New drug treats cataracts without the need for surgery
[July 14, 2022: Jamie Forsyth, Anglia Ruskin University]
Cataract is a clouding of the eye lens that develops over time and affects the quality of vision. (CREDIT: Creative Commons)
A revolutionary new treatment for cataracts has shown extremely positive results in laboratory tests, giving hope that the condition, that currently can only be cured with surgery, could soon be treated with drugs.
The results have been published today in the peer-reviewed journal Investigative Ophthalmology and Visual Science.
According to the World Health Organization (WHO), 65.2 million people worldwide are living with cataracts, the leading cause of blindness and vision impairment worldwide.
Cataract is a clouding of the eye lens that is caused by a disorganisation of the proteins in the lens that leads to clumps of protein forming that scatter light and severely reduce transmission to the retina. This often occurs with age, but can also be caused by the eye’s overexposure to the sun or injury, as well as smoking, medical conditions such as diabetes, and some medications.
Surgery can correct the condition by replacing the lens with an artificial one.
A team of international scientists, led by Professor Barbara Pierscionek, Deputy Dean (Research and Innovation) in the Faculty of Health, Education, Medicine and Social Care at Anglia Ruskin University (ARU), have been carrying out advanced optical tests on an oxysterol compound that had been proposed as an anti-cataract drug.
The compound oxysterol, is an oxygenated derivative of cholesterol that plays a role in the regulation and transport of cholesterol.
This means that the protein organisation of the lens is being restored, resulting in the lens being better able to focus. This was supported by a reduction in lens opacity in 46% of cases.
The researchers tested an assortment of 35 wild mice and mice genetically altered to develop lens cloudiness through an alteration of their αB-crystallin or αA-crystallin proteins.
In the right eye of 26 mice, the researchers administered a single drop of an oxysterol compound, VP1-001Trusted Source, directly onto the ocular surface. Meanwhile, they gave a neutral drop of cyclodextrin in their left eyes. Nine mice were left untreated as a control group.
The target of the treatment was the αA- and αB-crystallin mutations that often cause cataracts in aging.
The treatment with the oxysterol compound VP1-001 showed an improvement in refractive index profiles – a key optical parameter that is needed to maintain high focusing capacity – in 61% of lenses. They also observed a 1.0 improvement in the opacity grade of 46% in the treated mice.
Slit lamp images of eyes from mice of different genotypes. Representative slit lamp images show the extent of lens opacity in WT lenses aged (a) 255 days, (b) 493 days, and (c) 738 days with apparent cataract gradings of 1.0, 4.0, and 3.0, respectively. The 493-day-old WT lens is compared in d with 416-day-old Cryaa-R49C-Het lenses (e and f); both had lower apparent cataract gradings than the WT 493-day-old lens. The 493-day-old WT lens is compared in g with 402-day-old Cryab-R120G-Het lenses (h and i) and in j with 449-day-old Cryab-R120G-Hom lenses (k and l). The apparent cataract gradings for the Cryab-R120G-Het lenses were lower than in the WT lens; the Cryab-R120G-Hom lenses were very opacified and had the same apparent grading as the WT lens. Images shown are of OS (a, b, d, g, h, i, k, j) and OD (c, e, f, l) lenses. The nasal side is on the left side of the image in OS lenses and on the right side of the image in OD lenses. (CREDIT: journal Investigative Ophthalmology and Visual Science)
Professor Pierscionek, who is also a member of the Medical Technology Research Centre at Anglia Ruskin University (ARU) , said: “This study has shown the positive effects of a compound that had been proposed as an anti-cataract drug but never before tested on the optics of the lens. It is the first research of this kind in the world.
“It has shown that there is a remarkable difference and improvement in optics between eyes with the same type of cataract that were treated with the compound compared to those that were not.
“Improvements occurred in some types of cataract but not in all indicating that this may be a treatment for specific cataracts. This suggests distinctions may need to be made between cataract types when developing anti-cataract medications. It is a significant step forward towards treating this extremely common condition with drugs rather than surgery.”
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Note: Materials provided above by Anglia Ruskin University. Content may be edited for style and length.
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