Tag: Amsler grid

Categories
Macular Degeneration

Signs and Symptoms of Macular Degeneration

Symptoms of Macular Degeneration | Randall Wong MD Retina Specialist

is the deterioration of the central portion of the retina—the macula, which is the area of the retina that controls visual acuity and color perception. Macular degeneration usually occurs in people over the age of 55 and is more common in people of northern European ancestry.

Symptoms of Macular Degeneration

The most common symptoms of macular degeneration are blurry vision, blind spots, and distortion.  

New distortion should always be examined and can be monitored at home with the use of the Amsler grid.

Blurriness, blind spots, and distortions are also common symptoms in the following eye diseases:

  • macular edema (swelling) from many causes
  • epiretinal membrane
  • macular hole
  • diabetic retinopathy

Distortion is a common symptom of a disease of the macula and is does not signify a particular disease (i.e. get examined).

The Macula

The macula provides our central “20/20” vision.  As you are reading this article, your eyes are moving to keep the text focused on your macula.  When you are staring at an object, you are focusing the object on your macula.

Macular degeneration can be wet or dry and both types progressively affect the central vision causing blurriness, blind spots, and distortions. However, the wet form causes more serious vision loss.

Retinal Degeneration

For reasons yet to be discovered, the macula degenerates with age.  There are probably environmental risk factors, such as smoking, which increases the chances of developing macular degeneration.

The vast majority, 90% of cases, are the dry variety, which causes very slow, yet progressive blurry vision.  Wet ARMD causes the development of abnormal blood vessels within the layers of the macula.  These blood vessels cause destruction of the normal retinal tissue and can leak fluid and bleed.

Regardless of the type of macular degeneration, the initial symptoms are the same—blurriness, blind spots, and distortion.  However, wet macular degeneration can destroy vision rapidly—in days or weeks.  

What Can You Do?

If you have symptoms such as persistent blurry vision, blind spots, and/or distortion, make sure you get a complete dilated eye examination. 

While there are many causes of blurry and distorted vision other than macular degeneration, you want to make sure that you get an early diagnosis so whatever eye condition is causing your visual symptoms, the proper treatment can be initiated early in the process.  

Early diagnosis and treatment of eye diseases may prevent or limit permanent vision loss.

 

Categories
Macular Degeneration Treatments

Testing Your Eyes at Home

The major problem with wet macular degeneration is that the “wet” abnormal blood vessels tend to affect the macula.  This usually causes decreased vision and distortion.  Home monitoring, or self-monitoring, is based on the premise that new distortion may signify presence of neovascularization.

Patients with wet macular degeneration have two major concerns; recurrence in the same eye and wet macular degeneration developing in the other eye.  To alleviate their fears, doctors have long been recommending home monitoring as a method to catch the disease as early as possible.

Distortion from “wet” macular degeneration is similar to the “Princess and the Pea,” where the abnormal vessels are trying to sandwich themselves between the layers of the retina.  This causes the retinal surface to become uneven which translates into distortion.

Amsler Grid Testing – The Amsler Grid is used on a daily basis, testing each eye separately.  In this way, a patient with macular degeneration will become familiar with their own pattern of distortion.  Any new waviness should be reported to their doctor.  This may be a sign of active “wet” macular degeneration.

An electronic version of the Amsler Grid is available at “MyVisionTest.com.”  There is also a link on the left side panel if you ever forget.

The ForSeeHome™ AMD Monitor is the first telemedicine device for the home.  According to the company web page, this device offers self-monitoring of patients with known macular degeneration.  It is not a diagnostic tool, but monitors changes in distortion.  This information can then be transferred to the eye doctor for review.  The device has received FDA “510(k)” clearance.

What Does This Mean? The idea of self-monitoring is to catch the “wet” form as early as possible.  Early detection of wet macular degeneration usually translates to a better outcome.  In my experience patients with wet macular degeneration are pretty motivated to self-test regularly and the Amsler Grid seems to be a very good, cheap, and reliable test.  Remember that the macula is very sensitive and any change in distortion is usually pretty obvious.

It seems that a new telemedicine device might be “overdoing” it, at least from what I can tell from the web page and the press release.  It does not make a diagnosis and examination by the doctor is still necessary.

I see three scenarios; however, where this might be useful; 1) a patient is unable to tell, himself, if there are changes in his own vision (yes, it happens), 2)  a patient’s vision is so poor that subtle changes are unnoticed and 3) the device picks up earlier changes than can be noticed by the average individual, that is, the device is super-sensitive.

“Randy”

Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist
Fairfax, Virginia

Categories
How I Practice Macular Degeneration Retina

Visual Acuity – How We Measure Your Vision

A typical Snellen chart. Originally developed ...
Image via Wikipedia

When you go to your eye doctor, we check your “vision,” but there are several ways to actually monitor or evaluate your vision.  Basically, almost all vision testing is designed to measure the function of your macula.  Macular vision is your central vision.  It is our most useful vision.  When we are 20/20, we are testing central vision only.

