Testing When Eyes Become Vulnerable to Cataracts
Posted January 21, 2009 11:38 AM
Could it spot cataract-related proteins? His next step is not for the queasy. Ansari bought some calf eyes at a slaughterhouse and got his then-teenage daughter, now a doctor, to dissect the lenses in their kitchen. He stuck them in the refrigerator to test after the cold clouded them over. (Ansari hadn't known that biologists do just that step to create a model of human cataracts.)
When he warmed up the lenses and beamed his device, light scattering differed with the lens' changing opacity. It was time to ask eye specialists if the technique might allow usable alpha-crystallin measurement.
It took over a decade of laboratory and animal testing, but the result is a machine that does just that -- by aiming Ansari's special laser at the lens for five seconds and then calculating light scattering.
In last month's Archives of Ophthalmology, National Institutes of Health researchers reports tests of 235 people ages 7 to 86. Alpha-crystallin decreased steadily both as lenses began to fog and as people with seemingly clear lenses got older.
"What we are really looking at is the reserve of this alpha-crystallin," Ansari explains. It can "repair any damage if there is a certain concentration. If it depletes below that level then I think the game is over."
What next? NASA and NIH researchers separately are planning to study if special formulations of antioxidants -- nutrients that fight certain age-related tissue damage -- can slow alpha-crystallin loss.
Ansari also plans to measure the impact of long-term space travel on astronauts' vision.
Already, Datiles has used the test to diagnose cataracts beginning in some patients whose doctors found no other reason for their worsening vision.
And at Hopkins, ophthalmologist Dr. Walter Stark is using it to help tell if some patients complaining that their LASIK surgery for nearsightedness is wearing off need more vision-sharpening surgery -- or if they're really forming a cataract, which LASIK can't fix. Also, researchers are testing diabetics with a cataract-speeding eye disorder.
"This test does correlate significantly with cataract formation," Stark says. "We think it has great potential."
Source: , Associated Press/AP Online
Comments
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Posted January 23, 2009 4:23 PM
As an ophthalmologist (eye surgeon) I would only embrase this instrument as a "curiosity" because, at this point, we do not have medicines, additives, or treatments that will prevent the growth and progression of a cataract. The way in which a cataract presents, initially, and along the way to "maturity" is that the patients vision alters, deteriorates. Much of the time vision can be improved with a refraction, the measurment of the eys, and the prescription of a new prescription for glasses or contact lenses. However, at some point, almost inevitably, a time will be reached when NO change of spectacle will help to clarify the vision, and if the patient wishes to see more clearly, cataract surgery is in order. Cataract surgery is (probably) THE most frequently performed (major) surgery in the USA, and has a very high rate of success, with a small, but real rate of complications. Anyone who has reached the point where spectacles are of no more help in seeing clearly should consult with an ophthalmologist (eye surgeon) for evaluation and possible removal of the cataract IF it's a cataract that caused the decrease in vision. As people mature they not only develop cataracts, but also macular degeneration, and removing the cataract in a person with age related macular degeneration willl NOT improve their overall visual acuity.... if you are a patient with cataracts, seek out someone who is an excellent surgeon, rated by good post op results seen in your friends, and make an appointment to be evaluated...Good Luck to you.
UteCityDoc
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