New Cornea Without Transplantation

How is the lens different from the spleen? How is the cornea different from the heart?

Transparency is one of the unique characteristics of the human eye that distinguishes it from other organs. Nowhere else in the body are solid tissues so perfectly clear.

The clear cornea stays clear because of the optically-pure way its bundles of collagen are organized. These highly structured collagen bundles transmit visible light. The cornea must be relatively dry in order for the cornea to remain clear and that is the job of a delicate layer of cells called endothelia - the cornea's pumping cells. There is a finite supply of these nonregenerative endothelia; once they're gone they're gone forever (as well as the pump!) There are many reasons why endothelial disappear. When it happens the cornea will begin to imbibe water and develop corneal edema.

Corneal transplantation replaces the swollen, worn-out cornea with a younger, robust cornea. This operation has been performed routinely for 60 years. Now there is an alternative - it's called DSAEK.

DSAEK stands for Descemet's Stripping and Automated Endothelial Keratoplasty. Instead of replacing the entire cornea the surgeon strips-away a delicate membrane along the backside of the cornea and replaces it with a new membrane loaded with active endothelial pumping cells. This same-day surgery can be performed with topical anesthesia and small incisions. Unlike corneal transplantation no stitching is required. This new approach greatly accelerates the postoperative recovery and reduces the potential for serious complications.

WebMD Daily has produced a very informative video about this innovative procedure. Click here to see an actual DSAEK procedure being performed.

For many patients standard corneal transplantation remains the recommended procedure to restore a clear visual pathway. For those needing a resupply of those critical pumping cells DSAEK may be a very effective alternative.

Related Topics: LASIK Surgery: Safer than Contacts?, Are You a Candidate for LASIK?


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Which Creature Sees Best?

I just returned from a wonderful teaching visit to the University of Wisconsin School of Medicine. Besides giving some lectures and conducting lab sessions at the microscope I was fortunate to be invited to tour their world-famous Veterinary School. They have a large Comparative Ophthalmology program headed by Dr. Richard Dubielzig. Comparative Ophthalmology means studying the visual systems of different creatures: fishes, birds, reptiles, mammals, etc. How grateful I was to have had the opportunity to examine the visual systems of many different species.

This logically prompts the question, "Which creature, big or small, posessess the best overall eyesight?" Perhaps you were thinking about eagles or other predators. Nope. According to Dr. Dubielzig, human beings see the best day and night. Healthy human eyes have precise central vision, function well in the dark, and we can enjoy all the colors of the visible spectrum. Yeah, but do eagles need bifocals?!?

Here's another fact I did not know. Deer cannot see bright orange colors. That gives a tremendous advantage to hunters dressed in orange gear plus the enhanced visibility offers improved safety from potential accidents caused by fellow hunters.


Related Topics: Vision Tests, Your Guide to Eye Health

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Prize for Visionary Research

Here's a neat chance to brag about a colleague of mine, Dr. Ivan Schwab.

You probably know that this is the season for announcing the annual Nobel Prizes. Big money awarded in Stockholm to scientists, economists and poets for remarkable contributions to their field.

Dr. Schwab was not chosen for a Nobel Prize. Instead Harvard awarded him a 2006 IgNobel Prize. Like the Hasty Pudding Award, the IgNobel Prize is an Ivy League parody of the real thing. Nonetheless, it recognizes talent and dedication.

According to a recent press release, the IgNobel Prizes are awarded annually for achievements that "first make people laugh, and then make them think." Bestowed by the scientific humor journal Annals of Improbable Research, the awards are intended to "celebrate the unusual, honor the imaginative and spur people's interest in science, medicine and technology." This is the first year that the journal has awarded a prize in ornithology. In keeping with tradition, six genuine Nobel laureates presented this year's IgNobel Prizes.

