Call Us: 703.273.2398

Tag Archives: Glaucoma

January is Glaucoma Awareness Month

Glaucoma Awareness Month | Risk Factors of Glaucoma | Randall Wong, M.D.Happy New Year!  January is national Glaucoma Awareness Month.

Do you or a family member have glaucoma?

Glaucoma is a leading cause of blindness and affects over 3 million Americans and 60 million others globally.

There are many forms of glaucoma, but the most common type of glaucoma in the United States is called “open angle glaucoma.”

Risk Factors for Glaucoma

Everyone is at risk for developing glaucoma.  The disease becomes more prevalent (common) as we get older.  Family history is a huge risk factor, too.

Other risk factors for glaucoma;

  • Family History
  • Diabetes
  • African American patients have a higher chance > age 40
  • Everyone above the age of 60 – especially Latino/Hispanic patients
  • Farsighted/Asian patients

Symptoms of Glaucoma

In general, there are no immediate symptoms of glaucoma.  In other words, most patients with glaucoma do not even know they have the disease.  This is especially true of patients with open angle glaucoma.  They are completely unaware until they lose central vision.

Pain, redness, tearing and nausea/vomiting can be signs of “angle closure” glaucoma and result from sudden and large increases in the eye pressure (Intraocular Pressure – IOP).

This usually does not happen in open angle glaucoma.

How to Diagnose Glaucoma?

Talk to your family if you have glaucoma.  Early detection and treatment is vital to saving your vision.

Diagnosis of glaucoma can be made with a complete dilated eye exam.

One of the early findings of glaucoma is loss of peripheral or “side” vision.  This is true of every type of glaucoma.  Subtle loss of your visual field may be the only sign of the disease.

Here are some of the diagnostic tools your eye doctor may consider;

  • Visual field testing – looking for loss of peripheral vision
  • Optical coherence tomography (OCT) is useful for actually measuring destroyed optic nerve tissue
  • Eye pressure (Intraocular Pressure, IOP)
  • Dilated Eye Examination allows direct examination of your retina and optic nerve

If you have risk factors of glaucoma or if you are concerned, make a New Year’s resolution to get examined!  Early detection and treatment is the key to saving your sight.

All the best

Randy

Randall V. Wong, M.D. is a board certified ophthalmologist practicing in northern Virginia.  Though a retina specialist, this website contains information on various eye diseases.

 

Retinal Ischemia: Supply vs. Demand

Retinal ischemia causes VEGF to be liberated inside the eye.  In cases of diabetes this can lead to diabetic retinal detachment or neovascular glaucoma.  Treatments included pan-retinal photocoagulation (laser) or anit-VEGF medication such as Lucentis or Avastin.

Ischemia results when oxygen supply does not meet oxygen demand to any tissue.  Other examples  are the heart and legs.  With strenuous activity, O2 demand increases.  If the body can’t compensate, chest pain or leg pain develops.

In cases of proliferative diabetic retinopathy, the retina becomes ischemic due to the loss of the microcirculation of the eye.  The small capillary beds that help feed the retina often get blocked and close off.  Blood flow is reduced, and therefore, so are oxygen levels.

In response to this lack of blood, or oxygen, supply, the ischemic retina produces Vascular Endothelial Growth Factor (VEGF).  VEGF causes abnormal blood vessels to grow on the surface of the retina and other structures inside the eye.  This can lead to blindness by causing a diabetic retinal detachment or glaucoma.

Stop the Ischemia

If we were to stop the ischemia, the VEGF production would cease. If we can change conditions so that supply is equal to demand, the imbalance is gone.

But we don’t know how to improve oxygen supply to the retina.  Presently, laser treatment and anti-VEGF medications are employed.

Laser Treatment Reduces Demand

As we are unable to increase oxygen supply, laser photocoagulation (specifically, pan-retinal photocoagulatoin, aka PRP) is used to decrease demand.  By ablating, a fancy term for killing, retinal tissue, we are in effect, reducing the demand.

If enough laser is performed, the overall O2 requirements will decrease.  Ischemia is stopped and VEGF is no longer produced.

The eye becomes stable.  A diabetic retinal detachment and glaucoma are prevented.

anti-VEGF Medications Block VEGF

Anti-VEGF medications such as Lucentis and Avastin block VEGF from doing its job.  In doing so, neovascularization can not be initiated and diabetic retinal detachment and glaucoma are avoided.

