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Stem Cells for Stargardt's Macular Dystrophy and Macular Degeneration

RPE Transplantation for Stargardts Disease

 

Advanced Cell Technology recently announced the beginning of their landmark trial where stem cells are transplanted into patients with Stargardt’s Macular Dystrophy (aka Stargardt’s Disease) and dry macular degeneration.

Clinical Trials for Stargardt’s Begin

The company announced that their phase I/II clinical trials started in mid-July with one patient each of either Stargardt’s or macular degeneration.  Each patient received a relatively small dose of cells and subsequent patients will receive larger amounts of cells.  The first patients received about 50,000 cells.

The goal of the study, at this phase, is to test the safety and tolerability of the stem cell treatment over a 12 month period, that is, phase I/II will answer the question as to “how safe is the procedure?” and will also asses if this is a viable way to transplant stem cells.

Retinal RPE Cells are Replaced

The cells to be replaced are called RPE (retinal pigment epithelial) cells and are located underneath the top layer of the retina.  If you liken the retina to be an open faced sandwich with a slice of ham with cheese on top, the RPE cells are the slice of ham.  The “rods and cones” (otherwise known as photoreceptors) are located on the underside of the cheese.  The RPE cells nourish the photorecptors.

In cases of Stargardt’s disease and dry macular degeneration, the faulty RPE cells can no longer nurture, or feed, the photoreceptors, hence, the loss of vision.  It is hoped that by replacing the sick retinal pigment epithielial cells with stem cells, the vision can return.

What Does This Mean? This is really promising and exciting news.  On the horizon is the potential for a true “fix” for two of the most common forms of “blindness” in the world.  Actually, most of these patients are legally blind as you remember that the macula gives us central vision.  Thus, RPE transplantation should improve the central vision.

In my view, there are two large variables or areas of concern.  First, the actual technique of implanting the cells must be refined and perfected and at the same time, we need to see how long the stem cells can live or remain healthy.

While this is very promising, this may still be years away from becoming a viable treatment option.

Here is further information about patient inclusion into the study for either Stargardt’s Macular Dystrophy and dry ARMD.

 

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How To Diagnose Diabetic Retinopathy

The retina is the only part of the eye affected by diabetes.  The only way to diagnose diabetic retinopathy is by direct visualization of the retina.  Your eye doctor should be able to dilate your eyes and, by simply looking at your retina, diagnose the disease.  That’s all.

No Symptoms of the Eye Disease

Symptoms are the effects of a disease.  These are what a patient feels, not what a doctor sees.  Complaints of blurry vision, pain, shortness of breath, nervousness…all are types of symptoms.

The disease, diabetic retinopathy, can cause mild blurriness to complete blindness, or nothing at all.  Many patients see perfectly, yet have the disease.  They just don’t know it.

This is the danger of diabetic retinopathy.  Just like high blood pressure, it may cause absolutely no symptoms.

No Diagnostic “Tests”

A normal eye exam does not always include dilation of the pupils.  Every diabetic patient must have the pupils dilated at least annually.  These are the recommendations of the American Academy of Ophthalmology and the American Optometric Association.

Why?  A dilated exam is the only way to examine the retina.  A dilated exam is the only way your doctor  can “see” the characteristic changes of diabetic retinopathy.  There are no diagnostic tests for diabetic retinopathy.

In the absence of symptoms, the diabetic retinopathy can still be diagnosed.  Early detection means preventing loss of vision.

Fluorescein angiography and OCT (optical coherence tomography) are used commonly to study some of the aspects of your retina (i.e. is there retinal swelling?), but neither are necessary for the diagnosis.

The only way to diagnose diabetic retinopathy is for somone to “see” it.

What Does This Mean? Diabetic eye disease can be “silent.” Many people believe that the absence of symptoms means the absence of disease.  Obviously not true.

The patients with whom I have had the most trouble (i.e. they go blind despite my intervention) have had either no symptoms or ignored themselves for an extended period.  Certainly, they never had an eye exam until it was too late.

