From the Los Angeles Time, Dec 29'2010
Nintendo's 3DS video game system might be hazardous to the health of children younger than 6, according to a warning posted Wednesday on the Japanese video game company's website.
"Vision of children under the age of 6 [is in] the developmental stage," Nintendo's warning said, according to a Google translation of the website. "Nintendo 3DS, 3-D, including 3-D movies and television, delivers 3-D images with different left and right eye images," which "has a potential impact on the growth of children's eyes."
The 3DS is the gaming giant's latest version of its DS line of handheld video game consoles. The feature of the 3DS that separates it from Nintendo's popular other DS systems: It can handle 3-D gaming and movies, displaying the depth-adding effect without requiring users to wear 3-D glasses.
Although Nintendo is advising that only the preschool crowd refrain from using the new system's 3-D feature, it also recommends in its note that all players -- children and adults -- should take breaks from its glasses-free 3-D gaming every 30 minutes, or whenever a user feels sick.
The 3DS will also have a "3-D volume" sliding button that will let users tone down the level of depth of 3-D images, the notice said
It also said the 3DS would have a parental control feature that could restrict the console's screens to traditional 2-D images. Games, movies and other media displayed in 2-D will be safe for gamers younger than 6, the Nintendo warning said.
There is "enough for everyone to enjoy," it said.
Nintendo is set to release the 3DS in Japan on Feb. 26 for about $300. The 3DS is to arrive in U.S. stores in March, the company has said; a price hasn't yet been announced.
The 3DS isn't Nintendo's first try at 3-D video games. In 1995 the company released the Virtual Boy, which had two LED screens that displayed black and red 3-D effects in a viewfinder-like device.
The Virtual Boy didn't catch on. It was discontinued in 1996 and is one of Nintendo's few console failures.
Thursday, December 30, 2010
Friday, December 24, 2010
Canadian breakthrough in cataract treatment
Tuesday, Dec 21, 2010
The Canadian company Vision Rejuvenation™ Victoria (British Columbia) has become the first centre in Canada to implant the world’s first light adjustable intraocular lens.
The Calhoun Vision LAL® lens was implanted by Dr. Lawrence Brierley, surgeon and medical director at Vision Rejuvenation. Dr. Brierley is involved in a clinical study through Health Canada to determine the safety and effectiveness of the lens and the light delivery device.
The main problem with cataract surgery is that it is difficult to precisely determine in advance what lens power the patient needs. The patient has to live with the visual problems resulting from any errors or undergo further surgical procedures. The light adjustable lens is the solution to this problem. Once the eye has healed after surgery, the patient’s ability to see near and far is assessed and a light source is applied to change the shape of the lens.
“This breakthrough technology is one of the greatest advances in cataract surgery in years. I have been waiting all my life for the sort of precision that this lens allows me,” says Dr. Brierley. “It is like having an insurance policy that ensures accurate and precise outcomes based on specific patient requirements.”
The Canadian company Vision Rejuvenation™ Victoria (British Columbia) has become the first centre in Canada to implant the world’s first light adjustable intraocular lens.
The Calhoun Vision LAL® lens was implanted by Dr. Lawrence Brierley, surgeon and medical director at Vision Rejuvenation. Dr. Brierley is involved in a clinical study through Health Canada to determine the safety and effectiveness of the lens and the light delivery device.
The main problem with cataract surgery is that it is difficult to precisely determine in advance what lens power the patient needs. The patient has to live with the visual problems resulting from any errors or undergo further surgical procedures. The light adjustable lens is the solution to this problem. Once the eye has healed after surgery, the patient’s ability to see near and far is assessed and a light source is applied to change the shape of the lens.
“This breakthrough technology is one of the greatest advances in cataract surgery in years. I have been waiting all my life for the sort of precision that this lens allows me,” says Dr. Brierley. “It is like having an insurance policy that ensures accurate and precise outcomes based on specific patient requirements.”
Friday, December 17, 2010
Scientists May Have Partially Reversed Age-Related Degeneration In Mice.
SUNDAY, Nov. 28 (HealthDay News) -- U.S. scientists say they have partially reversed age-related degeneration in mice, leading to new brain and testes growth, improved fertility and the return of lost cognitive function, or thinking skills.