Is the eye stable?

What Does This Mean? Actually I am not sure.  The end result of laser (PRP) and anti-VEGF treatments are the same; preventing retinal detachment and glaucoma.

The use of laser for proliferative diabetic retinopathy is old hat.  It has been saving the sight of diabetics for about 40 years.  It is a good treatment because it fixes the problem.  PRP, when properly performed, stabilizes the eye by eliminating the ischemia.  It secondarily stops VEGF by halting the initial O2 imbalance.

I am not sure; however, if intraocular injections of Lucentis/Avastin actually fix the problem.  There is no mechanism to fix the ischemia.  VEGF is still liberated as the ischemia still exists.  Therefore, careful monitoring and repeated injections are needed.

Reblog this post [with Zemanta]

Why Glasses Won't Help You See

“Will glasses help?”  We often wonder if “correction” will help decreased vision in the presence of retinal disease such as macular degeneration and diabetic retinopathy.  Spectacles can only help so much yet won’t “reverse” the loss of vision from the disease.  This is opposite to those people who claim they are “blind,” yet with glasses see quite well.

How do Glasses Work?

The goal of corrective lenses is to focus an image, sharply, on the surface of your retina (technically the macula).  If you are nearsighted (myopic), the image of what you see falls short, or in front, of the macula.

Nearsighted Image is "TOO SHORT" and Falls in Front of Retina

Glasses are used to refocus the image on the retina.  This is exactly like a projector focusing on a movie screen.

If you are farsighted (hyperopic), the image actually is focused behind, or past, the macular surface and glasses are used to move the image forward onto the retina.

Farsighted Image is "TOO FAR" and Falls Behind the Macula

What is the Macula?

The macula is the functional center of the retina.  It measures only about 1.5 mm X 1.5 mm, yet it gives us all of the attributes of our “sight.”  It provides us our best color vision, central sight for reading and watching TV and is the only part of the retina sensitive enough to “see” 20/20.

"JUST RIGHT" - Image Falls ON the Retina

Will Glasses Work?

If there is macular disease, such as diabetic retinopathy or macular degeneration, even properly measured glasses won’t work.

The vision is decreased due to the macular disease.  It simply isn’t capable of “seeing” 20/20.  The disease is preventing the retina from working to its full potential.

When glasses are working, the image is properly focused on the retina, but the retina is not working well.

Low Vision Aids

It may now make sense why “low vision” aids don’t simply correct for the disease.  Low vision aids may be useful by enlarging the image focused on the retina.  It may make the image easier to “see,” but the disease is still present.  Sometimes, images can be focused to the side of the diseased macula, but these “para-macular” areas are not as sensitive as the macula itself.

In all cases, vision is compromised.

What Does This Mean?

When we speak of decreased vision, implicit in our discussion is the assumption that the proper glasses, or contacts, are being used.  The eye is a pretty remarkable optical system, and in most cases, it is pretty routine to find the right lens to help correct myopia, hyperopia and astigmatism.

The optical system can’t correct for disease.  while the unit may be functioning properly, that is, focusing an image precisely on the retina, the disease will always win.

This is true of macular disease, glaucoma and some cataract.

Reblog this post [with Zemanta]

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.

Reblog this post [with Zemanta]

Diabetes Causes Glaucoma

Glaucoma is a disease that can lead to blindness by destroying the optic nerve.  There is an increased risk in developing glaucoma if you have diabetic retinopathy.  I am not aware of such a risk with macular degeneration.

“Open Angle Glaucoma” is the Most Common for in the U.S.

There are many types of glaucoma, but most common in the U.S. is “open angle” glaucoma.  All the structures of the eye are normal, yet there tends to be an elevated eye pressure associated with typical glaucomatous nerve damage.  Most treatments are aimed at lowering the eye pressure with drops.  In many cases this may be an adequate way to slow down, or control the disease.

Risk factor for developing open angle glaucoma includes race (especially blacks/african american), family history, increasing age and steroid users.

There is mild increased chance of developing open angle glaucoma with …diabetes.

There are generally NO symptoms with open angle glaucoma.  It is painless and destroys optic nerve tissue very, very slowly.

During almost any exam, however, your doctor generally checks your intraocular pressure, or, IOP.  Glaucoma is not a cut and dry diagnosis, but higher than normal pressures probably warrant a glaucoma evaluation.