Sadly, in almost all cases, the blindness could have been prevented if someone had just “looked.”

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Legal Blindness and the IRS

Legally blind vision loss can result from either diabetic retinopathy or macular degeneration.  Complete blindness can result diabetic retinopathy, but not ARMD.  Legally blind, or partially sighted individuals, can still “see,” whereas completely blind patients see nothing.

Diabetic Blindness

Diabetic retinopathy can cause a spectrum of vision loss, from slightly blurry vision to complete blindness.  As we have discussed recently, one difference with diabetes as compared to macular degeneration is that diabetic retinopathy can affect the entire retina due to diabetic retinal detachment.

Proliferative diabetic retinopathy can also cause neovascular glaucoma which can completely destroy the optic nerve.

Both diabetic retinal detachment and neovascular glaucoma can blind completely.

Diabetes can also only affect the macula, thus, diabetic retinopathy can cause both legal and complete blindness.

Blindness from ARMD

In contrast, only the macular area of the retina is involved in macular degeneration.  Hence, central vision may be destroyed, yet the peripheral vision is spared.

Macular degeneration can NOT cause complete blindness.

Legal Blindness

Both eye diseases have the potential for causing legal blindness as both can affect the macula, or rather, both can affect central vision.

Legal blindness is defined as vision 20/200 or worse in both eyes despite use of corrective lenses.  There are also considerations of “blindness” for severely restricted visual fields.  Confirm this with your eye doctor.

Legal Blindness May Qualify for Tax Deduction

With tax day fast approaching, obtaining a qualifying statement from your eye doctor, may allow you a tax deduction. If you file jointly, your spouse may qualify, too.

What Does This Mean? Obviously, as one who deals with partially sighted patients, I attest to a patient’s “blindness” all the time.  A letter from your doctor is all you need to confirm your legal blindness.

I have also included a link to a  “Confirmation of Blindness”  form that can be used by your doc, but I don’t know for a fact if this grid is indeed acceptable by the IRS, but it is provided by the National Federation of the Blind.

NOTE:  There are many reasons a person may become legally blind, not just from retinal disease.  As always, feel free to share any of these articles with friends, family or doctors.

Disclaimer: The information contained in this posting should only be used as a reference. Should you have additional questions contact your tax attorney or local IRS office.

U.S. Treasury Circular 230 Notice: Any tax information contained in this communication (including any attachments) was not intended or written to be used, and cannot be used, for the purpose of (1) avoiding penalties that may be imposed under the Internal Revenue Code or by any other applicable tax authority; or (2) promoting, marketing or recommending to another party any tax-related matter addressed herein.

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Eye Surgery Can Blind

There are risks to eye surgery, especially intraocular operations such as cataract removal or vitrectomy.  Cataracts are the most common eye surgery and vitrectomy eye surgery is usually performed by a retina specialist for various problems of the retina and vitreous.  Infection, inside the eye, called endophthalmitis, is uncommon, yet can blind.

There are all sorts of “eye” surgery.  There is cosmetic “eye” surgery to lift the eyelids, there is “eye” muscle surgery to correct strabismus (crooked eyes), laser “eye” surgery to get rid of glasses, etc.  These are all procedures that do not invade the eyeball, and thus, are “extraocular” operations; surgeries that stay outside of the eye.

“Intraocular surgery” is surgery that cuts into the eye.  Cataract surgery, certain glaucoma operations and retina surgery are all invasive and, thus, introduce certain risks not found in other types of “eye” surgery.

Infection is the biggest risk of any intraocular procedure.  As with any surgical procedure, there is a risk of infection.  Intraoculuar infection; however, can be devastating to the vision as it can cause blindness.  Most cases of “endophthalmitis” occur shortly, within days, after intraocular surgery.  The cause is usually due to aggressive bacteria that attack the inside of the eye leading to damage of the retina.

The damaged retina, even after the infection is controlled, does not see.

Endophthalmitis following cataract surgery is estimated to be less than 1/2000.  Endophthalmitis from vitrectomy retina surgery is even less common.  I usually give the estimate of about 1/10,000 or lower.  Certain types of glaucoma surgery carry a life long chance of developing an infection.

