Eye Didn't Know!

Happy Birthday Stevie Wonder

Did you know? Singer Stevie Wonder was born prematurely, and developed an eye condition called retinopathy of prematurity, which left him blind. Eyes of pre-term babies do not have fully developed vascular systems. Sometimes the blood vessels will develop abnormally, leading to scarring and possible blindness. This condition was much more common in the 1940s and 50s. Studies eventually showed that high levels of supplemental oxygen was a primary risk factor for this disease. This led to discontinuing its routine use in incubators.

Did you also know? Stevie Wonder is still alive and well. He had his first #1 hit at age 12!

Glaucoma Linked to Low Pressure in Brain?

Did you know? A study published in the May 2008 journal Ophthalmology found a fascinating link, which, if verified, could alter how we think of glaucoma. The Mayo Clinic studied the records of all patients who had lumbar punctures (spinal taps) between 1996 and 2007. They identified 28 of these patients as having glaucoma, and compared them to 49 patients who did not.

During a lumbar puncture, the pressure within the spinal column (which connects to the brain) is measured. The spinal pressure in the glaucoma patients averaged 9 mm Hg, and the controls measured 13 mm Hg. Since the average eye pressure is between 10 and 21, (often higher in glaucoma) that means that the pressure gradient between the eye and the brain could be higher in the glaucoma patients. This would damage the optic nerve, which is seen in glaucoma.

Did you also know? The only accepted treatment we have now for glaucoma involves lowering eye pressure, with eyedrops, laser, or surgery.

Are we due for a new class of glaucoma medications?

Did you know? It has been twelve years since there have been any significant additions to our supply of medications for glaucoma. In 1996 Xalatan was introduced, the first of the prostaglandin agents which quickly took over first-line therapy for most glaucoma patients. The prostaglandins simply worked better with fewer side effects than the other medications available.

A new class of medication may be on the horizon. Rho-kinase inhibitors, (ROCK-inhibitors) are molecules which relax smooth muscle, a muscle which is found, among other places, in the drainage system within the eye.

When this drain does not work properly, the pressure within the eye rises, which can lead to damage to the optic nerve within the eye. When this happens, vision can be lost, and we call it glaucoma. Relaxing the mesh-like tissue within this drain can apparently cause pressure to be lowered.

Several pharmaceutical companies are looking into these molecules. Studies in monkeys have shown a larger pressure lowering effect than Xalatan!

Will these studies result in a new class of glaucoma medications? Only time will tell. Ophthalmologists and glaucoma patients could benefit from a new arrow in our quiver!

More information can be found here.

Did you also know? Statin drugs (lipid-lowering agents) such as Lipitor, Zocor and Crestor are also ROCK-inhibitors.

Measuring Eye Pressure

Did you know? Until 1905 there was no objective way to measure pressure within the eye. In that year, Norwegian ophthalmologist Hjalmar Schiotz invented the first tonometer, which now bears his name, the Schiotz tonometer.

Until this time, doctors estimated pressure within the eye by pushing on the eye through the eyelid, and guessing, much like you might push on a bicycle tire with your thumb and guess the pressure. The Schiotz tonometer actually works in much the same way, it measures the weight necessary to indent the cornea a standard amount.

Knowing the pressure more accurately allows us to better diagnose and treat glaucoma, a disease usually caused by elevated eye pressure damaging the optic nerve.

The Schiotz tonometer is still used in many parts of the world, and when I trained, it was what most doctors used as a portable tonometer.

Did you also know? Dr. Schiotz was also responsible for introducing the concept of sterilizing surgical instruments (by boiling) to Norway.

"You use lasers to remove cataracts, right?

Did you know that cataracts are NOT removed with a laser? Ophthalmologists use many types of lasers for dozens of indications, but removing cataracts is not one of them! The state of the art in cataract removal today is called phacoemulsification, which uses a tiny probe to dissolve the cloudy lens and remove it from inside the eye. After the cataract is removed, a soft, rolled-up implant made of silicone or acrylic is inserted through a three millimeter incision, and unfolds in place within the eye. Because the tiny incision heals very quickly, it is unusual to have any restrictions on activities after surgery.

