The Newly Diagnosed Patient
Chat Highlights
October 1, 2003

Norma Devine, Editor

On Wednesday, October 1, 2003, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "The Newly Diagnosed Patient."

Moderator:  Dr. Wilson, what criteria do you use to diagnose glaucoma?   

Dr. Rick Wilson:  The early diagnosis of the glaucoma patient is usually made by the appearance of the optic nerve and by the number of risk factors the patient has.  These risk factors include age, race, health, and family history.   

P:  What are the main health factors?

Dr. Rick Wilson:  The main health factors that concern me are blood pressure (low is worse than high); vasospastic disease, such as migraines or Raynaud's syndrome (cold hands); cardiac arrhythmias that could influence the effectiveness of the blood pumping; and vaso-occlusive disease, such as blocked carotid arteries.

P:  Should a newly diagnosed glaucoma patient get checked for other diseases? 

Dr. Rick Wilson:  I would just have a good general examination if you are discovered to have glaucoma.  There may be an association with diabetes.  There is weaker evidence suggesting an association with thyroid disease.  There seems to be a relationship between low-tension glaucoma and the vasospastic diseases, such as Raynaud's, which I mentioned earlier.  

P:  You mentioned low blood pressure.  Early on, should glaucoma patients with low blood pressure be checked for dips in blood pressure at night during sleep?  

Dr. Rick Wilson:  If your glaucoma is progressive, then I would consider 24-hour blood pressure monitoring, especially if you have low blood pressure.

Moderator:  What about elevated intraocular pressure (IOP)?

Dr. Rick Wilson:  The thinking used to be that most of the newly diagnosed glaucoma patients have elevated pressure (above 21 or 22 mm Hg).  However, about one in six patients has glaucoma without elevated intraocular pressure (normal-tension glaucoma)  Clearly, for these patients the diagnosis is based only on the appearance of the optic nerve and the visual field.

P:  Do any neurological problems cause elevated IOP? 

Dr. Rick Wilson:  Carotid-cavernous sinus fistula causes an increase in the venous blood pressure and, secondarily, the elevated eye pressure leading to glaucoma.  Thyroid disease, when the eyes are protuberant, also causes elevated IOP. 

P:  What is "borderline" glaucoma?  It sounds a little like "almost" pregnant.

Dr. Rick Wilson:  Borderline glaucoma means a strong suspicion for glaucoma, but no definite evidence.

P:  Can you make the diagnosis with only one exam or one visual field test?

Dr. Rick Wilson:  Yes, a diagnosis can usually be made with one thorough exam.  

P:  Which visual test is best for diagnostic purposes?  At the beginning of my (subjective) problems with glaucoma, I was given the Humphrey Full Field 120 Point Screening Test, which did not show the damage I had and contributed to a misdiagnosis by the doctor.

Dr. Rick Wilson:  The SITA standard would be the best diagnostic field test, unless the glaucoma was borderline.  Then the SITA normal, followed by the SWAP, would be best.

P:  Do you think a newly diagnosed patient should seek a second opinion with a glaucoma specialist?

Dr. Rick Wilson:  If there is any question about the diagnosis or the treatment, I think it makes sense to get a second opinion.  

P:  What distinguishes a glaucoma specialist from an ophthalmologist?  

Dr. Rick Wilson:  A glaucoma specialist has taken an extra year of training after serving a residency in glaucoma at a qualified academic institution.

P:  Is medication your first line of treatment for a newly diagnosed patient? 

Dr. Rick Wilson:  Yes.  I think the medications we have are so good that I use them as  first-line treatment in almost everyone.

P:  Which is more important in diagnosis, a poor visual field test, a large C/D ratio, or high IOP?

Dr. Rick Wilson:  All of the factors you cite are relevant.  A definitely abnormal visual field is diagnostic. The appearance of the optic nerve may also be diagnostic.  An intraocular pressure above 30 mm Hg may be almost diagnostic.

P:  Do you use short-wave-length-automated perimetry (SWAP) to help make the diagnosis?

Dr. Rick Wilson:  SWAP is a new test that helps diagnose borderline glaucoma.  The new optic nerve or nerve fiber layer imaging technologies may be useful, but they are much more useful in determining whether vision is getting worse over time than in trying to determine whether or not a person has glaucoma.  

Moderator:  Is SWAP available at most ophthalmologists' offices?  Is it expensive?

Dr. Rick Wilson:  SWAP is well known and no more expensive than the normal visual field test.  It is not available in all ophthalmologists' offices.

P:  Are you still wary of the HRT (Heidelberg Retinography) test?  I keep getting conflicting results that say I am either losing or gaining tissue, depending on the day.

Dr. Rick Wilson:  I am still leery of the HRT, the GDx (nerve fiber analyzer), and the OCT (optical coherence tomography).  They are still not as good as an ophthalmologist who can look carefully at the optic nerve.  The new technologies are poor at diagnosing glaucoma and better at following it.