The advance in aging science was achieved by working with telomerase genes in the mice, said the team at the Dana-Farber Cancer Institute in Boston.
The researchers developed mice with a controllable telomerase gene. (Telomerase is an enzyme that helps maintain telomeres -- the protective "caps" on the ends of chromosomes.) As people age, low levels of telomerase lead to progressive erosion and shortening of the telomeres, resulting in physical and mental decline, the study authors explained in a news release from the institute.
Creating mice with a controllable telomerase switch enabled the scientists to create prematurely aged mice. The switch also enabled the team to determine that reactivating telomerase in the mice could restore telomeres and reduce the signs and symptoms of aging.
In addition, the mice did not show signs of cancer -- a key concern because cancer cells can use telomerase to make themselves virtually immortal. Researchers noted that this is an important area of study for future investigation.
In the future, it may be possible to use this approach to treat people with conditions such as rare genetic premature aging syndromes, in which shortened telomeres play an important role, said study senior author Dr. Ronald A. DePinho, director of Dana-Farber's Belfer Institute of Applied Cancer Science.
"Whether this would impact on normal aging is a more difficult question," he said in the news release. "But it is notable that telomere loss is associated with age-associated disorders and thus restoration of telomeres could alleviate such decline."
DePinho also said the study may lead to new directions for regenerative medicine because the findings suggest that dormant adult stem cells in extremely aged tissues remain viable and can be reactivated to repair tissue damage.
"If you can remove the underlying damage and stresses that drive the aging process and cause stem cells to go into growth arrest, you may be able to recruit them back into a regenerative response to rejuvenate tissues and maintain health in the aged," he said in the release.
The study was released online in advance of publication in an upcoming print issue of the journal Nature.
The advance in aging science was achieved by working with telomerase genes in the mice, said the team at the Dana-Farber Cancer Institute in Boston.
The researchers developed mice with a controllable telomerase gene. (Telomerase is an enzyme that helps maintain telomeres -- the protective "caps" on the ends of chromosomes.) As people age, low levels of telomerase lead to progressive erosion and shortening of the telomeres, resulting in physical and mental decline, the study authors explained in a news release from the institute.
Creating mice with a controllable telomerase switch enabled the scientists to create prematurely aged mice. The switch also enabled the team to determine that reactivating telomerase in the mice could restore telomeres and reduce the signs and symptoms of aging.
In addition, the mice did not show signs of cancer -- a key concern because cancer cells can use telomerase to make themselves virtually immortal. Researchers noted that this is an important area of study for future investigation.
In the future, it may be possible to use this approach to treat people with conditions such as rare genetic premature aging syndromes, in which shortened telomeres play an important role, said study senior author Dr. Ronald A. DePinho, director of Dana-Farber's Belfer Institute of Applied Cancer Science.
"Whether this would impact on normal aging is a more difficult question," he said in the news release. "But it is notable that telomere loss is associated with age-associated disorders and thus restoration of telomeres could alleviate such decline."
DePinho also said the study may lead to new directions for regenerative medicine because the findings suggest that dormant adult stem cells in extremely aged tissues remain viable and can be reactivated to repair tissue damage.
"If you can remove the underlying damage and stresses that drive the aging process and cause stem cells to go into growth arrest, you may be able to recruit them back into a regenerative response to rejuvenate tissues and maintain health in the aged," he said in the release.
The study was released online in advance of publication in an upcoming print issue of the journal Nature.
Vodka eyeball shots a dangerous way to imbibe
By Elizabeth Weise, USA TODAY
College students have long done crazy things, from swallowing gold fish to jamming themselves into telephone booths. Not all things they try are dangerous, but some are.
Two new cases in point: consumption of controversial alcoholic energy drinks likely to be banned today; and a bizarre method of trying to get plastered by absorbing alcohol through the eyeball.
The eyeball shots don't succeed and definitely fall in the category of risky behaviors, experts say.
"This is an activity that has no upside to it," says David Granet, a professor of ophthalmology at the University of California, San Diego.
The theory among the students seems to be that alcohol can be absorbed through mucous membranes, and the eyeball and inner side of the eyelids are covered in mucous membrane, so, voila!— vodka eyeball shots. There are more than 30 homemade videos of young men doing this on YouTube.
Not only does it fail to get someone drunk, "it hurts and it will cause permanent damage to the surface of the eye," Granet says.
