Glaucoma: Irreversible but preventable blindness

glaucoa visual field defect - croppedAfter reading Dr. Weiss’ article last week on early detection of glaucoma, I was back in my office seeing one of my patients that drives this point home. My patient, let’s call him Jim, is a 59 year old gentleman who has lost vision from glaucoma. My partner and I had been seeing Jim for his annual exams and providing glasses to correct his vision since 1999. Beginning in about 2004, the pressure in his eyes started to increase. Normal intraocular pressure (IOP) is between the range of 10 to 20 millimeters of mercury (mmHg). Over a few years, his IOP slowly increased until they were running in the 20 to 21 range – not too bad – but enough that we discussed that we needed to monitor this more closely. In 2008 Jim’s IOP was 20, so he decided to skip his 2009 exam.

When, Jim came in for his “annual” exam in 2010, he had a very different complaint. He complained that if he covered his right eye, he could not see the lower part of his vision.  This fast loss of vision could be caused by a retinal detachment, but would be a very unusual symptom for glaucoma.

Vision loss with glaucoma usually takes years, or decades to advance to the point where it is noticeable to the patient. After ruling out a retinal tear or detachment, I took some time to look at glaucoma. The pressure in his eyes was up to 30mmHg, and close examination of the back of the eye showed glaucomatous damage to the optic nerve consistent with his visual field loss. We started treatment right away, and luckily stopped the progression of vision loss.

Over the years, my partners and I have created a large practice with increasing population of glaucoma patients. I am always amazed with the fact that no two patients progress in the same way. I have seen “normal pressure” glaucoma patients who have damage to their optic nerves even with “normal” pressures. I have patients with significantly high pressures who have no damage to their optic nerves. I have patients that we are able to control with eye drop medications that are only used one time each day. And, I have patients that need surgery to lower their eye pressure to prevent blindness. I am treating as many patients who have a family history of glaucoma as who have no family history. I have patients with glaucoma from 21 to 94 year old. The only way to prevent blindness from glaucoma is to catch it early with annual eye exams.

~ Steven Sage Hider, OD
California Optometric Association

Blindness & Glaucoma: Early detection and treatment is the key

Photo of listentothemountains on Flickr

Photo of listentothemountains on Flickr

I often hear from patients- “Why do I need to come in each year, I see fine!”

Well, there are many reasons to follow your Optometrist’s yearly examination recommendation. One of them is for the early detection and treatment of glaucoma.  Glaucoma is a disease that affects the optic nerve in the eye- the structure responsible for conveying visual information from your eye to your brain.  The progression of glaucoma is very slow and hardly noticeable to the patient in the early stages, but causes blindness in the later stages.  It starts with peripheral vision loss and progresses centrally.  Once the cells in the optic nerve are lost, they do not regenerate. That is why early detection and treatment is the key.

In order to screen patients for glaucoma, optometrists with begin with a thorough health and lifestyle history. Family history of eye disease and lifestyle factors such as smoking and exercise can be risk factors for the development of the disease. The optometrist will most likely perform basic glaucoma screening tests including eye pressures and visual fields and sometimes more advanced imagery such as retinal photos, Optomap, or optic nerve imaging. All of these tests can aid in the early detection of the disease.

Each year, your optometrist can compare the new results of these tests with the tests from the previous years to determine if glaucoma exists and if so, is it progressing, and how quickly.  A determination can be made if treatment is necessary.

There is no cure for glaucoma, but treatment with eye drops, surgery or a combination can prevent the permanent vision loss.

Just remember, early detection is the key. Visit your optometrist regularly!

~ Lisa M. Weiss, O.D.
California Optometric Association

April Fools’ Day – 6 silly eye care myths you should know about

Photo Courtesy of jenschapter3 on Flickr

Photo Courtesy of jenschapter3 on Flickr

It is April Fools’ Day and to help ensure you don’t look foolish, I wanted to share a little eye information with you. There are a number of myths out there about your eyes and I wanted to quickly clear up some of the confusion. I hear a few of these myths every week with my patients, so here are a few of the most common:

