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Article Date: 07 May 2010

An ophthalmologist at Washington University School of Medicine in St. Louis is implanting radioactive discs in the eyes of children with a rare cancer in an attempt to save their vision and their eyes. J. William Harbour, MD, is one of only a few doctors nationwide to use the approach for treating a rare, childhood eye cancer, called retinoblastoma.

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Article Date: 06 May 2010

For some years now a small group of scientists have been pioneering a revolutionary idea that the vertebrate immune system could have a role in the regulation of iron in the body. And now, a work soon to be published in the journal Immunology, shows that human lymphocytes (white blood cells) actually produce hepcidin, the most important protein in the regulation of iron levels in the body.

How Accurate Is Retinal Scanning?

Article Date: 05 May 2010

You can't change the back of your eye so it definitely is a proof positive method of identification," said Dr. Proctor. "Use of retinal scanning as a means of identification has been around for awhile; technology has now caught up with the idea and advanced computerization including database availability can make this a reality."

Blindness And Sense Of Smell

Article Date: 04 May 2010

"There is an urban legend that blind people have better smell than the sighted. We are proving this to be false," says Maurice Ptito, a professor at the Université de Montréal School of Optometry and Beaulieu-Lefebvre's thesis director. "However, the blind do set themselves apart when it comes to cognitive efforts."

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Retinal Detachment

A detached retina is a serious condition that can lead to severe visual impairment or even total blindness in the affected eye.

Having a retinal detachment (or retinal separation) means that a part of the retina – which lines the inside back wall of the eye – has been lifted from its normal position. The retina is like the film in a camera. Millions of light-sensitive retinal cells receive optical image bits, instantly “develop” them, and send tem to the brain to be seen. The retina is vital for seeing; if any area is detached some vision is lost.

Normal Eye:

Retinal Detachment:

A detached retina is a serious condition that can lead to severe visual impairment or even total blindness in the affected eye. Any new detachment is always considered an emergency. Though a detachment often begins in a small area, it almost never stays small. As it gets larger, vision loss increases.

A retina can detach at any age but it is more common in midlife and later, and in those who are extremely nearsighted. It affects men more than women and heredity may also play a part, since it tends to run in families.

WHAT CAUSES A RETINAL DETACHMENT?

A detachment is almost always caused by tiny tears or holes that form in the retina. These usually result from aging changes in the vitreous, the gel-like substance that fills the eye’s interior and helps maintain its round shape.

The vitreous contains millions of fine fibers that are attached over the entire surface of the retina. As we age, the vitreous slowly shrinks and eventually pulls free from the retina (a vitreous detachment). In about half of the population, the vitreous has separated from the retina by age 50. Nearsightedness, infection or injury such as a hard solid blow to the eye, can also make the vitreous separate. When the vitreous pulls away, it sometimes creates one or more tears in the retina.. If vitreous fluid seeps through a tear, the retina will begin to separate (peel) from the back wall of the eye.

Other causes of retinal detachments include:

Blow or injury to the eye.
Conditions that produce intraocular hemorrhage or inflammation, such as diabetes.

SYMPTOMS OF A RETINAL TEAR

You may have “floaters” and “flashes”. These are also symptoms of a vitreous detachment).

Floaters: Anything that tugs on or tears the retinal surface can break some retinal blood vessels. As a result you may have a sudden shower of floaters – spots or “cobwebs” that seem to float about in your field of vision. Normally, everyone has a few specks, but a sudden increase in their number and size is a warning that something has happened; it usually means that blood or debris has suddenly appeared in the vitreous. Most of these floaters decrease in a few weeks or months through they rarely disappear completely.

If a retinal tear happens to break a larger retinal blood vessel, the blood leakage into the vitreous can cause a massive increase in floaters that suddenly blocks vision in that eye. But this is rare.

Flashes: Anything that mechanically disturbs the retina can cause the sensation of a flashing bright light somewhere in your field of vision, usually when you move your eye quickly. “Lightning streaks” seen off to the side are likely caused by a vitreous detachment that pulls on the retina.

