What Is the Difference Between Glaucoma & Cataracts?

Eye conditions are common, but they aren’t always the simplest. They can cause anything from blurry vision to light sensitivity, and in some cases, they can even cause total vision loss. 

This is why it’s essential to learn the difference between eye conditions; this way, you can determine whether you’re experiencing a medical emergency. Glaucoma and cataracts are 2 common eye conditions, but what is the difference between them? 

Cataracts develop when the eye’s natural lens begins to cloud over. They cause blurry vision and difficulty distinguishing between different colours. Fortunately, they’re easily treatable. Meanwhile, glaucoma is a complicated group of eye conditions that can cause total vision loss if left untreated.

What Is Glaucoma?

Your eye has a plumbing system of sorts. Nutrients are brought into the eye in the form of aqueous humour, the clear gel-like fluid that makes up a large portion of the eye. However, this system isn’t perfect. Certain conditions can affect the drainage system or how the fluids enter the eye, potentially leading to increased intraocular pressure. The intraocular pressure can lead to chronic, progressive vision loss associated with the most forms glaucoma.   

It’s a group of eye diseases that can affect the eye slightly differently. However, even though the methods are different, the result is often the same—the internal pressure has nowhere to go and begins to damage the optic nerve. This can eventually lead to vision loss and blindness, and this damage is permanent.

The Different Types of Glaucoma

There are many different types of glaucoma, but the following are  the most common:

• Open-angle glaucoma
• Angle-closure glaucoma
• Normal-tension glaucoma
• Secondary glaucoma

Open-Angle Glaucoma

Open-angle glaucoma is the most common form of glaucoma, characterized by a gradual increase of pressure in the eye due to the poor drainage of your aqueous humour. It develops slowly and often without symptoms until the disease progresses significantly.

This can be effectively managed with the help of your optometrist. They can:

• Prescribe medications in the form of eye drops to reduce the production of aqueous humour or increase its outflow, effectively lowering intraocular pressure.
• Recommend lifestyle changes and regular monitoring to manage symptoms and prevent further damage to the optic nerve.
• In some cases, suggest laser treatment or surgical options to improve drainage of aqueous humour if medication is not sufficient.

Angle-Closure Glaucoma

Angle-closure glaucoma is less common but significantly more serious. This condition develops when the iris is too close to the eye’s natural drainage canal and begins to block it entirely.

Pressure can build up very quickly with angle-closure glaucoma. This condition often causes:

• Sudden, severe eye pain
• Headaches
• Blurred vision or vision loss
• Nausea and vomiting
• Eye redness
• Seeing halos around lights

This is a medical emergency; immediately seek medical attention if you notice these symptoms suddenly appearing. Angle-closure glaucoma can quickly lead to permanent vision loss if left unaddressed. You may need surgery to lower the eye pressure and reopen the drainage canal.

Normal-Tension Glaucoma

Normal-tension glaucoma, also known as low-tension or normal-pressure glaucoma, damages the optic nerve even though the fluid pressure inside the eye (intraocular pressure) is within the normal range.

Normal-tension glaucoma affects approximately 30% to 40% of people in Western populations, and that number is much higher in Asian countries. 

Since it is possible to have normal eye pressure and normal-tension glaucoma, it is important for your optometrist to do visual field and optic nerve (RNFL) measurements during an eye exam. 

Secondary Glaucoma

Secondary glaucoma develops when the rise of intraocular pressure is caused by another condition, like:

• An eye injury that disrupts the eye’s natural drainage system
• Inflammation inside the eye (uveitis)
• Advanced cases of cataracts
• Tumours in or around the eye
• Use of steroid medications, which can increase eye pressure
• Certain vascular diseases that affect blood flow to the eye

When treating secondary glaucoma, the treatment often involves addressing the underlying condition causing the pressure to rise. This can often help reduce the symptoms quickly.

What Are Cataracts?

Right near the front of your eye, you have a natural lens, just like a camera. This lens is usually clear and lets light refract into the eye to focus on the retina.

However, sometimes, this lens can become clouded. This is a cataract; a foggy or clouded area located inside this natural lens. This blocks light from fully entering the eye, which can lead to vision problems.

The Signs & Symptoms of Cataracts

When the natural lens is blocked, it often leads to slight blurriness in your vision. However, over time this can lead to:

• Increased difficulty in seeing at night
• Sensitivity to light
• Frequent changes in glasses or contact lens prescription
• Double vision in a single eye
• Seeing ‘halos’ around lights

Cataracts can take years to develop, and many people don’t notice visual changes in the condition’s early stages. However, it’s important to visit your optometrist when you notice changes in your vision.

How to Treat Cataracts

When it comes to cataracts, the only effective treatment is to remove the now-clouded natural lens and replace it with an artificial intraocular lens (IOL). Fortunately, cataract surgery is an extremely standard procedure—it’s one of the most commonly performed surgeries worldwide.

This process typically involves the following steps:

• Before the surgery, your eye care professional will perform a comprehensive eye examination. This assessment includes measuring the size and shape of your eye to choose the appropriate lens implant.
• On the day of the surgery, you’ll receive local anesthesia to numb your eye area so you won’t feel any pain during the procedure. In most cases, you’ll be awake but relaxed.
• The surgeon makes a small incision in the cornea, the clear, dome-shaped surface on the front of your eye. This incision is usually made using a precision laser or a handheld blade.
• Through this incision, the surgeon inserts a tiny probe that emits ultrasound waves to break up the clouded lens into small pieces.
• The fragmented cataract is then gently suctioned out of the eye through the same probe.
• Once the cataract is removed, the surgeon inserts the IOL into the lens capsule of your eye. This takes over the light-focusing function previously held by your natural lens.
• In most cases, the incision made during the surgery is so small that it self-seals without the need for stitches. However, your surgeon will determine if stitches are needed based on your specific situation.

After the surgery, you’ll spend a short period in the recovery area to make sure there are no immediate complications.

You’ll likely be able to go home the same day, but you’ll need someone else to drive. You won’t have immediate vision correction; it’ll likely take a few days before your vision significantly improves.

Find Eye Care in Ottawa

If you’re experiencing anything unusual with your vision, visit us at Downtown Eye Care & The Contact Lens Department. We can provide you with a proper diagnosis and help you begin treatment. Don’t let conditions like glaucoma and cataracts damage your sight; book an appointment with our team today!