  1. “Eye exercises can strengthen your eyes so you won’t need glasses.” While it is true you can make your eyes function better by doing eye exercises, for the majority of patients, glasses or contacts are needed to keep their vision consistently clear. The exception to this rule is that some children can benefit from eye exercises under the direction of an optometrist trained in vision therapy, which can help reduce a child’s need for glasses.
  2. “High pressure in your eyes means you have glaucoma.” Glaucoma is a very serious eye disease that can result in permanent vision loss. We know that having pressure beyond  a certain range significantly increases your risk of developing glaucoma, it does not mean you actually have glaucoma.
  3. “Contacts can slip behind the back of your eye and get struck in your brain.” Our body’s natural defense system ensures that this cannot happen. The conjunctiva is a tissue that covers the inner portions of your eyelids and the white of your eye. It is a continuous tissue that prevents anything from getting behind your eye, that includes contacts, eyelashes, or any other things that may get into your eye.
  4. “Wearing glasses makes your eyes weaker.” This common myth does not take into account that as your eyes age, your ability to see clearly without correction is reduced. Small prescriptions that did not require correction as child or young adult can present later in life as blur or visual discomfort requiring glasses.
  5. “If you can see clearly, you have healthy eyes.” Sadly, this is a common myth that keeps many people from getting their eyes checked on a regular basis. Comprehensive annual eye examinations with your doctor of optometry can help ensure that you have healthy eyes and detect serious vision-threatening or even life-threatening diseases well before they become a problem. Tumors, uncontrolled diabetes, strokes and other serious health problems can be caught during an eye exam with your optometrist. Regular exams with a doctor of optometry can help ensure clear vision and healthy eyes.
  6. “Eyes can actually pop out of your head.” This myth gets perpetuated by the many horror movies that show eyes being knocked out of a person’s head and rolling along the ground. Fortunately for us all, this does not happen. Your eyes are held in place by muscles that move your eye up, down, left and right. Additionally, you have a nerve that plugs into the back of your eye that can also hold it in place. Systemic health disease, such as thyroid eye disease, or compressive trauma can cause your eyes to protrude beyond your eyelids but they will never fall out of head like they do in the movies.

I hope shedding some light on the eye myths helped increase your knowledge and keep you from looking foolish.

 ~Ranjeet S. Bajwa, OD, FAAO
California Optometric Association

What did my doctor just say? Common terms your eye doctor will use and what they mean

Courtesy of riekhavoc (caughtup?) on Flickr

Courtesy of riekhavoc (caughtup?) on Flickr

Have you ever felt like you were not quite sure what just happened at your optometrist’s office? It is difficult enough to answer the “which is better, one or two?” questions and then at the end of the exam to try and understand the doctor’s explanations with difficult optometry terms without secretly worrying that you might have said something wrong!

Hopefully this blog will help you better understand some of the more common terms we use in our examinations.

1) First of all, most comprehensive exams will include a detailed case history. The doctor will want to know your family medical and ocular (eye) history. Some terms you may hear include the most common eye diseases – cataracts, glaucoma and macular degeneration.

  • Cataract is the term used when the natural lens of your eye becomes cloudy, causing blurred and distorted vision.
  • Glaucoma is the eye disease that causes your eye to have excessively high pressure, which can lead to long-term damage of the nerve in the eye.
  • Macular degeneration is a disease that affects your central or straight ahead vision.

Not only will the optometrist ask you about a family history of any of these conditions, they will also assess your eye health and your possible risk for developing any of them.

2) Next, the optometrist will perform a refraction to get you the best possible glasses or contacts that will correct your vision.

  • A refraction is just the process of determining for each individual what are the best lenses to give you maximum visual clarity and comfort at both distance and near.
  • Myopia – nearsightedness or the ability to see better at near than at far.
  • Hyperopia or farsightedness, really means that it is more difficult to focus at near and at far distances.
  • Astigmatism: this refers to the shape of the front surface of the eye being more football shaped rather than basketball shaped.

3) There are a few terms you might hear specifically in an child’s exam.

  • Pursuits: slow, smooth eye tracking.
  • Saccades: fast reading eye tracking.
  • Accommodation: focusing.
  • Binocularity: the ability of the eyes to work together as a team.

4) Finally, there are some terms regarding glasses that it might help to define.

  • Progressive lenses are the kind of “no line bifocal” that you might hear about on TV. But, unlike a bifocal, where there are two areas of vision, near and far, progressives have an unlimited amount of areas as you look from distance to near in the lens.
  • Transition lenses are the kind that change to dark outside. They undergo an anti-reflective treatment, which eliminates all glare and allows for crisper vision, especially at night.

Hopefully, this quick explanation helps with some of the confusing terms in an eye exam. As for any others, always ask your optometrist to explain something that does not make sense.

~Lisa Weiss, OD, MEd, FCOVD
California Optometric Association

What’s gradual, painless and dubbed the Silent Thief of Sight?

