Patients are misdiagnosed with glaucoma more often than you might think, according to the American Academy of Ophthalmology.* In fact, there is a wide variety of conditions that can mimic glaucoma. A misdiagnosis can result in treatments that don’t correct the problem and may even make it worse. Learn what other eye conditions present similarly to glaucoma and how to obtain an accurate diagnosis.

What else could it be?

Some of the diseases and conditions that mimic glaucoma include:

• Pituitary adenoma, a non-cancerous tumor on the pituitary gland
• Meningioma, a tumor on the membrane of the brain or spinal cord, of which about 90% are non-cancerous
• Carotid or ophthalmic artery aneurysm, a rare condition involving a weak artery wall
• Thyroid eye disease, an autoimmune disease that causes inflammation
• Orbital tumor, an abnormal lesion or tissue growth in the structures around the eye
• Ischemic or vascular optic neuropathy, involving insufficient blood flow to the optic nerve

How can my doctor tell the difference?

Even well-trained, highly experienced doctors can miss a subtle clue or misinterpret a known one, but your ophthalmologist should be taking into consideration your:

• Personal and medical history
• Age
• Signs and symptoms 
• Comprehensive test results

Personal and medical history

Your personal and medical history may provide valuable clues, even if certain events don’t seem related to your eyesight. 

Some potential examples of this could include:

• A car accident or sports injury may have resulted in a trauma that caused a lesion to develop, which is now pressing on a nerve. 
• A genetic predisposition for intracranial aneurysm could have been activated. 
• Cancer or a blood clot somewhere else in your body could be affecting multiple systems.

Age

Your doctor should consider your age when diagnosing your vision problem. Glaucoma is far more frequent in patients over 60 years old. In younger patients, genetics, traumatic injury,  inflammation, and infection are more likely causes of vision loss. Middle-aged patients may experience vascular issues that affect blood flow to the eye. Even older patients are just as likely to have ischemic neuropathies as they are to have glaucoma. Sudden vision loss is one indication that the issue may be vascular, as glaucoma occurs gradually over many years.

Signs and symptoms

There are a variety of signs and symptoms that are not common to glaucoma and would suggest that another kind of issue is at work. Tell your ophthalmologist if you have experienced or are experiencing any of the following ocular or neurological signs, symptoms, or events: 

 Ocular

• Sudden or quickly progressing vision loss
• Vision that’s different in only one eye
• Lack of color vision in one eye 
• Vision loss with eye movement
• Vision loss that came on with a severe headache
• Double vision
• Temporary graying or blacking out
• Orbital ache or pain
• Central vision loss without peripheral vision loss

Neurological

• Previous brain trauma or brain problem
• Numbness, weakness, or tingling
• Headaches, especially those that awaken them in the morning
• Reduced sex drive
• Droopy eyelid or facial asymmetry

Comprehensive testing

Your doctor should perform a comprehensive exam and evaluate all the results to make sure that they match the symptoms you’re experiencing. 

A comprehensive exam will include tests for:

• Visual acuity
• Color vision
• Pupil response
• Visual fields
• Eye movement
• Intraocular pressure (IOP)

They should also be looking for droopy eyelids and facial asymmetry. Your doctor may even send you for a medical check-up to test for high blood pressure and diabetes, which are high-risk factors for glaucoma.

What should they do if they’re not sure it’s glaucoma?

If after assessing your history, age, symptoms, and comprehensive test results, your ophthalmologist is still unsure, they can request further evaluation and testing. 

Your neuro-ophthalmologist may recommend such imaging tests as:

• Magnetic resonance imaging (MRI), to check for tumors, lesions, and structural abnormalities
• Magnetic resonance angiogram (MRA), to assess arteries for stenosis, occlusions, aneurysms
• Computed tomography angiography (CTA), to analyze arteries and veins for blockages or damage
• Optical coherence tomography (OCT), to map and assess the thickness of your retinal layers

While eye specialists have high-level technology and many tools at their disposal, their greatest resources are human. As Joseph Panarelli, MD, an associate professor of ophthalmology at NYU Langone Medical Center, said, “The biggest take-home message is listen to the patient and ask for help.”

*Stuart, A. (2018, Nov.). When It’s Not Glaucoma. EyeNet Magazine [American Academy of Opthamology]. https://www.aao.org/eyenet/article/when-its-not-glaucoma

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