Causes, types and symptoms of glaucoma, an eye condition that can lead to blindness if left untreated

Glaucoma is one of the leading causes of blindness, but regular eye check-ups can prevent significant vision loss (Image: Canva)

Glaucoma is an eye condition that is marked by increased intraocular pressure (IOP) that may later cause vision loss. The condition rarely presents symptoms in its early stage. Nevertheless, it causes a  gradual loss of peripheral vision, blurred or hazy sight, halos around lights, eye pain or pressure, and difficulty seeing in low light.

It happens when damage to the optic nerve, usually due to high eye pressure, leads to gradual vision loss. You might not notice any symptoms until it’s too late. But the good news is that early detection can help protect your eyesight, says Dr Vishal Arora, Senior Consultant, Cataract, LASIK, Keratoconus, and Dry Eye Specialist at Max Hospital, Gurugram. “Glaucoma is one of the leading causes of blindness, but regular eye check-ups can prevent significant vision loss,” he explains.

Dr Arora shares 5 main types of glaucoma, their symptoms and treatment options:

Also read | Slow down glaucoma: Exercise daily, eat healthy, reduce stress to manage eye pressure naturally

How to prevent glaucoma: Regular eye check-ups, including pressure checks and optic nerve assessments, are crucial (Image: Canva)

Primary open-angle glaucoma (POAG):

It is the most common form of glaucoma that develops gradually. “In its early stages, POAG does not cause pain or noticeable symptoms. You start facing problems when the eye’s drainage system stops working properly, which leads to increased eye pressure. By the time vision changes occur, permanent damage may have already happened,” he says.

Dr Arora cautions that the bigger challenge with POAG is that it’s painless and progresses slowly. “People don’t realise they have it until it’s quite advanced. People with a family history of glaucoma, diabetes, or high blood pressure are at greater risk. Regular eye check-ups, including pressure checks and optic nerve assessments, are crucial,” says Dr Arora, adding, “Treatment may include eye drops to lower eye pressure, but in some cases, laser therapy or surgery may be needed."

Angle-closure glaucoma:

While POAG progresses slowly, angle-closure glaucoma comes on suddenly and can be extremely painful. “It happens when the eye’s drainage system gets blocked, causing a rapid spike in eye pressure. Symptoms can include severe eye pain, headache, nausea, vomiting, and blurry vision,” the expert says.

Also read | Ophthalmologists stress early diagnosis to avoid irreversible blindness

Angle-closure glaucoma is a medical emergency, cautions Dr Arora. “The sudden increase in pressure can damage the optic nerve within hours. People with smaller eyes or a family history of this condition are more at risk,” he adds.

Eye specialists can use laser treatment or surgery to create a new drainage pathway, preventing future attacks. Regular eye check-ups can help identify those at risk.

Normal-tension glaucoma and congenital glaucoma:  

Normal-tension glaucoma is different because optic nerve damage occurs even when eye pressure is within the normal range. Experts believe poor blood circulation, low blood pressure, or genetic factors may play a role. “People with a history of migraines, Raynaud’s syndrome, or sleep apnea should be particularly cautious. Since there are no obvious warning signs, regular eye exams with optic nerve imaging and visual field tests are the best way to catch it early,” says Dr Arora.

Congenital glaucoma is a rare but serious form that affects babies due to an issue with the eye’s drainage system from birth. Symptoms include excessive tearing, sensitivity to light, and enlarged or cloudy eyes. “Early diagnosis is crucial because untreated congenital glaucoma can lead to severe vision loss,” explains Dr Arora. Surgery is usually the best option for correcting drainage problems in infants, helping to preserve their vision.

Secondary glaucoma:

This type of glaucoma develops due to an existing condition like an eye injury, inflammation, a tumor, or prolonged use of steroid medications. “Patients on long-term steroid therapy, whether for asthma, arthritis, or other conditions, should have their eye pressure monitored regularly,” advises Dr Arora. Secondary glaucoma can mimic other types, making diagnosis tricky.

Treatment focuses on addressing both the glaucoma and its root cause. “In some cases, stopping steroid medication or treating the underlying inflammation can help lower eye pressure. Other treatments may include eye drops, laser therapy, or surgery depending on the severity of the condition. Regular follow-ups with an eye specialist are essential for managing this type of glaucoma,” he suggests.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.