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Yearly Archives: 2010

3 Causes of Flashes of Light

Causes of Ocular Flashes

There are several causes of flashes.  The most common cause is a posterior vitreous detachment (PVD), but a retinal tear, migraine and inflammation can also cause the same visual symptoms.

In other articles, a PVD  and retinal tear have been well covered.

Flashes Due to Migraine

Without getting too specific, there are visual migraines that yield a scintillating light pattern, often confused with flashes.  The array of lights lasts about 20 minutes and migrates across the field of vision.  For instance, it may move from “right to left” over the 20 minute period.

This pattern generally resolves, or, there may be headache or other ocular symptoms that develop.  These, too, last only for a finite period.

Any migraine, or symptoms that you feel are migraine related, should be evaluated by a doctor as there are other neurologic conditions that can give the same symptoms.  This diagnosis, while seemingly benign, should be made as a diagnosis of exclusion, that is, make sure all other possibilities, such as tumor, are ruled out.

I often refer these types of cases to a neurologist or neuro-ophthalmologist to make sure I’m not missing something.

Flashes Related to Inflammation

Inflammation inside the eye is called uveitis, or iritis.  It is very similar in nature to arthritis, another type of inflammation.  Like arthritis of a joint, inflammation can occur just inside the eye.

Most commonly the inflammation is in the front of the eye, but on occasion, there can be types of inflammation affecting the retina.  Symptoms can include flashes of light.

The best way to diagnosis retinal or retinal vascular inflammation is with a dilated eye exam.  It is also probably prudent to seek the opinion of a retinal specialist in this case.

What Does This Mean?

In medicine, “everything has a differential.”  In other words, in medicine, for a given symptom, it is a doctor’s responsibility to think of all the causes of a particular symptom.

For instance, flashes of light are often caused by a PVD or retinal tear, but could be caused by migraine or inflammation.

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Persistent Flashes After Posterior Vitreous Detachment (PVD)

It is not uncommon for the symptoms of flashes to persist after a posterior vitreous detachment, or PVD.  Flashes and floaters, common symptoms of a PVD, may also be warning signs of a possible retinal tear.  Retinal tears can cause a retinal detachment.  Do persistent flashes mean increased risk for a tear or retinal detachment?

Ways to Stimulate the Retina

There are two ways to stimulate the retina.  Light is the most common stimulus.  Light enters the eye and falls onto the retina producing vision.  The second way to stimulate this inner lining of the eye is by physical manipulation.  Ever rub your eyes so hard you see patterns of light?

Another example of physical stimulation of the retina is a posterior vitreous detachment.  The posterior portion of the vitreous separates from the retina.  The anterior portion, however, remains adherent.  Simply remember that part of the vitreous separates, but the anterior part never does (and that’s where the tears occur).

Flashes from a PVD

Part of the vitreous is now free floating in the eye and the other part is “tethered” to the anterior retina.  As the eye moves, part of the vitreous is free floating, while the other portion is attached to the retina.  The part still attached  gently tugs causing “flashes” as the retina is stimulated, but can cause tears if the tugging is too hard.

(Think of a flag pole.  Half the flag is flapping freely in the wind, while the other half is attached to the pole.)

First 6 Weeks are the Scariest

The first six weeks following the initial symptoms of a PVD are the highest risk for developing a retinal tear.  Statistically, this is the period when MOST of retinal tears occur.  There are exceptions.

It is during this period, as the vitreous separates from the retina, where the tugging forces change inside the eye.  Usually if a tear is to occur it happens now.  But, sometimes it doesn’t, yet the persist.

What Does This Mean? After the diagnosis of a posterior vitreous detachment is made, I recommend re-evaluation at 6 weeks after the initial symptoms began, or sooner if the symptom worsen.

If the symptoms remain relatively the same, patients usually return at the 6 week mark.  I look for any new tears.  If none are found, the symptoms have remained the same or decreased…I don’t ask for a follow up exam.

