Ocular Ultrasound: What It Is

 

 

Ocular ultrasound is a test that uses sound waves to create pictures of the inside of your eye — especially helpful when your doctor can’t see the back of your eye clearly because of things like cataracts, bleeding, or severe swelling.

 

There are two main types of ocular ultrasound used in eye care: B-scan and A-scan. Each one helps with different things.

 

 

 

 

1. B-Scan Ultrasound

 

 

“B” stands for Brightness – this scan shows a picture of the inside of the eye.

 

What it does:

 

• Creates a two-dimensional image (like a black-and-white movie) of the inside of the eye and the space behind it.

• Used when the doctor can’t see the retina directly, such as if there’s a cataract, blood, or something blocking the view.

 

 

What it’s used for:

 

• Detecting retinal detachments

• Finding tumors or masses in or behind the eye

• Checking for bleeding (vitreous hemorrhage)

• Diagnosing trauma or injury to the eye

• Evaluating inflammation or infection in the back of the eye

 

 

What it’s like:

 

• A small probe is gently placed on your closed eyelid with gel, and the image shows up on a screen.

 

 

 

 

 

2. A-Scan Ultrasound

 

 

“A” stands for Amplitude – this scan measures eye structures in numbers, not pictures.

 

What it does:

 

• Measures the length of the eye and the size of its internal parts.

 

 

What it’s used for:

 

• Most commonly used before cataract surgery to calculate what power of lens implant you need.

• Also helps diagnose unusual eye growths or tumors.

 

 

What it’s like:

 

• The test is usually done with your eyes open using numbing drops, and a tiny probe gently touches the front of your eye.

 

 

 

 

 

3. UBM (Ultrasound Biomicroscopy)

 

 

A special high-frequency ultrasound for seeing the front part of the eye in great detail.

 

What it does:

 

• Shows detailed images of the structures in the front part of the eye — like the iris, lens, and drainage system.

 

 

What it’s used for:

 

• Diagnosing narrow or closed-angle glaucoma

• Detecting tumors or cysts in the front of the eye

• Checking for problems with the lens or implants after surgery

 

 

What it’s like:

 

• Usually done with numbing drops, and a special water bath or gel is used to help the probe move smoothly over the eye.