Chronic glaucoma used to be the most common cause of registered blindness in the UK. Nowadays thanks to better and more universal eye care and to better treatments it is no longer so prevalent.
Glaucoma develops when the pressure within the eye is sufficiently raised to stop essential nutrients getting out of the capillaries into the retina. As a consequence some of the nerve cells in the retina die off and glaucoma patients develop typical visual field defects. The central vision is rarely affected but the area around the central part – about 15 degrees out from the centre – becomes much less sensitive and possibly loses vision all together.
If the pressure rises suddenly – as in an attack of acute glaucoma – then the eye becomes painful and the cornea hazy with a very large oval pupil. This is quite a rare condition, one which a typical optometrist might see five to ten times in a career.
Chronic glaucoma is usually treated by eye drops to reduce the pressure in the eyes whereas acute glaucoma often needs surgery, which is usually done with a laser.
Measuring the pressure in the eye is now part of the routine eye exam that every adult patient receives in our practice. We have a very small, lightweight handheld instrument that beeps as it takes a measurement without you even feeling it.