When pressure in the eye increases, it can cause damage to the retina (the light-sensitive membrane at the back of the eye) and to the optic nerve that sends signals from the eye to the brain. This can result in serious vision loss and even blindness. 

The active substance in Catiolanze, latanoprost, is a prostaglandin analogue (a man-made version of a prostaglandin, substances naturally found in the body). In the eye, prostaglandins increase the drainage of the watery fluid (aqueous humour) out of the eyeball. Catiolanze acts in the same way and increases the flow of fluid out of the eye. This helps to reduce the pressure inside the eye and reduces the risk of damage to the retina.