Ophthalmologists have been speaking out against this trend ever since it appeared on U.S. campuses last spring. According to the American Academy of Ophthalmology, it appears to have begun in England.
"There is absolutely, positively nothing that can be construed as fun about this," Granet says.
These kinds of stunts are "a normal reflection of this developmental stage," says Paul Lyons, a professor of community medicine at Temple University School of Medicine in Philadelphia. Drinking pranks are really just experimentation by young adults who are not at full adult decision-making capacity, he says.
Another generally ineffectual means of becoming inebriated is the use of vodka-soaked tampons for both women and men (used as suppositories for males). No videos of this were found on YouTube.
Other less popular, but still Internet-flogged methods, include putting vodka in an asthma atomizer so it can be inhaled (no videos found) and snorting it (more than 300 videos).
What has changed is that the Internet now allows stupid behaviors to be amplified in ways they couldn't easily be before, Lyons says. For example, there's no epidemic of students punching themselves in the face, but there are more than 20 videos of youths doing so online.
Online sources such as Facebook and YouTube can distort social norms.
Research has shown that students overestimate how much their peers are drinking, says Laura Talbott, professor of health education at the University of Alabama-Birmingham.
College and university administrations are working hard to create peer programs to counteract the attention such social media can give to rare and destructive behaviors, says Talbott, who chairs the American College Health Association's Alcohol and Other Drug Coalition.
As the Internet amplifies what might otherwise be a stunt by a few students, marketers are entering the scene, says Peter Lake, a professor of higher education law at Stetson University law school in Gulfport, Fla.
"There are industries now that try to make money on this. They realize this is a susceptible group and they can market to it with products that more mature individuals wouldn't choose," he says.
College students have long done crazy things, from swallowing gold fish to jamming themselves into telephone booths. Not all things they try are dangerous, but some are.
Two new cases in point: consumption of controversial alcoholic energy drinks likely to be banned today; and a bizarre method of trying to get plastered by absorbing alcohol through the eyeball.
The eyeball shots don't succeed and definitely fall in the category of risky behaviors, experts say.
"This is an activity that has no upside to it," says David Granet, a professor of ophthalmology at the University of California, San Diego.
The theory among the students seems to be that alcohol can be absorbed through mucous membranes, and the eyeball and inner side of the eyelids are covered in mucous membrane, so, voila!— vodka eyeball shots. There are more than 30 homemade videos of young men doing this on YouTube.
Not only does it fail to get someone drunk, "it hurts and it will cause permanent damage to the surface of the eye," Granet says.
Ophthalmologists have been speaking out against this trend ever since it appeared on U.S. campuses last spring. According to the American Academy of Ophthalmology, it appears to have begun in England.
"There is absolutely, positively nothing that can be construed as fun about this," Granet says.
These kinds of stunts are "a normal reflection of this developmental stage," says Paul Lyons, a professor of community medicine at Temple University School of Medicine in Philadelphia. Drinking pranks are really just experimentation by young adults who are not at full adult decision-making capacity, he says.
Another generally ineffectual means of becoming inebriated is the use of vodka-soaked tampons for both women and men (used as suppositories for males). No videos of this were found on YouTube.
Other less popular, but still Internet-flogged methods, include putting vodka in an asthma atomizer so it can be inhaled (no videos found) and snorting it (more than 300 videos).
What has changed is that the Internet now allows stupid behaviors to be amplified in ways they couldn't easily be before, Lyons says. For example, there's no epidemic of students punching themselves in the face, but there are more than 20 videos of youths doing so online.
Online sources such as Facebook and YouTube can distort social norms.
Research has shown that students overestimate how much their peers are drinking, says Laura Talbott, professor of health education at the University of Alabama-Birmingham.
College and university administrations are working hard to create peer programs to counteract the attention such social media can give to rare and destructive behaviors, says Talbott, who chairs the American College Health Association's Alcohol and Other Drug Coalition.
As the Internet amplifies what might otherwise be a stunt by a few students, marketers are entering the scene, says Peter Lake, a professor of higher education law at Stetson University law school in Gulfport, Fla.
"There are industries now that try to make money on this. They realize this is a susceptible group and they can market to it with products that more mature individuals wouldn't choose," he says.
