Glaucoma is one of the leading causes of blindness. The cause of eye damage in some otherwise healthy eyes is a raised pressure within the eye, (the intraocular pressure), that can damage the nerve over a period of time and this damage results in poor blood supply or weak end eye structure. Its caused when raised pressure inside the eyeball damages the optic nerve leading to the brain. Fluid enters and leaves the eyeball all the time - it's when it drains away too slowly that pressure increases.
A team of researchers at University of Texas found that this is the first to assess the long-term effect of eye drops that lower the eyeball (intraocular) pressure on those at risk of glaucoma. They examined 1,502 people aged between 45 and 82 who had increased intraocular pressure - placing around half on a regime of daily eye drop treatment. The drops contain a medication known to lower the pressure. The rest were closely monitored by eye specialists, but did not receive eye drops.
At the end of the five year study, only 4.5 per cent in the eye drop group had developed glaucoma, compared to 8.2 per cent of the controls. Researchers felt that it is an impressive finding, given that the eye drops lower intraocular pressure by just 25 per cent.