So someone wanted to know about the ocular effects of digoxin and digoxin is digitalis it’s derived from foxglove it’s a very old medicine it’s been used for a lot of things in the modern era it’s a cardiac drug and so as opposed to losing your color vision or not being able to see things digoxin has a very unusual symptom it causes chromatopsia you see color
And you see more color than you’re supposed to see so it’s a chromatopsia as opposed to an a chromatopsia where you don’t see color or a disc chromatopsia where the color is wrong it is a chromatopsia because you see some color and that color is usually yellow but it can also be blue so the blue version is cyanopsia and the yellow version is xanthamsia and so you
Can see blue or yellow and perhaps the best illustration of what that would look like is vincent van gogh so if you’ve ever seen vincent van gogh paintings like sunflowers very prominent painting of his or irises it tends to be like either all blue like starry starry night or all yellow like sunflowers and some people have even hypothesized that perhaps vincent
Gengo had ocular digoxin toxicity so the patients are going to say things look yellow things look blue it can also cause loss of visual purity though because it is a toxicity at the level of the retina and it is leading to the sensation of chromatopsia and cyanopsia and you really should be thinking about this when the patient has this symptom everything looks
Yellow or everything looks blue that is a very distinctive symptom it’s an unusual symptom for someone who has an optic neuropathy to say things look yellow or things look blue usually they think say things look gray because they have dis chromatopsia they are losing color function not gaining color function so this is a gain of function problem and the reason is
This digoxin is probably affecting the electrical activity at the cellular level in the photoreceptors and there’s a number of animal models that suggest that it is related to electrolytes sodium potassium atp pumps at the level of the retina that is producing this the interesting thing is it doesn’t correlate with digoxin levels so they don’t have to actually be
Toxic systemically and uh it doesn’t seem to be dose related completely so some people get it at what would be considered reasonable doses so it’s not like other toxicities where there’s some sort of cumulative effect or it’s weight dependent or it’s duration dependent it’s somewhat idiosyncratic and so really it’s a clinical diagnosis so if the patient is on
Digoxin and says they have chromatopsia you should think about a d challenge take it away in order to prove it you have to have a re-challenge but most people don’t want to be re-challenged but because digoxin is such an important drug the re-challenge is sometimes necessary to show that the drug is actually the cause we’re going to check their acuity their field
Their oct do all the usual things but really it’s a clinical diagnosis supported by a d challenge and because the symptom is sensitive and specific for the ocular digoxin toxicity and usually just talking to the person there’s no testing that you do so digoxin chromatopsia vincent van gogh
Transcribed from video
Ocular Effects of Digoxin By Neuro-Ophthalmology with Dr. Andrew G. Lee