Thursday, December 9, 2010
Great-Grandmother Says She Has Some Eyesight Back After Undergoing Stem-Cell Treatment In China.
By Daily Mail Reporter
Last updated at 12:22 AM on 2nd November 2010
'When I got back to Heathrow Airport last Wednesday I could see such a lot. It was unbelievable,' said Dorothy.
'The other day I saw a crow on the fence in my garden and had to check with people that I could actually see it but I did see it. It is amazing.
'The doctors said it could take another six months to a year before my sight gets as good as it will be, but it is much better already. It was definitely worth it.'
Dorothy's plight began when she woke up one morning in February last year to discover she had gone blind.
She was diagnosed with giant cell arteritis, an inflammatory disease of blood vessels.
Doctors in the UK said they could not restore her sight, but the Chinese hospital said it offered pioneering stem cell treatment that could restore her vision.
Stem cells are the very early cells that can develop into almost all other types of cell and tissue.
Dorothy went through a course of daily wave therapy and acupuncture, with weekly stem cell injections, for 43 days before arriving back home to her husband Percival in Springfield, Hardwicke.
Dorothy's main aim is to see her two-year-old great grandson Chris this Christmas.
The mother-of-four, grandmother-of-seven and great-grandmother of two, said: 'I really looking forward to being able to see Chris.
'As soon as his parents can get here to visit I am hoping to see him. They live on the army camp so it might be a little while, but I'm keeping my fingers crossed.'
Well wishers had organised parachute jumps, bingo evenings and fun days to raise the money to send Dorothy on her trip.
Dorothy added: 'I am so pleased that everyone helped to raise this money. It is so wonderful that everybody did it for me. I really couldn't have done it without them.'
Her daughter Vicky, who kept a blog on the experience, said she and her mother went to Qingdao Hospital where her treatment was overseen by Dr Tony Lao.
'The main treatment was a weekly injection of stem cell fluid taken from umbilical cords at a maternity centre in Beijing and flown to Qingdao,' she said.
'Mum had to have two injections of the fluid into her right eye without anaesthetic, one of which was very painful. There were also six injections of fluid into her hand.
'Every day she had wave therapy, which involves electrical impulses to stimulate the parts of the brain involved. And she had acupuncture every day with one needle in the top of her head, two in her wrists, two in her knees and two in her ankles.
'The hospital has become known throughout the world for this treatment that it has been performing since 2004. We met other patients there who had flown in from Brazil, Canada and America for it.
'Mum has good days and bad days with her sight now. She can see shapes and bright lights and on some days much more than that. One day when we were out there she was able to see the writing on a sign quite clearly.
'The doctor said she should hopefully get steadily better over the next six to 12 months. After a year her sight will probably be as good as it's going to get.'
Monday, December 6, 2010
The cheap reading glasses that can damage your sight
By Sean Poulter
Last updated at 1:08 AM on 31st October 2010
They may save you money in the short term but cheap reading glasses could end up costing your eyesight.
The so-called ‘ready readers’, which sell for as little as £1 in high street shops, may leave wearers with eye strain, headaches or even blurred or double vision.
Millions have bought them after baulking at the high cost of buying glasses from an optician.
However, research suggests they could be putting their eyesight and health at risk.
By the age of 50, most adults have problems reading a book or newspaper without spectacles.
So the arrival of the cheap glasses in supermarkets, high street stores and market stalls less than ten years ago has been seen as a saviour for many
A consumer might have to pay more than £100 for a pair of reading glasses from an optician, which might easily be lost or broken.
Instead, many buy several cheap versions to stash around the house so that they can always find a pair.
A researcher at consumer champion Which? checked 14 pairs from seven high street chains.
He found problems with half of them, with those carrying a higher prescription – +3.5 to +4 – considered to cause the most concern. ‘Off-the-peg glasses could cause eye strain, blurred vision, headaches or double vision,’ the Which? researcher said.
‘For people with higher prescriptions, they’re not suitable for walking or other mobile activities.’
They could even ‘cause a nasty accident’, he warned.
The biggest problem is that the centre point of the two lenses might not be aligned.
This means the sight in one eye might be clear while the other is blurred. This was the case in a pair from Poundland – which also had a prescription strength that differed from the +3.5 on the pack – and a £16 pair from fashion eyewear store Sight Station.
‘This could cause eye problems or a head tilt,’ the researcher said.