P:  Is the Humphrey FDT (Frequency Doubling Technology) adequate for the visual field test?  

Dr. Rick Wilson:  Not at this time.  A thresholding visual field test is needed.  The FDT at this time is a screening test.  

P:  If a patient has normal vision, a normal visual field, and normal IOP, but a large optic nerve and conflicting HRT results, would you order more tests, such as SWAP or even  MRI (magnetic resonance imaging)?

Dr. Rick Wilson:  I certainly would not get an MRI.  Keep in mind that the visual field test does not pick up glaucoma until a third of the optic nerve is damaged, so that is not a good way to diagnose early glaucoma.  The diagnosis would depend upon your IOP and how thick your corneas were, along with the appearance of your optic nerve.

P:  I was told I have a large optic nerve, and even larger cups.  Does that sound like glaucoma to you?  So far, it hasn't to my doctor, but he is still on the fence about it.

Dr. Rick Wilson:  Larger-than-normal optic nerves have larger-than-normal cups.  The HRT, if the outline of the nerve is carefully drawn, will tell you the size of the optic nerve and whether or not it is abnormally large.  One thing you should consider is a central corneal thickness (CCT) measurement.  Since intraocular pressures are based upon a normal-thickness cornea, corneas that are significantly thicker or thinner than average will give falsely high or falsely low IOP readings.

P:  How significant is the cup-to-disc (C/D) ratio?  

Dr. Rick Wilson:  The C/D ratio is often a late change in glaucoma. The quality of the optic nerve tissue and the appearance of the nerve fiber layer will usually show the first sign of glaucoma damage.

P:  What is the significance of a horizontal or a vertical cup?  

Dr. Rick Wilson:  A horizontal cup argues against glaucoma.  A vertical cup makes you think more strongly of glaucoma.

P:  How do you deal with telling teenagers and their families about the lifelong prognosis of glaucoma?  I was diagnosed with glaucoma when I was 16 years old.  Even with surgeries and various eye drops, I wonder how well controlled my IOP can be over my lifetime of perhaps 80 years, and how much or how rapidly my vision is going to deteriorate as I get older.

Dr. Rick Wilson:  The most important thing I tell a newly diagnosed glaucoma suspect is that most of vision lost to glaucoma is lost before the patient sees the doctor for the first time.  We are really fairly good at preventing further visual field loss. I agree with you that 80 years is a long time.  However, I expect our capability in handling glaucoma to improve dramatically.  If our government will allow us to conduct stem cell research, I think the potential to regrow cells in the retina that have been killed by the glaucoma would be possible in the next 20 years.

P:  Some of us were diagnosed as glaucoma suspects before we were diagnosed as having glaucoma.  How do you define "glaucoma suspect?"

Dr. Rick Wilson:  A glaucoma suspect is the same as someone with borderline glaucoma, that is, there is a suspicion, but not a definite diagnosis.

P:  It seems that most newly diagnosed patients go through a period of denial, which could affect their treatment.  For example, not  being compliant about taking medications as prescribed.  What advice do you give new patients?

Dr. Rick Wilson:  You are right.  Denial is the most common cause for patients not taking their medication.  Since denial is born of anxiety and apprehension, the best way to prevent denial is to educate and reassure the patient.  Therefore, I inform the patient that glaucoma is a treatable disease, and that our medicines and surgeries are getting better all the time.  The doctor, however, needs patients to be partners with him or her in their care.  Using the eye drops is difficult if you don't understand the harm of not taking them.  Using the eye drops is easier to do if you want to preserve your vision.  

P:  I think compliance is harder when you've been diagnosed for a long time.  I find it harder and harder to remember to use my eye drops these days.  Thinking about using drops for 80 years is depressing!  Sometimes it seems almost inevitable -- and we all talk about it -- that we will lose our vision in 10 or 20 years.  Even after 10 years of diagnosis and treatment, my vision has declined from 20/70 to 20/80, and I'm getting a superior arcuate visual field loss (scotoma) in my good eye.

Dr. Rick Wilson:  You need to remain committed and conscientious about using drops. Many of my patients have been on drops for 30 to 40 years and still have reasonable vision. The drops and surgeries are getting so much better that we may come up with a Drano-type drop that clears out the drain (trabecular meshwork), but only has to be used  once a month.

P:  Do you go over all the options with a new patient, such as laser versus eye drops?  

Dr. Rick Wilson:  I try to educate them as much as possible, but do not offer new patients laser therapy unless they are the very unusual patient for whom laser therapy might be the best option.  Such a patient might be an older woman with pseudoexfoliation glaucoma and Parkinson's disease.  Parkinson's might make it impossible for her use to drops, but she would remain a good laser candidate.

Moderator:  Thanks again for your help, Dr. Rick. 

Dr. Rick Wilson:  You're welcome. I am going to have to run, so wish you all a very good week.

End of highlights for October 1, 2003.

On October 8, Dr. Wilson discussed "Post-operative Care" in the Chat room. Click here for highlights of that meeting.

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