WHAT IS OPHTHALMOSCOPY?
This is a test that your eye physician or ophthalmologist will be given the opportunity to take a look at the back part of your eye. That part of your eye is called the fundus and will consist of:
- The retina
- The optic disc
- The blood vessels
This is a routine eye exam that aims to identify and diagnose eye diseases. If you have conditions that affect your blood vessels, such as high blood pressure or diabetes, your eye physician will recommend that you undergo the examination so that you will know if you have any issues.
WHY IS THE PROCEDURE DONE?
Since your eye physician tests for eye diseases and conditions that affect the blood vessels, the test reveals whether you:
- Have damage to your optic nerve
- Have a retinal tear or detachment
- Have glaucoma (which is excessive pressure in your eye)
- Have macular degeneration, which is a loss of vision in the center of your visual range
- Have cytomegalovirus (CMV) retinitis [this is an infection of your retina]
- Have melanoma (which is a type of skin cancer that can spread to your eye)
- Have hypertension (this is also known as high-blood pressure)
- Have diabetes
HOW DO YOU PREPARE?
Before conducting an ophthalmoscopy, your eye doctor may use eye drops to dilate your pupils, this will make them larger and easier to look through. However, using eye drops can make your vision blurry and sensitive to light for a few hours therefore you should bring sunglasses to your appointment to protect your eyes from bright light while your pupils are dilated, in this case you should make arrangements for someone to drive you home after your test. If you do work that requires a focused and clear vision, you should also make arrangements to take the rest of the day off. If you are allergic to any medications you should then tell your eye physician, as they will likely avoid using eye drops if you are at a risk of an allergic reaction. This also goes for any medications as some may react to the eye drops, so it is best to inform your eye physician about any medications you are currently taking or have been taking recently, this includes over-the-counter medications, prescription medications, as well as dietary supplements.
If you have glaucoma or have a family history with glaucoma, you should tell your eye physician, as they will probably not use the eye drops as it could increase the pressure in your eye excessively.
WHAT HAPPENS DURING THE EXAMINATION?
In the beginning of the examination, the eye physician may or may not use eye drops to dilate your pupils. If the physician uses the drop it may cause a stinging sensation for a few seconds. This can also cause an unusual taste in your mouth. After this the physician will examine the back of your eye after your pupils are dilated. There are 3 different types of examinations that could follow:
- A direct examination - You'll be directed to sit on a chair. The lights in the room will be turned off, while your physician will sit across from you and will examine your eye using an ophthalmoscope. During the examination your physician may ask you to look in certain directions.
- An indirect examination - This test will allow your eye physician to see the structures in the back of your eye at greater detail. The position you'll be asked to assume is to either lie down completely or sit in a reclined position. Your eye physician will then wear a device with a bright light positioned on their forehead, in this position they will face down and shine the light in your eye while holding a lens in front of your eye as your physician then examines you. Your physician may also ask you to look in certain directions during the examination and may also apply some pressure to your eye using a small, blunt probe.
- Slit-lamp examination - This procedure will give your physician the same view of your eye as an indirect examination, but will use an instrument known as a slit-lamp for greater magnification. In this examination you'll be able to rest your chin and forehead as this will help you to keep your head steady during the examination. Once you are properly positioned your eye physician will turn on a bright light in front of your eye, then will use a microscope to look at the back of your eye as well. Your physician may also ask you to look in different directions, and may use their finger to open your eye to get a better view, your physician may also apply some pressure to your eye using a small, blunt probe.
Your doctor may perform one or more of these examinations to get a good view of your eye.
WHAT ARE THE RISKS?
An ophthalmoscopy may be sometimes uncomfortable, but it shouldn't be painful. You may see some afterimages after the light has been turned off, those afterimages however should go away after you blink several times.
In the rare case that you react to the eye drops, it may cause:
- Dry mouth
- Nausea and vomiting
- Narrow-angle glaucoma
Be sure to ask your physician for more information about the potential risks and side effects.