Learn more about glaucoma

Glaucoma can be treated with eye drops, medications, laser surgery, traditional surgery or a combination of these methods. The goal of any treatment is to prevent loss of vision, as vision loss from glaucoma is irreversible. The good news is that glaucoma can be managed if detected early, and that with medical and/or surgical treatment, most people with glaucoma will not lose their sight.

Taking medications regularly, as prescribed, is crucial to preventing vision-threatening damage. That is why it is important for you to discuss side effects with your doctor. While every drug has some potential side effects, it is important to note that many patients experience no side effects at all. You and your doctor need to work as a team in the battle against glaucoma. Your doctor has many options. They include:

Eye Drops: It is important to take your medications regularly and exactly as prescribed if you are to control your eye pressure. Typically glaucoma eyedrops are dosed with one drop once or twice a day in the affected eye. Medications should be taken on a fixed schedule every day to achieve the best long term control of the disease. Since eye drops are absorbed into the bloodstream, tell your doctor about all medications you are currently taking. Ask your doctor and/or pharmacist if the medications you are taking together are safe. Some drugs can be dangerous when mixed with other medications. To minimize absorption into the bloodstream and maximize the amount of drug absorbed in the eye, close your eye for one to two minutes after administering the drops and press your index finger lightly against the inferior nasal corner of your eyelid to close the tear duct which drains into the nose. While almost all eye drops may cause an uncomfortable burning or stinging sensation at first, the discomfort should last for only a few seconds.

Oral Medications: Sometimes, when eye drops don’t sufficiently control IOP, pills may be prescribed in addition to drops. These pills (ie. Acetazolamide or Methazolamide) have more systemic side effects than drops. They also serve to turn down the eye’s faucet and lessen the production of fluid. These medications are usually taken from two to four times daily. It is important to share this information with all your other doctors so they can prescribe medications for you that will not cause potentially dangerous interactions.

Surgical Procedures: When medications do not achieve the desired results, or have intolerable side effects, your ophthalmologist may suggest surgery.

Laser Surgery: Laser surgery has become increasingly popular as an initial treatment or an intermediate step between drugs and traditional surgery though the long-term success rates are variable. The most common type performed for open-angle glaucoma is called trabeculoplasty. This procedure takes between 2 and 5 minutes, is painless, and can be performed in either a doctor’s office or an outpatient facility. The laser beam (a high energy light beam) is focused upon the eye’s drain, called the Trabecular Meshwork. Contrary to what many people think, the laser does not burn a hole through the eye. Instead, the eye’s drainage system is changed in very subtle ways so that aqueous fluid is able to pass more easily out of the drain, thus lowering IOP.

You may go home and resume your normal activities following surgery. Your doctor will likely check your IOP one to two hours following laser surgery. After this procedure, many patients respond well enough to be able to avoid or delay surgery. While it may take a few weeks to see the full pressure-lowering effect of this procedure, during which time you may have to continue taking your medications, some patients are eventually able to discontinue some of their medications. This, however, is not true in all cases. Your doctor is the best judge of determining whether or not you will still need medication. Complications from laser are minimal, which is why this procedure has become increasingly popular and some centers are recommending the use of laser before drops in some patients.

Selective Laser Trabeculoplasty (SLT): Used for open-angle glaucoma, SLT is a laser that uses very low levels of energy to help stimulate the drainage network to drain more fluid out of the eye and into the bloodstream. It is termed “selective” since it specifically targets portions of the trabecular meshwork. Typically this procedure carries a 75-80% success rate as far as lowering intraocular pressure with very minimal risk. Additionally, SLT may be safely repeated if needed for further control later in life if the disease is noted to progress.

Laser Peripheral Iridotomy (LPI): Used for angle-closure glaucoma, this procedure is used to make an opening through the iris, allowing aqueous fluid to flow from behind the iris directly to the anterior chamber of the eye. This allows the fluid to bypass its normal route. LPI is the preferred method for managing a wide variety of angle-closure glaucomas that have some degree of pupillary blockage. This laser is most often used to treat an anatomically narrow angle and prevent both acute and chronic forms of angle-closure glaucoma.

Cycloablation: Two laser procedures for open-angle glaucoma involve reducing the amount of aqueous humor in the eye by destroying or suppressing part of the ciliary body, which produces the fluid.

Transscleral cyclophotocoagulation uses a laser to direct energy through the outer sclera of the eye to reach and destroy portions of the ciliary processes, without causing damage to the overlying tissues. There are two forms of transscleral cyclophotocoagulation- Micropulse or Diode technology. Both typically require some form of monitored anesthesia care to provide added comfort to the patient during treatments. Micropulse laser can be very effective in reducing intraocular pressure, but often times requires repeated efforts to maintain control of the disease. Diode laser is usually reserved for use in eyes that either have elevated IOP with limited visual potential or those in which incisional surgery is not possible or advisable due to the shape or other features of the eye.