Symptoms of endophthalmitis are pain and decreased vision, although with advances in technology, these symptoms are sometimes less apparent.  In general, if there are concerns about pain or decreased vision following eye surgery, make sure your doctor is aware.  The results can be devastating.

Early identification of possible infections is really, really key.  Treatment can range from antibiotic injections, intravenous antibiotics and vitrectomy surgery.

Retinal detachment is the second biggest risk of intraocular surgery.  By operating inside the eye, an inadvertent retinal tear can be made in the retina leading to a retinal detachment.  Retinal detachments usually do not lead to blindness, but they can.  Additional retinal surgery could be necessary to repair the retinal detachment, but some visual loss is possible.  The chance of developing a retinal detachment following intraocular surgery is somewhere from 1-3%.  Again, with advances in technology, I believe this rate has decreased over the past decade.

Other risks of intraocular procedures are relatively minor, but can include bleeding, but most bleeding into the eye is usually self-limited, sounds horrible, but usually does no permanent damage.  Cataract formation can be caused or enhanced by retina or glaucoma surgery.  This is not a true risk, per se, but hastened cataract formation following intraocular surgery is common.  Sometimes the intraocular pressure can be too high or low following surgery.  There are many reasons why either can occur.

What Does This Mean? These are the most common, and feared, complications of intraocular eye surgery.  This is not a complete listing, but certainly items that should be considered when contemplating surgery.

Your eye surgeon should be able to comfortably discuss, with you and your family, the risks and benefits of any surgery offered to you.  If not, move on.

Eye surgery, especially in America, is extremely safe.  Don’t get me wrong, cataract surgery enjoys about a 99% technical success rate, that is, over 99% of the time the cataract is removed and replaced with an implant…as planned!  Retina and glaucoma surgery, too, are both very successful and usually performed with a high rate of technical success.  Technical success is defined as the ability to perform the actual surgical task.

Complications are the risks undertaken with surgery despite technical success, and no surgery, however, is without risk.

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Two Kinds of Blind

There are two types of blindness that I deal with;  legal and complete.  Diabetic retinopathy can cause both types while macular degeneration generally causes just legal blindness.  Other types of vision loss are actually perceived; what I call “refractive” blindness and psychological blindness.

Legal blindness is defined as vision worse than 20/200, but it does not mean that there is total blindness.  Peripheral vision is usually intact and central vision is commonly decreased. Legal blindness typically indicates that central vision is lost.  Patients are usually able to function.

The macula, the functional center of the retina, provides our central vision.  The rest of the retina serves to provide peripheral vision.  Diseases such as macular degeneration and diabetic macular edema principally affect the macula, and, therefore,  central vision.  In fact, any macular disease, affects central, 20/20, vision.

Being legally blind, therefore, is based upon a person’s central vision.  While the definition also includes the peripheral vision, central vision is the most important criteria for declaring someone “legally blind.”  At this level, the central vision is so poor that reading may be impossible, even with glasses or most other visual aids.  At this level of vision, a person has difficulties performing the activities of daily living.  Patients that are legally blind may have difficulty performing everyday tasks and risk injury to themselves or others.  For example, they may have difficulty turning on a stove or navigating safely around the house.

Complete blindness causes complete darkness.  There is no light, color, shape or movement.  Nothing.

Complete loss of vision can be caused by proliferative diabetic retinopathy, but not macular degeneration.

Remember, macular degeneration only affects the macula.  Complete blindness, though rare, can be caused by any type of retinal detachment or damage to the entire optic nerve.  Both of these can be complications of proliferative diabetic retinopathy.  (There are diseases of the central nervous system that can cause complete blindness, such as brain tumors and stroke, but won’t be included today.)

Complete blindness is caused by disease of the entire retina, including the macula.  Legal blindness is damage limited to just the macula.

What Does This Mean? Diabetes can affect the entire retina.  Therefore, both central and peripheral vision can be affected and lead to complete, and absolute, loss of vision.  Macular degeneration causes legal blindness only.

