Lutein and zeaxanthin are compounds called xanthophylls (ZAN-thuh-fills), which are yellow pigments that occur naturally in many plants and vegetables. Xanthophylls belong to a class of organic compounds called carotenoids, which also includes orange and red plant pigments. Though lutein is considered a yellow pigment, in high concentrations it appears orange-red. In nature, lutein and zeaxanthin appear to absorb excess light energy to prevent damage to plants from too much sunlight, especially from high-energy light rays called blue light.

In addition to being found in many green leafy plants and colorful fruits and vegetables, lutein and zeaxanthin are found in high concentrations in themacula of the human eye, giving the macula its yellowish color. In fact, the macula also is called the “macula lutea” (from the Latin macula, meaning “spot,” and lutea, meaning “yellow”).

Recent research has discovered a third xanthophyll in the macula. Called meso-zeaxanthin, this carotenoid is not found in food sources and appears to be created in the retina from ingested lutein.

Lutein and zeaxanthin appear to have important antioxidant functions in the body. Along with other natural antioxidants, including vitamin C, beta carotene and vitamin E, these xanthophylls guard the body from damaging effects of free radicals, which are unstable molecules that can destroy cells and play a role in many diseases.

In addition to important eye and vision benefits, lutein may help protect against atherosclerosis (buildup of fatty deposits in arteries), the disease that leads to most heart attacks.

It is believed that lutein, zeaxanthin and meso-zeaxanthin in the macula block blue light from reaching the underlying structures in the retina, thereby reducing the risk of light-induced oxidative damage that could lead to macular degeneration (AMD).

A number of studies have found that lutein and zeaxanthin either help prevent AMD or may slow progression of the disease.

Alcohol increases your risk for cataract development. And it can trigger short-term double vision and the inflammation that causes ocular rosacea.

April is Alcohol Awareness Month and a good time to take a look at how alcohol may be affecting your eyes and your overall health.

The study just published in American Journal of Ophthalmology examined the records of 11,848 new cases of legal blindness. The rate of blindness from AMD fell from 522 cases per million inhabitants aged 50 years or older in 2000, to 257 cases per million in 2010, a reduction by over 50 per cent.

The bulk of the decrease occurred after 2006, following the introduction of new effective treatment for wet AMD, which is characterised by leaking blood vessels having formed under the fovea. The treatment consists of repeated injections into the eye of a medication that inhibits the signalling molecule vascular endothelial growth factor (VEGF).

Similar findings in Israel

The observations from Denmark were published together with a corroborating report from Israel that found comparable changes in the incidence of legal blindness in that country. Read the report “Time Trends in the Incidence and Causes of Blindness in Israel”.

Current treatment of wet AMD, also called neovascular AMD, consists of repeated injections into the vitreous, an inner compartment of the eye, of a medication designed to inhibit the action of VEGF. VEGF is a distress signal released from ailing cells of the aging retina. VEGF can cause formation of brittle blood vessels that leak blood and cause scar formation under the fovea. The fovea is central area of the retina where reading vision is located. Wet AMD is a very frequent cause of loss of reading vision.

Results show impact on public health

One of the authors behind the Danish study, Michael Larsen, Professor of Clinical Ophthalmology at the University of Copenhagen, is excited about the results.

“The massive implementation of modern wet AMD therapy has been a challenge. It is therefore very important that we can now show an impact on public health and it is wonderful to see a reduction in severe visual loss. The study did not examine moderate visual loss, but there are undoubtedly also a lot of people who avoided loosing their drivers licence and their reading vision,” says Michael Larsen.

A turning point in eye care

The data for the study is provided by Danish Association of the Blind, which membership enrolment during the period of 2000-2010 was charted and categorised by diagnoses.

“The reduction in new cases of blindness is a turning point for eyecare in Denmark. We look forward to seeing further progress in eye research, especially in the hereditary eye diseases that cause blindness in children and young adults,” says Thorkild Olesen, Chairman of the Danish Association of the Blind. 

