Cataracts: eye drops instead of surgery
Luise Heine has been an editor at since 2012. The qualified biologist studied in Regensburg and Brisbane (Australia) and gained experience as a journalist in television, in the Ratgeber-Verlag and in a print magazine. In addition to her work at , she also writes for children, for example for the Stuttgarter Kinderzeitung, and has her own breakfast blog, “Kuchen zum Frühstück”.
More posts by Luise Heine All content is checked by medical journalists.Gray veils and dull contrasts - in many older people, cataracts cloud the lens of the eye and thus the vision. So far, the only treatment option has been to replace the lens with an artificial one. But that could change: Researchers want to develop eye drops that are applied locally to clear the fog in the eye.
It's still a long way off, but Jason Gestwicki from the University of California-San Francisco and his colleagues are confident that surgical lens changes for cataracts will soon be a thing of the past. It has long been known that a substance called lanosterol can help clear vision.
Cells in rank and file
To understand this effect, you have to take a closer look at the structure of the eye lens. There are crystalline fibers whose job it is to bundle the light and direct it to the retina. "Shortly after you are born, the cells there lose the ability to produce new proteins," explains Gestwicki. So that the fibers remain transparent and flexible over the years and do not clump together, they have small auxiliary proteins, the so-called chaperones.
Taxi molecule
However, the efficiency of the proteins decreases more and more with age, the result: the order of the fibers gets mixed up, light can penetrate the lens more difficultly, the vision becomes cloudy. Lanosterol can reverse these processes and bring order back into the cells - but until now it was only possible to get the active ingredient into the lens by injecting it directly into the lens. However, Gestwicki and his colleagues have now found a kind of “taxi” molecule. His name: "Component 29".
This substance is the result of an extensive search that started with over 2,400 different substances. Component 29 is water-soluble and can therefore be used in the form of eye drops. With the help of component 29, the active ingredient lanosterol can diffuse from the surface of the eye directly to the place where it is happening, into the lens of the eye.
Increased transparency
The researchers have already tested precisely such eye drops on mammals. They were given the drops twice a day for six weeks. After this period, the transparency of the lens was markedly improved. Experiments with human lens cells in a culture medium also showed promising results. The scientists are now preparing clinical studies to test the effects on humans. Only when these have been completed can it be approved as a drug. But at least ten years will pass before that happens.
Widespread signs of aging
Cataract is an eye disease in which eyesight is steadily decreasing. The frequency with which cataracts occur increases with age. Cataracts affect almost half of all 52 to 64 year olds, even if they often do not notice any symptoms. From the age of 65, the lenses of the eyes are cloudy in almost everyone, but only about 50 percent are so pronounced that their vision is noticeably impaired. If left untreated, cataracts can lead to blindness.
Update 2020: Unfortunately, several subsequent studies could not prove the mentioned effect. For example, a paper from 2019 that cites three other studies in this regard. Therefore, according to the current state of knowledge, cataract surgery remains the only option for sustainable visual improvement if affected adults are impaired in everyday life by the visual disturbances of progressive cataracts.
Source: Leah N. Makley et al. Pharmacological chaperone for α-crystallin partially restores transparency in cataract models. Science, 6 November 2015: 674-677 DOI: 10.1126 / science.aac9145