When we read about the leading causes of blindness, we end up talking about macular degeneration and diabetic retinopathy.  We really should be saying that they are either the leading causes of legal blindness, or that macular degeneration is the leading cause of legal blindness and diabetic retinopathy is the leading cause of complete blindness.

Why?  There are two types of blind.

"Low Vision" Is Not "No Vision:" Part 1

I am happy and honored to introduce Dr.  Chris Renner as a contributor to RetinaEyeDoctor.com!  He and I practice closely together in Northern Virginia.  I asked him to write about Low Vision.“Randy”

What is Low Vision?

The great advances in treatment of eye disease have prevented many cases of blindness, however, many patients suffer partial visual loss and are left with reduced visual function.  This limited level of vision, whether lack of visual clarity or loss of peripheral vision is called “low vision.”  Common causes of low vision are macular degeneration, diabetic eye disease and stroke.

Low vision describes a decreased level of visual function and inability to perform the normal tasks of life even when you are wearing your best glasses.  Maybe you have difficulty reading the newspaper or computer screen, or writing a check or reading your mail.  A low vision evaluation can help you find the right tools to allow you to perform your normal daily activities.

A low vision evaluation and treatment will not improve your eye health or restore your sight.  The goal is to restore function, the ability to perform the tasks in day-to-day life. I ask each low vision patient to list three activities that they are struggling with and we focus on improving their ability to complete those tasks. This might require special eyeglasses, magnifiers, aids or computer programs.  Most patients have several different low vision “tools,” just like you might have several different screwdrivers in a toolbox. Most low vision devices help you by providing significant magnification.

The most powerful (and simplest) tool for allowing the patient with low vision to read is called a reading microscope.  It is a special high-power pair of eyeglasses, possibly with prism, which allows you to see items approximately five times larger than usual.  A reading microscope has the advantage of being relatively inexpensive, small and portable, and allows you to keep your hands free to hold whatever you are reading.  The disadvantage is that you must hold your reading material approximately four inches from your nose and can read only a few words at a time. Reading microscopes are the most popular form of low vision device.

Other low vision devices include hand magnifiers, spotting telescopes, closed circuit television cameras, visual field expanders and computer software to magnify or read text on the computer.  Each of these items can be extremely helpful in the right circumstances for the right patient.  In Part 2 I will discuss hand magnifiers and telescopes.

Chris Renner, O.D.

Optometrist, Low-Vision Specialist
Baileys Crossroads, Virginia

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The Risks of Eye Injections

The risks and complications of  injections into the eye are low.  The most dreaded complication of intravitreal injections is infection inside the eye (aka endophthalmitis).  The risk of endophthalmitis is reported to be about 0.09%.  Endophthalmitis can cause blindness.

As more and more intravitreal injections are delivered for the treatment of diabetic retinopathy and wet macular degeneration, the concern for causing blinding infection becomes greater.  The rates of infection have always been low, in fact, so low, it is difficult to estimate and study.

Intraocular Injection, Randall V. Wong, M.D., Retina Specialist, Fairfax, Virginia
Intraocular Injection

Complications of intraocular injections include;

  • Subconjunctival hemorrhage – bleeding outside the eye (scary looking), but benign
  • Pain/Discomfort
  • Cataract
  • Vitreous Hemorrhage – bleeding inside the eye
  • Retinal Detachment
  • Endophthalmitis – infection inside the eye

Retinal Detachment and Infection are the biggest concern.  The other “complications” are rather soft and either don’t cause damage or are reversible (cataract and vitreous hemorrhage).

Retinal detachment can occur if the needle enters the eye in the wrong spot and causes a hole/tear in the retina.  Additional surgery may be needed depending upon when this complication is diagnosed.  Retinal detachments can potentially cause permanent loss of vision depending upon timing.

Endophthalmitis is a nightmare.  It may occur in any intraocular procedure where the eye is penetrated by a surgical instrument.  It happens so infrequently, that it is difficult to really measure the rate at which it occurs and to study just how it occurs.  In theory, bacteria on the outside of the eye gets inside.  Does this happen during surgery, or, after?  We don’t really know.

