Dog eye lens with cataracts before lanosterol treatment (left) and after lanosterol treatment (right). Photos courtesy of Zhao et al./Nature.
Friday, July 31, 2015
New steroid-based eye drops clear up cataracts
Cataracts cause vision problems and blindness in tens of millions of people worldwide. So far, the only treatment is surgery. Now, new research led by opthalmogologists and engineers at UC San Diego shows a promising alternative treatment using eye drops made from a naturally occurring steroid in the human body.
Cataracts form when proteins in the eye lens, called crystallins, become malformed and clump together, clouding vision. The crystallin proteins malform either from aging, environmental factors, or genetic mutations. In this study, researchers identified a root cause for cataract formation and demonstrated a new potential remedy that doesn’t bring patients under the knife.
The team, led by Kang Zhang, a professor in the Department of Opthalmology and affiliated with the Department of NanoEngineering at UC San Diego, came up with the key ingredient for the eye drops after genetically screening children from two related families with an inherited form of cataracts. The studies revealed that these children share a genetic mutation that shuts down the production of lanosterol, a steroid that’s normally present in cataract-free eyes. With this finding, the team investigated whether lanosterol helps to prevent or clear up cataracts.
The researchers tested lanosterol on dogs with cataracts, first with an eye injection of lanosterol-loaded nanoparticles, followed by daily treatment with lanosterol eye drops. Over the course of six weeks, they observed that the cataracts in the dogs had decreased in size. The lanosterol eye drops also reduced cataracts in human lens cells and rabbit lenses, which were both grown in Petri dishes.
NanoEngineering professor Liangfang Zhang, a co-corresponding author on the study who worked on developing the lanosterol-loaded nanoparticles, said that the researchers are aiming to move this study to clinical trials.
The findings were published in the July 30 issue of Nature.