Persistent flashes are worrisome.  Are  you at risk for a retinal tear?

Persistent flashes occur because the vitreous remains adherent to the retina.  Gentle tugging causes the flashes.  If you had a retinal tear, the vitreous is still adherent to the tear, and it too is stimulated by the moving vitreous.

This vitreous pulling, or “vitreous traction,” is common and may last a long time.

Second, the recommendation of retinal specialists (and the AAO) is that you seek re-examination if the flashes INCREASE as this may be a sign of a new tear.

Flashes that persist, but not increased, are probably not an indication of a greater risk of tear.  It is a sign that you’ve had a PVD.

Vitrectomy surgery can be performed, at times, to alleviate the symptoms.

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Stem Cells Get FDA Nod for Stargardt's Disease

Advanced Cell Technology, Inc., received FDA approval for starting Phase I/II clinical trial to use stem cells for the treatment of Stargardt’s disease.  Stargardt’s disease is an inherited type of macular degeneration affecting individuals at age 10-20.  There is no cure.

Similar to other macular diseases, the photoreceptors, and the layer of cells just beneath, call the retinal pigment epithelium (RPE), become destroyed due to a genetic defect.  Due to the macular involvement, central vision is lost.

Stargardt’s disease is the a common form of “macular degeneration” that afflicts the young.  It is estimated to affect about 30,000 people worldwide.  It shares in common with ARMD (age related macular degeneration) the loss of photoreceptors secondary to RPE damage and degeneration.

Advanced Cell Technology (ACT) claims the ability to generate healthy RPE cells from human embryonic stem cells.  The idea is to replace the genetically diseased RPE cells with healthy replacements.  In theory, the healthy RPE cells should prevent loss of the photoreceptors, thereby preserving vision.

The phase I/II study will involve 12 patients enrolled into several centers across the United States.  The initial experiments will determine if the RPE cells are indeed safe and if they can be tolerated by the human recipients (i.e., does the body reject the new RPE cells?).

What Does This Mean?  Stargardt’s disease has no cure, and therefore, are great subjects to consider for this possible treatment.  In a way, there is nothing to lose.  Stargardt’s patients also have or had vision, that is, they have experience with vision.  We know that these patients have fully developed visual pathways.

While this group is very small in comparison to patients with macular degeneration, the significance this holds for a potential, effective treatment can only be left to our imagination.  Even a small success in this trial is exciting.

The news of this trial is exciting, but remember further testing (clinical trials III and IV) need to be completed.  Also, the techniques for introducing the cells safely underneath the retina need to be accomplished, too.

More later…I hope.

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Thanksgiving 2010: My Eyesight Returns

Happy Thanksgiving!  I had a great weekend and hope you did, too.  This year, I am thankful for my friends and family …and especially my eyesight.

Turkey Day

As with many of you, we had a marvelous feast.  We celebrated with our parents, friends and the kids.  Amy did a wonderful job with roasting a turkey, stuffing from scratch and her famous garlic mashed!

I usually smoke a turkey, but this year I fried a turkey!  3 gallons of peanut oil, a 12 lb. bird and 40 minutes is all it took!  No rubs, seasonings or marinades.  I recommend it.  (Actual cooking took place in the middle of the driveway to avoid any potential fire hazards!)

It was a great way to celebrate Thanksgiving.  I’ll be doing it again next year.

Double Vision from Accident

Last winter, I fractured my right orbit.  The orbit is also known as the eye socket.  I had a freak fall that broke my cheek bone…and that resulted in double vision.

Since last February, I had double vision any time I looked to the left.  Fortunately, I had single vision when looking straight ahead or to the right.  I had no problems working and operating as those activities require only that I look straight ahead.

I did, however, have to give up both tennis and kick-boxing.  Neither could I do with double vision.

