Visique | Visique Blog | National Glaucoma Awareness Month: Causes, Treatment and Research

January is National Glaucoma Awareness Month. In honor of this important month, we’re going to share key information about this disease and the steps you can take to prevent and treat it. Glaucoma affects 400,000 Canadians and 67 million people worldwide. It is one of the main causes of blindness, which is why it is important to know the causes and how doctors can diagnose this condition.

Usually, glaucoma occurs when the eye no longer drains fluids properly. This is caused by an ineffective drainage system, causing fluid to build up and an increase in intraocular pressure (IOP) in the eyes. This pressure damages the function of the optic nerve in the eye, which can lead to loss of visual field. Vision loss usually first appears in peripheral vision, a warning sign of the possible presence of glaucoma. Routine tests can usually determine the presence of glaucoma long before the patient notices this loss of peripheral vision.

Although glaucoma can affect anyone, the Mayo Clinic highlights certain risk factors that could contribute to the diagnosis. For example, being over 60 can increase the likelihood of developing the disease. Other factors could be a family history of glaucoma, or having medical problems like diabetes, heart disease, high blood pressure or sickle cell anemia. Corneas that are thin in the center can be a risk factor, as can having an eye injury, being extremely short-sighted or hyperopic, or taking corticosteroid medications (such as eye drops). for an extended period. Having any of these factors does not mean that you are going to develop glaucoma, but it is always a good idea to be aware of them and let your optometrist know. Regular eye exams are a great preventative measure to make sure your eyes are checked for symptoms.

Optometrists have many tools to diagnose glaucoma in a patient. Depending on the case, they can use a CT scan, eye drops, or simple diagnostic measures to determine if a person has the condition. Below is a list of the most common screening tools used by optometrists:

Ophthalmoscopy : Eye drops are used to dilate the pupil. The doctor is then able to more clearly examine the optic nerve to determine if there is damage.

Retinal imaging: As with ophthalmoscopy, the goal is to view the optic nerve. In this case, laser scanning is used to form a more complete image of the fundus of the eye. At Visique, we use Optomap retinal scanner during eye exams, for complete digital imaging.

Tonometry: It’s an eye pressure test. Drops are used to numb the eye and an instrument is carefully placed on the outside of the eye. The instrument gives a pressure reading. The average pressure is 16 mm Hg and a higher reading is not necessarily an indication of glaucoma, but is a possible sign that optometrists will analyze. Non-contact tonometry (an air breath test) is also an option.

Perimetry: A computerized visual field test in which the patient looks straight ahead and must identify the lights that appear on its periphery.

Gonioscopy: This test examines the drainage system of the eye directly. Doctors anesthetize the eye and place a special lens on the outside to closely examine the front surface.

Optical coherence tomography (OCT): A special type of optic nerve and macula imaging. OCT gives doctors precise information about the potential damage to the nerve fiber layer of the retina caused by glaucoma.

You may recognize some of these tests because optometrists perform similar tests as a preventive measure during regular eye exams. After a doctor has diagnosed a patient with glaucoma, the next step is to consider treatment options. Treatment is usually offered in one of two forms: medication or surgery.

The Canadian Glaucoma Research Society states “the main effect of most glaucoma medications is to reduce intraocular pressure (IOP). It has been proven over the years to be an effective way to prevent or slow the progression of the disease “. Drugs that lower IOP are a positive step forward in limiting the effects of glaucoma. Here are some commonly used eye drops to treat glaucoma:

Beta-blockers : The most commonly used beta blocker is timolol. These drugs reduce the production of aqueous humor (fluid in the eye), which lowers the pressure.Alpha Agonists : People who use alpha agonists apply them to the eye to decrease the production of aqueous humor and increase the flow of fluid from the eye. These two actions decrease IOP. Brimonidine is an example of an alpha agonist.

Carbonic anhydrase inhibitors : The most common ACIs are brinzolamide or dorzolamide. They are applied to the eye and decrease the production of aqueous humor.

Miotics : A common miotic is pilocarpine. This specific drug increases fluid flow and decreases IOP.

If treatment is ineffective, doctors may recommend a patient to have the operation. Patients with glaucoma can either undergo laser surgery or filtering microsurgery. Laser treatment is performed using a light beam, which leaves multiple marks on the eye’s drainage system, increasing the flow of fluid into the eye. In case laser surgery does not work, filtering microsurgery may be recommended. This technique is slightly more invasive: a drainage hole is created using a surgical instrument to drain the fluid. Your optometrist will know better than anyone what option to take in your particular situation.

Diagnoses and treatments are constantly evolving. As research advances and scientists understand glaucoma better, new options are appearing for patients. Glaucoma Today, a publication that explores new advances in the treatment of glaucoma, published several studies on new diagnostic efforts.

A new study examines the anterior segment of OCD, or otherwise known as TOC-AOS. This precision angular imaging device offers an alternative to gonioscopy; it does not require eye contact and can be performed in the dark, under standard lighting conditions. Glaucoma today suggests that “AS-OCT can be a valuable tool for the identification and sequential assessment of patients […] it is particularly advantageous for evaluating a narrow visual field and narrow-angle glaucoma “.

Tele-ophthalmology or telemedicine is the possibility of performing tests at the patient’s home without the latter having to go to a doctor’s office. The 2019 Glaucoma Today article mentions that “portable IOP monitoring devices such as the Icare tonometer (Icare USA) [qui] offer home pressure readings that can be shared with a remote operator. ”This type of diagnostic tool could limit a patient’s time in the doctor’s office and save health care resources.

What is certain is that glaucoma is a complicated disease that has many facets in diagnosis and care. It’s best to talk to your optometrist about possible treatments and have regular eye exams to help prevent glaucoma and possibly detect the disease at an early stage. Visit a Visique clinic near you today to schedule your next appointment.

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