What is ophthalmoscopy?
Ophthalmoscopy is a test that allows your ophthalmologist, or eye doctor, to look at the back of your eye. This part of your eye is called the fundus, and consists of:
- optic disc
- blood vessels
This test is often included in a routine eye exam to screen for eye diseases. Your eye doctor may also order it if you have a condition that affects your blood vessels, such as high blood pressure or diabetes.
Ophthalmoscopy may also be called funduscopy or retinal examination.
When is ophthalmoscopy used?
Your eye doctor can use ophthalmoscopy to screen for eye diseases and conditions that can affect blood vessels. These conditions include:
- damage to your optic nerve
- retinal tear or detachment
- glaucoma, which is excessive pressure in your eye
- macular degeneration, a loss of vision in the center of your visual field
- cytomegalovirus (CMV) retinitis, an infection of your retina
- melanoma, a type of skin cancer that can spread to your eye
- hypertension, which is also known as high blood pressure
How should you prepare for ophthalmoscopy?
Before conducting an ophthalmoscopy, your eye doctor may use eye drops to dilate your pupils. This makes them larger and easier to look through.
These eye drops can make your vision blurry and sensitive to light for a few hours. You should bring sunglasses to your appointment to protect your eyes from bright light while your pupils are dilated. And you should arrange for someone to drive you home after your test. If you do work that requires clear vision, such as operating heavy machinery, you should also arrange to take the rest of the day off.
If you’re allergic to any medications, tell your eye doctor. They will likely avoid using eye drops if you’re at risk of an allergic reaction.
Some medications may also interact with the eye drops. It’s important to tell your eye doctor about any medications that you take, including over-the-counter medications, prescription medications, and dietary supplements.
Finally, you should tell your eye doctor if you have glaucoma or a family history of glaucoma. They probably won’t use eye drops if they know or suspect that you have glaucoma. The drops could increase the pressure in your eye too much.
What happens during the test?
At the beginning of the procedure, your eye doctor may use eye drops to dilate your pupils. The drops may cause your eyes to sting for a few seconds. They can also cause an unusual taste in your mouth.
Your doctor will examine the back of your eye after your pupils are dilated. There are three different types of examinations that could be done:
- direct examination
- indirect examination
- slit-lamp examination
Your doctor may perform one or more of these examinations to get a good view of your eye.
You’ll be seated in a chair. The lights in the room will be turned off. Your eye doctor will sit across from you and use an ophthalmoscope to examine your eye.
An ophthalmoscope is an instrument that has a light and several small lenses on it. Your eye doctor can look through the lenses to examine your eye. They may ask you to look in certain directions as they conduct the examination.
This test allows your eye doctor to see the structures in the back of your eye in more detail.
For this test, you’ll be asked to lie down or sit in a reclined position. Your eye doctor will wear a bright light positioned on their forehead. They will shine it in your eye while holding a lens in front of your eye to help them examine it.
Your doctor may ask you to look in certain directions while they examine the back of your eye. They may also apply some pressure to your eye using a small, blunt probe.
This procedure gives your eye doctor the same view of your eye as an indirect examination, but with greater magnification.
You’ll sit with an instrument in front of you, known as a slit-lamp. It will have a place for you to rest your chin and forehead. This will help keep your head steady during your exam.
Once you’re positioned, your eye doctor will turn on a bright light in front of your eye. Then they will use a microscope to look at the back of your eye. They may ask you to look in different directions, and use their finger to open your eye to get a better view. They may also apply some pressure to your eye using a small, blunt probe.
What are the risks?
An ophthalmoscopy is sometimes uncomfortable, but it shouldn’t be painful. You may see afterimages after the light has been turned off. Those afterimages should go away after you blink several times.
In rare cases, you may react to the eye drops. This may cause:
- dry mouth
- nausea and vomiting
- narrow-angle glaucoma
Ask your doctor for more information about the potential risks and side effects.