The most frequently reported treatment-related side-effect was ocular hyperaemia, which was reported in 35% to 50% of patients. Approximately 3% of patients discontinued treatment due to conjunctival hyperaemia. The following undesirable effects assessed as definitely, probably or possibly related to treatment were reported during clinical trials with TRAVOPROSTIN. Their incidence was either very common (greater than 10.0%), common (1.0% to 10%), or uncommon (0.2% to less than 1.0%). All other effects were single reports, of which none were serious or related.