Thank you for your question regarding the eye symptoms experienced by your boyfriend's father. I am sorry he is experiencing itchy, watery, and red eyes. I recommend that you speak with an ophthalmologist
. Latanoprost, or Xalatan, is a medication known as a prostaglandin analog which works to lower the pressure in the eyes. Glaucoma is a condition when the pressure in the eyes becomes high, putting the optic nerve at risk for damage. With continued high eye pressures, the optic nerve can become damaged and can compromise vision. One condition that can be particularly dangerous is acute closed angle glaucoma. This is when the angle in the eye necessary for fluid drainage becomes closed off, resulting in a sudden, very high increase in the eye pressures. When developing a red eye in a patient with glaucoma, it is important to consider this condition; however, closed angle glaucoma would be extremely painful and cause a patient to seek medical attention. It is likely that your boyfriend's father is simply experiencing symptoms of conjunctivitis, or pink eye. Ketotifen eye drops are antihistamine drops that help relieve symptoms of pink eye caused by allergies. These drops are safe to use with latanoprost, as they will not further increase the eye pressure. However, if the eye symptoms do not dissipate within a few days, please seek an ophthalmologist for further investigation.