Understanding the Different Types of Glaucoma
Primary Open-Angle Glaucoma
This is the most common form of glaucoma in the United States. It often develops slowly without obvious symptoms, which is why we call it the silent thief of sight and why regular comprehensive eye exams are so important.
Primary open-angle glaucoma occurs when fluid drains too slowly from your eye's drainage system. This causes gradual pressure buildup inside your eye. The drainage angle looks open and normal when we examine it, but microscopic blockages prevent proper fluid flow. This type represents about 90 percent of all glaucoma cases. It can affect one or both eyes, though it may progress at different rates in each eye.
Several factors increase your chances of developing this condition. You are at higher risk if you have any of the following:
- Age over 40, with risk increasing every decade
- Family history of glaucoma, especially in parents or siblings
- African American, Hispanic, or Asian ancestry
- High eye pressure, also known as ocular hypertension
- Thin corneas or large cup-to-disc ratios in the optic nerve
- Diabetes, high blood pressure, or heart disease
- Severe nearsightedness
Early stages typically show no symptoms at all, which makes regular eye exams crucial for catching this disease. As the disease progresses, you may notice gradual loss of side vision, difficulty seeing in dim light, or trouble with depth perception. By the time you notice symptoms, significant vision loss may have already occurred. This is why we recommend routine screenings, even when your vision seems fine.
Our team uses several advanced tests to detect and monitor this condition. We measure your eye pressure using tonometry and examine your optic nerve through dilated pupils. We also perform visual field testing to map your peripheral vision and use optical coherence tomography to measure nerve fiber thickness. Additional tests include gonioscopy to examine the drainage angle and pachymetry to measure corneal thickness. These comprehensive tests help us catch glaucoma early and monitor its progression.
Our goal is to lower your eye pressure to prevent further optic nerve damage. We start with the most conservative approach and advance as needed. Common treatments include:
- Prescription eye drops such as prostaglandin analogs, beta-blockers, or alpha agonists
- Laser treatments like selective laser trabeculoplasty to improve drainage
- Minimally invasive glaucoma surgeries for mild to moderate cases
- Traditional surgeries like trabeculectomy for advanced cases
- Glaucoma drainage devices when other surgeries are not suitable
Most patients with well-controlled open-angle glaucoma maintain good vision and continue normal activities. Your success depends on following your treatment plan, attending regular check-ups with us, and monitoring for any vision changes. Many of our patients live full, active lives with proper management and consistent care.
Angle-Closure Glaucoma
This type can cause sudden, severe increases in eye pressure and requires immediate medical attention. It accounts for about 10 percent of glaucoma cases in the United States but is more common in certain populations.
Angle-closure glaucoma happens when your iris moves forward and blocks your eye's drainage angle. This prevents fluid from leaving your eye. The blockage can be gradual, which we call chronic angle-closure, or sudden, which we call acute. Acute attacks are medical emergencies that can cause permanent vision loss within hours if not treated immediately.
Certain anatomical features and demographics increase your risk for this type of glaucoma. Risk factors include:
- Asian, Inuit, or Hispanic descent
- Being female, as women are affected more often than men
- Adults over 55, with risk increasing with age
- Farsightedness, which creates shorter, more crowded eyes
- Family history of angle-closure glaucoma
- Cataracts that cause your lens to swell
- Taking certain medications that dilate pupils, such as some antidepressants or decongestants
Acute angle-closure attacks cause severe symptoms that require immediate emergency care. Call us or go to the emergency room right away if you experience:
- Intense eye pain and headache
- Sudden blurred or decreased vision
- Seeing halos or rainbows around lights
- Red, watery eyes
- Nausea and vomiting
- An eye that feels hard to the touch
The chronic form develops slowly with mild or no symptoms, similar to open-angle glaucoma. You might experience occasional mild eye discomfort, brief episodes of blurred vision, or halos around lights. These symptoms often occur in dim lighting or when your pupils dilate. If you notice these signs, schedule an appointment with us for evaluation.
Acute attacks require immediate treatment to prevent permanent vision loss. We use medications to rapidly lower your eye pressure. We then perform a laser iridotomy to create a small drainage hole in your iris, which restores fluid flow. We typically treat your other eye as well to prevent future attacks. If laser treatment is not sufficient, we may recommend surgery such as trabeculectomy or lens extraction.
If you are at risk for angle-closure glaucoma, we may recommend preventive laser treatment. Regular monitoring helps us detect gradual angle narrowing before acute attacks occur. We typically treat both eyes since the condition often affects both sides, even if symptoms appear in only one eye initially.
Normal-Tension Glaucoma
This form affects about one-third of people with open-angle glaucoma. Despite having eye pressure in the normal range, your optic nerve still becomes damaged and vision loss occurs.
Normal-tension glaucoma involves progressive optic nerve damage and vision loss even though your eye pressure measurements remain within the statistically normal range, below 21 mmHg. The exact cause is not fully understood. We believe factors beyond eye pressure contribute to optic nerve damage, including reduced blood flow to the optic nerve.