Endoscopic cyclophotocoagulation (ECP) is another method where a probe is placed inside the eye through a surgical incision and laser energy is applied to the ciliary body tissue with direct visualization. The ciliary processes are suppressed by way of the laser to help reduce the amount of aqueous fluid produced by the eye and thus lower intraocular pressure.

Trabeculectomy: When medications and laser therapies do not adequately lower eye pressure, doctors may recommend conventional surgery. The most common of these operations is called a Trabeculectomy, which is used in both open-angle and closed-angle glaucoma’s. In this procedure, the surgeon creates a passage in the sclera (the white part of the eye) for draining excess eye fluid. A flap is created that allows fluid to escape, but which does not deflate the eyeball. A small bubble of fluid called a “bleb” often forms over the opening on the surface of the eye, which is a sign that fluid is draining out into the space between the sclera and conjunctiva. Occasionally, the surgically created drainage hole begins to close and the IOP rises again. This happens because the body tries to heal the new opening, as if it was an injury. Many surgeons perform Trabeculectomy with an anti-fibrotic agent that is placed on the eye during surgery and reduces such scarring during the healing period. The most common anti-fibrotic agent is Mitomycin-C. Another is 5-Fluorouracil, or 5-FU.

About 50 percent of patients no longer require glaucoma medications after surgery for a significant length of time. Thirty-five to 40 percent of those who still need medication have better control of their IOP. A Trabeculectomy is usually an outpatient procedure. The number of post-operative visits to the doctor varies, and some activities, such as driving, reading, bending and heavy lifting must be limited for two to four weeks after surgery.

Express Mini Glaucoma Shunt: This is another form of filtration surgery but avoids creation of a drainage hole, or sclerotomy. It is a stainless steel device that is inserted into the anterior chamber of the eye and placed under a scleral flap. It lowers IOP by diverting aqueous humor from the anterior chamber. The ExPress offers the glaucoma surgeon an alternative to Trabeculectomy or placing a more extensive silicone tube shunt in those patients whose IOP is higher than the optic nerve can tolerate. This procedure also requires a fair amount of close postoperative care to ensure adequate control of the disease.

Drainage Implant Surgery: Several different devices have been developed to aid the drainage of aqueous humor out of the anterior chamber and lower IOP. All of these drainage devices share a similar design, which consists of a small silicone tube that extends into the anterior chamber of the eye. The tube is connected to one or more plates, which are sutured to the surface of the eye, usually not visible. Fluid is collected on the plate and then absorbed by the tissues in the eye. This type of surgery is usually preferred in patients whose IOP cannot be controlled with traditional surgery or who have previous scarring.

 

Surgical Alternatives: There are also a number of surgical alternatives for the treatment of glaucoma. Your glaucoma specialist can explain each, and together, you can decide which might be appropriate for you.

iStent: The iStent is a 1 millimeter titanium device that is directly inserted into the trabecular meshwork to help bypass outflow resistance and reduce intraocular pressure. It is a low risk, effective instrument that can help control open angle glaucoma with the potential of eliminating use of topical glaucoma medications when combined with cataract surgery. At this point in time, this device is approved for use and covered by insurances only at the same time of cataract surgery. Other similar devices, such as the Hydrus stent and CyPass shunt, will also be readily available in the coming years.

Trabectome: Trabectome is a technique involving a probe-like device that is inserted into the anterior chamber through the cornea. The procedure uses a small probe that opens the eye’s drainage system through a tiny incision and delivers thermal energy to the trabecular meshwork, reducing resistance to outflow of aqueous humor and, as a result, lowering IOP.

Canaloplasty: Canaloplasty is designed to improve the aqueous circulation through the trabecular outflow process, thereby reducing IOP. Unlike traditional Trabeculectomy, which creates a small hole in the eye to allow fluid to drain out, canaloplasty has been compared to an ocular version of angioplasty, in which the physician uses an extremely fine catheter to clear the drainage canal.

Xen Stent: The Xen Stent is one of the newest options available to surgically treat and control glaucoma. It is a collagen based flexible device that allows steady filtration of aqueous fluid from the anterior chamber to the subconjunctival space. It often requires use of antimetabolites to prevent scar tissue formation.

We have all read the labels on over-the-counter medications that say “do not take if you have glaucoma.” Many of these are cold and allergy medications containing a decongestant.  These and other drugs prescribed for conditions as diverse as depression and systemic hypertension can dilate the pupil and provoke angle closure in people with narrow angles. They don't seem to have an effect on people with open-angle glaucoma.

Patients should ask their doctor before taking any drug that has warnings about usage in people with glaucoma. Glaucoma is a group of different diseases. Only a doctor who examines your eyes can determine the most appropriate treatment for you and answer specific questions. You can also discuss possible drug interactions with your pharmacist.

