Childhood blindness: improving treatment of cataracts

Published on 22 November 2011

Each year, up to 200,000 of the world’s children lose their sight to cataracts.¹ Although surgery can restore their vision, virtually every child who has surgery develops a complication called posterior capsule opacity (PCO), sometimes known as ‘secondary cataracts’. This can lead to further eyesight problems and even blindness, meaning children have to undergo more procedures. Professor John Marshall, from University College London, aims to stop children from developing PCO by improving cataract surgery.

What is the problem and who does it affect?

Around half a million children are born or become blind each year worldwide – roughly one child every minute.¹ Up to 39 per cent of these children have cataracts.¹

“Most people will get a cataract if they live long enough,” explains Professor John Marshall. “Cataracts in very young children and babies are thankfully very rare. However, when cataracts do develop early on in life, it is traumatic for the child, as they cannot see, and it is equally traumatic for the parents.”

The only treatment for cataracts is surgery. Sadly, a condition called posterior capsule opacity (PCO), or secondary cataracts, is virtually inevitable after children undergo this type of surgery.

“Children with secondary cataracts have cloudy areas on the lens of the eye which, if left untreated, can lead to further problems with their eyesight and even blindness,” says Professor Marshall. “Children therefore have to undergo yet more procedures, which are technically difficult and bring a risk of further complications. Unfortunately, some children keep on developing secondary cataracts, meaning they have to undergo repeated procedures. There is an urgent need to find a better way to treat cataracts in children.”

What is the project trying to achieve?

Professor Marshall aims to improve cataract surgery in children, by developing a way to stop them from getting secondary cataracts.

Cataract surgery involves removing the eye’s lens and replacing it with an artificial one. “It’s not normally possible to remove every last bit of the lens,” explains Professor Marshall. “A few cells tend to be left behind, which grow and cause secondary cataracts.”

The team is developing a way to remove more of the cells during surgery using chemicals that make the cells burst. They are perfecting the procedure in the laboratory, using cultures of human cells, in preparation for the start of clinical trials.

“If it works, our technique could bring huge cost savings to the NHS,” says Professor Marshall. “It could bring huge savings in emotion for the children’s parents and, most importantly, it could mean children have to undergo just a one-off operation instead of repeated procedures.”

What are the researchers’ credentials?

Professor Marshall is part of a group that received £26 million of government funding - for Moorfield’s Eye Hospital and University College London’s Institute of Ophthalmology. “The money from the government allows us to create the infrastructure, says Professor Marshall, “and funding like this from Action Medical Research is absolutely wonderful because it helps with more targeted research, dealing with very specific problems like cataracts in children.”

The members of the project team are all world leaders in their individual areas of expertise. Professor Marshall, for example, pioneered laser eye surgery to correct short sightedness, a ground-breaking treatment that has now been used over 35 million times.

References

1. Wilson ME et al. Childhood blindness and paediatric cataract. Cataract and refractive surgery today 2005; October: 52-4.