Neovascular Glaucoma Hurts and Blinds

Neovascular glaucoma can develop in patients with proliferative diabetic retinopathy.  By definition, patients with proliferative diabetic retinopathy have neovascularization (abnormal blood vessels) growing on the surface of the retina or on other structures.   If  you recall, the neovascularization cause a diabetic retinal detachment, vitreous hemorrhage and neovascular glaucoma.

At times, the abnormal blood vessels, the neovascular blood vessels, can grow over the “angle” of the eye.  The “angle” is a specific area in the front of  the eye and it is the only area that provides drainage to the interior of the eye.

The eye pressure can rise significantly if the “angle” becomes closed, or clogged, with neovascular tissue.  The pressure can cause severe redness, headache, nausea and pain.  Pressures can be 3-4x normal!  At these pressures, permanent vision loss, including blindness can occur rapidly.

Treatment for Neovascular Glaucoma Includes Laser

The same laser treatment, namely panretinal photocoagulation (PRP), used to treat proliferative diabetic retinopathy is the preferred treatment for neovascular glaucoma (NVG).  The mechanism of the disease is still the same.

Vascular Endothelial Growth Factor (VEGF) is liberated in response to insufficient oxygen supply.  The VEGF causes the blood vessels to form on the retinal surface and the “angle.”

While the real “fix” is PRP, temporary improvements may be possible with intermitten anti-VEGF medications.  At this time; however, it appears as though the anti-VEGF injections, such as Avastin, Lucentis or Macugen need to be repeated.  In most cases, the laser treatment does not need to be repeated.

What Does This Mean? This is the second way a patient with proliferative diabetic retinopathy can go blind.  Patients that develop retinal detachments from diabetic retinopathy can also go blond.   Uncontrolled neovascular glaucoma is a late complication of only proliferative diabetic retinopathy.

It does not occur in the more common, non-proliferative phase of the disease.

While diabetics are at risk for developing “open-angle” glaucoma, your doctor should be monitoring you for that anyway by taking your IOP everytime you reach the office.   Part of your retinal exam should also entail looking for signs of the proliferative disease as well.

“Randy”

Randall V. Wong, M.D.

Ophthalmologist, Retina Specialist
Fairfax, Virginia

Your Retina Feels No Pain

Retinal disease is painless.  Diabetic retinopathy doesn’t hurt and neither does macular degeneration.  For that matter, a retinal detachment is nothing.  What does cause eye pain?  It can be sinus disease.

There are only a handful of problems that cause eye pain.  Neither diabetic retinopathy nor macular degeneration causes eye pain, not even a feeling.

Corneal abrasions, like skinning your knee, causes is lot of pain and sensitivity to light.  The cornea is a has a lot of nerve endings.  Scraping across the superficial layer of the cornea exposes a lot of these nerve endings causing severe pain.  It may be one of the more painful conditions you can experience. There should be obvious redness of the eye.

Nerve endings in the cornea are important.  How else could you tell if you are poking yourself in the eye?

Certain types of glaucoma can cause pain, but only the ones that cause really high eye pressure.  Most types of glaucoma don’t hurt and are painless.

Normal pressure is somewhere between 18 and 21 mmHG, but severe pain usually doesn’t happen until the pressure is greater that 40 mmHG.  The only way you’d know your eye pressure is too high is to have your eye doctor test it.  Many times redness is associated with this type of pain.

While proliferative diabetic retinopathy can cause neovascular glaucoma, leading to extremely high pressure and pain, the retinopathy itself is painless.

Iritis, also know as uveitis, is a type of inflammation that occurs inside the eye.  It is not unlike a painful arthritic joint, but only it’s the eye.  The ciliary body, a very sensitive tissue inside the eye, can become very painful with certain type of intraocular inflammation.  Eye redness is common.

Sinus Disease causes many cases of eye pain.  Really.  The nerve fibers that transmit pain from the sinuses and the eye actually course together as they wind their way to the brain to alert you of discomfort.  Because the pain fibers run so close, it is sometimes difficult to distinguish “eye pain” from “sinus pain.”

Many times I am able to distinguish between the two by a very simple observation.  In my opinion, if the eyeball itself is not red, “eye pain” is probably not coming from the eye.

Please remember, this article represents my opinion and does not, in any way, substitute for medical advice.  If you are experiencing eye pain, please inform your doctor.