SYMPTOMS OF A RETINAL DETACHMENT

Some retinal tears do not cause problems and are not especially dangerous. However, if fluid starts to leak through a tear, the retina will start to peel (like wallpaper) and the detachment process begins.

At first you may have no symptoms, especially if the detachment starts off to the side. Gradually (over hours, days or weeks), a “curtain” of darkness will move in and block out a portion of your visual field from one direction (the area of vision lost depends on the location of the detachment). Your sharp central acuity may not be affected immediately. It is when the detachment reaches the central zone of the retina (the macula) that vision will suddenly blur. The loss is so dramatic, that this is when people notice the problem and seek help.

Sometimes, even this sudden loss of vision goes unnoticed because it is masked by the good vision in the other eye. The vision loss is revealed only when the good eye is accidentally covered, which can happen much later.

A detached retina is painless and cannot be seen from the outside of the eye. If you notice symptoms, you should see your eye care practitioner right away. If you are very nearsighted or have a family history of retinal detachment, you should have regular eye exams to detect changes and prevent retinal detachment.

EXAMINATION

A prompt and thorough retinal examination is needed for a careful and accurate evaluation. A dilated exam with eye-drops allows for the best visualization of all retinal tears and holes.

TREATMENT

If you are found to have a suspicious-looking retinal tear or one associated with a detachment that is still very small, you may need only laser or cryotherapy to seal the tear.

Once the retina detaches, however, all holes and tears that have allowed fluid to collect under the retina must be located and sealed, and this repair usually requires major eye surgery. Whether you are hospitalized or not, and the type of anesthesia used, will depend on how complicated the detachment is and the location, type and size of the retinal tears. A combination of procedures and appliances are often required. These are some common ones:

Cryotherapy: an extremely cold probe is used to “freeze-burn” a small area on the outside of the eyeball that overlies the retinal tears. The purpose is to seal the tears and create an eventual scar that will “stick” the retina to that spot.
Lasers: high energy light beams that can coagulate (burn) tissue to help seal tears and holes. This is usually used as a supplement to surgery.
Vitreous surgery: opaque debris and membranes can be removed from the inside of the eye ad from the retinal surface to relieve any vitreous pull (traction) on the retina.
Intraocular gas: bubbles of air or a special gas is injected into the eye to temporarily push or hold the retina in place; it sometimes liquid silicone is used.
Drainage: the fluid from under the retina is surgically drained, to allow the retina to settle back down into its normal position. Sometimes the fluid is not drained, but left to absorb on its own. Other times, the drainage is combined with intraocular gas (a gas/fluid exchange).

AFTER SURGERY

You will need to use various types of eye-drops and/or ointments (cycloplegics, steroids, antibiotics), possibly for several weeks.

Your activities will be somewhat restricted, depending on the type and extent of the detachment. After some procedures, you will need to keep your head in a particular position during healing. It often takes a few weeks for the retinal tears to become firmly “welded” shut. Once recovery is complete, most patients can lead a completely normal life.

If you plan to take part in a sport that exposes your eyes to injury, always wear polycarbonate protective goggles or a facemask. Direct blows to any eye can be harmful, but they are especially risky to one that was previously detached.

Regular examination (at least annually) are important because there is some risk that the retina can detach again. Regular exams are also important if you have any condition that predisposes you to a retinal detachment, such as high myopia. Preventive laser treatment or cryotherapy may be advised for suspicious tears found in either eye, though usually they are merely identified and watched.

PROGNOSIS

With modern therapy, over 95 percent of detachment can be successfully treated and the retina reattached. The visual outcome, however, is not really predictable. For the best visual result (which can approach normal), treatment must take place early, before the critical, center part of the retina (the macula) detaches. If the macula has already detached when the repair is undertaken, full return of your previous acuity is less likely. Still, the side vision in that eye can be normal, and that eye will almost always be useful despite its lesser acuity.

Realistic expectations are important. Even under the best of circumstances, and even after multiple attempts at repair, treatment sometimes fails and useful vision may not be regained.

Remember, the earlier a retinal tear or detachment is detected, the better the chance for preserving vision.

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