Dyes Flashcards
Characteristics of fluorescein
- Water soluble
- Weakly acidic anion in alkaline solution such as
tears - Maximum fluorescence at pH 8
- Commonly available as sodium salt (NaFL)
- Metabolised by liver
- Eliminated in urine
- Absorption spectrum in blood: 465 nm
- Absorption spectrum on ocular surface: 450-493 nm (blue)
produced through a Cobalt blue slit lamp filter - Emission 520 nm (yellow-green) isolated with a Kodak
Wratten barrier filter - Absorption/emission spectra are dependent on the absorption spectrum, pH and concentration of the fluor; fluorescence is best at [0.1%] vs negligible at [2%]; avoid excess application of fluorescein
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Fluorescein quenching phenomenon
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/778/813/a_image_thumb.png?1634316922)
Fluorescein formulations with standard molecular weight topical (376kD)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/779/511/a_image_thumb.png?1634317219)
Fluorescein formulations with high molecular weight (topical) (710kD)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/779/917/a_image_thumb.png?1634317480)
What % of circulating fluorescein is bound to serum proteins RBCs (inactive)
70-85%
Dose of IV or oral fluorescein
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/781/751/a_image_thumb.png?1634318923)
Indications of topical fluorescein
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/781/969/a_image_thumb.png?1634319031)
Corneal abrasion vs ulcer
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/782/091/a_image_thumb.png?1634319264)
How does fluorescein help with dry eye assesment
Fluorescein pools in gaps created on the ocular surface by lost
epithelial cells following exposure-mediated damage to tight-junctions
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/782/539/a_image_thumb.png?1634319430)
Diffuse punctate keratitis
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/782/751/a_image_thumb.png?1634319918)
Tear meniscus height
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/783/261/a_image_thumb.png?1634320239)
Rigid gas permeable (RGP) contact lens fit evaluation with topical fluorescein
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![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/783/626/a_image_thumb.png?1634320482)
Jones I Test: Diagnosis of Tear Duct Obstruction
- Jones I: fluorescein is applied to ocular surface; an anesthetized cotton-tipped swab is inserted into the ipsilateral nostril for 5 min, then evaluated for staining
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/783/816/a_image_thumb.png?1634320787)
Jones II (Irrigation) Test
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/784/150/a_image_thumb.png?1634320973)
Diagnosis of Epithelial Keratitis
![](https://s3.amazonaws.com/brainscape-prod/system/cm/359/784/554/a_image_thumb.png?1634321616)