Get the Facts on Glaucoma

Open-angle glaucoma

This is the most common type of glaucoma, responsible for approximately 90 percent of cases. It’s called the “silent thief of sight,” because it generally happens slowly and gradually, usually with no warning signs in the early stages. As new fluid flows into your eye, the same amount should drain out through a mesh-like channel, called the trabecular meshwork (an area of tissue located at the base of the cornea). But in open-angle glaucoma, the meshwork becomes partially blocked over time, allowing less fluid to drain from the eye. The pressure in the eye gradually builds and over time can irreversibly damage the optic nerve.

The earliest symptom is usually some loss of peripheral vision, which can only be found through measurable findings at an eye exam, Iwach says: “Patients can actually have quite a bit of loss and never realize it.”

Treatment

Fortunately, regular checkups and treatment can help slow or prevent vision loss, especially if symptoms are detected early. Along with a measurement of your visual acuity, a standard eye exam will also include a measurement of eye pressure and a field vision test, which assesses your peripheral (or side) vision. “The COVID crisis has accentuated interest in figuring out ways to help monitor patients at home,” Iwach says. MyEyes is a company that rents devices to patients to use at home to test their intraocular pressure (IOP). Researchers are also developing devices, similar to the virtual reality goggles that gamers use, to test peripheral vision at home. Pretty cool, to be sure. “But these types of devices do not replace the need to see an ophthalmologist,” Iwach says. “They are an adjunct.”

While glaucoma damage cannot be reversed, Iwach says, most patients can typically control and manage the disease with medicated eye drops, in-office laser treatment or surgery.

Medication

• Prescription eye drops, used every day, are the most common way to lower eye pressure and control glaucoma. Your doctor may prescribe one or more to be used in combination. Some tackle glaucoma by reducing the amount of fluid your eye produces; others increase the amount of fluid that drains out of the eye.
  
  
• Prostaglandin analogues are the treatment of choice for many patients. This category includes Latanoprost (Xalatan), travoprost (Travatan), bimatoprost (Lumigan) and latanoprostene bunod (Vyzulta). Another class of drugs, Rho kinase inhibitors, which includes netarsudil (Rhopressa), also lowers IOP by helping with the outflow of fluid. A new entry, approved by the Food and Drug Administration in 2019: Rocklatan. It contains two active ingredients: netarsudi and latanoprost. “Rhopressa as a standalone drop works pretty well,” says Iwach. “But when combined with latanoprost, a powerful pressure-lowering medication, it can be very effective.”
  
  
• Though prescription eye drops can be effective, they’re not necessarily practical. Some patients may forget to use them; others find it challenging to get them into the eye (a particularly tricky endeavor for seniors with shaky hands). Durysta, FDA approved in 2020, is a welcome development. This dissolvable pellet, injected into the eye during a five-minute in-office procedure, slow-releases IOP-lowering medication and is designed to last for up to six months.

Surgery

• Laser surgery There are also two main types of laser surgery that help with fluid drainage. The most common type performed for open-angle glaucoma is selective laser trabeculoplasty, a procedure in which a laser is used to open clogged channels in the trabecular meshwork to increase the outflow of fluid.
  
  Selective laser trabeculoplasty is typically used in patients whose glaucoma is being controlled by eye drops, but it can sometimes be used in place of medication. “There has been data to suggest that there are side effects with medications taken every day and they are inconvenient for patients, and that maybe we should consider doing laser treatments before we even start drops,” says Iwach. “There was an interesting study out of the [United Kingdom], which recommended considering doing selective laser trabeculoplasty treatment — which can reduce pressure in approximately 80 percent of patients — and delay the need for eye drops for some patients. In fact, over the past 10 years, there’s been a gradual migration to using lasers earlier in the treatment regimen, though they are not appropriate for everyone.”
  
  
• Traditional surgery If eye drops and laser treatments aren’t doing the trick, or you can’t handle the side effects from medications, then your ophthalmologist may recommend conventional surgery to create a new way for fluid to leave the eye. In trabeculectomy, an opening is made in the sclera (the white of the eye), which allows excess fluid to drain out of the eye and into a small reservoir, which is hidden under the upper eyelid. From there, the fluid is absorbed by tissue around the eye. Implant devices also increase the outflow of fluid. A tiny drainage tube is inserted into the front chamber of the eye, leading back behind the eye, where a small collection area is created to drain off excess fluid.
  
