Fundus fluorescein angiography is a common procedure that is performed to give your doctor more information about the condition of the back of your eye. A small amount of yellow fluorescein dye will be injected into a vein in your arm. The dye travels to your eye where it highlights the blood vessels. It is particularly useful in showing leaking blood vessels and highlighting where the blood supply at the back of the eye is poor. Photographs will then be taken of the eye.
The test takes place at Javed Eye Centre and lasts between 10 and 15 minutes. The results will help your ophthalmologist to decide the best way to treat your eye condition.
Why should I have a fundus fluorescein angiography?
This test will give your eye doctor important information to help understand your eye condition and plan how to treat it.
What happens before the procedure?
You will have eye drops put in to dilate your pupils (make them bigger). The drops will give us a clearer view of the retina at the back of the eye (also known as the fundus). You will also be asked a few questions about your general health.
What happens during the procedure?
A small tube will be placed into a vein in your arm. This is called an intravenous cannula. The fluorescein dye will then be injected through this into the blood stream. Within seconds, the dye travels through the blood vessels to reach your eye.
A series of rapid photographs will then be taken and it is important that you keep as still as possible at this stage. The nurse may help you to keep your eyes open by gently holding your eye lids. You will then be asked to sit back for a few minutes to rest before a further series of photos are taken. The test should take no longer than 15 minutes to complete.
Please tell the nurse if you feel unwell at any point. It is common to feel slightly nauseous as the dye goes in, but this passes quickly. Taking deep breaths often helps.
What are the side effects of FFA?
After the injection of fluorescein dye, your skin and your urine will turn yellow for approximately 24–48 hours. This is normal and is not harmful and you should not be worried by this. Drinking plenty of water afterwards can help flush the dye through your system.
Some of the other more common side effects (affecting approximately five people out of a 100) include:
It is important that you let us know if you have any allergies or if you have had an unexpected reaction to fluorescein dye before.
Very rarely, people can have a serious allergic reaction (anaphylaxis) to the fluorescein dye causing breathing or circulatory difficulties. We are equipped to deal with this emergency and if it happens the emergency medical team will be contacted.
What happens after the procedure?
You will be asked to stay in the department for approximately 30 minutes after the test so that you can be observed for any late side effects. The cannula will then be removed before you go home.
As your pupils will still be dilated (bigger than usual), your eyes will be very sensitive to sunlight for at least two hours. It is advisable to wear sunglasses or a hat to reduce the discomfort.
You must not drive for at least 2 hours after the procedure or until your pupils return to their normal size. You are advised to bring someone with you to help you get home.
OCT is useful in the diagnosis of many retinal conditions, especially when the media is clear. In general, lesions in the macula are easier to image than lesions in the mid and far periphery. OCT can be particularly helpful in diagnosing:
In some cases, OCT alone may yield the diagnosis (e.g. macular hole). Yet, in other disorders, especially retinal vascular disorders, it may be helpful to order additional tests (e.g. fluorescein angiogram).
The GALILEI Dual Scheimpflug Analyzer is a high precision optical system for corneal topography and three dimensional analysis of the anterior eye segment, based on a Revolving Dual Channel Scheimpflug Camera and a Placido Disk. GALILEI combines the advantages of two technologies: Placido imaging furnishes high accuracy curvature data, while Scheimpflug imaging is optimal for precise elevation data.
The Galilei Scanner helps your surgeon determine if your eyes are suitable for corrective surgery.
A-scan ultrasound biometry, commonly referred to as an A-scan, is routine type of diagnostic test used in ophthalmology. The A-scan provides data on the length of the eye, which is a major determinant in common sight disorders. The most common use of the A-scan is to determine eye length for calculation of intraocular lens power. Briefly, the total refractive power of the emmetropic eye is approximately 60. Of this power, the cornea provides roughly 40 diopters, and the crystalline lens 20 diopters. When a cataract is removed, the lens is replaced by an artificial lens implant. By measuring both the length of the eye (A-scan) and the power of the cornea (keratometry), a simple formula can be used to calculate the power of the intraocular lens needed. There are several different formulas that can be used depending on the actual characteristics of the eye.
The other major use of the A-scan is to determine the size and ultrasound characteristics of masses in the eye, in order to determine the type of mass. This is often termed quantitative A-scan.
Instruments used in this type of test require direct contact with the cornea, however a non-contact instrument has been reported. Disposable covers, which come in actual contact with the eye, have also been evaluated.
B-scan ultrasonography is done to look at the inside part of the eye or the space behind the eye that cannot be seen directly. This may occur when you have cataracts or other conditions that make it hard for the doctor to see into the back of your eye. The test may help diagnose retinal detachment, tumors, or other disorders.
A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, brain tumours or other neurological deficits. Visual field testing can be performed clinically by keeping the subject's gaze fixed while presenting objects at various places within their visual field.