The broken bone caused damage to one of the muscles of my right eye.  As a result, my right eye didn’t move to the left easily and I saw double.  To compensate, I’d close my right eye when looking to the left, but at the same time, I’d lose my depth perception.

Multiple Operations to Fix Me

I had three surgeries to fix my “eye.”  The first two were performed over the Spring and Summer.  The goal, at that time, was to simply fix the broken eye socket and see if function returned.  I had limited success.

The most recent surgery was about 3 weeks ago.  I immediately saw an improvement and 2 days later hit some tennis balls for the first time in over 9 months!

What Does This Mean? I realized how hard it is to be a patient.  Not only is the vision compromised, but the surgical results were disappointing.  How similar this must be with my own patients with retinal disease!

As a physician, I am now more empathetic and sympathetic to my own patients.  Many of my patients have lost depth perception, and I was surprised how this impacts every aspect of our life!

I would guess that I have about 85% of my function returned (far up and to the left is still weird).  For that, I am very grateful.  I thank my coworkers, family, and especially Amy for helping me through this difficult year.

I am lucky.  I have great support systems and resources.  I am also lucky that this was not a disease.

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VEGF Trap-Eye Treats Macular Degeneration

VEGF Trap-Eye (aflibercept) is another treatment for wet macular degeneration.  The sponsoring pharmaceutical companies, Bayer and Regeneron, just reported favorable results in their own Phase III studies.  Basically these studies compared aflibercept against well known Lucentis (ranibizumab).  They report that VEGF Trap is just as good as Lucentis.

Funny Name, But Still an Injection

Despite the misleading name, VEGF Trap-Eye is still an intraocular injection, but instead of monthly dosing (as is often the case for Lucentis and Avastin), the injections may be repeated every 2 months.

Similar to Avastin and Lucentis

Aflibercept, or VEGF Trap-Eye, is a drug that binds to growth factor molecules and prevents them from reaching their targets, or receptors.  In effect, this medication takes any free-floating VEGF molecules and takes them out of circulation.

Though we don’t know for sure, basically this drug, like Avastin, Lucentis and Macugen, will neutralize the effects of VEGF.  As with the others, it will be used to treat wet macular degeneration.

Also Used Against Cancer

There are many similarities between wet macular degeneration and cancer.  Sure enough, as was also the case with Avastin, aflibercept stems from chemotherapy research.  Regeneron, the U.S. based parent, has ongoing trials using VEGF Trap for treatment against metastatic colorectal cancer, certain lung cancers and prostate cancer.

Other Uses in the Eye

Other uses of aflibercept in the eye may include treatment for diabetic macular edema.  Clinical trials for its use in diabetic retinopathy are ongoing.

What Does This Mean? Yet another treatment may be available for wet macular degeneration.  This treatment, however, has the potential to be just as good as Lucentis (and probably Avastin), but, it needs only to be given every 2 months instead of every month.

While the best treatment of Lucentis/Avastin is not known for sure, many doctors including myself, favor injections monthly.  This seems to yield the best results in terms of vision and ultimately reduces the recurrence rate.

VEGF Trap-Eye seems to be equally effective in all these areas, yet differs only by the injection frequency.  Decrease frequency translates into decreased cost, increased compliance (fewer appointments) and improved convenience.

The advantages of sustained release drug delivery systems are highlighted by the advantages of this less frequently used drug.

The company hopes to have some product available as early as end of 2011.

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Update on Implantable CentraSight Telescope

VisionCare’s implantable telescope for patients with advanced macular degeneration was FDA approved in August.  Since then, little information has been available, but I received an update from the company last week.

Telescope is Not Being Shipped

Though FDA approval has been received, VisionCare, the parent company, has not started shipping this implantable device.  The company is quite small and is gearing up for market release.  Reading between the lines, this may occur in the next 6 months.

Medicare Reimbursement

In simplest terms, Medicare has yet to approve this device for insurance coverage, that is, they haven’t agreed to pay for it yet.  The parent company must submit an application based upon the FDA approval and the fact that this is a brand new type of medical device.

