Overview of Seidel Test
About 3% of people visiting the emergency department each year do so due to eye-related problems. Out of this group, between 38 to 52% are dealing with eye injuries ranging from minor scrapes to severe damage like a ruptured eyeball. Eye trauma is a significant problem worldwide, and is known to cause complete vision loss in both eyes for over a million people. Additionally, it results in vision loss in one eye for around 500,000 individuals. This makes eye injury one of the chief causes of vision loss. Because of this, it’s vitally important that eye injuries are thoroughly checked to ensure any damage present is identified as it can help prevent further loss of vision.
The Seidel test is one method that can be used to check for eye trauma. This test looks for any leaking of a liquid from the eye called aqueous humor, which generally means there’s a defect in the cornea (the clear front surface of the eye) or sclera (the white part of the eye). Leaks can occur for a variety of reasons: an eye injury, a leak after eye surgery, a hole in the cornea, or degeneration of the cornea. The test was originally developed in 1921 by Dr Erich Seidel, a German eye doctor. At first, Dr Seidel used the test to find leaks in patients who’d just had surgery. Later, the Seidel test was also used to check for leaks that were caused by other reasons.
Anatomy and Physiology of Seidel Test
The eye is a rather complicated organ that requires several parts to work together for it to function properly. One test, called the Seidel test, checks for any damage to the cornea (the clear protective layer in the front of the eye) or sclera (the “white” part of the eye). The sclera gives your eye its shape and protection, and it becomes clear at the front, forming what we know as the cornea.
The cornea is a transparent layer that sits in front of the pupil, iris, and lens of the eye; it is the first point of contact for incoming light. The cornea has a lot to do with the eye’s focusing power. It’s fascinating to know that the cornea is made up of 5 thin layers: the corneal epithelium, Bowman’s layer, corneal stroma, Descemet’s membrane, and corneal endothelium.
Despite the complexity of the cornea, its combined layers are approximately 550 micrometers thick – a bit more than half a millimeter. The outermost layer, the epithelium, is around 5 to 7 cells thick and provides the eye with a smooth surface for forming tear film. This tear film keeps the eye moist, healthy, and helps to see clearly. The epithelium is replaced routinely over about a week. Just beneath it is the Bowman layer, a fibrous sheet that guards other deeper layers of the cornea. A scratch that extends beyond this layer has a high chance of leaving a scar.
Beneath Bowman’s layer is the stromal layer, which comprises about 90% of the cornea. It is made of a type of connective tissue called collagen fibrils, arranged neatly in rows, which enables it to be transparent. Descemet’s membrane is a very thin layer coming next, separating stroma from the endothelial layer. Finally, the endothelium is one cell thick and directly communicates with the eye’s anterior chamber, a fluid-filled space located just behind the cornea and ahead of the iris and pupil. Behind the iris and the pupil is an area called the posterior chamber, home to various structures not covered in this particular explanation.
Why do People Need Seidel Test
When you have had an injury around your eyes, a Seidel test can help doctors to check if there’s a leakage from your eyes. This test is used if you’ve had facial injuries, eye injuries, or eye surgery and there are signs of leakage from the eyes, which can cause serious complications if not detected in time. Some things that might make your doctor think that you need a Seidel test include:
* A change in your pupils (the black circles in the middle of your eyes)
* A cut through your eyelid
* A shallow or less deep part just behind the clear dome of your eye (the cornea)
* The presence of blood inside the clear dome of your eye
* Blood building up under the clear skin that covers the white part of your eyes
* A recent eye surgery with signs of leaking
* Checking whether a cut or tear on the clear dome of your eye (cornea) has closed up properly
* A hole in the clear dome of your eye caused by damage over time.
In these cases, your doctor will likely perform a Seidel test to confirm any leaks from your eye and provide necessary treatment.
When a Person Should Avoid Seidel Test
There are several reasons why a person may not be able to have the Seidel test, which is a procedure used to check for leakage in the eye after an injury:
- If the globe of the eye (the eyeball itself) is visibly ruptured, the test cannot be performed.
- If the person has an eye laceration, or a deep cut, that goes through the full thickness of the eye, they cannot have the Seidel test.
- The test isn’t possible if there is an obvious perforation or hole in the cornea, which is the clear front surface of the eye that helps your eye focus light.
- If a person is hypersensitive, or extremely allergic, to a dye called fluorescein that is used during the test, they also cannot have the Seidel test.
