What do soul musician Ray Charles, astronaut John Glenn, tenor Andrea Bocelli, Canadian visual artist Tony Max, guitarist Jose Feliciano, and over other 60.5 million people in the world have in common?
Glaucoma. The second leading cause of blindness globally after cataracts, it’s a common but deadly eye disease.
What’s particularly insidious about glaucoma is that it causes vision loss that’s progresses so slowly that by the time you notice it, it’s a bit too late—the disease is at an advanced stage. And even with treatment, 10 percent of sufferers still end up blind.
What’s worse, over 60.5 million people worldwide and 120,000 Americans have glaucoma—but only half know that they have it. That’s why it’s called the “silent thief of sight.”
The World Health Organization considers glaucoma a great public health challenge, not only because the blindness it causes is irreversible, but because of the large numbers of people who have it. In terms of proportion, it affects one in 200 people aged 50 and younger—with that number rising to one in 10 for people over the age of eighty. By 2020, ophthalmologists estimate that their numbers will rise to 79.6 million.
But while the vision loss brought by glaucoma is irreversible, it’s possible to arrest or slow the progression if the condition is detected early and treated immediately.
The key to treating glaucoma is keeping eye pressure within normal bounds. Eye pressure is normally elevated in people with glaucoma and even in those just about to develop the disease.
For quite some time eye pressure was kept in check by prostaglandin analog ophthalmic solutions. Unfortunately, most solutions of this type use preservatives that cause some serious side effects like oozing or discharge from your eye, increased sensitivity to light, vision changes and chest pain.
The good news is that the U.S. Food and Drug Administration has recently approved the first preservative-free prostaglandin analog ophthalmic solution to reduce elevated intraocular pressure.
Zioptan, also known chemically as tafluprost is the first preservative-free prostaglandin analog ophthalmic solution. It’s an eye drop that should be used once daily in the evening.
On Feb. 10, the FDA approved its use for treatment of both the elevated intraocular pressure in people with the most common form of glaucoma known as open-angle, as well as people with a pre-glaucoma condition called ocular hypertension.
Like all drugs, Zioptan does have side effects, but these aren’t as alarming as those of older prostaglandin analog ophthalmic solutions. Side effects of the new drug involve a change in the color of the iris, the skin around the eyes and the eyelashes.
“Prostaglandin analogs are often used as a first line of treatment to lower intraocular pressure in patients with open-angle glaucoma, explains Dr. George L. Spaeth of the Wills Eye Institute in Philadelphia in a Merck press release.
“The approval of Zioptan will provide a new, effective option to lower IOP,” says, adding that he anticipates using Zioptan in many of his patients.
“Zioptan’s approval provides an alternative treatment option for patients living with this potentially blinding disease,” says Dr. Edward Cox, M.D., M.P.H, director of the Office of Antimicrobial Products in FDA’s Center for Drug Evaluation and Research.
Manufactured by pharmaceutical giant Merck & Co, it’s previously been approved for use in certain European countries under the brand Saflutan.
FDA approved Zioptan after Merck conducted five efficacy and safety clinical tests on 905 patients in tests that run for up to two years. In these clinical studies, both preservative-containing and preservative-free formulations of tafluprost were used in these clinical studies.
In the tests, patients with open-angle glaucoma or ocular hypertension treated with Zioptan in the evening showed reduced eye pressure at three and six months.
To be precise, pressure was reduced by 6-8 mmHg at three months and by 5-8 mmHg at six months, from a baseline pressure of 23-26 mmHg—or millimeters of mercury, a measure of fluid in the eye. Normal eye pressure ranges from 10-21 mm Hg. If pressure is greater than 21 mm Hg, it’s considered to ocular hypertension.
Zioptan is expected to become available to U.S. consumers in March, at US$97 for a 30-day supply, the Wall Street Journal reported.
The drug was developed in cooperation with specialist drug maker Santen Pharmaceutical, an Osaka, Japan-based company that specializes in ophthalmic and anti-rheumatic fields.
Trusopt and Cosopt, two of Merck’s older drugs designed to reduce intraocular pressure have lost market exclusivity in the U.S. and some other countries, as has Pfizer Inc’s Xalatan eye solution. This clears the way for cheaper generic copies.
Zioptan Side Effects