(Image courtesy IMI)

Clinical research to develop artificial vision devices has accelerated greatly over the past 3 years. American researchers first introduced a retinal chip with 16 electrodes called Second Sight back in 2003. German scientists have recently reported their success with an innovative 50-electrode retinal chip they call the Learning Retinal Implant (LRI).

The normal visual pathway consists of light rays that stimulate the retina which, in turn, transmits a neural signal to the brain. People with hereditary and degenerative eye disorders have a problem with the conversion of the light impulse into an electrical charge. They lack a healthy supply of vision cells called photoreceptors. This is where the retinal chip does its job.

So far, four blind human volunteers have received LRIs. Customized spectacles have a miniature camera mounted in the frame that transmits the camera image to a tiny computer carried in a fanny pack (the developers use a more sophisticated name). The computer sends a wireless digital signal to the chip. Electrodes inside the chip directly stimulate the retinal ganglion cells and a visual ‘image’ is sent to the brain.

Retinal chip recipients report the presence of lights and shapes. True, this new ‘vision’ is very crude compared to your ability to read this blog, however, for individuals denied all eyesight most of their lives the recovery of any visual stimulation is a remarkable achievement. The inventors behind both of these retinal chips forecast continued success as optoelectronic technology evolves.

Related Topics: Diet, Lifestyle May Affect Eye Health, Blind Sleep Disorders

Technorati Tags: eye health, eye disorders, eye implants

If you are reading this blog on a handheld device then you already have firsthand experience with the topic of this post. Keep reading, if you can.

So much written information in our lives is being presented to us via dimly lit miniature screens. Just walking around my house I was kept squinting by looking at the coffee maker, the video recorder, a digital camera, several iPods, my beeper, two cell phones, a larger PDA, as well as our home security keypad and a state-of-the-art oven. Even the lawn sprinkler timer has a teeny-weeny digital readout!

More and more people are complaining about text displays. There are two main concerns:

1. The characters are just too darn small; and
2. The screen illumination is inadequate. Not long ago novice computer users had the same problems but hardware manufacturers were able to enhance screen resolution and text readability.

Don’t you hate it when you get beeped in daylight and you cannot see the characters on the digital readout? You tilt it every way possible to catch a glimpse of the screen – it’s most annoying while trying to drive and still carry on a cell phone conversation!

Eyestrain is a big problem because most of these devices are intended to be held within arms distance – up close. The closer you hold it the more your eyes will need to accommodate (boost near-focusing power). Continuous accommodation is uncomfortable so take frequent rest breaks and simply ’stare off into the distance’. Beyond age 40 many adults have lost so much of their accommodative reserve they need bifocals to compensate (presbyopia). That makes a difficult task unbearable.

Before you invest in another new digital gadget make sure you test drive it in the store and, hopefully, outdoors in the parking lot. Do not expect your eyes to eventually adapt. What you see (or don’t see) is what you get. If you cannot read the screen display clearly you should consider an alternate model. Once again, you get what you pay for. Cheaper units typically have weaker, shorter-life batteries and that means uncomfortable squinting.

Read the fine print. You’ll enjoy your new electronic gizmo more if you can see what it is you are doing.

Related Topics: Setting Up Your Office For Minimum Injury, Clean that Computer Keyboard

The healthy eye needs to be able to deliver focused rays of visible light through various transparent media (cornea, crystalline lens, vitreous gel), so that those rays strike the retina and transmit a visual image to the brain.

Like other organs in the body, the eyes need a variety of specific nutrients in order to do their job. Vitamin A is critical to good vision. Vitamin A is a fat-soluble vitamin. That means it is absorbed into the bloodstream and stored in the liver, (the same is true for Vitamins D, E, and K). Vitamin A can be stored but those stores can also become depleted.

Vitamin A is essential for producing tears and keeping the surface of the eye moist and free of infection. Inadequate Vitamin A levels will also damage the clear cornea. Nearly everyone knows that carrots (loaded with Vitamin A) are healthy for the retinal cells – the photoreceptors. Poor vision in dim light (nyctalopia) is one of the earliest symptoms of Vitamin A deficiency, hypovitaminosis A. High-dose supplemental Vitamin A is prescribed as a treatment for some hereditary retinal disorders.

People tend to think of underserved Third World populations when the subject of malnutrition is discussed. It might surprise you to know that many Americans are malnourished, deficient in the key nutrients, minerals and vitamins essential for healthy living.

Malnourishment occurs in one of three situations: when a person fails to consume an adequate quantity of a necessary nutrient; when an individual’s digestive tract cannot properly absorb the nutrition; or when a person’s metabolism cannot correctly convert and store the digested products. Folks who have low Vitamin A levels can fit into each of these categories. I’ve got a few examples to share.