Obviously, VisionCare isn’t going to ship the Centrasight telescope if it isn’t going to be covered by insurance.

Training Centers for Eye Doctors

If you read my last article regarding the CentraSight, the implantation of the telescope involves a team approach and, thus, training for all the eye professionals involved.  Training will be required for the surgeons, eye doctors, nurses, technicians, etc.

The company is hopeful to start the initial “launch” at the centers involved in the clinical trials.  Additional sites and doctors will be added as time goes on.  My own practice is hopeful to be one of the first to train.

Information for Patients

Additional information has been provided on the CentraSite web page.

What Does This Mean?  At the very least, the telescope will have limited availability for the first half of the year.  Without Medicare approval, the device simply won’t be marketed.  The development of other centers for the device to be implanted will depend upon the initial revenues and popularity of the device.  This is not unlike cell phone coverage. 

The CentraSight telescope is also a good example of how the FDA and Medicare together to bring devices to market.  FDA approval doesn’t mean Medicare’s endorsement as the two operate independently.

Overall, there are many variables to watch;  the speed or rate in which new centers are developed and new doctors trained and the fiscal issue of insurance payment.   Be patient.

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10 Facts About Diabetic Retinopathy

I will be speaking to a local patient group regarding the implications of diabetic retinopathy later this week.  These are my “Top Ten” factoids about the eye disease.

Patients With Diabetes Need Annual Eye Exams

Without exception and at a minimum, both the AAO and AOA recommend that every patient with diabetes receive an annual eye exam.  The pupils must be dilated to allow proper examination of the retina.

It doesn’t matter if you take insulin or not.  The disease has no bias.

Diabetes Mellitus Affects the Retina

The retina is the light sensitive tissue that lines the inside of the eye.  It is the principle tissue in the eye targeted by diabetes.  Without a healthy retina, you can not see.  It is perhaps the most important structure of the eye.

Diabetic Retinopathy May be Asymptomatic

Diabetic retinopathy is a slowly progressive disease.  The key to saving vision is early diagnosis and before there are any symptoms of blurred or decreased vision.  Don’t let good vision fool you into thinking there is nothing wrong with your eyes!

Good Sugar Control Does NOT Prevent the Disease

There is nothing to prevent the development of diabetic retinopathy.  While sugar control may slow the development of the disease, there is no proof that it will actually prevent the disease.  Most doctors and patients are unaware of this one fact.

Diabetic Retinopathy Can Cause Blindness

While diabetic retinopathy can cause a spectrum of vision loss, true blindness is quite rare.  In fact, fewer than 1% of patients with diabetes will sustain “significant” vision loss in their lifetime.

In other words, blindness may be prevented most of the time, but early detection and treatment is essential.

Ophthalmologist or Optometrist Doesn’t Matter

In my opinion, not shared by many of my colleagues, I don’t think it matters if you are examined by an ophthalmologist (M.D.) or optometrist (O.D.).  In my experience, most eye doctors are able to identify/recognize diabetic retinopathy.  You should then be referred to a retinal specialist.

Diabetic retinopathy has a characteristic appearance that can be recognized easily.

Retinal Specialists Treat Retinal Disease

Okay, no kidding, but my point is that there are many ways to treat diabetic retinopathy.  While you may not be examined regularly by a retina specialist, you should evaluated by a retinal specialist once the disease is diagnosed.

There are so many treatments available to you at this time to improve or stabilize your condition.

Every Patient With Diabetes Will Develop the Disease

I have seen very few patients with diabetes over 30 years that are lucky enough not to have developed the disease.  I think it is safe to say that most will develop the disease and I tell all my patients to expect the diabetic retinopathy to develop.

Why?  If you expect the disease to develop, you are most likely going to have regular exams.  If you expect the disease to develop, then you get rid of the “denial” and seek proper medical treatment.  Also, by expecting to develop the disease, you won’t feel disappointed in yourself for failing to take better care of your health.