Several factors may increase your susceptibility to normal-tension glaucoma. These include:
- Japanese ancestry, where this type is more common
- Being female, particularly after menopause
- Family history of normal-tension or low-pressure glaucoma
- History of systemic diseases affecting blood flow
- Low blood pressure, especially at night
- History of vasospastic disorders such as migraine headaches or Raynaud phenomenon
- Sleep apnea or other conditions affecting blood oxygen levels
We believe several factors may contribute to optic nerve damage in normal-tension glaucoma. Poor blood flow to the optic nerve may starve it of oxygen and nutrients. Some people may have optic nerves that are more sensitive to pressure, even at normal levels. Autoimmune factors may also play a role by attacking nerve tissue.
Symptoms mirror those of regular open-angle glaucoma, with gradual peripheral vision loss that often goes unnoticed. Because your eye pressure appears normal, this type may be harder to detect. This emphasizes the importance of comprehensive eye exams at our practice that include thorough optic nerve evaluation and visual field testing, not just pressure checks.
Our treatment strategies aim to protect your optic nerve by lowering your eye pressure even further below normal levels and improving blood flow. We use prescription eye drops to lower your eye pressure. We also recommend lifestyle changes to improve blood flow to your optic nerve, such as managing your blood pressure carefully and exercising regularly. We may treat underlying conditions like sleep apnea that can affect optic nerve health. Our goal is to target both pressure reduction and improved circulation.
Secondary Glaucoma
Secondary glaucoma develops when another eye condition, injury, or medication interferes with your eye's normal fluid drainage system. Unlike primary glaucoma, there is usually a clear underlying reason for the condition.
Secondary glaucoma occurs when an identifiable cause disrupts normal fluid flow in your eye, leading to increased pressure and optic nerve damage. Successful treatment often requires addressing both the underlying cause and the elevated eye pressure. We work closely with you to identify and manage the root cause while protecting your vision.
Several conditions can trigger secondary glaucoma. The most common types we see include:
- Inflammatory glaucoma from uveitis or other eye infections
- Steroid-induced glaucoma from prolonged use of steroid medications
- Pigmentary glaucoma when pigment granules from your iris block drainage channels
- Pseudoexfoliation glaucoma from protein deposits in your eye
- Neovascular glaucoma from abnormal blood vessel growth, often linked to diabetes
- Traumatic glaucoma following an eye injury
- Lens-induced glaucoma from cataract complications or a dislocated lens
Symptoms vary widely based on the underlying cause. You may experience eye pain, redness, vision changes, light sensitivity, or seeing halos around lights. Some types cause gradual vision loss similar to primary glaucoma, while others may cause sudden symptoms. Any unexplained eye symptoms should prompt a call to our office.
Treatment aims to control the underlying cause and lower your eye pressure. This may involve treating inflammation with anti-inflammatory medications or managing diabetes or other systemic diseases. We may recommend discontinuing or reducing steroid medications when possible, in coordination with your other doctors. We also use standard glaucoma medications, laser treatments, or surgery to lower your eye pressure as needed.
Congenital Glaucoma
This rare condition affects about 1 in 10,000 babies and requires immediate attention to prevent permanent vision loss. Early recognition and treatment are critical for preserving a child's sight and normal development.
Congenital glaucoma occurs when your baby's eye drainage system does not develop properly before birth. This causes fluid to build up and increase pressure inside the eye. The elevated pressure can damage the developing optic nerve and cause the eye to enlarge abnormally. This is why babies with this condition often have eyes that appear larger than normal.
Parents and caregivers should watch for these warning signs in infants and young children. Call our office immediately if you notice:
- Eyes that appear unusually large or are different sizes
- Cloudy or hazy corneas
- Excessive tearing without crying
- Sensitivity to light, causing squinting or eye covering
- Frequent eye rubbing or keeping eyes closed
- Irritability that improves in dim lighting
Surgery is usually the first line of treatment for congenital glaucoma, as medications are often less effective in children. Common procedures include goniotomy to open blocked drainage channels or trabeculotomy to create new drainage pathways. We work with specialized pediatric ophthalmologists to ensure your child receives the best possible care.
With early surgical treatment, many children with congenital glaucoma can develop good vision and lead normal lives. However, they require lifelong monitoring by our eye care team and may need additional treatments or surgeries as they grow. We partner with families to provide comprehensive, ongoing care throughout childhood and into adulthood.
Frequently Asked Questions
Here are answers to some of the most common questions our patients ask about glaucoma.
Currently, there is no cure for glaucoma, but we can successfully manage it to prevent or slow further vision loss. With proper treatment and regular monitoring at our practice, most people with glaucoma maintain good, functional vision throughout their lives.
Adults over 40 should have comprehensive eye exams every one to two years. If you have a family history or other risk factors, we may recommend more frequent screening. Patients diagnosed with glaucoma typically need check-ups every three to six months so we can closely monitor the condition.
