Glaucoma Testing and Treatment

You might be surprised at how many tests eye doctors use to diagnose glaucoma. A proper diagnosis requires careful evaluation of many aspects of your eye’s health – from eye pressure to cornea thickness to the health of your optic nerve. This article describes how your eye doctor assesses your risk and all the tests needed to properly diagnose glaucoma.
 

Risk Factor Assessment

Your eye doctor will begin by assessing your risk level for developing glaucoma. This will help determine the frequency and extent of testing needed. Through a family history and medical questionnaire, the eye doctor is looking for the following risk factors:

• Over the age of 60

• Ethnic background such as African or black Caribbean descent, Hispanic, or Asian

• Family history of glaucoma, such as a sibling or parent with glaucoma

• History of eye conditions, injuries or surgeries

• Prolonged corticosteroid use (eye drops, pills, inhalers or creams)

• Chronic conditions that affect blood flow, such as migraines, diabetes, low blood
  pressure or hypertension

• Current or former smoker
   

If you’ve already had a comprehensive eye exam, your eye doctor will also consider these risk factors:

• Eye pressure higher than normal (above 21 mm Hg)

• Thin corneas (less than 0.5 millimeters)
   

Your type of eyesight is also important. People with farsightedness are at a higher risk for narrow-angle glaucoma, a more serious type that can advance quickly. While nearsightedness is associated with open-angle glaucoma, which progresses slowly without any symptoms.
 

Standard Glaucoma Tests

During a comprehensive eye exam, your eye doctor will always check for glaucoma, regardless of the risk level. This provides a baseline for comparison as you age. There are two tests: tonometry and ophthalmoscopy.
 

Tonometry

Tonometry measures the pressure within your eye. Your eye doctor will give you drops to numb your eyes. Then he/she will use a device called a tonometer, which applies a small amount of pressure with a warm puff of air.

Eye pressure is unique to each person, so it’s not always a reliable indicator for glaucoma. It’s simply another piece of information to help your eye doctor assess your eyes. The range for normal pressure is 12-22 mm Hg (“mm Hg” in millimeters of mercury, a scale for recording eye pressure). Most glaucoma cases are diagnosed with pressure over 20mm Hg. However, some people can have glaucoma at pressures between 12 -22mm Hg.
 

Ophthalmoscopy

This is an examination of your optic nerve. Your eye doctor will use eye drops to dilate the pupil, which makes it possible to see through your eye to examine the shape and color of the optic nerve. Then, using a small device with a light on the end, your optic nerve is magnified. Based on the results of these tests, your doctor may ask you to have more glaucoma exams.
 

Supplemental Glaucoma Tests

Perimetry

Perimetry is a visual field test. It creates a map of your complete field of vision. During this test, you’ll look straight ahead and then indicate when a moving light passes your peripheral (or side) vision. Try to relax and respond as accurately as possible. To ensure accuracy, your doctor may repeat the test to see if the results are the same the next time. If you’ve been diagnosed with glaucoma, a visual field test is usually recommended at least once per year to assess changes to your vision.
 

Gonioscopy

This diagnostic exam helps determine the angle of your iris and cornea. First, you’ll receive eye drops to numb the eye. A hand-held contact lens is gently placed on the eye. A mirror on the contact lens shows the doctor if the angle is closed and blocked (a possible sign of angle-closure or acute glaucoma) or wide and open (a possible sign of open-angle, chronic glaucoma).
 

Pachymetry

Last, your eye doctor may want to use pachymetry as another way to confirm a diagnosis. Pachymetry measures the thickness of your cornea, the clear window at the front of the eye. A probe called a pachymeter is gently placed on your cornea to measure its thickness. Pachymetry can help clarify your diagnosis because corneal thickness has the potential to influence eye pressure readings.

Glaucoma diagnosis is not as simple as you might expect. Be sure to have regular eye exams, especially if you have any of the risk factors, to detect glaucoma early.
 

If you’ve been diagnosed with glaucoma, you’re probably already familiar with the typical options in glaucoma treatment – eye drops, laser treatment or traditional surgery. While these are certainly effective, especially when glaucoma is diagnosed early, researchers have been working hard to offer new glaucoma treatments. Their goal is not only to improve outcomes but also reduce the treatment’s side effects and frequency of use.
 

What is the Goal of Glaucoma Treatment?

Before we dive into the new options, it’s important to understand the goal of any glaucoma treatment. At present, glaucoma is not curable. However, treatment can significantly slow the progression of the disease. Glaucoma damages your eye's optic nerve. Extra fluid builds up in the front part of your eye (cornea), which increases the pressure in your eye. Reducing this pressure is the primary objective of any glaucoma treatment. This is often referred to as intraocular pressure or IOP.
 

What are the Limitations of Standard Glaucoma Treatments?

Eye drops for glaucoma treatment seem like an easy option but there are several challenges that can reduce its effectiveness. It can be difficult to get all the medicine in the eye, especially for older adults with less of a steady hand. In addition, since it must be applied daily, individuals may forget. Since the drops have no perceivable benefit because early stages of glaucoma have no symptoms, patients might make it a lower priority which is understandable since it may also have unpleasant side effects like burning, red eyes.

Beyond eye drops, laser surgery is a less invasive option. The laser opens clogged tubes and drains fluid. It can take a few weeks to see the full results. If laser surgery or drugs don’t relieve your eye pressure, you may need a more traditional operation. You would have to go into the hospital and will need a few weeks to heal and recover. Although usually effective, glaucoma surgery can make you more likely to get cataracts later on. It can also cause eye pain or redness, infection, inflammation, or bleeding in your eye.

What are Recent Advances in Glaucoma Treatment?

Alternatives or Improvements to Eye Drops
The Glaucoma Research Foundation reported several new developments on the horizon. These technologies focus on reducing patient error in applying eye drops which would make the medication more effective and improve the quality of life for the patient. Here are some of the products underway:

• A polymer, like a contact lens, would contain the drug; it would sit under the eyelid and release the medication over several months

• Microneedles would inject medication into a specific spot to be most effective

• Implantable extended-release devices using engineered highly precise microparticles and nanoparticles

• Polymer-based intraocular delivery technologies that would allow customizable sustained release

• Drops that allow the medication to get into the eye more easily

• Tear duct plugs that release medication

In addition, people with glaucoma who take more than one eye drop per day are beginning to see those medications available as a single, combined eye drop. New products include Cosopt (timolol and dorzolamide), Combigan (timolol and brimonidine) and Simbrinza (brinzolamide and brimonidine).

 

Minimally Invasive Glaucoma Surgery

Minimally Invasive Glaucoma Surgery (MIGS) procedures are small cuts or micro-incisions through the cornea that cause the least amount of trauma to the surrounding tissues. Doctors implant a tiny device to allow fluid to drain from the eye, reducing internal pressure. Some devices (iStent) are implanted during cataract surgery. Cataract surgery alone lowers pressure, but the combination of both is more effective and can lower the need for medication.

These new techniques minimize tissue scarring, allowing for the possibility of traditional glaucoma surgery in the future if needed. They also give doctors the opportunity to treat patients earlier and more safely than older surgeries.
 

Monitoring Eye Pressure

An easy, accurate way to measure eye pressure is critical to monitoring the progress of glaucoma and adjusting treatment as needed. For patients that require more frequent testing of their eye pressure, there’s now an at-home tonometer called iCare HOME. There’s no puff of air and no eye drops. The patient can easily share the information with their eye doctor.

If you have a glaucoma diagnosis, you can feel confident that your glaucoma treatment options are only going to improve in the years ahead. Although the disease is not curable, it is very manageable with the right treatment.