Equipment used for Seidel Test
The Seidel test is a simple procedure that doesn’t need many resources. However, it does need specific items to make sure the results are accurate. The things you need include:
- Fluorescein strip: a small, thin paper strip coated with a special dye.
- Topical ophthalmic anesthetic: a type of eye drops used to numb the eye for the procedure.
- Slit-lamp with cobalt blue light: a special microscope with a blue light used by doctors to examine the eye in detail.
These tools are necessary for the test to work correctly.
Who is needed to perform Seidel Test?
The Seidel test is a simple procedure that can be carried out by healthcare professionals who are trained to use the necessary dye and understand the results generated. Generally, this test is done by doctors and their medical assistants. They don’t require any extra help from other medical staff to carry out the test.
Preparing for Seidel Test
Get the room ready for the check-up and gather all the required tools and medicines. The outermost layer of the eye, called the cornea, is extremely delicate. If it gets damaged, it could lead to a condition called photophobia, which makes a patient very sensitive to light, making it difficult for them to go through an eye examination. That’s why it’s best to reduce the amount of light in the room as much as you can. This not only ensures that the patient is comfortable, but also helps make the check-up process more effective.
How is Seidel Test performed
The Seidel test is a process to check for injuries in your eye such as cuts or scratches on your cornea (the clear front surface of your eye). Here’s a simple breakdown of the steps:
1. The room is prepared with all needed equipment.
2. A special microscope, known as a slit lamp, is set up.
3. The process is explained to you so you know what to expect.
4. A numbing eye drop is applied to your eye.
5. A strip of dye, known as fluorescein, is wet with a salt solution.
6. This dye strip is then placed just above the suspected injury or at the upper part inside of your eyelid.
7. You will be asked to blink so the dye can spread across your eye.
8. The injury site is then examined under a blue light.[6]
The dye is usually orange to red color, but when it gets diluted, or spread out, it turns green under the blue light. If there’s a wound or scratch on your cornea, the dye will stick to it. If the Seidel test is positive, it means you might have a severe eye injury. This is evident from the dye turning bright green and trickling down your eye like a waterfall, especially when viewed under the blue light.
Sometimes, a test can show a false negative (meaning, the test says you’re free of injury, but you’re not) in certain cases:
– If there’s a tiny injury that has healed on its own
– If there’s a large cut that has become blocked in some way
– If there’s a tear or rupture behind your eyeball
If the doctor still suspects serious eye damage despite a negative Seidel test, they might recommend a CT scan of your orbit (eye socket). This can help to check for a collapsed front part of your eye or any foreign objects in the eye.[7]
Possible Complications of Seidel Test
Before getting your eye checked with a stain, you need to take out your contact lenses. This is because the solution used for staining, called fluorescein, can permanently discolor the lenses. After this test, if no injury is discovered, you should keep your contact lenses off for about an hour. Don’t worry about the skin around your eye – any stain from the fluorescein fades away after a few hours.
There is a potential risk of missing a burst eye globe if the cut or puncture has already closed up or if it’s in a location that can’t be properly checked using the Seidel test. This test is typically used to detect if the back part of your eye has been ruptured or punctured. Your doctor will use this test if there are concerns that your eye may have been seriously damaged.
What Else Should I Know About Seidel Test?
If the Seidel test is positive, it means that the fluid inside of your eye (the aqueous humor) is leaking from the front chamber. This is a serious eye emergency.
If you’ve received a positive Seidel test:
- You’ll need to contact an eye specialist right away for surgery to fix the issue.
- You should avoid further injury by not touching or putting pressure on the eye. It is particularly important not to test your eye pressure or get an eye ultrasound done.
- You can protect your eye by covering it with a metal shield or another cover that won’t press against the eyeball. However, you should avoid covering the eye with a patch.
Since a rise in the pressure inside your eye can cause damage, you should:
- Rest in bed and avoid straining, bending, or lifting heavy objects.
- Consider anti-nausea medication and using a Foley catheter (a type of tube placed in the bladder to drain urine).
Your doctor may also suggest taking steps for pain control, updating your tetanus shot, and intravenous (through a vein) antibiotics.
There are different antibiotics depending on whether or not you have something foreign in your eye. For example, if there is no foreign body in the eye, they might start with one type of antibiotic (fluoroquinolone), and if that does not work, they could switch to a combination of Vancomycin and Ceftazidime.
If there is a foreign body in your eye, doctors prefer to start with Ceftazidime and Vancomycin. For those allergic to penicillin, a combination of Cipro and Vancomycin could work.
No antibiotics are to be taken directly into your eye to treat this condition.
