Glaucoma
First-line therapies

The biggest obstacle towards the improvement of glaucoma treatment may be identifying people early in the disease, before any real visual field damage has been done. “If we don’t catch them until late in the course of the disease, nothing works as well as when you catch them early,” Dr. Singh said.
Prostaglandins are presently the first-line therapy for most glaucoma specialists, said Dr. Noecker, and they’ve had small, incremental changes over the past few years, most notably changing the preservative used to improve tolerability.
Combination drugs, typically a prostaglandin and a beta blocker, “on a compliance and formulary-covered cost level are very positive,” Dr. Noecker said.
What concerns him is the upcoming year, when the prostaglandins will begin to have competition from generic equivalents. “Some patients are not going to do well with the generic,” he said. “They’re going to have to stay on the branded product.”
Generic timolol has moved to second-line therapy, he said. “In parts of the country, it has a $4 per bottle cost to the patient. It’s the lowest you’ll ever pay for a glaucoma drug. And that changes the way we think about what to prescribe.”
The influx of generic competition to all other classes of drugs except the prostaglandins “has changed what we prescribe when there’s a fairly large cost difference,” Dr. Noecker said. Formulary status of a particular drug plays a role in how it’s prescribed as well, he added.
“Adding a beta blocker to a prostaglandin is not an effective means for significantly reducing the pressure more,” Dr. Mundorf said, noting the major pharmaceutical companies all have studies showing an additional 2 mm Hg decrease is typical when adding the beta blocker.
“By going to an alpha agonist or carbonic anhydrase inhibitor (CAI) topically as the second adjunctive drug will add another 4 or 5 point drop,” he said. When the combination drugs were first introduced, Dr. Mundorf said he would add Alphagan first, then Trusopt/Azopt, and then a beta blocker.
“Now I go to the combination drugs first for the quickness. Getting an additional 2 mm Hg drop initially is welcomed. Take Combigan, for instance. It’s the same co-pay as Alphagan P, but you’re getting the beta blocker for free,” he said.
Additionally, the allergy rate in the combination drug is “about 5%; for Alphagan P it’s about 9%, and Alphagan 0.15% is about 10%. If a patient has never seen the Alphagan molecule, I debate on the combination drug,” he said.
With Cosopt, Dr. Mundorf said he’s found adding a CAI “can be a little bit better pressure in the afternoon than Combigan.”
Taking a prostaglandin daily over the course of five years has been shown to maintain the IOP reductions from baseline without significant tachyphylaxis, Dr. Singh said.
“Despite the limitations of taking drops daily, if the goal is prevention of functional vision loss, drops do appear to work. The most important thing we need to remember is that practically speaking, non-compliance with therapy is not much different than lack of drug efficacy. In either case, you will generally need to move on to the next step.” he said.
Glaucoma specialists see a skewed glaucoma population and must be careful not to forget the big picture, he added.
“Despite all the supposed limitations of our therapeutic approaches, most patients receiving therapy for glaucoma in the United States do quite well and only a small proportion go blind.” Dr. Singh said.