The Effect of Body Posture on Intraocular Pressure in Progressive Glaucoma

Glaucoma is a condition where the optic nerve (the nerve responsible for sight) shows progressive damage with characteristic loss of visual field. Glaucoma is very commonly associated with raised pressure in the eye (intraocular pressure \[IOP\]). IOP has been shown to increase when lying down in normal subjects as well as patients with glaucoma. It is possible that this effect can make glaucoma worse. This study is designed to investigate the effect of body posture (particularly when sleeping) on the IOP fluctuation in the eye. Each patient will be required to attend for 2 separate 24 hour visits. On one visit the patient will be required to sleep flat and on the other visit at a 30° head up sleeping position. During this time the patient will be required to wear a soft contact lens (SENSIMED Triggerfish®) which has a special sensor on it that monitors the IOP continuously. The IOP measurements are wirelessly transmitted to a recorder.