While lifestyle changes cannot prevent glaucoma, healthy habits can support overall eye health and may slow progression. Regular moderate exercise, a diet rich in leafy greens and omega-3 fatty acids, not smoking, limiting caffeine, and managing stress can all be beneficial. We provide personalized recommendations based on your specific type of glaucoma.
Most people can continue their normal activities without restrictions. However, you should avoid activities that put your head in a downward position for extended periods, such as certain yoga poses like headstands. You should also avoid lifting extremely heavy weights. Discuss any specific concerns about your favorite activities with our team during your visit.
Early-stage glaucoma usually does not affect your driving ability. However, advanced cases with significant peripheral vision loss may impact driving safety. We can assess whether your vision meets legal driving requirements and help you make informed decisions about when it might be time to limit or stop driving.
Yes, family history significantly increases your risk. First-degree relatives of someone with glaucoma have a four to nine times higher chance of developing the condition. If you have a family history, you should have regular comprehensive eye exams with us, even if you have no symptoms.
Missing an occasional dose is usually not harmful, but consistency is key to controlling your eye pressure. Try to take a missed dose as soon as you remember, but do not double up on doses. If you frequently forget, talk to us about reminder strategies, smartphone apps, or longer-acting medications that might work better for your lifestyle.
Yes, children can develop juvenile glaucoma, which appears after infancy but before adulthood. They can also develop secondary glaucoma from eye injuries, medications, or other health conditions. Any vision concerns in a child should be evaluated promptly by our team or a pediatric eye specialist.
We monitor your treatment success through regular eye pressure checks, optic nerve examinations, and visual field tests. Stable test results over time indicate that your treatment is effectively controlling the disease. It is important to attend all follow-up appointments even if you feel fine, as glaucoma damage often occurs without symptoms.
Yes, research is very active and exciting. Recent advancements include minimally invasive glaucoma surgeries, improved laser therapies, and sustained-release drug delivery implants that can reduce the need for daily eye drops. Future treatments being explored include neuroprotective drugs to preserve optic nerve cells, gene therapies, and stem cell treatments.
If left untreated, glaucoma can eventually cause complete blindness. However, this outcome is preventable with early detection and proper, consistent care. Even with significant vision loss, most people retain some central vision. This is why we emphasize the importance of regular screenings and following your treatment plan.
Sudden severe eye pain, rapid vision loss, or seeing halos around lights could indicate an acute glaucoma attack or another serious eye emergency. You should seek immediate medical attention. Call our office during business hours or go to the nearest emergency room after hours. Quick action can save your vision.
In addition to measuring your eye pressure, we use advanced imaging tests to get a complete picture of your eye health. Optical coherence tomography allows us to see your optic nerve in high detail and measure nerve fiber thickness. We also use fundus photography to document your optic nerve appearance and visual field testing to map any peripheral vision loss. These comprehensive tests help us detect glaucoma early and monitor changes over time.
Yes, medication choice depends on the type of glaucoma and your individual health. For example, prostaglandin analogs are often our first choice for open-angle glaucoma because they work well and have few side effects. Your ophthalmologist will tailor the treatment to your specific needs, medical history, and the type of glaucoma you have.
Without treatment, the progressive damage to your optic nerve from glaucoma can cause irreversible vision loss and eventually lead to blindness. The vision you lose cannot be recovered, which is why early diagnosis and consistent management are the only ways to prevent these serious outcomes. We are here to help you protect your sight.
Primary open-angle glaucoma, the most common type, is typically painless. However, some forms of secondary glaucoma or chronic angle-closure glaucoma can cause intermittent discomfort, pressure, or mild pain. Any eye pain should be evaluated to determine the cause and ensure you receive appropriate treatment.
Most glaucoma surgeries work by creating a new drainage pathway or improving your existing one to help fluid exit your eye more efficiently. This lowers the internal eye pressure, which reduces stress on your optic nerve and helps preserve your remaining vision. We offer several surgical options, from minimally invasive procedures to traditional surgeries, depending on the severity of your glaucoma.
Yes, patient education and support groups can provide valuable information, coping strategies, and peer support. Organizations like the Glaucoma Research Foundation and the American Academy of Ophthalmology offer many resources for patients and families. We can also connect you with local support resources and educational materials.
Protecting Your Vision at ReFocus Eye Health Stamford
Understanding the different types of glaucoma empowers you to work effectively with our team in protecting your vision. Regular eye exams, following your treatment plan, and staying informed about your condition are the best ways to maintain healthy eyesight and quality of life for years to come. We are committed to providing you with expert glaucoma care using advanced diagnostic technology and personalized treatment approaches. If you have concerns about glaucoma or are due for a comprehensive eye exam, we welcome you to schedule an appointment with our experienced ophthalmologists.
Dr. Gallousis is an excellent surgeon who saved my eyesight twice. I’ve been his patient 18 years and drive over an hour. Petty is also wonderful and kind.
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Referred to my doctor after my ophthalmologist retired. She’s knowledgeable, professional, and has a wonderful bedside manner. Front desk Pettie & Bridget are efficient & kind.
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Very goood team friendly helpful and knowledgeable I recommend Dr Gallousis for your eye care.
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