Who Benefits Most from Glaucoma Testing
Certain groups of people have a higher chance of developing glaucoma. If you fall into any of these categories, regular glaucoma screening is especially important for protecting your vision. Your eye doctor may recommend more frequent testing based on your individual risk profile.
- Adults older than sixty, as the risk of glaucoma increases with age
- People of African, Hispanic, or Asian descent, who face higher rates of certain types of glaucoma
- Anyone with a family history of glaucoma, particularly a parent or sibling with the condition
- People who have experienced an eye injury or have had eye surgery in the past
- Individuals with high eye pressure, also known as ocular hypertension
- People who have used corticosteroid medications for extended periods of time
Even if you do not have any known risk factors, screening for glaucoma should begin by the time you reach your early forties. Open-angle glaucoma, which is the most common form of the disease, develops gradually and often produces no noticeable symptoms in its early stages. A baseline eye exam at this age gives your doctor a point of comparison for future visits and helps identify subtle changes over time.
The American Academy of Ophthalmology recommends comprehensive eye exams every one to two years for adults older than forty who have risk factors, and at least every two to four years for those without risk factors in the same age group. After reaching your mid-fifties, more frequent exams become important for everyone.
Several medical and eye conditions can increase your risk of developing glaucoma. If you have any of the following, your doctor may want to include glaucoma testing as part of your regular care.
- Diabetes, which can affect blood flow to the optic nerve
- Extreme nearsightedness or farsightedness
- High blood pressure or poor blood circulation
- Thin corneas, which are the clear front windows of the eyes
- Previous eye injuries, inflammation, or surgeries
If a previous eye exam revealed that you have borderline high eye pressure, an unusual optic nerve appearance, or other findings that raise concern, you may have been labeled a 'glaucoma suspect.' This does not mean you have glaucoma. It means your eye doctor wants to monitor you more closely over time to watch for any changes that could signal the start of the disease. Regular diagnostic testing is essential for glaucoma suspects.
Who Is a Good Candidate for Glaucoma Testing
Glaucoma diagnostic tests are safe, noninvasive (meaning they do not require cuts or needles), and comfortable for most patients. There are very few reasons why a person could not undergo glaucoma testing. The tests do not require general anesthesia, do not involve radiation, and are typically completed in a single office visit. People of all ages, including children and older adults, can have these tests performed.
If you have not had a detailed glaucoma evaluation before, you are a good candidate for a comprehensive baseline exam. This type of evaluation includes multiple tests that measure different aspects of your eye health. The results serve as a reference point so your doctor can track any changes at future appointments. A baseline evaluation is especially valuable for people who are newly diagnosed as glaucoma suspects or who have recently developed risk factors.
People who have already been diagnosed with glaucoma need ongoing testing to monitor the disease and make sure treatment is working effectively. Follow-up testing allows your doctor to see whether eye pressure is staying within a safe range, whether the optic nerve is stable, and whether your field of vision has changed. The frequency of follow-up visits depends on the severity of your condition and how well it responds to treatment.
Although glaucoma is more common in older adults, it can occur in children and young adults as well. Pediatric glaucoma, also called childhood glaucoma, may be present at birth or develop during the early years of life. Young adults can also develop glaucoma, particularly if they have a strong family history or other risk factors. The same diagnostic tests used for adults can be adapted for younger patients.
How Glaucoma Diagnostic Testing Works
Tonometry is the test that measures the pressure inside your eye, known as intraocular pressure. High eye pressure is one of the most important risk factors for glaucoma, so this measurement is a key part of every glaucoma evaluation.
The most common method used in a full eye exam is called Goldmann applanation tonometry. During this test, your doctor places numbing drops in your eyes and then gently touches the surface of your eye with a small, flat-tipped instrument. The instrument measures how much force is needed to slightly flatten a tiny area of your cornea, which tells the doctor what your eye pressure is. The test takes only a few seconds and is not painful.
