Cataracts Affect Sleep and Cognitive Function, Says Study
June 2015 If you've been feeling tired and sleepy during the day, maybe it's time to get that cataract surgery you've been putting off. A recent study found that people with cataracts often experience poor sleep quality.
Advanced cataracts can reduce the amount of light that reaches the retina in the back of the eye, and this may cause an abnormal circadian rhythm that affects sleep. Removing the cataracts lets the light come into the eyes again, which may bring circadian rhythm and sleep quality back to normal.
Besides improved sleep efficiency, patients in the study also had a 33 percent lower chance of being diagnosed with cognitive impairment. According to the researchers, people who have disturbed sleep patterns are more likely to be cognitively impaired.
The study, which took place in Japan, was presented at the annual meeting of the Associated Professional Sleep Societies this month.
Penny Pusher Game Shows How Cataracts May Form
March 2015 In a penny pusher arcade game, the player drops a coin on a moving platform that contains other coins. Coins fall off the edge of the platform onto a lower one, and if the player timed his drop correctly, then coins eventually accumulate where the player can collect them.
Researchers studied mouse eyes for nearly four years to see how their lens cells grow and found similarities to the penny pusher game.
The cells tended to multiply in a narrow line on the lens surface, pushing neighboring cells toward the equator of the lens. Cells already at the equator were pushed away from the surface, into the center of the lens.
Since the penny pusher-style cell movement is relatively orderly, the eye maintains its shape over time, for consistent vision.
Cataracts (lens cloudiness) may start as mutations in a few cells, and the penny pusher model may explain the growth of the cataract over time.
"We are currently examining whether mutations in the DNA of individual lens cells can be transmitted to large numbers of lens cells, potentially influencing the clarity of the tissue and resulting in cataract," said Steven Bassnett, PhD, of Washington University School of Medicine, Department of Ophthalmology and Visual Sciences.
A full report of this study appears in the latest issue of Investigative Ophthalmology & Visual Science .
New DNA Test Quickly Diagnoses Cause of Congenital Cataracts
October 2014 An advanced test that quickly identifies the different DNA mutations that can cause congenital cataracts in children has been developed.
Prior to this DNA test, doctors diagnosed the rare diseases that result in congenital cataracts through extensive family health reports and numerous costly clinical assessments that were often inconclusive.
Using "next-generation" DNA sequencing, researchers at the University of Manchester, in collaboration with Manchester Royal Eye Hospital, were able to diagnose the exact genetic cause of congenital cataracts in 75 percent of the cases in only a few weeks. Because congenital cataracts can appear as a symptom of hundreds of rare diseases, be inherited, or arise from a maternal infection, knowing the exact cause helps doctors tailor care and begin treatment or counseling right away.
Currently the test is available in the U.K., but registered facilities can request it through international referral, according to the American Academy of Ophthalmology.
A full report of this study appears in the September issue of Ophthalmology.
Is It Worth It for Someone with Alzheimer's to Undergo Cataract Surgery?
July 2014 The notion that cataract surgery for someone with Alzheimer's or other type of dementia is unnecessary, too risky or too stressful for the patient is going by the wayside. New evidence shows that improved vision after cataract surgery enhances both cognition and quality of life.
According to a clinical study presented at the Alzheimer's Association International Conference 2014 this month, both dementia patients and their caregivers benefit when the patient can see better.
By and large, the patients are more mobile, can function better and demonstrate slower memory decline than those who don't have needed cataract surgery.
The stance of the Alzheimer's Association is that people with dementia have the right to any medical treatment available, including cataract surgery.
Which Are Better for Infants After Cataract Surgery: Contact Lenses or Intraocular Lenses?
July 2014 If your child has surgery to remove a cataract, should he or she wear a contact lens for vision correction? Or does it make more sense to have an intraocular lens (IOL) implanted at the time of the surgery?
Normally, both adults and children receive IOLs during cataract surgery. But according to a recent clinical trial funded by the National Eye Institute (NEI), for most babies, using contact lenses for a few years and having lens implants later could work better.
During the trial, contact lenses were safer and just as effective as implants for infants under 7 months old. But it was important that their families be able to manage the contact lens wear, monitoring it to make sure the contacts stayed in place and were cleaned and removed per their eye doctor's instructions.
For some parents, the discomfort of contact lens application and removal makes the contact lens option impractical. And a few contact lens-wearing children in the study developed minor eye infections, though they cleared up with antibiotic eye drops.
In general, children may undergo IOL implantation at all ages some may be infants or toddlers, while others may be entering adulthood. Problems with IOLs include potential post-operative complications that could require more surgery, and the difficulty for a surgeon to choose the best focusing power of an IOL for a baby, since the eyes are still growing at that age.
On the other hand, the expense of contact lenses could be an issue for some families (IOLs are usually covered by health insurance).
While the NEI study challenges some long-held assumptions, ultimately the choice of contacts or IOLs is something that parents must discuss with their child's eye surgeon. L.S.
Cataract Surgery Lowers Risk of Falls
May 2014 The risk of falling increases with age for just about everyone. But with the poor vision that a cataract brings, that risk increases dramatically.
A study of more than 400 Vietnamese people aged 50 or more with cataracts in both eyes looked at how many falls each person had before and after undergoing cataract surgery.
In the year after surgery on one eye, the risk of a fall decreased by 78 percent.
The results suggest that waiting for a cataract to worsen before having it removed increases the possibility of a fall, so it may be wiser not to wait.
The study was presented this month at the annual meeting of the Association for Research in Vision and Ophthalmology.
Stopping Smoking May Lower Risk of Cataracts
January 2014 Researchers in Sweden have released findings from a study of smokers that shows decreased levels of smoking may lower cataract risk.
Researchers followed nearly 45,000 Swedish men and found a gradual drop in cataract risk among former smokers: 20 years after quitting, their risk had fallen by about half.
The researchers found that smokers of more than 15 cigarettes a day had a 42 percent increased risk of cataract extraction compared with men who had never smoked. They also found that men who had smoked an average of more than 15 cigarettes a day but had stopped smoking more than 20 years earlier had a 21 percent increased risk.
For men who had been lighter smokers, the increased risk of cataract fell more quickly after quitting, but never reached the level of those who had never smoked.
The researchers also published a study in 2005 detailing the relationship between smoking cessation and cataract risk in women. Women who smoked six to 10 cigarettes a day but had ceased smoking 10 years earlier, and women who smoked more than 10 cigarettes a day but had ceased smoking 20 years earlier, were found to have a relative risk of cataracts not significantly different from women who had never smoked.
But for women who smoked more, it took 20 years before cataract risk was no longer greater than for women who had never smoked, the study concluded.
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[Page updated March 21, 2016]