Many available natural compounds used as non-pharmaceutical therapy have been reported to show beneficial effects on circulation, the immune system and neuroprotective activities. The mechanism of action of neuroprotection most common to natural compounds is antioxidant/free radical scavenging activity. However, many other actions are present and some extracts, such as Ginkgo biloba and curcumin, have widespread activity on a number of enzyme systems. There has been a paucity of clinical trials examining neuroprotective effects of these compounds on ocular diseases. More are warranted.

Among natural compounds and extracts of great interest for glaucoma are curcumin, omega-3 fatty acids and Ginkgo biloba. Curcumin, a component of the commonly used spice, turmeric, is a potential neuroprotective candidate for glaucoma.Curcumin studies have increased greatly in recent years, with over 2000 papers published since 2000. Curcumin has shown possible beneficial effects in most of the mechanisms thought to be involved in the development and progression of glaucoma. A pilot study has shown that it slows disease progression. A clinical trial on patients with glaucoma is on the horizon.

Omega-3 fatty acids, found most notably in fish oil, play an important role in reducing oxidative damage in the retina, improving ocular blood flow and protecting against retinal ischemia (decrease in the blood supply) induced by increased IOP. While studies have not specifically addressed glaucoma, it has been suggested that fish oil may reduce IOP and be relevant to glaucoma because of its protective effect on the macula and its benefits for other eye problems.

Ginkgo biloba extract has been claimed effective in the treatment of a variety of disorders associated with aging. It appears to have many qualities applicable to the treatment of non-IOP-dependent risk factors for glaucomatous damage. It is believed to improve central and peripheral blood flow, reduce spasm of the blood vessels, and have protective effects against free radicals because of its antioxidant property. It has been shown to be effective in treating Raynaud’s disease, which is strongly associated with normal-tension glaucoma. These and other properties raise the possibility that this herb may be a potential antiglaucoma therapy.

Glaucoma is an eye condition in which the optic nerve becomes damaged over time, first reducing peripheral vision before possibly leading to total blindness. One cause of optic nerve damage in glaucoma is higher-than-normal eye pressure (also called intraocular pressure or IOP).

Cannabis Isn't a Practical Way To Treat Eye Conditions — Here's Why

Glaucoma and other eye conditions cannot be treated with cannabis or other compounds derived from marijuana, such as CBD. That's because eye pressure must be managed 24 hours a day to effectively treat glaucoma. It's simply not practical to use marijuana constantly.

To reduce eye pressure in a noticeable way — and maintain that reduction — you would have to ingest about 18 to 20 mg of THC six to eight times a day, every day. Ingesting such a large amount of cannabis would dramatically affect your mood, mental clarity and (if smoked) lung health. You would not be able to drive, operate machinery or engage in many daily activities. Not to mention the cost of using marijuana every three to four hours, every day. Most patients could not afford this.

Marijuana Could Damage the Optic Nerve in People with Glaucoma

It's not well understood how cannabis affects eye pressure and glaucoma. It's possible that long-term use of cannabis could damage the eyes or worsen vision in some patients.

It's become clear that high eye pressure is not the only cause of optic nerve damage. The optic nerve can also be damaged by low blood flow. This is a problem because marijuana not only lowers eye pressure — it lowers blood pressure throughout the body. It's possible that marijuana could lower blood flow to the optic nerve, effectively canceling out the benefit of lowered eye pressure.

Until more research is done, the American Academy of Ophthalmology does not recommend marijuana or other cannabis products for the treatment of glaucoma. The American Glaucoma Society agrees, and the Glaucoma Research Foundation has come to the same conclusion.

Could CBD Help With Glaucoma?

There's been a lot of attention on CBD, a derivative of cannabis that doesn’t have mood-altering effects. But just like cannabis that’s smoked or eaten, there is no compelling research that shows CBD to be an effective treatment for glaucoma. In fact, one recent study showed that CBD may actually increase eye pressure, which could make glaucoma worse.

Scientists are exploring whether the active ingredients in marijuana may yet offer a glaucoma treatment. If the effects of cannabis compounds can be isolated, made to be long-acting, and the side effects eliminated, they may lead to new treatments in the future. However, such developments require more research and are years away from becoming a reality.

The Bottom Line About Marijuana and Glaucoma

• The largest association of eye physicians and surgeons in the world does not endorse cannabis or its derivatives as a glaucoma treatment.
• Do not self-medicate with marijuana in an attempt to treat glaucoma. You can lose your vision if you don’t have a reliable, effective treatment for glaucoma.
• Speak with your ophthalmologist to find the glaucoma treatment option that’s best for you.
• Tell your doctor if you do use marijuana regularly.

Currently, the only way to control glaucoma and prevent vision loss is to lower the pressure in your eye. Several current, effective treatments for glaucoma are more reliable and safer than marijuana.

Your ophthalmologist can treat glaucoma with medicine, such as prescription glaucoma eye drops, or glaucoma surgery, depending on the type of glaucoma and how severe it is. If you have glaucoma, follow your ophthalmologist’s advice to get the treatment that’s right for you.

Source: American Academy of Ophthalmology | Eye Smart