You Have a Dirty Mouth - The eye, nose and mouth are all connected.  This is why you blow your nose after crying.   Your eye is as dirty as your mouth and nose.  There is a lot of bacteria that can cause an infection.

Pre-Operative Antibiotics are controversial.  In theory, it makes sense to treat the eye with antibiotics prior to anticipated surgery or injection.  Many cataract surgeons prescribe antibiotic drops prior to surgery, but many don’t.  The rate of infection is so low, it is hard to measure.  Many retina specialists prescribe antibiotic drops prior to intraocular injection, but many don’t (I do).

A study was just published that found no difference in the rate of infection between using antibiotics before (and after) injection compared to no antibiotics.  Over 3800 injections were studied.  What is crucial; however, is the use of a lid speculum (small wire device that keeps the eyelids spread apart) and the application of a topical iodine/povidone antiseptic.

What Does This Mean? My point is to highlight that the risk of blindness due to infection is low in intraocular injections.  As injections become more widely used for diabetic retinopathy and macular degeneration, we’ll be able to better define the rate and causes of this potentially blinding complication.  Incidentally, as the use of sustained release technology is emerging, infection will become less of a concern as fewer ‘injections” will be necessary.

“Randy”

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

A "Toy Story"…………Stories that Blind

Most retina specialists are also surgeons.  We operate on retinal detachments, advanced diabetic retinopathy………….and trauma.  Trauma includes careless accidents involving projectiles………..like toys.  This holiday season, think about eye safety.

Airsoft with Safety Eyeware
Airsoft with Safety Eyeware

Paintball - I hate this one.  A compact canister fired at a high rate of speed.  The fancier the gun, the faster the projectile.  These things even can even travel around corners!  The size of the paintball is a perfect fit between your brow and cheekbone.  Thus, ALL the force is absorbed to the eye.  I think the safety/protection is satisfactory, but the accidents happen “off the field” when the players are not expecting a shot to be fired.

I had a 14 year boy several years ago who developed a retinal detachment, had surgery and still went blind.  The impact of the pellet was so severe, it detached his retina and severed his optic nerve.  The other problem with paintball is that the age group is old enough to know right from wrong and may lie to conceal the truth to avoid punishment.  Had I originally known a paintball was involved, we might have approached him differently.

Pocket Knife - I know many people that carry them for small odd jobs around the house; cutting string, small screw drivers, etc.

Airsoft Rifle and Safety Mask
Airsoft Rifle and Safety Mask

Then there was this “kid,” who tried to see how many times he could throw his knife and get it stuck into a tree.  The knife bounced off the tree and landed in his right eye.  The tip of the knife went right through the center of the cornea.  While his retina never detached, the knife cut his natural lens and ruined his cornea.  He needed a corneal transplant, removal of the damaged lens and a possible implant.  He’ll need life long follow up.  The “kid” was 19.

BB Gun – Believe it or not parents, BB guns are either fired on purpose at a “friend” or go off accidentally.  I have had several cases (the term we substitute for “patients”) where the BB went directly into the eye.  Most times it doesn’t penetrate the eye, but can still cause permanent damage.

Blood can fill the front of the eye and is called a hyphema.   My 12 year old boy developed a cataract and is at lifelong risk for developing glaucoma; all due to the trauma.

The kids don’t think that these low-speed projectiles are dangerous and don’t bother to don safety glasses.  They usually don’t even penetrate the skin, so the feeling is these are “safe.”

I have no opinion about “Air Soft.”

“Nerf Gun” That spongy material that has been around for generations can be blinding.  My worst “toy story” is the kid who shot a Nerf dart at a friend.  The Nerf dart had a suction cup at one end which was designed to stick to flat surfaces (e.g. window, refrigerator door, etc.).  This guy modified the suction cup with a straight pin.  I don’t think he meant it to get stuck right in his buddies eye.  They were 9 years old.

