Primary Open-Angle Glaucoma (cont.)

Current medical therapy for primary open-angle glaucoma is limited toward lowering intraocular pressure.

The ideal drug for treatment of primary open-angle glaucoma should effectively lower intraocular pressure, have no side effects, and be inexpensive with once-a-day dosing; however, no medicine possesses all of the above. When choosing a medicine for you, your ophthalmologist prioritizes these qualities based on your specific needs.

Medicines are classified according to their chemical makeup and how they affect the eye. For primary open-angle glaucoma, the major drug classes include the following:

• Alpha-agonists
  
  
• Beta-blockers
  
  
• Carbonic anhydrase inhibitors
  
  
• Miotics
  
  
• Prostaglandin analogs

Alpha-agonists, beta-blockers, and carbonic anhydrase inhibitors reduce the amount of fluid (aqueous humor) in the eye, whereas prostaglandin analogs and miotics increase the outflow of aqueous humor from the eye.

These medicated eyedrops are prescribed to help lower increased intraocular pressure. Sometimes, more than 1 medicine is needed. See Understanding Glaucoma Medications.

Initially, your ophthalmologist might have you use the eyedrops in only one eye to see how effective the drug is in lowering the pressure inside your eye. If it is effective, then your doctor will most likely have you use the eyedrops in both eyes. See How to Instill Your Eyedrops.

Once a medicine is prescribed, you have regular follow-up visits with your ophthalmologist. The first follow-up visit is usually 3-4 weeks after beginning the medicine. Your pressures are checked to ensure the drug is helping to lower your intraocular pressure. If the drug is working and is not causing any side effects, then it is continued and you are reevaluated 2-4 months later. If the drug is not helping to lower your intraocular pressure, then you will stop taking that drug and a new drug will be prescribed.

Your ophthalmologist may schedule your follow-up visits in accordance with the particular drug you are taking, because some medicines (eg, latanoprost [Xalatan], travoprost [Travatan], bimatoprost [Lumigan]) may take 6-8 weeks to be fully effective.

During these follow-up visits, your ophthalmologist also observes you for any allergic reactions to the drug. If you are experiencing any side effects or symptoms while on the drug, be sure to tell your ophthalmologist.

Generally, if the pressure inside the eye cannot be lowered with 1-2 medicines, surgery may be necessary (see Surgery).