Dr. Schwab is an ophthalmologist and Professor at UC Davis School of Medicine. He has a fascination with the visual systems of nonhumans -- yes, another blog about Comparative Ophthalmology. Schwab received the prize for authoring "Cure for a Headache," a 2002 study about woodpeckers published in the British Journal of Ophthalmology. The headache refers to woodpeckers, who bang away 20 times per second at forces equivalent to 1200G. Click here to read a complete explanation of this interesting work.

Congratulations to Dr. Ivan Schwab. Keep 'pecking away' at nature's mysteries!


Related Topics: Give Your Body a Boost -- With Laughter, Laughter Heals (WebMD Video)

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Microacupuncture: Thought I'd Seen It All

"Check this out!"

Charlotte, a feisty 85 year-old neighbor, handed me a clipping from the local senior citizens' toss-away newspaper. Now I know why they call them toss-aways!

The headline read: Microacupuncture Effective for Macular Degeneration. There it was in large bold letters. I was stunned. Microacupuncture? How come I never read anything about it in the eye journals?

Apparently some enterprising alternative healer from Denmark claims to reverse the irreversible damage caused by advanced macular degeneration and other serious eye problems. Specially trained disciples, microacupuncturists, are now spreading the word. Be careful. Be skeptical.

True, traditional acupuncture has been shown to offer relief for many different kinds of health and behavioral problems. It has withstood the critical scrutiny of diligent scientific research. Most experts believe acupuncture stimulates release of powerful neurotransmitters to exert its effect. That is to say, acupuncture works best with neurologic disorders. The tissue changes that occur with Age Related Macular Degeneration involve abnormal blood vessels, bleeding, inflammation and scarring. There is no needlestick to the hand that can make that go away.

What is most worrisome are the anecdotal claims. One promise is that microacupuncture will correct ARMD at any age. They reported success with a 15 year-old. Guess what? ARMD does not occur that early in life. (Remember, it's age-related!) Who knows what eye problem the poor teenager was dealing with: familial drusen, Best's disease, fundus flavimaculatus?

Beware claims of cure-alls that haven't withstood the tests of multiple studies and followed sound medical principles.

Related Topics: Alternative Medicine, Herbals & Supplements, Hospitals Add Alternative Medicine

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Reducing the Triple Threat

Seems if you get one, you get them all.

I'm talking about a combination of serious health problems that often begin with Type 2 Adult Diabetes. Repeat after me: '23 million Americans are diabetic and one-third don't even know it!'

Adult diabetics often develop elevated cholesterol and high blood pressure. From a medical standpoint that situation is really the triangle of death. Hey, does that sound harsh to you? All three of these complex problems damage blood vessels - from tiny capillaries to larger arteries. Restricted bloodflow ensues and inadequate perfusion of oxygen and nutrients to the brain, the heart, the kidneys and everywhere else is devastating.

Now, if only one leg of that three-legged coffee table could be removed the whole thing might collapse! Using an obese diabetic as an example, weight loss not only reverses the diabetes (glucose intolerance) it simultaneously improves blood lipid levels and lowers blood pressure.

Well, now it seems that some medications can achieve a similar affect. According to a clinical study in this month's British Journal of Ophthalmology, the cholesterol-lowering pill Lipitor greatly improves retinal circulation in diabetics. Type II diabetics with diabetic retinopathy were prescribed either Lipitor or a placebo. Whereas no changes were recorded in the sugar-pill volunteers, those taking the Lipitor not only had much healthier serum lipis levels (as expected) they also were found to have greatly improved retinal circulation as measured with color doppler imaging. Improved retinal bloodflow is critical to preventing the blinding complications of diabetic retinopathy.

As an aside, an internist friend confided to me that in his opinion everyone over 50 ought to be taking Lipitor every day as well as an aspirin. You might want to check with your doctor to test this theory.

Reference: Ozkiris A, Erkilic K, Koc A, Mistik S. The effect of atorvastatin on ocular blood flow velocities in patients with diabetic retinopathy. Br J Ophthalmol 2006

Related Topics: Got Type 2 Diabetes? Get More Sleep, Diabetes Prevention: 6 New Guidelines

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