A £4 pair from Tiger were ‘unwearable’ because the centre point of the lenses did not match, while a £2 pair from Primark had ‘a very large difference’.
A £15 pair from Marks & Spencer were so ‘poorly made’ that the lenses were likely to drop out.
Which? advises people who have a prescription above +2 to test reading glasses for two minutes to check the centre points of each lens are aligned correctly.
Opticians say eye examinations are essential before buying glasses.
As well as ensuring the correct prescription is used, they can detect serious health issues, such as cataracts and brain tumours.
Last updated at 1:08 AM on 31st October 2010
They may save you money in the short term but cheap reading glasses could end up costing your eyesight.
The so-called ‘ready readers’, which sell for as little as £1 in high street shops, may leave wearers with eye strain, headaches or even blurred or double vision.
Millions have bought them after baulking at the high cost of buying glasses from an optician.
However, research suggests they could be putting their eyesight and health at risk.
By the age of 50, most adults have problems reading a book or newspaper without spectacles.
So the arrival of the cheap glasses in supermarkets, high street stores and market stalls less than ten years ago has been seen as a saviour for many
A consumer might have to pay more than £100 for a pair of reading glasses from an optician, which might easily be lost or broken.
Instead, many buy several cheap versions to stash around the house so that they can always find a pair.
A researcher at consumer champion Which? checked 14 pairs from seven high street chains.
He found problems with half of them, with those carrying a higher prescription – +3.5 to +4 – considered to cause the most concern. ‘Off-the-peg glasses could cause eye strain, blurred vision, headaches or double vision,’ the Which? researcher said.
‘For people with higher prescriptions, they’re not suitable for walking or other mobile activities.’
They could even ‘cause a nasty accident’, he warned.
The biggest problem is that the centre point of the two lenses might not be aligned.
This means the sight in one eye might be clear while the other is blurred. This was the case in a pair from Poundland – which also had a prescription strength that differed from the +3.5 on the pack – and a £16 pair from fashion eyewear store Sight Station.
‘This could cause eye problems or a head tilt,’ the researcher said.
A £4 pair from Tiger were ‘unwearable’ because the centre point of the lenses did not match, while a £2 pair from Primark had ‘a very large difference’.
A £15 pair from Marks & Spencer were so ‘poorly made’ that the lenses were likely to drop out.
Which? advises people who have a prescription above +2 to test reading glasses for two minutes to check the centre points of each lens are aligned correctly.
Opticians say eye examinations are essential before buying glasses.
As well as ensuring the correct prescription is used, they can detect serious health issues, such as cataracts and brain tumours.
Can Boomers Throw Away Their Reading Glasses?
By John Gever, Senior Editor, MedPage Today
Published: October 25, 2010
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
CHICAGO -- With the baby-boom generation now firmly in the age range when near-range vision goes blurry, advances in refractive surgery and implants could allow many of them to do away with reading glasses, researchers said here.
A series of presentations at the American Academy of Ophthalmology's annual meeting indicated that new types of intracorneal implants and LASIK-like procedures show promise for eliminating presbyopia, the progressive deterioration of near vision that afflicts virtually everyone older than 45.
Among the innovations highlighted at the meeting: a doughnut-shaped corrective lens inserted under the cornea; a thin disk that restricts the pupillary opening, improving depth of focus in the same way as a pinhole camera; and a noninvasive, implant-free laser procedure that cuts concentric rings in the corneal stroma to alter its refractive power.
None of these are yet approved by the FDA.
At a press briefing, Gustavo Tamayo, MD, of the Bogota Laser Refractive Institute in Bogota, Colombia, described in broad strokes the procedures that are available in South America and Europe, which can target the cornea, the sclera, the anterior chamber, or the lens itself.
Many procedures are owned and developed by U.S. companies, though, and eventual FDA approval is expected. Several of these were the focus of scientific presentations at the AAO meeting, including a report from one U.S. clinical trial.
Intracorneal lens
Ioannis Pallikaris, MD, of the University of Crete in Greece, discussed a recent one-year clinical study with an intracorneal bifocal lens called Flexivue.
The implant has a hole in the center, not as part of its refractive design but to aid in centering it over the pupil.
