What are Fluorescein sodium ophthalmic strips?
Fluorescein sodium ophthalmic strips are mainly used diagnostic strips that stain areas of cellular loss in the corneal epithelium. Fluorescein sodium is a red-orange vital dye and its molecular formula is C20H14Na2O7. It is a member of the Xanthine group of dyes. It is synthesized from the petroleum derivatives- Resorcinol and Phthalic anhydride and is a highly fluorescent chemical compound.
The captivating property of fluorescein sodium is that it absorbs blue light with peak excitation at wavelengths between 495 nm (blue light) and emission at 590nm (green light) in water. An intern emits light at yellow-green wavelengths of 520 to 530 nanometers this phenomenon is fluorescence and It is a form of luminescence. The eye is a complex and delicate optical system and is essential to its optimal functioning. The first refractive surface is the precorneal tear film. The tear film is the silent and unseen hero responsible for our vision. Fluorescein staining makes it prominent its assessment possible.
Read our another article on >>> What is Fluorescein Sodium
Here is the list of Brands and the countries that make Fluorescein sodium ophthalmic strips
|Sports World Vision||Ireland|
|American Fluor Corp||America|
How to make Fluorescein sodium ophthalmic strips?
For the making of fluorescein sodium ophthalmic strips first, you need to accumulate all the necessary items and follow the procedure.
What do you need
- Sterile filter paper (e.g., Whatman no. 1)
- A sterile bowl
- Fluorescein sodium powder (20 g)
- Distilled sterile water (100 ml)
- A pair of scissors
- Empty injectable vials or any small sealed containers
- A sterile surface
- Sterile gloves, mask, and apron.
- Take a clean tray and assemble all the materials on it.
- Dress up properly with- apron, sterile gloves, and mask.
- By dissolving 20 g of fluorescein sodium powder in 100 ml distilled sterile water make a 20% fluorescein solution
- Of approximately 5 cm wide and 8–10 cm long, cut the filter paper into rectangles pieces.
- Now, pour a little amount of fluorescein solution into the sterile bowl.
- As fluorescein leaves stains, be very careful not to spill it.
- In this fluorescein solution dip the long edge of the filter paper and remove it immediately, because the solution spreads very quickly through the paper.
- To dry the dipped filter papers, place them on a sterile surface.
- Once they get dry, use a pair of scissors to cut the paper into strips from the dipped edge at one end.
- At last, Store the strips in a sterile sealed container.
To find out several eye problems Fluorescein sodium ophthalmic strips are used. Below are some of its uses-
- Fluorescein sodium ophthalmic strips are used in detecting damage in corneal surface
- In evaluating ocular adaptability to hard contact lens
- In inspecting leakage from incision caused by ophthalmic surgery
- Examination of the anterior segment of the eye look for corneal abrasion
- fundus photography.
- In checking the Intra-ocular pressure.
- Indicated for use in Contact lens fitment
- Also to compute tear film breakup time.
- Medical grade cellulose fibre substrate.
- In Pharmaceutical grade dye.
- Improved concentration for consistent staining and fluorescence.
Fluorescein reveals the health and sickness of the tear film, allowing us to figure out why a calm eye with appropriate tears is still in pain. The unstable tears may suggest mucin deficient dry eyes, or they may highlight the changed lipids in an evaporative dry eye, resulting in toxic tears, which lead to the inflammatory cycle at the centre of dry eye sickness.
With severe dry eye due to primary or secondary Sjogren’s syndrome cries out for attention via the fluorescein without ocular surface staining one cannot understand the extent of the disease and its severity. Fluorescein can be essential for the completion of the thalamic assessment of a normal subject as well it will highlight the tear meniscal Myers and help us assess the intraocular pressure.
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- Sterile gloves, mask, and apron
- small sealed containers
- A sterile bowl
- Fluorescein sodium powder
- Distilled sterile water
- Pair of scissors
How to use
To apply fluorescein sodium ophthalmic strip, follow the steps given below-
- Add a single drop of anaesthetic or saline to the tip of the fluorescein strip.