The right eye of our little patient has now undergone at least 5 retinal surgeries.  The cornea may need replacing soon due to the original accident and repeated surgeries.  The visual potential?  Legally blind, at best.

What Does This Mean? I am not advocating changing your shopping list.  I am not advocating anything.  All of these “toy stories” are true and have horrible endings.  All of these patients were young and old enough to know better. They are unfortunate.

We have five kids.  Our only rule – no real guns.  They are the same ages of everyone one of my stories.

We have everyone one of the “toys” listed above except the high-velocity paintball guns.  We encourage them about safety (especially eyes).  We encourage them to have fun with their toys and to use them as they were meant to be used.  We try not to over control.   Accidents will happen.

“Randy”

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

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Macular Degeneration; How Do We Cope?

I see patients that have lost vision from macular degeneration; wet macular degeneration and dry macular degeneration.

Wet Macular Degeneration. The most severe form of macular degeneration is the wet form.  Abnormal blood vessels, aka choroidal neovascularization, develop within in the layers of the retina/macula.  These vessels destroy normal macular tissue and proceed rapidly to destroy central vision.

Geographic Atrophy. The most severe lesion or form of the dry form of macular degeneration.  There is no neovascularization.  In this case, the middle layer of the retina, called the RPE degenerates.  The result is the same.  Severe loss of central vision.  Geographic atrophy does not develop suddenly.  It can take years or even decades to progress.

In either case, many of patients today will be “suffering” severe vision loss due to macular degeneration.  How do we cope?

I am a psychologist.  Though a “retina specialist,” I function often as a therapist, helping patients and their families, cope with loss of vision.  It often is not easy.  Remember, this is a disease that affects older individuals and I have to inject “hope” into situations that seem hopeless.

What is Lost? Loss of vision means loss of independence.  Most people like to read, watch TV and drive.  Frequently all 3 are wiped out.  I believe the hardest issue to deal with psychologically is losing the ability to drive.  Now, patients must depend upon others.  It is tough for many accept.

“Glass is half full.” For many, only one eye may be involved.  The other eye may continue to function normally.  It is usually reassuring to patients to hear that driving a car in most states requires one eye (not true if you have a CDL license). In no case does macular degeneration cause complete blindness.

Peripheral vision is almost always normal in macular degeneration; dry or wet.  Macular degeneration may lead to “legal blindness,” but not complete blindness.  Most are able to function without a problem.  Activities of daily living; cooking, brushing teeth, writing checks may need to be relearned or can be completed with certain visual aids/tools.

On Low Vision. Visual aids or tools are also known as low vision aids.  In my experience, low vision aids are NOT a thicker pair of glasses.  These are aids, or tools, and one must learn how to use them.  I have found, that unless a patient is motivated to relearn a task, say writing a check or reading with use of a computer, there is no reason for low vision therapy.  It is too likely that the patient is simply going to fail…………….yet another obstacle.  No reason to beat a man when he is down.

Patient’s Perspective. Low vision therapy is usually introduced at a time when the shock losing functional vision has been better accepted.  If accepted, the patient may approach relearning with a more optimistic attitude.  Their perspective is important.

Many times, too, I’ll stage the “message” over several visits, giving my patient time to absorb and understand.

“Randy”

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

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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

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offices

Currently, I see patients with retinal diseases; macular degeneration, retinal detachment, macular holes, macular pucker within several different practices.....it's a different arrangement, but it allows more continuous care with many eye specialists. In addition, I am very accessible via the web. To schedule your own appointment, call any of the numbers below.

Capital Eye Consultants
Randall V. Wong, M.D.
Contact: Brigitte O’Brien

A: 3025 Hamaker Court, Suite 101 • Fairfax, Virginia 22031
Ph: 703.876.9630
F: 703.876.0163
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Dressler Ophthalmology Associates, PLC
Randall V. Wong, M.D.
Contact: Andrea Armstrong (Surgery/Web)
Chrissy Megargee (Web)

A: 3930 Pender Drive, Suite 10 • Fairfax, Virginia 22030
Ph: 703.273.2398
F: 703.273.0239
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