Medical Mondays 2Dr. Pat likes to work as a collaborative physician. Her patients, she believes, will be her best partners in providing diagnostic information—as long as they are asked the right questions. She also believes in consulting with the best medical minds on issues that require specialization or unique clinical experience.

This week, during Glaucoma Awareness Month, she calls upon the expertise of ophthalmologist Leila Rafla-Demetrious, M.D., who specializes in glaucoma, to interpret the current recommendations on screening for this vision-stealing condition.

 

Dear Dr. Pat:

I am a 54-year-old African American woman with hypertension that is well controlled, plus some slight enlargement of the heart that causes no symptoms. I am a master teacher in a highly regarded magnet school in New York. I asked my primary care doctor for a referral for an eye exam, since my sister recently developed older-age glaucoma (she is 70) and may become blind from a late diagnosis. The primary care doctor did a basic exam (finger wiggling to check if I could see from the sides of my vision and looking into my eyes with a simple hand held instrument). She told me that since I had no symptoms and had no change in my vision (I wear drugstore readers in restaurants with dim light), I did not need a referral for a visit to an ophthalmologist. She told me that the U.S. Preventive Services Task Force had found no reason to support screening for glaucoma in adults who had no symptoms. She said that the screening tests were inconclusive and that I would be given eye drops that might cause cataracts.

I had read about glaucoma and found that it is increased in African Americans and that I was at greater risk because I had a sister with glaucoma. She still refused to give me a referral.  So I went to a major teaching hospital here in New York City, where I was examined by a resident, then by the senior doctor in charge of the clinic. I still had to pay for my visit, but certainly less than I would have paid to see a private ophthalmologist.

The resident doctor dilated the pupils of my eyes and examined them thoroughly. He measured the pressure inside my eye and looked at my eye nerve disc with a more sophisticated instrument than the hand-held device used by the primary care doctor. He then asked the senior doctor in the clinic to evaluate his findings. I do have glaucoma after all, even though my vision has not changed. I have wide-angle glaucoma, and the pressure inside the eye is still normal. The doctors told me to use two eye drops daily in each eye and to come back to the clinic in three months. There has been change already in the nerve disc, but they are hopeful that they can arrest the progression of damage. I always thought that glaucoma was caused by high pressure in the eye, but apparently not.

I am relieved that I have this diagnosis before I have lots of damage, and that I have a place to go where I can get good care. But how many other primary care doctors are there who do simple visual field testing by wiggling their fingers and looking into the eyes of patients that have not been dilated, and then refuse to allow patients access for screening? My sister may become blind because her glaucoma was found very late. Who makes these recommendations?  Should my brothers and sisters be screened?  What causes this kind of glaucoma, anyway? Can these drops keep me from losing my sight?

Jeryln

Dear Jeryln:

I have asked our WVFC Medical Advisory Board member Leila Rafla Demetrious, M.D., a board-certified ophthalmologist, to answer this question. She is fellowship-trained in the medical and surgical treatment of glaucoma. Glaucoma is the No. 1 cause of blindness in African Americans, and the risk of developing this kind of glaucoma is increased when a brother or sister develops it. You should tell your family members about this.

Primary care doctors are all aware of the recommendations from the U.S. Preventive Services Task Force (USPSTF) these days. Insurance companies plan to hold down costs by refusing to pay for a great many previously available preventive care evaluations—such as a visit to an ophthalmologist for glaucoma testing—in order to improve their bottom line, while pointing to the increasing health care costs as the reason.

Most patients do not have your determination to do the research that you did, then choose to pay for your evaluation because you made a decision that the “recommendations” did not make sense. Do share this information and the medical evaluations from the ophthalmology clinic with your current primary care doctor. All health care providers need to know their diagnostic limitations, and doctors need to really listen to the patient. You were at greater risk for glaucoma, and you did need an evaluation.

Thank you for sharing your experience and sending in your questions.

Dr. Pat

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Dr. Rafla-Demetrious responds:

Dear Jeryln,

First of all, I applaud your perseverance in seeking proper screening and eye care. I hope your story is an unusual one, and that most people do not have to go to such lengths—but I’m glad you did.  I also hope that you share your glaucoma diagnosis with your medical practitioner, as it may serve as an opportunity for her to review screening protocols and glaucoma risk factors.

As you probably know, glaucoma is a disease of the optic nerve in the eyes, in which the pressure in the eye is too high for the optic nerve, and causes progressive damage. There are chronic and acute forms of glaucoma, though the vast majority of people have the chronic version. In this form, the optic nerve damage is insidious and symptom-free; glaucoma is known as the “sneak thief of sight” for this reason. Much less common is an acute attack of glaucoma, which is associated with a dramatic rise in eye pressure and brings people to medical attention due to pain and acute visual loss. As a result of its being a mostly quiet disease, most people who have glaucoma do not even know it, and the diagnosis is usually made in the setting of an eye doctor’s office.

So, what does glaucoma actually cause? It is a disease that tends to affect the peripheral vision in its early stages, and initially causes only subtle changes in the visual field. Unchecked, this visual field loss will progress, and the classic hallmark of advanced glaucoma is tunnel vision, in which a person may be seeing 20/20, but only through a small window of central vision.  Even with that damage, however, people may sometimes be unaware of this field loss, since it has occurred slowly enough over time to allow the brain to adapt. Optic nerve damage can also occasionally cause central vision loss early on, a rarer symptom, though one that does bring people sooner to medical attention.