Another common method is non-contact tonometry, sometimes called the 'air puff test.' This device sends a brief puff of air toward your eye and measures the pressure based on how your cornea responds. While this test is quick and does not require numbing drops, it is generally considered a screening tool. If the results suggest high pressure, your doctor will likely confirm the reading with applanation tonometry.
Optical coherence tomography, commonly referred to as OCT, is an advanced imaging technology that creates highly detailed, cross-sectional pictures of the structures inside your eye. OCT is one of the most valuable tools available for detecting and monitoring glaucoma.
During an OCT scan, you sit in front of the machine and look at a target light. The device scans your eye without touching it, and the entire process takes only a few minutes. The resulting images show the layers of nerve fiber tissue around your optic nerve and in your retina, which is the light-sensitive tissue at the back of your eye. Your doctor can measure the thickness of these layers and compare them to normal values.
In glaucoma, the nerve fiber layer becomes thinner as nerve cells are damaged and lost. OCT can detect this thinning even before you notice any changes in your vision. This makes it an extremely powerful tool for early detection. Over time, your doctor will compare OCT scans from different visits to see whether the nerve fiber layer is stable or thinning, which helps guide treatment decisions.
Visual field testing, also called perimetry, measures your full range of vision, including your central vision and your peripheral (side) vision. Glaucoma often affects peripheral vision first, so this test is essential for finding early damage and tracking how the disease may be progressing.
During a visual field test, you sit in front of a bowl-shaped instrument and look straight ahead at a central point. Small lights of varying brightness flash at different locations throughout the bowl. Each time you see a light, you press a button. The machine records which lights you saw and which ones you missed, creating a map of your visual field.
The test typically takes five to ten minutes per eye. It requires your concentration and cooperation, so it is normal for the results to vary slightly from one visit to the next. Your doctor looks at the overall pattern of results and compares them over time. Specific patterns of vision loss can help confirm a glaucoma diagnosis and show how well treatment is controlling the disease.
Gonioscopy is a test that allows your doctor to examine the drainage angle of your eye. The drainage angle is the area where the iris (the colored part of your eye) meets the cornea (the clear front surface). This is where fluid inside the eye, called aqueous humor, drains out of the eye. The condition of this drainage angle helps determine what type of glaucoma you may have.
To perform gonioscopy, your doctor places numbing drops in your eye and then gently places a special lens on the surface of your eye. This lens has mirrors that allow the doctor to see the drainage angle, which is otherwise hidden from view. The exam takes just a few minutes and causes little to no discomfort.
If the drainage angle is open and appears normal, you may have open-angle glaucoma or be at risk for it. If the angle is narrow or closed, you may have or be at risk for angle-closure glaucoma, which is a less common but potentially more urgent form of the disease. Open-angle glaucoma accounts for 90% of all glaucoma cases in the United States (National Eye Institute, 2023). Knowing which type of glaucoma you have is important because treatment approaches differ.
Pachymetry is a quick and simple test that measures the thickness of your cornea. Corneal thickness matters in glaucoma care because it can affect the accuracy of eye pressure readings. People with thicker corneas may get eye pressure readings that appear higher than their true pressure, while people with thinner corneas may get readings that appear lower than their true pressure.
During pachymetry, your doctor places numbing drops in your eyes and then briefly touches the surface of your eye with a small probe. The probe uses ultrasound waves to measure the thickness of your cornea in a matter of seconds. Some newer devices can measure corneal thickness without touching the eye at all. Knowing your corneal thickness helps your doctor interpret your eye pressure readings more accurately.
A direct examination of the optic nerve is one of the most important parts of a glaucoma evaluation. Your doctor will use special magnifying lenses and a bright light to look at the optic nerve head, which is the point where the optic nerve enters the back of the eye. This area is also called the optic disc.
In a healthy eye, the optic disc has a characteristic shape with a small cup-shaped depression in the center. In glaucoma, this cup becomes larger as nerve fibers are damaged and lost. Your doctor will assess the size and shape of the cup, the color of the optic nerve, and the health of the surrounding tissue. Photographs or digital images of the optic nerve are often taken so they can be compared at future visits.