Did you also know? Most modern cataract surgeries take less than 15 minutes, and many doctors only use eyedrops (no needles!) to anesthetize the eye.

Omega-3 Oils for Dry Eye?

Did you know? A new study published in the February 2008 issue of Archives of Ophthalmology showed that applying omega-3 fatty acids to the surface of the eyes of laboratory mice protected them from the effects of dry conditions. Eyedrops containing two compounds, alpha-linoleic acid, and linoleic acid, a mixture of the two, as well as a drop containing neither compound, and no treatment, were compared. The mice receiving the alpha-linoleic acid had less dryness and inflammation compared to the other groups.

Did you also know? Many ophthalmologists recommend taking fish oil or flaxseed oil to improve dry eye, including the dry eye which can sometimes occur after Lasik surgery (though I would like to see more well-designed studies proving their benefit). This, however, is the first study I have seen suggesting that a drop containing the oils may prove beneficial.

Happy Birthday Abe!

Did you know? There is a story about Abraham Lincoln seeing his ghost while looking into a mirror from his bed, shortly after being elected in 1860. By studying numerous photographs and portraits of Lincoln, ophthalmologists have determined that Lincoln had a weakness of a muscle in his left eye (the trochlea), which made the eye unable to look downward in certain positions, including when trying to look into a mirror from a supine position. This would explain his double vision during the incident. Others have ascribed this story to a mirror having two reflecting surfaces, but I find that less convincing.

Did you also know? Physicians say there’s a 50/50 chance that Lincoln had Marfan’s Syndrome, which causes elongation of the hands and jaw during adulthood, due to an excess of human growth hormone. (Marfan's Syndrome can also can dislocation of the lens within the eye).

photo courtesy wikimedia commons

New approach to macular degeneration treatment

Did you know? Researchers at the University of Florida are testing a new compound, Compstatin, for its effectiveness in preventing complications of macular degeneration. This small protein blocks complement, which promotes inflammation in the body. It is believed that complement is involved upstream in the process which eventually leads to abnormal blood vessels forming and bleeding in macular degeneration.

Three volunteers with macular degeneration have had their eyes injected with compstatin, and they are now being monitored for side-effects. I am very interested to know the frequency that these medicines would be needed, as it is not pleasant to have medicine injected into the eye!

Did you also know? The drugs Avastin and Lucentis, both produced by Genentech, have revolutionized treatment of macular degeneration. These compounds, unlike any previous treatment, can cause regression of bleeding in the eye and improvement of vision!

Happy Birthday Louis Braille

Did you know? Louis Braille (1809–1852), invented the braille system of writing for the blind and visually impaired. Braille became blind at age four when he accidentally stabbed himself in the eye with his father's awl. This caused inflammation and eventual blindness in the other eye as well, a condition called sympathetic ophthalmia. Braille's system uses six raised dots to represent letters of the alphabet. Later he extended the system for use in music and mathematics.

Did you also know? The Braille Institute of America is a private, non–profit organization whose mission is "to eliminate blindness and severe sight loss as a barrier to a fulfilling life."

Steroid for Glaucoma?

Did you know? It may be possible to lower eye pressure in glaucoma with injections of a steroid called anecortave acetate. Although most steroids have to potential to raise eye pressure, this steroid has been shown in a number of studies to lower eye pressure. Researchers at Johns Hopkins, in Baltimore, injected a small amount of medicine or placebo just under the surface of the eye in 85 patients. After three months, the patients receiving the medicine had a pressure reduction of 7.4 mm Hg compared with 1.4 mm Hg in the placebo group. Read more here.

Did you also know? Many patients have enormous difficulty taking their glaucoma eyedrops properly. If it becomes possible to control eye pressure with a painless injection under the eye every three, six, or twelve months, that would give us a very important additional measure to preserve vision in glaucoma.