Tag Archives: Ophthalmology

Half the world will need glasses by 2050

Nearly half the world’s population, close to some 5 billion people, will develop myopia by 2050 according to a study recently published in the journal Ophthalmology. The paper also estimates that one-fifth of these people will have a significantly increased risk of becoming permanently blind from the condition if recent trends continue.

"Can you come a bit closer? I can't see you yet." Image via flikr @ Paul Stevenson.

“Can you come a bit closer? I can’t see you yet.”
Image via flikr @ Paul Stevenson.

The number of myopia cases is rapidly rising across the globe, making it one of the most common sight-impairment conditions of the modern world. This increase is attributed to “environmental factors (nurture), principally lifestyle changes resulting from a combination of decreased time outdoors and increased near work activities, among other factors,” according to a new study from Brien Holden Vision Institute, University of New South Wales Australia and Singapore Eye Research Institute.

Even worse, if the current trends continue, the paper warns that we’ll see a seven-fold increase in cases from 2000 to 2050. Myopia will also become one of the leading causes of permanent blindness by that date.

But why? Short-sightedness has always been around but never at the scale this study predicts.

It’s mostly due to the way we use our eyes today. For most purposes, our eyes are good at spotting far away objects, but they have been mostly relegated to short distance duty nowadays. Our daily activities involve a lot of “near work activities,” such as using a computer, scrolling on a smartphone or reading. Constantly keeping focus on a short distance leaves the crystalline lens in our eyes set on them, in a sense, and unable to effectively focus on objects farther away.

The authors point out that this has become a major public health issue, one that we’ll have to tackle — preferably sooner rather than later. They suggest that planning for comprehensive eye care services is needed to manage the rapid increase in high myopes (a five-fold increase from 2000), along with the development of treatments to control the progression of myopia and prevent people from becoming highly myopic.

“We also need to ensure our children receive a regular eye examination from an optometrist or ophthalmologist, preferably each year, so that preventative strategies can be employed if they are at risk,” said co-author Professor Kovin Naidoo, CEO of Brien Holden Vision Institute. “These strategies may include increased time outdoors and reduced time spent on near based activities including electronic devices that require constant focussing up close.

“Furthermore there are other options such as specially designed spectacle lenses and contact lenses or drug interventions but increased investment in research is needed to improve the efficacy and access of such interventions.”

Yea so….I’d say investing in the glasses industry will probably net you a nice return in a few years.

But there is an upside to this paper. Don’t want myopia? Drop your laptop and spend some time in the park. Put your smartphone in your pocket and look at the city as you walk to work or school. You might even end up having fun.

The full paper, titled “Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050” is available online in the journal Ophthalmology here.

 

(c) Nickolay Lamm

How cats see the world (with pictures)

As a cat owner myself, I’ve often wondered how feline vision differs from that of humans. Clearly, with their huge pupils and crocodile-like eyes, their view of the world must be truly different from ours. Artist Nickolay Lamm recently showcased a project that features various photos from two points of view: the human and the cat. While not the most realistic take on how cats see, these photos offer an interesting glimpse on how felines see.

(c) Nickolay Lamm

(c) Nickolay Lamm

To alter his photographs in a way similar to how a cat would see, Lamm consulted with ophthalmologists at the University of Pennsylvania’s veterinary school and a few other animal eye specialists. For each photo, the top view is an unfiltered photograph that portrays what we humans normally see, while the bottom view shows the same photo from the cat’s perspective.

(c) Nickolay Lamm

(c) Nickolay Lamm

You might notice that cat vision is much more blurry than ours. Cat’s see really well in the dark, but for this, they had to sacrifice fine details and some colours to be able to see well in low-light conditions. Also, notice that the cat’s vision is slightly broader than ours.  That’s because cats see 200 degrees compared to our 180 degrees.

(c) Nickolay Lamm

(c) Nickolay Lamm

Cats don’t see very well at a distance. While human vision is perfectly adapted for seeing sharply 100 feet away, cats barely can distinguish fine details past 20 feet. Apparently, kitties miss out on the beauties of foreground landscapes.

Nickolay Lamm

(c) Nickolay Lamm

But no matter, kitties are fine with seeing in the dark. Cat eyes have much more rods than humans – photoreceptor cells in the retina – which allows them to absorb more light and see better in low-light conditions. Their elliptical pupils can open very wide in dim light, but contract to a tiny slit to protect the sensitive retina from bright light.  Ever took a picture of a cat only to see afterward that it looked like the spawn of Satan, with fire blazing from its eyes? This Terminator-feel happens because cats have what’s called an atapetum lucidum – a reflective layer that bounces light that hits the back of the eye out through the retina again for a second chance to be absorbed by the rods, which allows them to see even better at night.

via PopSci

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Artificial Cornea Saves Eyesight

 

cornea

With the growing number of people with eye problems it is harder and harder to find answers to problems raised;  some cases are so bad that there is no other sollution and a cornea transplant is needed. Every year, in Germany alone, around 7000 people wait for a new cornea to save their eyesight. The bad thing is that there are not nearly that many around.

In an EU project, researchers have developed an artificial cornea which is to be clinically tested in early 2008. A man who has a damaged or worse cornea because of a congenital malformation, hereditary disease or corrosion is at risk of going blind, and often the only solution is to implant a donor cornea. Many attempts have therefore been made at producing artificial corneas, so far with little success. This is due to the conflicting requirements imposed; it has to grow firmly but the cells have to deposit themselves at the center of the cornea, as this impairs the patient’s vision.

The research scientists at the Fraunhofer Institute for Applied Polymer Research (IAP) in Potsdam and the Department of Ophthalmology at the University Hospital of Regensburg have worked with other colleagues in the EU-funded CORNEA project and they have found a solution.

“Our artificial corneas are based on a commercially available polymer which absorbs no water and allows no cells to grow on it,” says IAP project manager Dr. Joachim Storsberg. “Once our partner Dr. Schmidt Intraokularlinsen GmbH has suitably shaped the polymers, we selectively coat the implants: We lay masks on them and apply a special protein to the edge of the cornea, which the cells of the natural cornea can latch onto. In this way, the cornea implant can firmly connect with the natural part of the cornea, while the center remains free of cells and therefore clear.”

They have tested the corneas in the laboratory and found that their cells graft very well at the edge. This means that the optical center of the implant manages to stay clear. The first implants have already been tested in rabbits’ eyes and the results are very good so humans are probably going to benefit from this.