What Does This Mean? It’s pretty straightforward; the retina has NO nerve endings, thus, retinal disease, including diabetic retinopathy and macular degeneration don’t hurt because…it can’t.  You can’t even feel a retinal tear or retinal detachment.

Many times patients relate loss of vision to pain or a certain “feeling.”

“Randy”

Randall V. Wong, M.D.

Ophthalmologist, Retina Specialist
Fairfax, Virginia

Neovascularization Causes Blindness

Both macular degeneration and diabetic retinopathy can cause “blindness” from neovascularization.  Both are diseases of the retina, both can lead to “blindness,” both increase with age/time and both can be associated with abnormal blood vessel formation known as neovascularization.”

The two diseases differ in the location of the neovascularization.

Diabetic Retinopathy – In cases of diabetic retinopathy, the presence of neovascularization defines a particular stage of eye disease; proliferative diabetic retinopathy.  The neovascularization may “proliferate” along the surface of the retina and other structures inside the eye.  As long as the VEGF is circulating, the vessels will continue to grow.

Diabetic retinal detachments may occur if the the neovascular tissue proliferates out of control.  Neovascular glaucoma may develop if the abnormal blood vessels “clog” the internal drain of the eye.  In this case, intraocular fluid that normally filters out of the eye can no longer escape as the drain is closed.  The pressure escalates out of control and severe pain (and redness) develop.

In short, proliferative diabetic retinopathy, as defined by the presence of neovascularization, can causes retinal detachments and neovascular glaucoma (not the usual form of glaucoma).  Both are mechanisms by which diabetes can cause blindness.

Macular Degeneration – “Wet” macular degeneration, by definition, exists when neovascularization develops underneath the retina.  This neovascular tissue causes physical separation of the layers of the retina and destruction of the normal tissue.  Almost all neovascularization leaks, and, at times, bleeds.  Loss of central vision occurs due to this rather rapid growth of abnormal blood vessels.

VEGF – In either case, neovascular tissue is a complex of “abnormal blood vessels.”  As best we can tell, neovascular tissue develops in response to Vascular Endothelial Growth Factor, or VEGF.  This growth factor causes both proliferation of the neovascular tissue and sustains existing neovascularization.  Without circulating VEGF, the neovascular tissue shrinks up and goes away.

Anti-VEGF treatments are simply directed at blocking the effects of VEGF.

Anti-VEGF medications (e.g. Avastin, Lucentis and Macugen) are antibody like molecules that find circulating VEGF and prevent VEGF from “doing its duty.”   The treatment of choice for proliferative diabetic retinopathy remains pan-retinal photocoagulation (PRP).  The end result of PRP is decreased … VEGF.

With timely diagnosis, both diseases can usually be controlled.  Neovascularization in diabetes can be reversed before a retinal detachment is formed, neovascular glaucoma may be reversed and “wet” macular degeneration can be halted.

What Does This Mean? A few years ago, I would not have been able to write this article.  We have learned a lot about the mechanisms by which both diabetic retinopathy and macular degeneration cause blindness.  It amazes me how the pathogenesis (i.e. the disease process) of both diseases are so similar.  Both diseases can cause blindness via VEGF.

This is why it is so confusing.  Two separate diseases that respond to the same treatment.

Reblog this post [with Zemanta]

Avastin: An Adjunctive Therapy for Proliferative Diabetic Retinopathy

Avastin® is useful for a variety of eye conditions;  it is principally used to treat wet macular degeneration and is becoming a popular option to treat diabetic macular edema.  On occasion, Avastin has also been useful, in my practice, to treat patients with proliferative diabetic retinopathy.

VEGF (Vascular Endothelial Growth Factor) also causes abnormal blood vessels to grow in cases of “wet” macular degeneration and … proliferative diabetic retinopathy.

Proliferative Diabetic Retinopathy (PDR) is defined by the presence of abnormal “neovascularization.”  These are abnormal proliferations of blood vessels that grow inside the eye.  In patients with diabetic retinopathy, the VEGF is produced in response retinal ischemia; retinal demand for oxygen exceeds the supply due to poor blood supply.  VEGF then causes neovascularization to develop.  This neovascularization can cause blindness by causing retinal detachments or neovascular glaucoma.

