anti-oxidant food supplements.
-
Snuff your butts. People who smoke are 300 times more likely to suffer macular degeneration, according to Olsen.
If
he could undo one odd misconception people have, Olsen said, it would be
that eyes are transplantable. Corneas are transplanted, and artificial
lenses can be implanted. But whole eyeballs are not transplantable, and
probably will not be. The neurocircuitry of the eye is just too complex
and too delicate.
Or, as ophthalmologist Lauren Baker puts it, describing the unique anatomy that allows us to see: “Eyeballs are not toenails.”
Figure
this:
-
North Dakota has the highest incidence of blindness of any state, with 3.79%.
-
Alaska has the lowest rate, with 1.3%.
-
(Minnesota is among the top half, with 3.15%.)
Odd question: Why are Alaska and North Dakota so different?
Source: A joint report of the National Eye Institute and Prevent Blindness America
Michael Finley