Patients who have undergone weight-loss surgery, like those popular gastric bypass procedures, are at risk of Vitamin A deficiency because their reconfigured anatomy short-circuits the absorption pathway. Anyone with liver problems is also at risk. Combine those people with the hordes who observe quirky exclusionary diets that deny the body of a healthy balance of vitamins and minerals. Your primary care doctor can help you determine if you are at risk.

Preserving your eyesight is a daily responsibility. Consuming a balanced diet rich in essential nutrients is an important part of maintaining healthy vision. It begins with Vitamin A.

Related Topics: Fruits, Veggies May Help Avoid Cataracts, Madonna’s Fountain of Youth

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Good news from Hollywood. Teri Hatcher, star of ABCs ‘Desperate Housewives’ suffered an accidental eye injury when a light bulb exploded on-set. A glass fragment struck her eye and may have become embedded in her clear cornea. She has been successfully treated and will soon be able to resume work.

The eye has remarkable protective properties. The blink reflex is faster than a deploying airbag (faster than 50 milliseconds). Teri’s blink reflex likely protected her from multiple injuries to both eyes. The clear cornea is also a remarkably durable tissue. It’s made of pure collagen and its outer layers are most dense – trapping fragments at more superficial layers.

After applying an anesthetic eyedrop the eye surgeon can gently retrieve the piece of debris with a fine-tipped forceps (you call ‘em tweezers!)

Corneal healing is not like skin. Since the transparent cornea has no blood vessels the corneal tissue will heal without bleeding, scarring or serious inflammation. In a matter of days the injury site will likely become invisible.

TV fans around the world are relieved that Teri Hatcher is safely recovering from this accident and excited that she will soon be back on Wisteria Lane flashing those voluptuous peepers!

Related Topics: Eye Injuries Twice as Common in Men, First Aid for Eye Injuries

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Sad but true, most medical school graduates have had little formal instruction regarding eye exam techniques and even less clinical experience. Your family’s medical care may suffer down the road because of this serious shortcoming in medical education.

This problem is not confined to one medical school or to a particular region. Recently the AUPO (Association of University Professors in Ophthalmology) held a symposium to raise awareness of this serious concern and to develop strategies to restore ophthalmology into the medical school curriculum.

In a country with 23 million diabetics many of our newest MDs are unable to determine if a patient has experienced bleeding inside the eye. How did things get this way?

Since the advent of managed care so much emphasis has been placed on primary care medicine that most medical specialties (like ophthalmology, ENT, and urology) have been given less emphasis. There goes the baby with the bath water…

Here’s the problem in a nutshell. Basic clinical skills like ophthalmoscopy are practiced by nearly all doctors regardless of specialty. The ability to look inside the eye and to identify problems is comparable to interpreting an EKG or listening to breath sounds with a stethoscope. Patients have no way of knowing whether or not their doctors are truly proficient in all examination skills. Most of us equate medical licensure with medical proficiency.

National and state medical regulatory boards recognize this problem and have begun incorporating eye exam skills in the mandatory practical examinations needed for medical licensure. This forces the young doctors and their medical schools to reassess what is taught – if it’s not enough become better physicians at least it’s enough to pass the stupid test!

Related Topics: Common Vision Problems, Diet, Lifestyle May Affect Eye Health

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Taking a once-a-day pill to control your blood pressure or cholesterol level is a very efficient way to manage a health problem. Once the pill is swallowed your metabolism takes over – it’s a closed system. That’s not the same with eyedrops.

There are a variety of once-a-day drops to help control intraocular pressure for folks with glaucoma, but the eye relies on that one drop of medication to work continuously for 24 hours. Unlike swallowing a pill, instilling an eyedrop is a more risky proposition. The eye medication can disappear.

It only takes three blinks for all of the medicine to be washed away by the tears, long before the clear cornea can adequately absorb the drug. Three blinks.

If you are taking prescription eyedrops there are some simple steps you can take to maximize drug availability and minimize drug washout.

First, once the eyedrop is instilled close your eyes. If you do not blink the medication can linger. At the same time gently apply fingertip pressure for 2-3 minutes to the skin between the inner eyelid corner (medial canthus) and the bridge of the nose. This is especially valuable for anyone taking once-a-day eyedrops. Get the full value of your medication.


Finally, if you need to take more than one eyedrop in any eye allow five minutes to pass between doses to keep the second drop from washing away the first drop.

Related Topics: Eye Health Center, Eye Problems

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Next time you have an important doctor’s visit, and not just the eye doctor, bring along a partner. It doesn’t have to be a spouse or immediate relative – sometimes a good friend is best.

How many times have you had a key question pop into your head as soon as you depart the clinic? I frequently receive distressed messages from visitors to our WebMD Eye & Vision Disorder Community who seek clarification regarding proposed surgery, treatment alternatives, or suspected complications. Here’s why having that third person in the room optimizes the physician-patient encounter:

Accurate recollections- “Did she say once- or twice-a-day?” Having a partner handy with a notepad improves compliance with the doctor’s recommendations. The two of you can debrief each other afterwards to resolve any misunderstandings.

