Eye Drops for Cataracts

A Future Alternative to Cataract Surgery?

A cataract illustration

Scientists in California are investigating a naturally occurring steroid called lanosterol that could be used one day to treat cataracts. It may be possible one day to simply use lanosterol in the form of a topical eye drop to reduce cataract development. The cost of lanosterol drops would be much lower than the cost of cataract surgery. Millions of dollars are spent by patients, insurance companies and government health care to pay ophthalmologists and co-managing optometrists to remove cataracts surgically.

Lanosterol eye drops could potentially be a safe, non-invasive alternative to cataract surgery in patients that have moderate forms of cataracts

What Are Cataracts?

A cataract is a clouding or loss of transparency in the natural lens of the eye. The human lens is composed of crystalline proteins. When young and healthy, these proteins act to keep the lens clear. Cataracts develop because as we age, these proteins become disrupted, clump together and break down. Cataracts affect vision and cause images to appear cloudy, fuzzy or blurry similar to looking through a foggy window. Cataracts are the leading cause of blindness among people older than 55. Gradual cataract development occurs as a part of the normal aging process and it is rare to find a complete absence of a cataract in older individuals.

Cataracts can occur more severely or prematurely in some people. Cataracts can be caused by taking certain medications, such as prednisone steroids.

Cataracts can also be caused by other types of eye surgery, such as retinal surgery. Health conditions such as diabetes can cause cataracts to develop at a much earlier age. Habits such as smoking can cause more severe cataracts than in someone that does not smoke. Also, babies can be born with congenital cataracts.

Cataract Surgery

Cataracts are usually treated by cataract surgery. Cataract surgery involves extracting the cataract and inserting a new, clear lens implant in its place. The procedure is usually performed under local anesthesia on an outpatient basis, taking less than an hour in most cases. During cataract surgery, an ophthalmologist removes the cataract by ultrasound or laser and inserts a new intraocular lens implant.

Lanosterol and Cataracts

Scientists discovered lanosterol’s cataract reducing ability by studying two children that had an inherited condition in which they developed cataracts at an early age. These children shared a genetic mutation in which their bodies blocked the production of lanosterol. Interestingly, their parents lacked this mutation and never developed cataracts. The scientist surmised that lanosterol functions to keep the human lens clear by stopping the breakdown and clumping of the normally clear proteins in the lens.

The scientist first tested their theory on human lens cells.

The studies showed that when lanosterol was applied to the cells, lens proteins stopped clumping and transparency increased. Next, they studied rabbits suffering from cataracts. After administering lanosterol for six days, 85% of the rabbits had a significant lessening of the severity of their cataracts. Cataracts in dogs were also investigated. Black Labrador Retrievers, Queensland Heelers and Miniature Pinschers, all dogs with significant naturally occurring cataracts, responded in similar fashion as the rabbits.

Lanosterol was able to significantly shrink the size of the cataracts and improve lens transparency. Scientists caution that more research is needed before deeming the drops a reliable and viable treatment for cataracts in humans. However, it could be a very exciting discovery. Because cataract is a condition that will most likely affect almost all of us, we will probably hear more about lanosterol soon.

Source: Zhao L, Chen X, Zhu J. Lanosterol reverses protein aggregation in cataracts. Nature, 2015.

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