Session discussant Karl Stonecipher, MD, of TLC Laser Eye Center in Greensboro, N.C., noted that "centration" is a major issue for all types of refractive alteration intended to assist the natural lens -- vision will be imperfect and sometimes worse than before if the corrective intervention is even slightly out of alignment with the lens.
Pallikaris said the lens is 20 microns thick and 3 mm in diameter and is inserted into a pocket created within the stroma with a femtosecond laser.
He reported data on 15 patients with a mean age of 51 receiving the implant -- one per patient in the nondominant eye.
Mean baseline near-vision acuity was 20/50. Within one week of the implant, it improved to 20/32, settling at 20/25 by the third month where it remained for the full year of follow-up in the study.
The bifocal lens also provides a focal point for distance vision, to compensate for the impairment of distance vision that otherwise would result from an anti-presbyopic change in corneal refraction.
In the implanted eye, mean uncorrected distance-vision acuity dropped from 20/20 at baseline to 20/40 during the first month, and then recovered to 20/30 at six months.
Pallikaris noted, though, that uncorrected binocular distance vision remained perfect throughout the entire study, because the artificial lens is placed only in the nondominant eye.
He reported that all of the patients reported their uncorrected near vision after the procedure was excellent or good, and 92% had stopped all use of reading glasses.
Light-restricting disk
Another approach alters the eye's optics not with a lens but with a small disk that reduces the effective pupillary diameter to create a pinhole effect.
Daniel Durrie, MD, of the University of Kansas Medical Center and DurrieVision in Overland Park, Kan., explained that the concept is similar to the F-stop setting of a camera that opens and closes the lens aperture.
A small aperture setting increases the so-called depth of field, such that objects both near and far are in focus. Consequently, this product does not impair distance vision and could actually improve it.
He is leading U.S. testing of the implant, called AcuFocus, which in its current version (the third to date) cuts the effective pupillary diameter from about 4 mm under indoor artificial light to 1.6 mm. The reduction in light transmission is 95%.
As with the Flexivue lens, it's implanted in only one eye. Durrie told MedPage Today that patients do notice that the reduction in light transmission, but it doesn't diminish their overall binocular vision.
The disk also contains 8,400 tiny holes, 5 to 11 microns each, to allow ocular fluids to pass back and forth across the implant to anterior tissues.
Durrie said the implant can be placed under a corneal flap or in a pocket. He said he prefers a flap because it eases positioning and removal, if necessary.
He reported three-year follow-up data from 163 patients receiving two earlier versions of the implant, which were somewhat thicker, with a larger aperture (restricting light by 89% and 93%) and fewer, larger holes for fluid porosity.
Unlike the Flexivue lens and other approaches that change the cornea's refractive properties, the Acufocus lens had almost no impact on the distance acuity, Durrie said.
Among 44 patients receiving the product's first version, the average uncorrected near-vision grade was J2 and mean uncorrected distance vision was 20/25.
The second version, which had a smaller aperture than the first, produced mean uncorrected distance vision of 20/20 and an uncorrected near-vision grade of J1 in 119 patients.
Durrie said a U.S. clinical trial with the third version is now under way in 504 patients. The product is already marketed in Europe and Asia, he said.
He indicated that the disk, at least currently, is not color-matched to the patient's iris and therefore is visible in some patients, especially those with blue eyes. He indicated that one patient didn't like the cosmetic effect and demanded the implant's removal.
Laser-etched rings
A third approach is somewhat similar to laser keratotomy, except that it uses a femtosecond laser to make concentric circular cuts in the stroma.
Mike Holzer, MD, of the University of Heidelberg in Germany, said that procedure takes just 20 seconds once everything is set up.
The arrangement of the rings and the stromal depth can be adjusted to achieve the desired refractive correction, he said.
He also noted that it does not involve any incisions in eye's surface, virtually eliminating infection risk.
He described results in 25 patients with a mean age of 56 treated in mid-2008, with up to 24 months of follow-up available.
At baseline, the patients had uncorrected near vision of 0.70 logMAR units (SD 0.16), equivalent to about 20/100.
Three months after treatment, their mean near-vision acuity had improved to 0.20 logMAR units, or about 20/30, Holzer said.
At 12 months, the mean value worsened slightly to 0.30 logMAR, but among patients evaluable at 18 and 24 months, it was back to 0.20.
