Glaucoma is an eye condition caused by a build-up of pressure in your eye. Over time, it can lead to damage to your optic nerve (which transmits electrical impulses from your eye to the brain). This damage can cause changes in your vision, including loss of vision.
Secondary glaucoma is what we call any type of glaucoma where there’s an identifiable underlying problem, such as a medical condition or trauma. In primary glaucoma (the most common type of glaucoma), there is no identifiable cause. Although the two types of glaucoma have different causes, the increase in eye pressure and potential damage to the optic nerve is the same in secondary glaucoma as it is in primary glaucoma.
Diagnosing and treating secondary glaucoma is essential for your vision. If left untreated, the damage to your optic nerve can cause permanent visual impairment and lead to blindness. In this blog post, we will look at the main causes of secondary glaucoma, glaucoma symptoms and what treatments are available. Explore secondary glaucoma with The McIndoe Centre.
Causes of secondary glaucoma
There are many possible causes of secondary glaucoma such as injuries, accidents, and underlying health conditions.
Trauma or injury
Trauma to your eye, such as a penetrating injury or chemical burn can cause immediate secondary glaucoma or it can occur over time. Blunt trauma to your eye can even change its shape, causing pressure to build up over a longer period, eventually leading to secondary glaucoma.
This eye condition develops when the uvea (the middle layer of your eye) becomes swollen — leading to increased eye pressure and potentially causing secondary glaucoma.
Secondary ocular hypertension
This type of secondary glaucoma can occur after surgery on your cornea (the clear window in the front of your eye) or as a result of corneal disease. Steroids are often used to treat corneal disease, which can lead to increased eye pressure.
Iatrogenic secondary glaucoma
This type of secondary glaucoma most commonly occurs as a result of retinal surgery. During retinal surgery, gas or silicone oil is sometimes inserted into the eye. Both of these can increase the pressure in your eye and lead to secondary glaucoma.
Lens-related secondary glaucoma
Conditions that affect the lens in your eye, like cataracts, can increase your eye pressure. Advanced cataracts can block pathways between your pupil (the opening at the centre of your eye) and the rest of your eye, leading to secondary glaucoma.
Medicine-related secondary glaucoma
This type of secondary glaucoma is caused by inflammatory medications, like steroids, which can increase pressure in your eye. Medicine-related secondary glaucoma is most common when steroids are applied locally to your eye when treating conditions like uveitis.
Pigment dispersion syndrome and pseudoexfoliation secondary glaucoma
These are two of the most common types of secondary open-angle glaucoma. Pigment dispersion and pseudoexfoliation are grouped together because they both cause blockages in the drainage system of your eye.
Pigment dispersion is where pigment from your iris (the coloured part of your eye) breaks away and causes blockages. Pseudoexfoliation is where deposits of protein develop in your eye. These deposits can be moved into the drainage system as your eye moves, which leads to blockages over time. These blockages increase your eye pressure and lead to secondary glaucoma.
Neovascular secondary glaucoma
This type of secondary glaucoma develops when poor blood supply in your eye causes new blood vessels to grow. These new blood vessels increase your eye pressure and lead to secondary glaucoma. Neovascular secondary glaucoma is often caused by diabetic retinopathy.
Symptoms and diagnosis
Secondary glaucoma may not cause symptoms until it becomes more advanced. However, early signs can include needing more light to read or noticing that colours aren’t as bright. You may also find that your peripheral vision changes. The damage to your optic nerve doesn’t cause pain.
Some forms of secondary glaucoma may have early warning signs. For example, when the pressure in your eye is suddenly elevated due to trauma or injury, symptoms such as headaches, blurred vision and pain in the eye can occur.
Diagnosing secondary glaucoma
Secondary glaucoma is diagnosed with the support of comprehensive eye examinations and specialised glaucoma tests. The main nerve in your eye can be checked with an ophthalmoscope to view your retina and examine the blood vessels in your eye. Your intraocular eye pressure is also measured in a tonometry test. Finally, your field of vision is checked in a perimetry test. None of these tests are invasive and are easily carried out with minimal discomfort.
These tests can only be carried out by an optometrist or an ophthalmologist and they will show early signs or advanced stages of secondary glaucoma.
If you experience sudden changes in vision or pain in your eyes, always seek medical attention immediately.
The treatment options for primary and secondary glaucoma are essentially the same. This is because the main goal is to reduce your intraocular eye pressure and prevent further damage to your vision. However, treatment can also include managing or controlling the underlying cause of your glaucoma, such as diabetes.
Medications for secondary glaucoma
Different medications can be used to lower your eye pressure and decrease the risk of damage to your optic nerve. Medication can be in the form of tablets or eye drops and can sometimes be combined for optimal results.
Common medications used to manage secondary glaucoma include topical beta-blockers, carbonic anhydrase inhibitors (CAI) and prostaglandin analogues. The dosage and type of medication used will depend on the severity of your condition and how well you respond to initial treatments.
Like any medicine, medications for secondary glaucoma may cause some side effects. These will depend on the medication you are taking, but side effects can include nausea, frequent urination or eyelid swelling.
Laser treatments, such as trabeculoplasty and laser peripheral iridotomy, can be used to enhance the drainage within your eye or create small holes to allow more light to pass through respectively.
These treatments are often advised if medication hasn’t helped or your condition is getting worse.
Surgery can sometimes be the best option when treating secondary glaucoma. Minimally invasive glaucoma surgery (MIGS) is used for mild to moderate cases of the condition and is recommended if you don’t respond to medication or laser treatments. MIGS uses different stents to open up the drainage system in your eye and prevent the blockages causing further eye pressure.
All surgeries have potential risks, such as infection or complications during the procedure. But these are relatively rare and surgery can be a successful way to prevent further vision loss caused by secondary glaucoma.
Leading a healthy lifestyle is an important part of managing secondary glaucoma. This is because conditions like diabetic retinopathy can be an underlying cause.
Eating a well-balanced diet and exercising regularly is crucial for your overall eye health. When undergoing treatment for secondary glaucoma, you may be advised to make lifestyle adjustments to complement medical treatment.
Prevention and risk reduction of secondary glaucoma
It’s not always possible to prevent the development of secondary glaucoma, but there are things you can do to reduce your risk. For example, wearing protective eyewear when partaking in activities that may damage your eye. Keeping your eyes safe from harm can drastically reduce the risk of trauma-related secondary glaucoma.
Another important aspect when preventing secondary glaucoma is effectively controlling or managing any underlying health conditions. For instance, diabetic retinopathy puts you at an increased risk, so keeping your condition under control is essential.
Having regular eye check-ups is also a key factor in the risk reduction of secondary glaucoma. At these check-ups, early signs of secondary glaucoma can be spotted. These signs ordinarily don’t cause symptoms, so you might not notice them yourself. But with the support of a professional ophthalmologist, your condition can be diagnosed and treated as soon as possible.
Book a consultation at The McIndoe Centre
If you are concerned about developing secondary glaucoma or if you’re experiencing problems with your vision, book a consultation with The McIndoe Centre. Our expert team is here to support you from the very beginning of your journey to diagnosis, treatment and beyond.
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