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How many medications should be tried to lower IOP before moving on to SLT or glaucoma filtering surgery?
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Use laser procedures first
 Nils Loewen |
My first choice is almost always SLT, no matter what age group. It is easier on the patient in the long term, it is cheaper and more effective, and it provides more physiologic 24-hour pressure control by enhancing trabecular outflow. The dreaded medication compliance, one of the most important reasons for treatment failure, is a non-issue, and the daily reminder of having a chronic disease when taking drops is not there. Ocular and periocular changes that come with eye drops (lash growth, pigmentation, redness, allergy) are a problem as well.
If I have to use eye drops, I do not use more than two for the same reasons. In addition, we can presently only reduce aqueous humor production and increase uveoscleral outflow. As a result, any third eye drop only adds a tiny fraction (single digit percentage) to pressure lowering. Perhaps that will change once we have eye drops for clinical use that increase trabecular outflow (eg, Rho-kinase inhibitors) and do not have unpleasant side effects (eg, pilocarpine).
Because glaucoma is a 24-hour disease with highest eye pressures in the very early morning, I prefer prostaglandin analogues and carbonic anhydrase inhibitors that work around the clock and have complementary mechanisms. Beta-blockers and alpha-2 agonists do not work at night and should not be used at the end of the day. (It is a little known fact that although both use different surface receptors, both function via the same intracellular pathway.)
Nils Loewen, MD, PhD, is director of the Glaucoma Fellowship Program at Yale.
Offer a choice between laser and medication
 Joel S. Schuman |
I tell patients that there are different ways of treating their glaucoma. I explain that they can take drops, which have low risk but need to be used every day for the rest of their lives. I explain that the most commonly used first-line medication does not have many systemic effects, but it has side effects that are unusual and affect only the eye. Their eye color may turn brown, which is a permanent change. I also warn them that they might see longer, thicker, darker eyelashes, and the skin around the eye may become darker, but these changes may reverse if they were to stop taking the drug.
The other option is to use laser. I explain the risks with that as well. It works for about 70% of people for at least 1 year, for about 50% of people for 5 years and for about 30% of people for 10 years. It can be repeated if necessary. Risks include inflammation and swelling of the eye, the pressure can go up instead of down, and there can be scarring in the tissue that is treated. The chance of any of those complications is low, but they can occur.
If patients ask, “What would you do?” I tell them that if it were me, I would probably undergo a laser procedure, knowing that it may eliminate the need to take drops every day.
If the patient opts for medications, I will start with a prostaglandin and then add a beta-blocker. After that, I switch the beta-blocker to a fixed combination. A third bottle reduces compliance; however, if the patient still opts against having a laser procedure, I will try a fourth medication.
Once the patient is at maximum-tolerated treatment and has undergone a laser procedure, I will recommend surgery if there is progressive glaucoma damage. In cases in which the patient’s optic nerve shows very bad damage and IOP is above 30 mm Hg, I will go to the OR based on that, even without documentation of progression. Otherwise, I would wait to detect significant field progression.
Joel S. Schuman, MD, FACS, is an OSN Glaucoma Board Member, chairman of the Department of Ophthalmology at the University of Pittsburgh and director of the UPMC Eye Center.