Most patients evaluated at 24 months had gained five to six lines of uncorrected near acuity on a standard chart relative to baseline, Holzer said, allowing them to read newspapers held at a normal distance without reading glasses.
He noted that the procedure does induce a degree of myopia for distance vision. "The ideal patient should be a little bit hyperopic [at baseline]," he said.
However, there was no diminution of middle-distance acuity, he added.
At the press briefing, Richard Lindstrom, MD, of Minnesota Eye Consultants in Bloomington, Minn., discussed still other approaches involving the lens -- either replacing it entirely with a multifocal synthetic lens as part of cataract surgery, or implanting a so-called phakic intraocular lens that rests on top of the natural lens.
These also are largely development-stage products in the U.S., though they are marketed elsewhere in the world.
Lindstrom said a major consideration for all these treatments is the limited reimbursement available from third-party payers.
He noted that Medicare has ruled out payment for surgeries and implants for acuity problems that could be corrected with glasses, and private insurers have largely followed suit.
Consequently, at least for the near future, baby boomers facing combination problems such as cataracts, myopia, and presbyopia will have to pay for these do-it-all procedures out of pocket.
Lindstrom said such patients therefore have a decision to make, regarding how much they're willing to pay for uncorrected perfect vision versus settling for cheaper procedures that correct some problems but still leave them needing glasses or contact lenses for driving or reading restaurant menus.
Published: October 25, 2010
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner
CHICAGO -- With the baby-boom generation now firmly in the age range when near-range vision goes blurry, advances in refractive surgery and implants could allow many of them to do away with reading glasses, researchers said here.
A series of presentations at the American Academy of Ophthalmology's annual meeting indicated that new types of intracorneal implants and LASIK-like procedures show promise for eliminating presbyopia, the progressive deterioration of near vision that afflicts virtually everyone older than 45.
Among the innovations highlighted at the meeting: a doughnut-shaped corrective lens inserted under the cornea; a thin disk that restricts the pupillary opening, improving depth of focus in the same way as a pinhole camera; and a noninvasive, implant-free laser procedure that cuts concentric rings in the corneal stroma to alter its refractive power.
None of these are yet approved by the FDA.
At a press briefing, Gustavo Tamayo, MD, of the Bogota Laser Refractive Institute in Bogota, Colombia, described in broad strokes the procedures that are available in South America and Europe, which can target the cornea, the sclera, the anterior chamber, or the lens itself.
Many procedures are owned and developed by U.S. companies, though, and eventual FDA approval is expected. Several of these were the focus of scientific presentations at the AAO meeting, including a report from one U.S. clinical trial.
Intracorneal lens
Ioannis Pallikaris, MD, of the University of Crete in Greece, discussed a recent one-year clinical study with an intracorneal bifocal lens called Flexivue.
The implant has a hole in the center, not as part of its refractive design but to aid in centering it over the pupil.
Session discussant Karl Stonecipher, MD, of TLC Laser Eye Center in Greensboro, N.C., noted that "centration" is a major issue for all types of refractive alteration intended to assist the natural lens -- vision will be imperfect and sometimes worse than before if the corrective intervention is even slightly out of alignment with the lens.
Pallikaris said the lens is 20 microns thick and 3 mm in diameter and is inserted into a pocket created within the stroma with a femtosecond laser.
He reported data on 15 patients with a mean age of 51 receiving the implant -- one per patient in the nondominant eye.
Mean baseline near-vision acuity was 20/50. Within one week of the implant, it improved to 20/32, settling at 20/25 by the third month where it remained for the full year of follow-up in the study.
The bifocal lens also provides a focal point for distance vision, to compensate for the impairment of distance vision that otherwise would result from an anti-presbyopic change in corneal refraction.
In the implanted eye, mean uncorrected distance-vision acuity dropped from 20/20 at baseline to 20/40 during the first month, and then recovered to 20/30 at six months.
Pallikaris noted, though, that uncorrected binocular distance vision remained perfect throughout the entire study, because the artificial lens is placed only in the nondominant eye.
He reported that all of the patients reported their uncorrected near vision after the procedure was excellent or good, and 92% had stopped all use of reading glasses.
Light-restricting disk
Another approach alters the eye's optics not with a lens but with a small disk that reduces the effective pupillary diameter to create a pinhole effect.