All points get covered – In the middle of a focused dialogue it’s easy to overlook other concerns. Your partner can help keep the conversation on track.

All questions get asked – Having a second brain and another pair of ears in the room doubles the chances that all of your concerns are mentioned and thoroughly discussed.

Calmer interactions – People are more civilized when observers are present. Your partner can speak on your behalf if you get too emotional or simply call for a ‘timeout’.

Sure, you have to accept personal responsibility for preserving your own good health, but that does not mean you have to go it alone!

Related Topics: Integrative Medicine Resource Center, 7 Key Traits of an Ideal Doctor

Technorati Tags: patientadvocacy, eyedoctor, talkingtodoctor

Lately I’ve been dealing with some dissatisfied patients. No, not angry patients – just puzzled because new eyeglasses prescribed just a month ago no longer work.

Whenever I hear that a large alarm goes off inside my head: Put on your thinking cap, doc!

Although it is true that refractive errors like nearsightedness or farsightedness gradually change throughout life, a significant shift occurring within weeks or a few months deserves careful attention. Three common situations ought to be explored.

1. It is possible that the original prescription did not completely correct the optical error. This can happen with farsighted hyperopes. Initially the patient may have been able to compensate by accommodating (borrowing near-focusing power to see at distance) but eventually the person can no longer tolerate such ‘optical embezzlement’. A dilated cycloplegic refraction will quickly unmask any hidden refractive errors.

   If the new glasses no longer work ask the eye doctor if you were prescribed the full correction.

2. Progressive corneal thinning, as happens in keratoconus, can generate all kinds of wacky focusing problems. As a young ophthalmologist-in-training I encountered a patient who had purchased four pairs of glasses over six months before his keratoconus was recognized. Corneal topography can confirm the presence of keratoconus.

   If the new glasses no longer work ask the eye doctor if there is any chance you have keratoconus.

3. Finally, untreated (or inadequately treated) diabetics experience wide fluctuations in blood glucose levels. The body responds by altering the chemical pathway used for energy metabolism. This shortcut causes the crystalline lens to swell and distort the optics of the diabetic eye. Simple blood tests can verify the presence of diabetes or a pre-diabetic state.

   If the new glasses no longer work ask the eye doctor if you might be glucose intolerant.

In general, the more questions you ask the better health care you will receive.

Related Topics: Diabetes Control Benefits Surgery, Healthy Diet May Help Seniors’ Vision

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Most folks know about CAT Scans (Computer Assisted Tomography) that capture thin x-ray images of specific areas of the anatomy. Maybe you haven’t done a FAT Scan. FAT stands for Family Album Tomography. Yep, use your family album to get better medical care.

Here’s how FAT Scans work.

If you need to see the doctor for any kind of symptom that involves a change in your physical appearance (like a mild eyelid droop or change in the size of an unwanted freckle) bring some old photographs with you to the clinic for the doctor to examine. Expect a hearty “Thank You!” from the physician for actively participating in your own care – for being such a helpful partner.

Depending on the specifics of your problem, utilizing the FAT Scan can spare you unnecessary tests and additional visits. At the same time it can accelerate treatment decisions. That will save you time, money and worry.

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A new spectacle prescription can be exciting because you expect to see better and it’s an opportunity to update the style of your eyeglass frames. There are times, however, when those new glasses disappoint. “Did the doctor make a mistake?”

Information about your refractive error (and its correction) is transcribed by hand many times by different people before you pickup those prescription spectacles: the eye doctor verbally dictates refraction measurements to the technician, the data is then entered into patient record, a handwritten Rx is issued, an optical shop prepares new spectacle work order, and the optician fabricates new lenses. For most eyewear prescriptions 6 different numbers are recorded and 4 require (+) or (-) signs. Yeah, there’s room for plenty of errors! Some studies note that new prescription spectacles deviate significantly from the doctor’s refraction more than 20% of the time.

Here’s how to make sure you get what you deserve. Always keep a photocopy of the original prescription; that will protect you from misrepresentation by others. If you cannot see clearly in your new specs you should ask the optician to verify the lens powers right there in the store. Those numbers should match the original written prescription.

If the prescription was correctly fabricated and you remain dissatisfied visit the prescribing eye doctor. Ask to have the prescription of your new eyeglasses verified with the eye doctor’s original refraction. The clinic may uncover a reversed number or minus sign. In that situation the clinic will issue a corrected prescription and you should not be charged to have the eyeglass error corrected.

Now, if the eyeglass shop did not make a mistake, and the eye clinic did not make a mistake you likely need to adapt to the new eyewear (especially if there is new or changed correction for astigmatism). Otherwise, you may have a fluctuating refractive error due to a related eye disorder like diabetes or keratoconus. Bottom line – if those new glasses don’t work right make sure you notify your eye doctor.

Related Topics: Vision Tests, Reading Your Eyeglass Prescription

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