To get the best view of the optic nerve, your doctor may need to dilate your pupils using special eye drops. Dilation makes your pupils larger, allowing more light to enter the eye and giving the doctor a wider view of the internal structures. The drops take fifteen to thirty minutes to take full effect, and their effects typically wear off within a few hours.
Types of Testing Approaches and Combinations
There is an important difference between a simple glaucoma screening and a comprehensive diagnostic evaluation. A screening is a quick check, often involving just an eye pressure measurement and a brief look at the optic nerve. Screenings are useful for identifying people who need further evaluation, but they are not thorough enough to diagnose glaucoma on their own.
A comprehensive diagnostic exam includes multiple tests that work together to paint a complete picture of your eye health. This type of exam may include tonometry, OCT, visual field testing, gonioscopy, pachymetry, and a detailed optic nerve evaluation. By combining the results of all these tests, your doctor can make a more confident and accurate diagnosis.
When you come in for your first comprehensive glaucoma evaluation, your doctor will likely perform a full set of diagnostic tests. These baseline measurements establish a starting point for your care. Future test results will be compared to these baseline values to detect any changes over time. Baseline testing is especially important because glaucoma develops gradually, and detecting small changes early can make a significant difference in preserving your vision.
Once a baseline has been established, follow-up visits focus on monitoring for changes. Your doctor may not perform every test at every visit. Instead, the testing plan will be tailored to your specific situation. For example, someone with stable glaucoma that is well controlled by medication may need visual field testing and OCT scans once or twice a year. Someone with more advanced or harder-to-control glaucoma may need more frequent testing.
- Eye pressure checks are typically done at every visit
- OCT scans may be performed every three to twelve months depending on your situation
- Visual field tests are usually done one to three times per year
- Gonioscopy may be repeated if your doctor suspects changes in the drainage angle
- Optic nerve photographs or images are updated periodically for comparison
In addition to the standard tests described above, newer technologies continue to improve glaucoma diagnosis and monitoring. Some of these advanced tools include OCT angiography, which can image the tiny blood vessels that supply the optic nerve and retina without the need for injectable dyes. Other emerging technologies aim to detect changes in the optic nerve and retina at even earlier stages of the disease.
Your doctor will recommend the tests that are most appropriate for your individual needs. Not every patient requires advanced imaging, but when it is indicated, these technologies can provide valuable additional information that helps guide your care.
What to Expect During a Glaucoma Evaluation
Preparing for a glaucoma evaluation is straightforward. You should bring a list of all medications you currently take, including eye drops, prescription drugs, and supplements. If you have had previous eye exams elsewhere, it is helpful to bring or have those records sent to our office so your doctor can review them. You should also bring your current eyeglasses or contact lenses.
Plan for your appointment to last one to two hours, depending on which tests are needed. Because your pupils may be dilated during the exam, your vision may be blurry and sensitive to light for several hours afterward. You may want to bring sunglasses and arrange for someone to drive you home, especially if this is your first visit or if you are uncomfortable driving with dilated pupils.
When you arrive, a technician will begin by gathering some preliminary information. This may include checking your vision, measuring your eye pressure, and taking initial images of your eyes. You will then see your doctor, who will review the results and perform additional tests as needed.
Most glaucoma tests are painless. You may feel a brief touch on the surface of your eye during tonometry, gonioscopy, or pachymetry, but numbing drops are used to keep you comfortable. OCT scanning and visual field testing do not involve any contact with your eyes at all. Your doctor will explain each test before it is performed and answer any questions you may have along the way.
Once all the tests are complete, your doctor will review the results with you. If glaucoma is diagnosed, your doctor will explain the type and severity of the condition and discuss treatment options. If no glaucoma is found but your results suggest you are at increased risk, your doctor will recommend a schedule for follow-up monitoring.
It is normal to have questions after your appointment. Our team is available to help you understand your results and your next steps. You will receive clear instructions about any recommended treatments, medications, or follow-up visits before you leave.