The  traditional treatment for proliferative diabetic retinopathy has been laser photocoagulation.  The laser treatment, called pan-retinal photocoagulation (PRP), has been the treatment of choice for years.  The PRP destroys enough tissue so that the available blood supply is adequate to meet the oxygen requirements of the tissue.  When this occurs the “ischemia” is cured, VEGF is no longer produced and the proliferative retinopathy becomes stable.

Occasionally, I have  patients that do not respond well, or completely, to pan-retinal photocoagulation.  Lately, on select cases, I have used Avastin as an alternative to pan-retinal photocoagulation for the treatment of proliferative diabetic retinopathy.

So far the treatment works well.  The neovascular tissue regresses quickly and I recheck patients every 4-6 weeks.  The injections do need to be repeated.

What Does This Mean? Pan-retinal Photocoagulation has been the gold-standard for the treatment of proliferative diabetic retinopathy.  The PRP can decrease light to dark adapatation, that is, it takes awhile to get used to light when coming out of a movie theater.  It is a difficult procedure to perform, but has been very effective over the years.  I consider it a good “fix.”

An alternative therapy is welcomed for two reasons.  Avastin injections are certainly easier to perform and seem not too affect the vision.  Avastin also treats the disease by a different mechanism and may increase the chances of achieving stability.  On the other hand, Avastin does NOT change the relative ischemia in the retina, that is, the oxygen demand is still greater than oxygen supply.  It may be less of a permanent “fix.”

“Randy”

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

Reblog this post [with Zemanta]

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

Reblog this post [with Zemanta]

You Only Need Good Vision in One Eye to Keep Driving!

In most states, you only need one eye to maintain a driver’s license.  Most states require one eye to have at least  20/40.  In addition, a certain degree of peripheral vision, or continuous field of vision, is required to qualify for an unrestricted license.  A restricted license may still be obtained with slightly lower requirements.  Please check your own state laws.

Can I Drive? Obviously, loss of independence is one of the biggest concerns a patient has after being told of permanent vision loss.  While many eye doctors may not be comfortable with this conversation, most retina specialists, dealing with diabetic retinopathy and macular degeneration, have to be well versed.

Professional Driving Fortunately, in most circumstances where there may be significant vision loss in one eye, the fellow eye is still in good shape.  I am usually quick to point out that one eye is all that is required to maintain a driver’s license.  There are a few professional exceptions; those with commercial driver’s license (CDL), pilots and locomotive engineers require both eyes to see well.  I am sure there are a few others, but my point is that loss of vision in one eye does NOT usually cause a change in careers.

Failing the Vision Test When you take the vision test at the motor vehicle department, keep in mind that these are screening tests.  Patients that do not see well out of both eyes will fail, but this does not mean loss of the driver’s license.  Screening tests are designed to make sure that “one-eyed” patients are seen by an eye doctor.

Most states have a separate form that must be completed by an eye doctor upon failing the screening test.  Completion of this form ensures passing or failing the vision requirements of the driver’s license exam.

The Visual Requirements One eye must have a visual acuity of at least 20/40 and have a continuous field of vision.  We have mentioned different ways to measure visual acuity in other articles.  The peripheral vision, however, is measured in degrees.  The continuous field of vision pertains to the amount of peripheral vision and is measured in the number of degrees of intact, peripheral vision.

Diabetic retinopathy and macular degeneration involve central vision.  There can be complications from retinal detachment that may affect the peripheral vision, but basically, diabetic retinopathy and macular degeneration would decrease central acuity.  Other diseases such as glaucoma, or certain strokes, might reduce the peripheral vision.  Though patients may have excellent central vision, the peripheral vision may be so compromised (e.g. tunnel vision), that passing the driver’s license requirements are impossible.

What Does This Mean? Remember, in most cases of diabetic retinopathy and macular degeneration, the chance of significant vision loss is low.  Still, in many more instances, the fellow eye may be good enough so that independence is not jeopardized.

Another reason to see your eye doctor……………..early.

“Randy”

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

Reblog this post [with Zemanta]

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.

Virginia Lasik | Office of Anh Nguyen, M.D.
Randall V. Wong, M.D.
Contact: Layla

A: 431 Park Avenue, Suite 103 • Falls Church, Virginia 22046
Ph: 703.534. 4393
F:703.992.8158
View Map

Dressler Ophthalmology Associates, PLC
Randall V. Wong, M.D.
Contact: Ashley (Surgery/Web)
Chrissy Megargee (Web)

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