  The standard treatment for closed-angle glaucoma is laser peripheral iridotomy. “A laser is used to make a tiny hole in the iris to help release fluid,” says Anne Coleman, a Los Angeles-based ophthalmologist who's affiliated with the Ronald Reagan UCLA Medical Center. These procedures are very comfortable and are usually done at the ophthalmologist’s office or an outpatient facility.
  
  
• Microsurgery A number of techniques and devices are being used to address glaucoma that don’t have the complexity or carry the risks of traditional surgery, Iwach says. These newer, faster, less invasive procedures, called MIGS (short for micro-invasive glaucoma surgeries), use microscopic-size equipment and tiny incisions. These procedures are performed in an operating room and can take as little as five minutes. Because these procedures aren’t as effective in lowering eye pressure, however, they’re more appropriate for those who are in the early-to-moderate stage of the disease. Talk to your doctor and insurance company about coverage.
  
  MIGS can be done as a standalone procedure but are more commonly done at the time of cataract surgery. “When patients undergo cataract surgery we open the eye, take the cataracts out and put lenses in,” Iwach says. “That gives us opportunity to have access to the trabecular meshwork.” Performing a two-in-one surgery can also cut down on complications. “One of the risks when doing eye surgery is that the incision can create a potential pathway for bacteria and infection,” Iwach says. “But here you’re making a smaller incision, so there’s less of a chance of that happening.” If you’re going to have cataract surgery, it may be worth asking if your doctor would consider doing one of these procedures at the same time.

Prevention

It’s scary stuff, but here’s the good news: If glaucoma is diagnosed in time and treated, you may be able to prevent additional vision loss and prevent blindness. “The prognosis is excellent, but people often take their eyes for granted and forget about them until they notice symptoms,” says Coleman. “That’s why it’s important to get examined to assess what your risk is.”

The American Academy of Ophthalmology recommends that adults, beginning at age 40, get regular comprehensive eye exams with an ophthalmologist. People who are 65 and older should get an eye exam every one to two years. Those with chronic conditions, such as diabetes or high blood pressure, known eye diseases or other risk factors may need to get checked more often.   

What’s next?

These promising breakthroughs may be coming to an ophthalmologist’s office near you.  

Long-lasting injectables: Researchers at Georgia Tech have developed a possible alternative to daily eye drops: a twice-a-year injection to control a buildup of eye pressure. The premise: An injection of a biodegradable hydrogel, placed just below the surface of the eye, opens an alternative pathway for excess fluid to drain out of the eye, when the dominant pathway, the trabecular meshwork, is blocked.

Non-contact lasers: When doing selective laser trabeculoplasty, eye doctors use a gonioscope (an instrument including a contact lens which is placed directly over the cornea). While the procedure isn’t painful, there is a certain, well, ick factor. A company in Israel has created a possible alternative laser treatment to reduce IOP. Direct selective laser trabeculoplasty is performed through the limbus (the border between the cornea and sclera) and doesn’t involve a lens, so there’s no contact with the surface of the eye. What’s more, it takes less time to perform than selective laser trabeculoplasty: “about a second or less for the whole treatment,” Iwach says.

24/7 drug delivery: Researchers are working on a tiny implantable tube, connected to a little reservoir, that delivers just the right amount of medication to the eye. (Every so often, the reservoir is refilled with medication.) “There are some interesting benefits,” Iwach says. “First, there’s the convenience — you wouldn’t have to do two drops every day.” And then there’s the slow-release delivery system, which allows for a long-term delivery of the drug. “It’s like watering your garden,” he says. “You can flood the plant or you can do a drip irrigation system. The drip irrigation system is like low dosing. You don’t get high drug levels, and that can reduce side effects.”

Barbara Stepko is a longtime health and lifestyle writer, and former editor at Women’s Health and InStyle. Her work has appeared in The Wall Street Journal, Parade, and other national magazines.

Editor's note: This article, originally published on January 7, 2019, was updated to reflect new medical developments.