The answer is Glaucoma, an eye disease that slowly causes you to lose your vision.  If you’ve been proactive in monitoring your health, you should hopefully have a pretty good idea of certain health conditions that run in the family.  For example, mom has high cholesterol, dad has diabetes and you remember your grandmother uses eye drops for something.  Knowing your family eye history is very important because most eye diseases tend to be genetic.  Glaucoma, for example, tends to run on the mother’s side of the family.  If your mom has glaucoma, make sure you tell your optometrist.


Courtesy of 55Laney69 on Flickr
(Left – Normal Vision, Right – with glaucoma)

What exactly is Glaucoma?  It’s a disease where the optic nerve slowly deteriorates as a result of poor blood flow and is often accompanied by high intraocular pressures.  The optic nerve is a bundle of smaller nerve fibers, similar to a conduit, which transmits electrical signals from the retina to the brain.  In glaucoma, the smaller nerve fibers slowly deteriorate, resulting in a gradual loss of vision.  The first areas of vision loss will occur in the periphery, off to the sides, which is very difficult to detect since we are not often aware of our peripheral visual field.  If a patient experiences symptoms, the first symptom may be poor night vision.  As the disease progresses, vision loss creeps in toward the center of your visual field.  By the time you notice that you are losing your peripheral vision and developing “tunnel vision,” you will be in the late stages of glaucoma.

The good news is that glaucoma is the leading cause of PREVENTABLE blindness.  Routine eye examinations will allow an optometrist to detect glaucoma sooner.  There are a variety of tests necessary to detect glaucoma such as a visual field screening, measurement of the intraocular pressures, and careful evaluation of the optic nerve to detect changes.  Many offices now incorporate retinal photos into their routine examinations that are invaluable in detecting many retinal diseases including glaucoma.  Glaucoma is a diagnosis over time, it is rarely diagnosed on a first visit.  When change is detected in the structure of the optic nerve or in the thickness of its surrounding nerve layer over time, then glaucoma is diagnosed.  This is where comparing current retinal photos to older ones are helpful in detecting small changes over time.  Another important tool in the last few years is the Optical Coherence Tomography, which measures microscopic layers of the retina to detect microscopic changes.

So what happens if you do have glaucoma?  Treatment is often pretty simple.  There are a few different forms of glaucoma.  The majority of them are treated with eye drops with dosages as little as once a day.  The medicated eye drops lower the intraocular pressures in the eyes, which help to slow down the progression of glaucoma.  Some patients require laser treatments to lower their pressures.  Most cases of glaucoma are manageable and treatable if detected early.

I usually tell my patients that the ages of 20s and 30s is for establishing a baseline.  This is where routine examinations and photos are useful.  The ages of 40s and onward is for detecting change and eye diseases, and treating early.  Of course, as with any other diseases of the body, staying healthy is key.  Those with diabetes have a much higher likelihood of developing glaucoma so keep your blood sugar under control.  Those of Asian, Latino and African descent have a higher tendency for developing glaucoma.  Having a high amount of nearsightedness also puts you at greater risk.

The take home message is that glaucoma is treatable if detected early.  So know your family health history, stay healthy and see your optometrist routinely for comprehensive eye examinations.

~Cindy P. Wang, O.D., F.A.A.O.
California Optometric Association   

Color blindness – the causes and the effects

When we think of someone being color blind, we may think that he sees the world in black and white, or shades of gray.  But that is extremely rare.  In fact, almost 8% of men have some form of color vision deficiency where certain colors are more difficult to distinguish, or do not appear as vivid as other colors.  (Perhaps that explains the questionable wardrobe choices my husband sometimes makes.)

What causes it?

Most cases of color vision deficiency are inherited and passed down from the mom.  The photoreceptors in the retina responsible for color are called cones.  Each cone is sensitive to a certain color, in particular, red, green or blue.  If a person has inherited a recessive gene that causes one or more of the cones to be absent or to not function properly, then he will have abnormal color perception.

Photo courtesy of entirelysubjective on Flickr

Photo courtesy of entirelysubjective on Flickr

Some cases of color vision deficiency are acquired later in life as a result of a disease.  More common causative diseases are glaucoma, macular degeneration, and diabetes.  If you notice a change in your color vision, make sure to be evaluated by your optometrist. For eyecare providers, we tend to distinguish color vision deficiency into two broad categories.  Red-green and blue-yellow.  Red-green is inherited and the most common deficiency.  Those with this defect can still see red and green, but the colors are more difficult to distinguish and they may not appear as vivid as to the normal eye.  For example, red and green signal lights may look the same.  One may appear brighter but the lights may both look white.  (For this reason, I’m not a fan of the horizontal traffic lights in some smaller towns.)  Most people who have color vision deficiency have a mild form and are not disabled by this condition.