Macular Edema and Proliferative Diabetic Retinopathy

There are only two “stages” that require treatment.  Swelling in the macular area is called macular edema.  Macular edema causes blurry vision.  Most diabetic patients get this form.

Proliferative diabetic retinopathy (PDR) affects fewer patients, but can lead to blindness if not treated.

Both macular edema and PDR may occur simultaneously.

anti-VEGF, Laser, Steroids and Vitrectomy for Diabetic Retinopathy

We now have an array of treatments depending on the stage and severity.  Regardless of the treatment, early detection gives you the best prognosis for maintaining your vision!

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Retina Specialists Have Classes All Their Own

Preceeding the AAO, retina specialists have a 2 day meeting of their own.  It’s a time for me to take classes or instructional courses on subjects related to my sub-specialty of retinal disease. Other sub-specialists (cornea, pediatic ophthalmology, glaucoma) do the same.  Our meeting is focused on all things retina…naturally.

Not much new information was presented during the sub specialty meeting.  This may be due to the fact that either not much is happening in the retina world, or, the dissemination of new information is easily achieved due to the Internet.  Probably a bit of both.

I did not hear about any new treatment for macular degeneration or diabetic retinopathy, but there was some further buzz that Iluvien is getting closer to FDA approval, perhaps by December.

Avastin and Lucentis Still Best for Wet Macular Degeneration

The treatments using anti-VEGF (injections such as Avastin and Lucentis) continue to be the best for wet macular degeneration.  More evidence that the two drugs work equally well was supported.  Even more evidence supports the notion that this is the preferred mode of treatment for wet macular degeneration and proliferative diabetic retinopathy.

In a nutshell, in one form or another, these medications will be around for the foreseeable future.

Iluvien Soon to Treat Diabetic Retinopathy

To me, this is the biggest development in retinal diseases.  I spoke with several representatives of the pharmaceutical company (Alimera Sciences) and they are all excited.  They should be.

Iluvien is represents a new era in eye treatments.  Ozurdex was approved last year, and, it too, is a sustained release drug delivery system.  Both release steroid drugs inside the eye for a predictable length of time.  The concept is fascinating.

Sure, it will likely be used to treat diabetic retinopathy, but it endorses this new age.  Few eye doctors understand the impact of this new era.  Better treatments for eye disease will evolve simply because we can get the drugs into the eye and treat disease for months at a time.

What Does This Mean?

We are doing a great job at sharing information.  I am happy we didn’t “miss” anything,  and that, overall, we are doing a pretty good job at keeping current with this web site.

Retinal diseases have traditionally been difficult to treat due to the blood brain barrier, that is, it’s really hard to get drugs into the inside of the eye.  With intraocular injections and injectable drug delivery systems, we are doing quite well, thank you.

The subspecialty day preceding the AAO is a great way for me to make sure I am up to date and gives me the opportunity to explore areas in that interest me.

It’s called continuing medical education.  It is the best way that I can go back to school.  To maintain my medical license I need 50 hours of continuing education per year.  We are really never done with school.

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AAO Chicago 2010: Social Media and Medicine

I just returned from the American Academy of Ophthalmology held in Chicago.  It is the largest ophthalmology meeting in the world.  It is a great way for me to get my CME (continuing medical education) credits and have fun with friends and family.

The AAO is the largest in the world.  This year the meeting was combined with MEACO (Middle East Africa Council of Ophthalmology).   There were a lot of people in town.  Conservatively, I’d guess 30-35,000 were in Chicago for the 4 day event.

Continuing Medical Education (CME)

Every physician is required to attend educational activities during the year to maintain state licensure.  Attending classes and lectures are the most common ways to fulfill these requirements.

I went to learn how ophthalmologists are using their web pages, social media and the Internet to educate their patients and grow their practice.