Currently, 2.2 million people in the U.S. have glaucoma.  By 2020, this number is expected to be near 3.3 million. Given the potential devastation to one’s vision that can be wrought by glaucoma, why isn’t everyone routinely checked for it? Why did you, Jerlyn, have to proactively seek out care?  Your medical doctor was only following the 2005 findings of the U.S. Preventive Services Task Force, which looked at population-based screening for glaucoma. The study found “insufficient evidence to determine the extent to which screening . . . would reduce impairment in vision-related function or quality of life.”  The study conclusion also cited the potential harms of early treatment, including cataracts, and summarized its findings in saying that the USPSTF “could not determine the balance between the benefits and harms of screening for glaucoma.”

Since this study, however, multiple professional groups, including the American Academy of Ophthalmology, have addressed the issue of screening for glaucoma. While almost all agree that widespread population screens are not effective, it is useful and productive to target those at risk for glaucoma. All agree that those at risk include people over the age of 60; people with a family history of glaucoma; and African Americans, who are especially at risk as they get older. Other risk factors that most agree on are extreme nearsightedness; prior history of eye trauma; diabetes; and Hispanic background, especially over the age of 65.

The reasons for focused, risk factor–based glaucoma screenings are many. We know that glaucoma is generally asymptomatic, and that very few people report to a doctor with actual complaints related to glaucoma.  We know that early treatment delays or prevents the progression of the disease, and preserves vision by slowing the worsening of visual field defects. From even a purely economic standpoint, diagnosing glaucoma early pays for itself. By preserving visual function in older people, and by maintaining peoples’ ability to continue unassisted in their activities of daily living, glaucoma diagnosis and treatment decreases the disease’s overall burden to society.

Glaucoma screening is, in itself, a multifactorial process, and one that requires a skilled eye professional. It involves measuring intraocular pressures, assessing optic nerve head damage, and performing visual field testing. While measuring intraocular pressure tends to be the traditional barometer, it is actually not very sensitive in picking up glaucoma after all. Intraocular pressures tend to vary quite widely, and up to the number 21 can be considered “normal.”  However, many people with glaucoma never actually have elevated eye pressures, so a so-called normal pressure reading alone does not protect you. In fact, despite evidence of optic nerve damage, only 1 in 10 to 15 people actually has high eye pressures at screening.

A second element in the screen is the optic nerve head assessment. This can be done visually through a dilated pupil, in which the eye doctor uses a lens to assess nerve appearance, and inspects for evidence of damage. There are also automated nerve analysis machines, which digitally map the optic nerve and surrounding nerve fiber layer. This technology is useful in conjunction with an optic nerve exam; in and of itself it tends to be less diagnostic, because of intra-observer variation and measurement artifacts.

Lastly, there is the automated visual field exam. This exam, when done correctly, can pick up visual field defects well before any confrontational (finger wiggling) field exams could. However, these exams do tend to be a bit long, and can be subject to multiple testing errors and difficulties, including a test-taker’s lack of focus, sleepiness, distraction, and other issues.

Newer types of visual field machines, like those employing frequency-doubling technology, are much faster and tend to have a higher predictive value. This technology will likely eventually replace traditional fields, at least for screening purposes.

Despite the USPSTF’s study findings, the Centers for Medicare and Medicaid Services does support, since 2002, annual glaucoma screening for those at high risk.  Again, these groups include African Americans (over the age of 50, per CMS protocol); Hispanic Americans (over the age of 65); people of any age with a family history; and diabetics. The agency also recommends an initial screen of African Americans, or those of African descent, to be performed at ages 20 to 29. People aged 40 to 64 are recommended to be checked for glaucoma every 2 to 4 years, and those over 65 should be checked every 1 to 2 years.  Other than Medicare, several organizations do offer free glaucoma screens. These include Eye Care America, The Lions Clubs, Vision USA, and Friends of the Congressional Glaucoma Caucus Foundation.  If you feel that you are at risk for glaucoma, these organizations may be helpful in providing at least an initial assessment.

In summary, Jeryln, given your risk factors of African American race, age older than 50, and family history, you did the right thing in getting yourself thoroughly checked for glaucoma. Luckily, your glaucoma seems to be in its fairly early stages, and was picked up before any functional damage or impact on your central vision occurred. You should indeed encourage your family members to be checked by an ophthalmologist for evidence of glaucoma, and remind them that even if they have no symptoms, glaucoma may be lurking. The good news is that if found and treated early, glaucoma progression can usually be halted or slowed, thus preserving vision for many years.

Dr. Leila Rafla- Demetrious

 

Leila Rafla-Demetrious, M.D., is a board-certified ophthalmologist. She is fellowship-trained in the medical and surgical treatment of glaucoma, a potentially blinding disease. She also sees and treats general ophthalmologic medical and surgical conditions. Dr. Rafla-Demetrious performs cataract surgery, as well as other anterior segment procedures. She has been a proud part of the Ophthalmology service at Weill-Cornell Medical Center at Presbyterian Hospital for more than eleven years.