by Dr. Robert Benza, MD
10. January 2014 09:24

How do glaucoma drops work? Why are there so many different types of glaucoma drops? How are they different? These are some of the questions we frequently hear from our patients. To have a better understanding, lets talk about how the eye works in regard to eye pressure.
The eye is a closed system. It constantly produces a fluid and drains a fluid. Why do some patients have a higher eye pressure than other patients? In most patients with higher eye pressures, the drainage system doesn't work as well. Using a sink and faucet analogy, when turned on, the faucet will continually run fluid into the sink. If the drain works well, the sink will drain. If you place a paper towel over the drain, the sink will build up with fluid. In a closed system, when the drain is less functional, the fluid build up causes a higher pressure.
How do the eye drops work? There are two common mechanisms which allow glaucoma drops to work. They can reduce the amount of fluid production ("turn down the faucet") or they can help open the drainage system to allow better outflow. For years, the most common medicines used were topical beta blockers (example: timolol) which decreased the amount of fluid production. In recent years, prostaglandin medicines (Xalatan, Travatan, Lumigan) have dominated the market due to their ability to open the drain and successfully decrease eye pressure. They also tend to have less systemic side effects. There are other types of eye drops as well which may have a dual
mechanism.
If you have elevated eye pressure, it is very important to see your eye care professional on a regular basis. Compliance with these type of patients is important since they are at risk for side vision loss (peripheral vision) which can be vision threatening over time. There are often no symptoms so the patient may be unaware of their problem. Today, glaucoma drops are better than ever and can definitely slow the progression of the disease.
Remember, protect those eyes!