Understanding Different Types of Glaucoma

The Most Common Type of Glaucoma: Open Angle Glaucoma 

Primary open-angle glaucoma is the most common type of glaucoma. It progresses slowly and is often detected during a routine eye test with an optometrist. While there is no specific cause, your risk increases if you: 

• are over the age of 50 years old  

• have a family history of glaucoma (especially a direct relative such as a parent) 

• are short-sighted 

Prognosis and Treatment 

Early stages of glaucoma can affect your peripheral vision without you noticing, whilst more advanced stages can cause ‘tunnel vision.’ Hence, early detection is key as lost vision cannot be restored.  

Treatment involves instilling and being compliant with eye drops every day and attending regular scheduled appointments with your ophthalmologist and/or optometrist. Other treatment options include laser and surgery, and there are many different types depending on your needs. Your ophthalmologist will help you determine the most suitable treatment option based on the severity of your glaucoma.  

The Most Urgent Need for Treatment: Acute Angle Closure Glaucoma 

Acute angle closure glaucoma is an urgent eye condition that requires immediate treatment. The “angle” that we refer to is formed where the cornea (windscreen of the eye) meets the iris (colored part of the eye). At the apex of the angle there is a drainage system that allows fluid produced by the eye to leave at a controlled, safe pace. When this drainage system is compromised by either something blocking the angle or the angle itself shutting inwards, the fluid builds up within the eye which then causes the eye pressure to increase. This increased pressure often happens quickly and can go up quite high, leading to significant pain and discomfort, and in some cases nerve damage. 

Diagnosis 

Unlike open-angle glaucoma, which is slow to progress, and often symptom-free, acute angle closure causes significant pain, nausea, vomiting and headaches. The eyes may be overly sensitive to bright lights and can appear quite red. Your optometrist/ophthalmologist will measure your eye pressure and may assess your angles for closure with a special lens.  

Chronic angle closure glaucoma can occur in people who have naturally narrow angles, which is more often found in people who are very long sighted or are of East Asian descent. This type of glaucoma can take longer to manifest and may end up being similar to open-angle glaucoma. 

Prognosis and Treatment 

Urgent treatment is key for acute angle closure glaucoma. If you live in the city where there is an eye hospital nearby, it is recommended you go to the emergency department straight away where you will likely receive treatment. If there is no hospital nearby, a glaucoma drug can be given as an oral tablet alongside the pressure lowering eye drops as a first aid measure until you can get to an ophthalmologist.  

Once the eye pressure has been brought back to normal, your ophthalmologist can assess how much/if any vision loss has occurred and whether any procedures need to be performed to prevent reoccurence . Depending on how quickly treatment was administered, complete vision may return.  

Chronic angle-closure glaucoma can be treated with drops and surgery, but ideally, it can be prevented through routine eye testing and a referral to an ophthalmologist. 

Secondary Glaucoma 

Secondary glaucoma is very similar to primary open-angle glaucoma however there is an identifiable underlying cause. For example:   

• Steroid-induced glaucoma: Steroid medication can raise the eye pressure in some people. For this reason, eye pressure is normally checked when starting steroid drops or steroid medication.  

• Congenital glaucoma: Babies can be born with glaucoma due to abnormal development of the eye in utero.  

• Trauma-related glaucoma: There is also a risk of glaucoma after trauma to the eye, where a physical force may damage the angle. This is called angle recession. 

Inflammatory or diabetic-related glaucoma: Glaucoma can also be brought about by ocular conditions like uveitis or diabetic retinopathy. New blood vessels can form in the angle that can block the drainage system, causing the eye pressure to rise.  

Pseudo-exfoliative glaucoma: Dandruff-like material from the lens can block the drainage angle. 

Pigment dispersion syndrome: More commonly found in younger males in their 30s, occurs when pigment from the iris falls off and slowly collects in the angle. In these individuals the eye pressure can rise quite dramatically when exercising or doing excessive movements, which then settles down when resting.  

Glaucoma is one of the leading causes of blindness worldwide. However, with greater understanding of the symptoms and risks, and adherence to treatments and regular eye health checks with your local optometrist/ophthalmologist, vision loss due to glaucoma is often preventable. The easiest way to protect your sight is by having your eyes checked regularly – every 2 years if you are under 65, and once a year if you are 65 or older, or if you have a close family member with glaucoma.  

If changes are detected, it is essential to attend follow up appointments and ensure your optometrist/ophthalmologist is assessing your eyes at the recommended schedule; usually 3 monthly to start with, followed by 6-12 monthly ongoing.  

Between appointments, if you have any questions about your condition or feel overwhelmed with your diagnosis, you can access the free educational resources and expert patient support and advice by calling Glaucoma Australia on 1800 500 880.