“Build It and They Will Come”

Most doctors still feel that by simply building website, patients will flock through their doors.  So many of my friends (doctors) are planning to “refurbish” their websites with the expectations of improved rankings and visibility.  They have no understanding of how to really improve their rankings.

Many practices have a web site, but use the site as a reference page.  The site contains office hours, locations, insurance in formation, etc.  The patients that use these sites are already known to the practice.

The only way for a medical practice to improve their exposure is to construct a website (or blog like this one) and provide relevant content that is refreshed at a regular rate.  This method, called Search Engine Optimization (SEO), is the only method that can work for a medical practice.

As a reward for providing fresh new content, Google (Yahoo and Bing, too) will elevate these sites in the rankings.  It has nothing to do with fancy graphics and a new design.

What Does This Mean? Doctors are finally embracing the Internet.  They don’t know how to use it, but at least they have their heads out of the sand are pointed in the right direction.  By embracing the Internet, they are admitting that most patients now use the Internet.  It will take several more years for medical docs to “get it,” but at least it’s a start.

As an aside, I was overwhelmed, and encouraged, by how much I’ve learned over the past 20 months.  The last time I was in Chicago was 20 months ago.  Amy, my wife, an attorney and Internet guru, brought us to a premier Internet marketing seminar.

She is why I started this blog.  There is a lot of “white space” with medicine and the Internet…alot.

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Low Vision Aids: Hand Held Magnifiers

I welcome back Dr. Chris Renner. Chris has contributed before to He practices locally in Northern Virginia and is an expert on Low Vision. – “Randy”

In my last column I defined low vision as visual impairment not improved by normal eyeglasses.  Low vision aids are optical devices which attempt to improve visual function.  Remember, low vision doctors can’t bring your vision back, but we can try and help you perform your favorite activities.  Today I will discuss hand magnifiers.

A hand magnifier or magnifying glass is a lens which focuses light in such a way that objects appear larger when they are viewed through the lens.  This is different than a reading microscope, which is designed to allow you to hold items of interest very close, but still be in focus.

Generally, the smaller and thicker the lens, the higher the magnification will be.  For example, a small high-powered magnifier might be noted as 10X and give magnification ten times larger than normal.  This magnifier might also be used by jewelers or others who need extremely high magnification.  A low-power magnifier, such as a 3X, will allow you to have a wider field of vision and be able to see entire words or phrases, but they won’t be as large.

A high-power magnifier will allow you to see the smallest print, but you must have very steady hands to align things perfectly.  You might have to hold your reading material and the lens close to your best eye.

Low-power magnifiers let you use both eyes at the same time, which might be an advantage.  They also allow you to see more of a line at one time, making it easier to keep your place while reading or navigate around a page.

A magnifier can be hand-held or mounted on a stand.  The stand is set directly on your reading material, and is calibrated to be at the correct distance to have the reading material in focus.  Stand-mounted magnifiers are very helpful for anyone with a tremor, or maybe limited use of their hands.   Some stand-mounted magnifiers are available on a moveable arm and can be put in any convenient position.

Some magnifiers have lights attached, ensuring proper illumination.  I prefer the battery-operated models, so that you can easily carry them around.  However, plug-in models often have brighter lighting.

Here is what I recommend:  Most patients will benefit from the hands-free and high-power features of a reading microscope.  Second, a low-power hand or stand-mounted magnifier is useful for reading at home, reading mail, paying bills, etc.  Third, many people like a small high-power hand magnifier, often on a necklace or in a breast pocket for easy access.  These three items are low-tech, relatively inexpensive and highly effective.  They are type of “starter set” for the low vision patient who is highly motivated to continue to perform as many normal activities as possible.

For my next column I will discuss spotting telescopes and reading microscopes.

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Currently, I see patients with retinal diseases; macular degeneration, retinal detachment, macular holes, macular pucker within several different'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
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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
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