Eye drops will replace cataract surgery
Researchers at the University of California at San Diego have demonstrated that instilling a solution containing the natural steroid lanosterol into the eyes reduces the severity of cataract manifestations in dogs.
The lens of the eye consists mainly of crystallin proteins that perform two main functions: ensuring the ability of the eye to change the focal length and maintaining the transparency of the lens. The exact mechanisms that allow crystallins to perform these functions are not clear to date.
Cataract, which is the cause of 51% of cases of blindness in the world, is a disease that develops mainly in old age, characterized by a violation of the fine structure of crystallins and the formation of protein aggregates that reduce the transparency of the lens. To date, the gold standard of cataract treatment is the surgical replacement of a clouded lens with an artificial one.
In addition to crystallins, the lens contains a fairly large amount of lanosterol, a molecule that is an important building block of many steroid hormones. Lanosterol is synthesized by the enzyme lanosterol synthase.
The authors drew attention to lanosterol after they discovered that all children with a hereditary form of cataract are carriers of the same mutation that blocks the activity of lanosterol synthase. They suggested that under normal conditions, a high concentration of lanosterol prevents the formation of protein aggregates in the lens.
To test their hypothesis, the scientists conducted three series of experiments on cell cultures and animal models.
At the first stage, in experiments on human lens cells, researchers demonstrated that the addition of lanosterol to culture suppresses the formation of aggregates of cataract-forming proteins. After that, they showed that the effect of lanosterol on the affected lenses of rabbits in vitro reduces the severity of cataracts and increases the transparency of the lenses.
Finally, a lanosterol-containing solution was tested on dogs with simulated cataracts. Both injections and instillation of the drug into the eyes of animals provided the expected effect – reducing the manifestations of cataracts and increasing the transparency of the lens.
The authors hope that over time, lanosterol-containing eye drops will become a worthy alternative to surgical intervention, inaccessible to many people in developing countries due to the high cost and the possibility of undesirable side effects and complications.
Article by Ling Zhao et al. Lanosterol reverses protein aggregation in cataracts is published in the journal Nature.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to Medical News Today:
Cataracts may be treatable with eye drops instead of surgery.
Cataracts may be treatable with eye drops instead of surgery.
24.07.2015