The other form of color deficiency is blue-yellow where patients have a difficult time distinguishing blue from green or yellow from violet.  This is less common and is usually caused by certain eye diseases.  Unfortunately, for many of these patients, color deficiency is just one visual problem among others.  These patients may also suffer from dimming of vision or distortion of vision.  Often times, bright lighting is helpful for these patients, and occasionally tinted lenses. 

How can I help someone that’s color deficient?

Of course, a comprehensive eye examination is important to rule out any causes of color vision deficiency other than genetics.  This also helps to determine the severity.  Most color deficient individuals carry on like normal without it interfering with their daily lives.  A helpful tip would be to not use the colors red and green as markers because the two colors may appear very similar.  Blue and red will be easier to distinguish.  Unfortunately, those with color vision deficiency should avoid careers that require distinguishing color differences such as airplane pilots, paint mixer, interior designer, etc.

Recently, new developments in tinted lenses have been able to allow some color vision deficient patients be able to see colors they have never seen before.  Sounds promising!

~Cindy P. Wang, OD, FAAO
California Optometric Association

Night blindness 101

The term night blindness sounds alarming, as though some people are actually blind at night.  There is a small percentage of the population that does in fact experience true night blindness, but it is rare and often the result of late stage eye disease.  In optometry, it is not common to use the term night blindness although we do encounter a significant number of patients who complain of poor night vision.  The symptoms are usually blur and dimming of vision at night, glare and haloes around lights and poor adaptation from light to dark environments.  How do you know if what you are experiencing is normal or a result of something more serious?

There are a handful of eye conditions that can create symptoms of poor night vision.

Photo Courtesy of kenleewrites on Flickr

Photo Courtesy of kenleewrites on Flickr

  1.  Patients who have had surgery to the corneas such as LASIK or corneal transplants may notice glare and haloes around light.  They may also experience diminished contrast sensitivity which can cause images in the evening to appear more dim.  Unfortunately, surgical results usually cannot be reversed.
  2. Cataracts are the number one cause of decreased night vision.  Patients over the age of 40 will begin developing mild cataracts.  This is when the natural lens inside the eye becomes more yellow and opaque as a result of age and ultraviolet exposure.  Cataracts can cause haloes and dimming of vision in the dark and decreased contrast sensitivity.  Fortunately, cataracts are easily removed thereby restoring problems with night vision.
  3. Corneal diseases such as keratoconus and severe dry eyes may also affect one’s vision in the evenings causing double vision or haloes.  For some of these patients, specialty contact lenses or eyedrops will alleviate these symptoms.
  4. Newer technology has also allowed optometrists to detect higher order aberrations in some patients.  For these patients, standard spectacle lenses may not improve night vision problems.  An instrument to detect higher order aberrations will determine whether a patient requires a specialty custom-made spectacle lens to improve night vision.

Some patients do in fact have true night blindness caused by an eye disease in its late stage.  Usually, symptoms begin slowly over time and progress to an inability to see in the dark.  These patients usually suffer from one of two eye conditions.

  1.  Retinitis pigmentosa is an inherited eye disease of the retina, the tissue that lines the back wall of the eye and captures visual images.  Retinitis pigmentosa affects the rods of the retina and causes slow deterioration of these structures.  The rods (unlike the cones) are responsible for night vision and for peripheral vision.  As the disease progresses, patients will notice a decrease in their ability to see in the dark and in the periphery.  Unfortunately, there is no current cure for retinitis pigmentosa.
  2. Glaucoma is an eye disease where the optic nerve slowly degenerates.  Patients with glaucoma usually have no symptoms in the early stages of the disease.  As the disease progresses, nerve fibers in the retina begin to deteriorate resulting in a decrease in peripheral vision as well as night vision.  Usually, patients do not experience symptoms of poor night vision and poor peripheral vision until the late stages of the disease.

Now that you know the causes, what are some ways to alleviate or improve poor night vision?  The simplest solution is to wear an updated pair of prescription glasses (if you have a prescription) with higher index lenses and an anti-glare coat.  Your optometrist can also inform you if you require customized lenses to correct for higher-order aberrations.  If your night vision problems are not a result of surgery or any eye diseases that you are aware of, then it is important that you visit your optometrist for a comprehensive eye examination.

– Cindy P. Wang, O.D., F.A.A.O.
California Optometric Association