Glaucoma and cataracts are two common and potentially serious eye conditions. Learn the key differences you need to know.
Glaucoma and cataracts are two of the most common eye conditions. Both are potentially serious disorders that can damage the eye and lead to vision loss.
While the two share things in common, there are important differences to be aware of. Understanding the unique causes, symptoms, and treatment options for glaucoma vs. cataracts can help patients make more informed choices about their eye care.
Glaucoma is a progressive disease that damages the optic nerve. It occurs when fluid builds up and causes high pressure in the eye.
Our eyes produce a fluid called aqueous humor. Healthy eyes both drain and replenish this fluid to keep levels in balance. When the fluid cannot drain naturally and begins to accumulate, intraocular pressure builds up.
This pressure damages the eye’s optic nerves. When left untreated, the damage to the optic nerve can lead to vision loss and permanent blindness.
There are two notable types of glaucoma:
Open-angle glaucoma: This is the most common type of glaucoma. It occurs when the eye does not drain fluid as it should. Open-angle glaucoma is gradual. Patients may appear asymptomatic, but as pressure builds their vision will deteriorate.
Angle-closure glaucoma: This type of glaucoma is less common but more serious. It occurs when the iris blocks the eye’s drainage angle, causing pressure to rapidly rise.
The rising pressure can cause an “acute attack.” These sudden attacks are considered eye emergencies. If a patient is experiencing an acute attack, they should seek immediate medical attention or risk permanent vision loss.
Glaucoma can be difficult to diagnose as symptoms build up slowly over time. In open-angle glaucoma, loss of peripheral vision is usually the first symptom to develop. Many people with open-angle glaucoma do not notice changes in vision until the damage becomes severe.
Patients are more likely to notice symptoms in closed-angle glaucoma as symptoms often manifest in an acute attack, which can include:
Sudden blurry vision
Severe eye pain
Strong headache that can produce nausea and vomiting
Seeing rainbow-colored rings or halos around lights
Patients with a family history of glaucoma should be especially cautious. Glaucoma is hereditary. If a member of your immediate family has the disease, you are at a greater risk.
A cataract is the clouding of the normally clear lens in the eye. In a healthy eye, the lens bends and refracts light, allowing us to see clearly. If someone develops a cataract, this normally clear lens begins to cloud.
As the lens continues to cloud, patients may experience issues such as blurry vision, trouble reading, or in serious cases, vision loss.
Cataracts are a normal part of the aging process. Around half of Americans over the age of 80 have cataracts or have had surgery to remove cataracts.
There is no genetic component to cataracts. They develop over time and become more common with age.
Normal proteins in the eye begin to break down around 40. By age 60, most people will have some clouding in their lenses.
In the early stages, patients may not be aware they have a cataract. Vision problems and other symptoms can take years to develop after a cataract forms.
If the cataract remains untreated, patients may experience:
Double or ghosted vision in the eye with the cataract
Sensitivity to light
Difficulty seeing at night
Seeing bright colors as yellow or faded
Frequent changes in eyeglass or contact lens prescription
Seeing halos around light
Glaucoma and cataracts are two of the most common causes of blindness. However, the severity of vision loss varies between the disorders.
Glaucoma is the leading cause of irreversible blindness. Once a patient is blinded from glaucoma, they cannot regain their vision.
Cataracts are the leading cause of reversible blindness. Patients with cataract-related blindness can restore their vision with successful cataract surgery.
There are multiple medical and surgical treatments available for glaucoma. Some of these treatments aim to prevent the disease from progressing further.
The most common ways to treat glaucoma are:
Eyedrops: Prescription eye drops can reduce high pressure by either decreasing the aqueous humor created in the eye or by helping the fluid drain from the eye.
Laser Treatment: This glaucoma treatment, called selective laser trabeculoplasty (SLT), applies laser energy to drain fluid from the eye and lower pressure. At our office, we often recommend SLT as a first-line therapy.
Surgery: If a patient cannot manage glaucoma through eye drops or laser treatment, they can receive glaucoma surgery. Modern minimally invasive glaucoma surgeries (MIGS) are considered the safest surgical option. MIGS avoid complications that may occur in more invasive glaucoma procedures.
Some patients can treat early or mild cataracts by changing prescription glasses. As cataracts continue to progress and become cloudier, the only treatment option is surgery. Medication and eye drops cannot be used to treat serious cataracts.
Cataract surgery is typically recommended for patients with severe cataracts that disrupt day-to-day activities.
During surgery, the eye doctor will remove the patient's cloudy lens and replace it with an artificial intraocular lens (IOL). This lens allows the patient to enjoy clearer, crisper vision. Surgery restores vision completely, and cataracts will not grow back.
The primary differences between glaucoma vs. cataracts relate to the nature of the disorders, their potential impact on the patient, and the treatments available:
Glaucoma is a disease that damages the optic nerve, whereas a cataract is a natural condition where the lens in the eye becomes cloudy.
Glaucoma leads to irreversible blindness, while cataract blindness is reversible.
Family history plays a role in glaucoma, but not with cataracts.
There are numerous medical and surgical options available for glaucoma (eyedrops, laser treatment, and surgery). Serious cataracts can only be treated with surgery.
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