“The Eye Chart” measures Snellen acuity.  This is the common eye chart that has the big “E” at the top of the chart.  Snellen was a Dutch ophthalmologist who developed the chart in the 1800’s.  It is the chart on the right.  Almost every emergency room and doctor’s office has this chart.

Snellen acuity measures your vision as a “fraction.”  We, in the U.S., call 20/20 vision the standard or “perfect” vision.

20/20 means that you are able to see at 20 feet, what “normal” person sees at 20 feet.  Another example, 20/50 means that you must stand 20 feet from a target/chart to see the same as the “normal” person standing 50 feet away.

Legal blindness is defined as 20/200 or worse.  If the vision is worse than the big “E” we use the following conventions;

  • Counting Fingers – measuring your ability to count the examiners fingers at a given distance.
  • Hand Motions – vision is limited to seeing movement, such as a waving hand.
  • Light Perception – vision is poor, retaining only the ability to see light.
  • No Light Perception – nothing, completely black.

Snellen acuity has many limitations, but it has been the basis for testing visual acuity.  Snellen acuity can NOT measure distortion, color, glare or blind spots.  Snellen acuity is a measure of your macular function, that is, how well your macula works.

The Amsler Grid is a commonly used to self-monitor central vision, especially distortion.  It is most often given to patients with macular degeneration.  Patients are instructed to place the chart in a common area, for instance, refrigerator door or bathroom.  The grid looks like a piece of graph paper.  It gets you accustomed to any distortion that may be present.  You are looking for new areas distortion.  If new areas develop, one should alert their eye care professional.  The American Academy of Ophthalmology has a link for an Amsler grid, including directions.

Glare Testing is a slight variation of measuring Snellen acuity.  A small light that may cause glare is shining into your eyes while reading the eye chart.  Typically, if a cataract is causing glare, it will reduce your acuity when the glare is recreated.  Some people actually see well until glare is introduced. A typical scenario where glare becomes problematic is driving at night with oncoming headlights.

A Visual Field measures your peripheral vision.  This is usually used to monitor glaucoma, but can be used to diagnose strokes, intracranial tumors or other visual abnormalities.  There are several types of visual fields; Humphrey, Goldmann, Octopus.

Potential Acuity Meter (PAM) is a device that projects an eye chart onto your retina.  Not all offices use these, but they are very helpful in testing retinal function more directly if vision is decreased, but not sure of the etiology.

Color vision and stereo-acuity are specialized tests and are not routinely used to test vision in adults.  There are special images and puzzles designed to measure either.  I never utilize these for examining patients either diabetic retinopathy or macular degeneration.

“Randy”

Randall V. Wong, M.D.
www.TotalRetina.com
Ophthalmologist, Retina Specialist

Reblog this post [with Zemanta]
Categories
Diabetic retinopathy Macular Degeneration Testing

Routine Examination Schedule for Diabetic Retinopathy and Macular Degeneration

What is routine?  In this case, routine should be the usual and regular times that you see your eye doctor when there are no perceived problems.  For instance, the American Academy of Ophthalmology and the American Optometric Association recommend that all patients with diabetes be examined no less than once a year.

How often you actually go for an eye exam is determined by your own personal eye doctor.

All Patients with Diabetes need to have an eye exam at least once a year.  The exam should include dilating the pupils to allow the best possible examination by your eye doctor.  You may seek the advice of a retina specialist, or, you may choose to consult with your eye doctor about seeing a specialist.

In my practice, patients with stable diabetic retinopathy (no active macular edema or signs of proliferative disease) may be seen as often as quarterly.  If there are active problems, more often may be appropriate.  If there are patients with early diabetic retinopathy, no history of laser treatment or loss of vision, sometimes an annual visit suffices.

Remember, early detection of diabetic retinopathy is essential.  Patients with diabetes can NOT monitor their own vision, as there is no association between active diabetic retinopathy and quality of vision.

Patients with Macular Degeneration are somewhat easier to “follow.”  In contrast to patients with diabetes, patients with macular degeneration can self monitor using the Amsler Grid.  If a patient notices sustained decreased vision, or, sustained distortion, then a prompt exam may be warranted.

Most patients that have macular degeneration should have some symptoms of either decreased vision and/or distortion.  Not all patients are aware of decreased vision, especially when it involves only one eye.  Yes, read on.  Many, many patients are unaware when there are vision changes only in one eye.

There is no golden rule for regular examination for patient with macular degeneration.  I personally do not see all my patients with macular degeneration on a regular basis, but I usually give patients the option of returning regularly.

Certainly, any time you are concerned about any vision changes, you should call your eye doctor.  My existing patients are also getting used to the idea of using email, or texting, to notify me.

“Randy”

Randall V. Wong, M.D.
www.TotalRetina.com
Ophthalmologist, Retina Specialist

Reblog this post [with Zemanta]
Verified by MonsterInsights