- Retract the lower eyelid with your finger and touch the fluorescent strip gently against the palpebral conjunctiva.
- Do not touch the fluorescent strip directly on the cornea or conjunctiva as this will cause a corneal or conjunctival abrasion.
- Now ask the patient to blink multiple times to allow for the stain to distribute evenly across the surface of the eye.
- Do not place too much fluorescein into the eye which causes the entire tear film to become illuminated. This makes it difficult to visualize small lesions.
- If this occurs have the patient blink multiple times and try and clear the fluorescein at times placing one to two drops of saline into the eye may be required.
- Once the stain has been applied evaluate the eye with a cobalt blue light either with a Woods lamp or slip lamp.
- To identify any corneal abrasions have the patient look up and down and left and right.
- A corneal defect will appear yellow under the cobalt blue light.
Generally, the storage Instructions given for fluorescein sodium ophthalmic strips are to Store them at room temperature.
Dosage and administration
For pediatric patients- The dose is made according to 35 mg per 10 pounds of body weight.
Approximately 80% of the dye molecules bind to plasma proteins upon entering the circulation. The remaining unbound or free fluorescein molecules (fluoresce) when excited with light of appropriate wavelength, Fluorescein diffuses out freely of all capillaries except those of the central nervous system, including the retina.
Fluorescein is eliminated by the liver and kidneys within a span of 24 hours, although the traces may be found within the body for up to a week after application. Retention may get increased if renal function is impaired. The skin has a yellowish tinge for a few hours and the urine has a characteristic yellow-orange colour for most of the first day after application.
Fluorescein enters only in damaged cells on the ocular surface, but not the healthy cells, it is believed traditionally. And it appears as fluorescent staining which can help the doctors to identify slight threatening conditions for example corneal ulcers and foreign bodies.
Generally, fluorescein sodium ophthalmic strips do not show any side effects. The Strip is made up of filter paper, which is sterilized by oxirane and impregnated with a highly pure fluorescein sodium solution. It is free of side effects, non-toxic, and also non-irritative to the eye.
But You should handle it with care-
- Do not apply the fluorescein to a suspected infected eye and then use the same strip for the other eye. This can result in nitrogen.
- Transmission of infection another word of caution is to ensure you remove the patient’s contact lenses before applying fluorescein. This can cause permanent staining of the contact.
Read our another article on >>> Side Effects of Fluorescein Sodium and Precautions to be taken
What is a fluorescein test?
This test is used to diagnose the corneal injury. The test uses an orange-red dye called fluorescein and blue light to detect foreign bodies in the eye. Fluorescein sodium ophthalmic strips are an essential diagnostic tool in eye care. These strips can be used to assess dry eyes, detect corneal abrasions, and measure intraocular pressure.
How do you use fluorescein in the eye?
The dye is placed into your eye with a little eyedropper or blotting paper by an ophthalmologist. After applying you are asked to blink. The dye spreads and coats the tear film and covers the surface of the cornea after blinking. After the installation in the eye, a slit lamp blue filter is also used to observe the fluorescence which is visible as an intense green colour on the ocular surface. The blue filter allows only those light of wavelengths that are approximately very close to the excitatory spectrum of fluorescein to reach the eye.
Why do they put the yellow dye in your eyes?
The doctors put yellow dye in your eyes because it helps them to find out small foreign objects or particles in the eye and to detect corneal injuries or any abnormal tear production.
Other Fluorescein Sodium articles:-
Updates from Macsen Labs on API- Macsen files a patent for Process for the preparation of crystalline Fluorescein Sodium from Diacetyl Fluorescein or Fluorescein
The information provided here is based on general knowledge, articles, research publications etc and we do not claim the authenticity of any of the information provided above. We do not claim or suggest/advise any medical, therapeutic, health or nutritional benefits of Fluorescein Sodium. We do not supply or promote our Fluorescein Sodium product for the applications which are covered by valid patents and which are not approved by the FDA.
Macsen Labs is a manufacturer and supplier of several grades of Fluorescein Sodium such as:-