Voice of the Diabetic

Voice of the Diabetic

Back|

Next|

Table of Contents|

Home

ASK THE DOCTOR

by Roger Barth, MD

NOTE: If you have any questions for "Ask the Doctor," please

send them to the VOICE editorial office. The only questions we will be able

to answer are the ones used in this column.

Dr. Roger Barth received his MD degree from the University

of Washington, completed his ophthalmology training at Washington Medical Center

in Washington, D.C. and then completed a fellowship in glaucoma speciality training

at the University of Iowa. He is now practicing ophthalmology at the Glacier

Eye Clinic in Kalispell, MT.

Q: I have diabetic retinopathy and have suffered recurrent retinal hemorrhages.

My ophthalmologist has not taken an ocular pressure reading recently and states

that elevated ocular pressure and retinal bleeding is not related. Is he correct?

How is glaucoma detected and treated in a diabetic who is already

suffering from retinal hemorrhages? Can untreated retinal bleeding lead to glaucoma?

A: Your question brings up many good points about diabetes and glaucoma. Elevated

intra-ocular pressure and retinal bleeding are not related. Your ophthalmologist

is correct. But diabetics are at increased risk for glaucoma. Monitoring your

eyes for glaucoma is important.

Glaucoma is a common, but poorly understood, disease that affects

the eyes of millions of people and can lead to blindness. By definition, glaucoma

is damage to the nerve cells that transmit the message from your retina to your

brain. Please notice that I didn't say glaucoma is high pressure in the eye.

Many factors combine to cause glaucoma. These are called "risk

factors" and include elevated intra-ocular pressure, family history, the

shape of the eye, and to a lesser degree, nearsightedness and diabetes. Because

the eye pressure is the only variable we can manipulate (and the number one

risk factor), it is important that it is checked periodically and put into context

with the rest of your exam. Normal eye pressure ranges between 10 and 21 mm

of Mercury. Up to 1/3 of patients develop glaucoma damage with pressure in the

"normal" range. Merely knowing that your pressure is OK does not mean

you don't have glaucoma or are not at risk for it.

By analyzing the appearance of your optic nerve and considering

your other risk factors your ophthalmologist should be able to assess your relative

risk for glaucoma. If there is increased suspicion, other tests may be ordered,

such as visual field testing, optic nerve photographs, measurement of the nerve

thickness, etc.

Retinal hemorrhages (or background diabetic retinopathy) should

not make the detection of glaucoma any more difficult, and won't by themselves

lead to glaucoma. If there has been bleeding into the vitreous (the clear fluid

at the back of the eye), it may be difficult to see into the back of the eye,

making evaluation for glaucoma more difficult. In addition, vitreous hemorrhage

can by itself sometimes cause increased eye pressure.

A particularly devastating form of glaucoma (neovascular glaucoma)

can develop in patients with diabetes. It is fairly rare, and can be prevented

if caught early, which reinforces the importance of regular eye exams for diabetics.

The good news when it comes to glaucoma is that as a disease process, it typically

takes years to develop. Your ophthalmologist has no doubt been observing your

eyes for signs of glaucoma, even if the eye pressure has not been checked at

each visit. If there is evidence of glaucoma, a variety of treatments can help

lower the eye pressure and help slow or stop any glaucoma damage to your vision.

Because people with diabetes are typically seen more often for eye exams, they

and you should be in good shape as far as early detection of glaucoma is concerned.

Back to Top