The retinal pigment epithelium (RPE) cells were developed by the US stem cell company Advanced Cell Technology (ACT), and the trials were conducted at the Jules Stein Eye Institute at the University of California, Los Angeles. The report appeared online in The Lancet on Monday 23 January.

Both trials are designed as prospective “open label” trials to test the safety and tolerability of sub-retinal transplantation of RPE cells made from stem cells derived from human embryos.

As well as these two trials taking place in the US, another trial for SMD is just starting in the UK, and the first patient was treated at Moorfields Eye Hospital in London last Friday.

The researchers write in The Lancet:

“It has been 13 years since the discovery of human embryonic stem cells (hESCs). Our report provides the first description of hESC-derived cells transplanted into human patients.”

The apparent success of the trials, which at best showed that vision improved slightly, and at worst, that it did not deteriorate and there were no adverse safety issues, could signify a major boost to the field of stem cell research which has found itself in the doldrums lately.

And in this particular case, they offer hope to millions of people with AMD, whose numbers are increasing every year. In the US alone, the number of people with AMD is estimated to reach 2.95 million by 2020, according to the Centers for Disease Control and Prevention (CDC).

Macular degeneration, often called age-related macular degeneration (AMD), is an eye disorder associated with aging where people’s vision becomes less sharp and they gradually lose central vision, which is essential every day tasks such as reading and driving.

AMD affects the macula, the middle part the retina that allows the eye to see fine details. There are two forms of AMD, wet and dry. And although dry is by far the most common form of AMD, unfortunately drugs are only available for wet AMD.

Dr Robert Lanza is the chief scientific officer of ACT and the senior author of the paper. He told the press the “safety and engraftment data to date look very encouraging”, and that despite the progressive nature of Stargardt’s macular dystrophy (SMD) and AMD:

In a move that could revolutionize the way we think of hands-free communication, scientists have invented a bionic contact lens that could display real-time news, emails and text messages only millimeters from your retina.

“People may find all sorts of applications for it that we have not thought about,” Babak Parviz, UW assistant professor of electrical engineering said in a research announcement poste on the department’s website. “Our goal is to demonstrate the basic technology and make sure it works and that it’s safe.”

In the joint study between the University of Washington and Aalto University in Finland, researchers safely tested the bionic display contact lenses on rabbits for up to 20 minutes with no adverse effects.

According to TIME magazine, the anesthetized animals could tolerate the wearable contact lensesfor short periods of time while showing no abrasions or thermal burning.

Photo courtesy of the University of Washington
To create the bionic contacts, scientists installed a single LED light and wireless antenna into the contact lens, which is made from delicately thin materials, according to the Daily Mail.

But scientists still have plenty of hurdles to clear before they can can bring the Terminator-like lenses to the market. The device’s small size means researchers only have enough space for one LED, making the display of complex information much more difficult.

Another challenge is powering the microscopic circuits inside the lens. Currently, the lens can only function if it stays within centimeters of its wireless battery.

“Our next goal is to incorporate some predetermined text in the contact lens,” Praviz said in an interview with the BBC.

The study comes at a time when scientists are similarly looking to develop an alternative pain-free device to monitor glucose levels of diabetics by utilizing a sensor to read eye whites or tears.

BRAND NAME: Latisse, Lumigan

DRUG CLASS AND MECHANISM: Bimatoprost is a synthetic (man-made) drug that resembles and mimics the effects of natural chemicals (prostaglandins) produced by the body. It is used for reducing intraocular pressure (IOP) and increasing the growth of eyelashes. The exact mechanism of action is unknown. Bimatoprost may reduce IOP by increasing the outflow of aqueous humor from the eye of individuals with narrow angle glaucoma. Excessive aqueous humor may cause optic nerve damage and visual loss. It may increase eyelash growth by increasing the duration of the growing phase of the eyelash. The FDA approved Lumigan in March 2001 and Latisse in December 2008.