Medical Management of Glaucoma

Abstract

The medical management of glaucoma has exponentially evolved over the last two decades. Since pilocarpine was first used to treat glaucoma over 100 years ago, and acetazolamide’s use in glaucoma started in 1954, followed by beta-blockers in the 1970s, topical carbonic anhydrase inhibitors, alpha-adrenergics, prostaglandin analogs and prostamides, and finally nitric oxide-releasing compounds and rho kinase inhibitors have all been released into the market in the last 20 years.

Standard of care still dictates that medications should be tried first, prior to proceeding with laser or surgical treatments that include risk of complications, mild or severe. Maximal medical therapy is a common term used to indicate that the patient has reached the maximal amount of medications that are tolerable and practical to use daily for treatment. This includes consideration for cost, lifestyle, as well as local and systemic side effects.

Most ophthalmologists start treatment with one of the first-line therapy approved agents: a beta-blocker once daily in the morning or a prostaglandin analog once daily at night, depending on training, personal experience, and patient’s medical history. Both medication classes have a generic compound.

Realistically, any medication can be used for first-line therapy, but the remainder classes are usually second-line therapy. The alpha-adrenergic brimonidine, available as generic, is currently the most commonly used drug for normal pressure glaucoma in view of its likely neuroprotection. Carbonic anhydrase inhibitors dorzolamide, also available as a generic, and brinzolamide are also a regular second line and very additive to the other classes. Brimonidine and dorzolamide are available as fixed combination with timolol and with each other. The latter, available as a suspension, was the only combination product without timolol, until the most recent addition of the netarsudil-latanoprost combination.

The rho kinase inhibitors and nitric oxide-releasing molecules, which entered the US market in 2018, are the first new medication class since the early 2000s, when the prostaglandins revolutionized glaucoma medical treatment. Naturally, these medications are under patent, which increases cost for the patients and healthcare market. In the current climate where the need to contain healthcare costs is front and center, there might be a delay in widespread experience with the new compounds, unless their efficacy and safety profile continues to deliver as promised.