To date, cataracts are the leading cause of legal blindness in the world. The progress is usually quite slow and gradually leads to blurred vision before resulting in significant vision loss. Currently, the only treatment is surgical removal of cataractous lenses. It is known that changes to the proteins in the lens in the eye change in such a way that the lens changes to become yellow or cloudy during cataract formation, as opposed to transparent for people who have normal vision.

A team of researchers at The University of California, San Diego, has made an advancement in non-surgical therapy approaches to prevent or treat cataracts. The researchers identified two distinct homozygous lanosterol synthase (LSS) missense mutations in two families with comprehensive congenital cataracts. Both mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins.

Treatment by lanosterol, in the form of eye drops, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. Furthermore, lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs.

The study was published in Nature, and identified lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Image 1: National Eye Institute
Image 2: Elizabeth Hahn