Many patients worry that glaucoma testing will be uncomfortable or frightening. In reality, the tests are well tolerated by most people. The numbing drops used for contact tests work quickly and effectively. The air puff test may startle you the first time, but it is not painful. Visual field testing requires concentration but is not physically uncomfortable. If you have anxiety about eye exams, let your care team know so they can take extra steps to help you feel at ease.
Your Journey at Washington Eye Institute
Your glaucoma evaluation begins when you contact our office to schedule an appointment. Our scheduling team will ask about your eye health history, any current symptoms, and whether you have been referred by another doctor. This information helps us prepare for your visit and ensure we have enough time to perform all necessary tests. When you arrive, you will complete a brief intake process that includes reviewing your medical history and current medications.
A trained ophthalmic technician will perform several initial measurements and tests. These typically include checking your visual acuity (how clearly you can see at various distances), measuring your eye pressure, and taking digital photographs or scans of your optic nerve. These preliminary results give your doctor important information before the detailed examination begins.
Your doctor will perform a thorough examination of your eyes, including all the diagnostic tests appropriate for your situation. This may include gonioscopy to examine the drainage angle, pachymetry to measure corneal thickness, detailed OCT imaging, and visual field testing. Your doctor will look carefully at the health of your optic nerve and all the structures inside your eye. Throughout the examination, your doctor will explain what is being done and why.
After completing the evaluation, your doctor will sit down with you to discuss the findings. You will learn what each test revealed and what the overall picture means for your eye health. If treatment is needed, your doctor will explain the available options, which may include eye drops, laser procedures, or surgical approaches. Together, you and your doctor will develop a plan that fits your needs and lifestyle.
Glaucoma management is a long-term process. After your initial evaluation, you will be scheduled for regular follow-up visits to monitor your condition and adjust your treatment as needed. Our team is committed to providing continuous, personalized care. We encourage you to ask questions, report any changes in your vision, and keep all scheduled appointments. Consistent monitoring is one of the most important things you can do to protect your eyesight.
Questions and Answers About Glaucoma Diagnosis
Glaucoma testing is not painful for the vast majority of patients. Some tests involve placing numbing drops in your eyes before gently touching the surface of the eye with a small instrument. You may feel a slight sensation of pressure, but the numbing drops prevent pain. Other tests, like OCT imaging and visual field testing, do not require any contact with your eyes at all. If you are nervous about having your eyes examined, let your care team know so they can help you feel comfortable throughout the process.
The recommended frequency of glaucoma testing depends on your age, risk factors, and whether you have already been diagnosed with glaucoma or are a glaucoma suspect. Adults older than forty with risk factors should have a comprehensive eye exam every one to two years. Adults without risk factors in the same age group should be seen every two to four years. After reaching your mid-fifties, more frequent exams are recommended for everyone. If you have been diagnosed with glaucoma, your doctor will create a monitoring schedule based on the severity of your condition and how well it is responding to treatment.
Yes. In fact, one of the primary goals of glaucoma testing is to detect the disease before noticeable vision loss occurs. Modern diagnostic tools like OCT and visual field testing can identify early damage to the optic nerve and subtle changes in your field of vision that you would not be able to detect on your own. This is why regular comprehensive eye exams are so important. Early detection allows treatment to begin sooner, which can significantly slow or halt the progression of the disease and help preserve your vision for years to come.
Borderline test results are common and do not necessarily mean you have glaucoma. They may indicate that you are a glaucoma suspect, meaning your doctor wants to watch you more closely over time. In these cases, your doctor may recommend more frequent follow-up visits and repeat testing to look for any changes. Comparing results over time is one of the most effective ways to determine whether glaucoma is developing. Many people with borderline results do not go on to develop glaucoma, but careful monitoring ensures that any changes are caught quickly.
The specific tests performed during your evaluation depend on your individual situation. During a comprehensive baseline exam, your doctor may perform most or all of the tests described on this page to get a complete picture of your eye health. At follow-up visits, the testing may be more focused, concentrating on the measurements that are most relevant to monitoring your condition. Your doctor will explain which tests are recommended and why. If you have questions about any part of the testing process, do not hesitate to ask.