A major clinical trial proves widely prescribed eye drops prevent sight loss in glaucoma.

Published (Updated )

Prostaglandin analog eye drops, the most commonly prescribed treatment for glaucoma, have been proven to reduce risk of vision loss in people with open angle glaucoma (OAG) according to research led by academics at Moorfields Eye Hospital and City University London.

The study, which is published in The Lancet, is the first placebo-controlled trial to assess their vision-preserving effect and could make a major impact in fight to prevent one of the leading causes of blindness.

"Medication to lower raised eye pressure has been used for decades as the main treatment for OAG to delay progressive vision loss. But, until now, whether the most frequently prescribed class of drugs have a protective effect on vision was not known", explains David Garway-Heath, lead author and Professor of Ophthalmology at Moorfields Eye Hospital, London, UK.

David Crabb, co-author and Professor of Statistics and Vision Research at City University London, helped design the innovative testing and monitoring regime used in the trial. Commenting on the research, he said:

"Professor David Crabb's study could make a major impact in fight to prevent one of the leading causes of blindness."

"Glaucoma is normally a slow acting disease and observation periods in trials are long. We shortened this trial with the novel use of more frequent testing of patient's vision and the use of precise statistical tests. This trial sets a new benchmark for speeding up novel drug development, reducing costs of trials and increasing the likelihood of bringing new drugs to patients."

OAG is the most common form of glaucoma affecting more than 500 000 people in England and Wales and about 45 million worldwide. Vision loss from glaucoma occurs when the optic nerve is damaged. In most cases, increased pressure inside the eye (intraocular pressure), is thought to contribute to this damage.

To assess the effectiveness of the medication, the United Kingdom Glaucoma Treatment Study (UKGTS) recruited 516 newly diagnosed, previously untreated individuals with OAG from 10 hospitals across the UK. Half were randomly assigned to daily pressure-lowering eye drops and the other half to a matching placebo. Over the course of 2 years, participants underwent frequent visual field tests to measure the rate of glaucoma progression.

The study found that the risk of visual deterioration was over 50% lower in the group treated with daily pressure-lowering eye drops compared to those using placebo drops over 2 years. Importantly, because of the trial design, a significant difference in treatment effects could be seen between the groups after just 12 months.

Professor Crabb added: "This clinical trial was a true national effort involving several clinical centres from around the UK. Glaucoma research in the UK has an outstanding international reputation and our work at City is placed firmly within it."

For full Article and Comment see The Lancet.

Definition: Glaucoma

Describes a group of ocular (eye) disorders resulting in optic nerve damage or loss to the field of vision, in many patients caused by a clinically characterized pressure buildup in regards to the fluid of the eye (intraocular pressure-associated optic neuropathy).