Perspective: Ocular Side Effects From Herbal Medicines
and Nutritional Supplements
by: F.W. Fraunfelder
(AJO, 2004)
Selected Quotes or In-context Paraphrases:
“The National Registry of Drug-Inducted Ocular Side Effects
received 263 spontaneous reports, in addition to 60 case reports
from the literature. Canthaxanthine, chamomile, Datura, Echinacea
purpurea, ginkgo biloba, licorice, niacin, and Vitamin A are
all associated with clinically significant ocular side effects.”
“Approximately 40% of patients who use alternative therapies
do not disclose this information to their doctor. A variety
of these therapies are touted as beneficial for eye disease
and many are associated with ocular side effects.”
The following table succinctly summarizes the most common
ocular associations with the selected agents:
|
Word Health Organization (WHO) Classification of Ocular Side Effects Associated
With Herbal Medicines and Nutritional Supplements |
|
Drug |
Ocular Reaction |
WHO Classification |
|
Canthaxanthine |
Crystalline Retinopathy |
Certain |
|
Chamomile |
Conjunctivitis |
Probable (when topically applied) |
|
Datura |
Mydriasis |
Certain |
|
Echinacea |
Conjunctivitis |
Possible |
|
Gingko biloba |
Retinal hemorrhage |
Probable |
|
|
Hyphema |
Possible |
|
|
Retrobulbar hemorrhage |
Possible |
|
Licorice |
Abnormal vision |
Possible (in large doses) |
|
Niacin |
Cystoid macular edema |
Certain |
|
|
Blurred vision |
Probable |
|
Vitamin A |
Intracranial hypertension |
Certain (in large doses) |
|
|
|
|
“An example of the difficulty clinicians have when examining
patients taking herbal medicines comes from bilberry (Vaccinium
myrtillus). This fruit is commonly used to treat diabetes
and diabetic retinopathy. There are, however, no well-constructed
clinical studies in humans to support the use of bilberry in
the treatment of diabetic retinopathy. Some animal models
support the vasoprotective and antiedema properties of the
fruit, and there are animal models indicating the successful
treatment of diabetes. Before clinicians recommend an herbal
medicine, it is appropriate to wait for proof of efficacy and
safety.”
“Herbal medicines and nutritional supplements are being used,
by a large segment of the population, many times without strong
evidence on efficacy or safety. Therefore, clinicians must
remain vigilant in recognizing adverse ocular reactions as
well as inquiring whether these alternative treatments are
being used, as patients frequently do not disclose this information
to their physicians.”
M & T Commentary
Dr. Fraunfelder coauthors an excellent text reference entitled,
Drug-Induced Ocular Side Effects, (Butterworth-Heineman,
www.bh.com) which we find enormously helpful when the need
arises.
This “perspective” article sheds light on some of the most
common ocular expressions of these selected agents. As with
all the articles we review, the reader will get the full educational
benefit by reading the entire article.
The best comprehensive reference text we have found regarding
herbal and alternative products is entitled, “Review of Natural
Products.” This extraordinary book is available from the publishers
of Drug Facts and Comparisons (www.drugfacts.com, or 1-800-223-0554).
If you have a patient who you believe has had an adverse effect
from any drug or agent, we encourage you to report it to www.eyedrugregistry.com. |