Daniel Durrie, MD, of the University of Kansas Medical Center and DurrieVision in Overland Park, Kan., explained that the concept is similar to the F-stop setting of a camera that opens and closes the lens aperture.
A small aperture setting increases the so-called depth of field, such that objects both near and far are in focus. Consequently, this product does not impair distance vision and could actually improve it.
He is leading U.S. testing of the implant, called AcuFocus, which in its current version (the third to date) cuts the effective pupillary diameter from about 4 mm under indoor artificial light to 1.6 mm. The reduction in light transmission is 95%.
As with the Flexivue lens, it's implanted in only one eye. Durrie told MedPage Today that patients do notice that the reduction in light transmission, but it doesn't diminish their overall binocular vision.
The disk also contains 8,400 tiny holes, 5 to 11 microns each, to allow ocular fluids to pass back and forth across the implant to anterior tissues.
Durrie said the implant can be placed under a corneal flap or in a pocket. He said he prefers a flap because it eases positioning and removal, if necessary.
He reported three-year follow-up data from 163 patients receiving two earlier versions of the implant, which were somewhat thicker, with a larger aperture (restricting light by 89% and 93%) and fewer, larger holes for fluid porosity.
Unlike the Flexivue lens and other approaches that change the cornea's refractive properties, the Acufocus lens had almost no impact on the distance acuity, Durrie said.
Among 44 patients receiving the product's first version, the average uncorrected near-vision grade was J2 and mean uncorrected distance vision was 20/25.
The second version, which had a smaller aperture than the first, produced mean uncorrected distance vision of 20/20 and an uncorrected near-vision grade of J1 in 119 patients.
Durrie said a U.S. clinical trial with the third version is now under way in 504 patients. The product is already marketed in Europe and Asia, he said.
He indicated that the disk, at least currently, is not color-matched to the patient's iris and therefore is visible in some patients, especially those with blue eyes. He indicated that one patient didn't like the cosmetic effect and demanded the implant's removal.
Laser-etched rings
A third approach is somewhat similar to laser keratotomy, except that it uses a femtosecond laser to make concentric circular cuts in the stroma.
Mike Holzer, MD, of the University of Heidelberg in Germany, said that procedure takes just 20 seconds once everything is set up.
The arrangement of the rings and the stromal depth can be adjusted to achieve the desired refractive correction, he said.
He also noted that it does not involve any incisions in eye's surface, virtually eliminating infection risk.
He described results in 25 patients with a mean age of 56 treated in mid-2008, with up to 24 months of follow-up available.
At baseline, the patients had uncorrected near vision of 0.70 logMAR units (SD 0.16), equivalent to about 20/100.
Three months after treatment, their mean near-vision acuity had improved to 0.20 logMAR units, or about 20/30, Holzer said.
At 12 months, the mean value worsened slightly to 0.30 logMAR, but among patients evaluable at 18 and 24 months, it was back to 0.20.
Most patients evaluated at 24 months had gained five to six lines of uncorrected near acuity on a standard chart relative to baseline, Holzer said, allowing them to read newspapers held at a normal distance without reading glasses.
He noted that the procedure does induce a degree of myopia for distance vision. "The ideal patient should be a little bit hyperopic [at baseline]," he said.
However, there was no diminution of middle-distance acuity, he added.
At the press briefing, Richard Lindstrom, MD, of Minnesota Eye Consultants in Bloomington, Minn., discussed still other approaches involving the lens -- either replacing it entirely with a multifocal synthetic lens as part of cataract surgery, or implanting a so-called phakic intraocular lens that rests on top of the natural lens.
These also are largely development-stage products in the U.S., though they are marketed elsewhere in the world.
Lindstrom said a major consideration for all these treatments is the limited reimbursement available from third-party payers.
He noted that Medicare has ruled out payment for surgeries and implants for acuity problems that could be corrected with glasses, and private insurers have largely followed suit.
Consequently, at least for the near future, baby boomers facing combination problems such as cataracts, myopia, and presbyopia will have to pay for these do-it-all procedures out of pocket.
Lindstrom said such patients therefore have a decision to make, regarding how much they're willing to pay for uncorrected perfect vision versus settling for cheaper procedures that correct some problems but still leave them needing glasses or contact lenses for driving or reading restaurant menus.
Subscribe to:
Posts (Atom)
Posts
