EYE DISORDERS
DRUGS and the EYE
This page discusses interactions of drugs with the eyes and the
vision. This is not intended to be a complete catalog of all possible
ocular side effects from different medications. Instead, it lists common
ocular side effects, or those which deserve special mention. Just
because a drug is not listed here does not mean that it does not have
any possible ocular side effects. Included are over-the-counter
medications, prescription medications, and legal and illegal
recreational drugs. Eye medications are not included here.
- Antihistamines are found as prescription and non-prescription pills,
capsules, liquids, and effervescent tablets (like alka-seltzer). They
may be sold as and individual medication or in combination with other
medications such as decongestants, pain medications, etc. Often listed
as a warning in package information sheets for antihistamines is that
the drug should not be used if one has glaucoma. However, for most
people with glaucoma, antihistamines can be used safely. The most
common type of glaucoma is termed "open angle glaucoma".
Antihistamines generally should have no effect with this type of glaucoma.
With a more rare type of glaucoma termed "angle closure glaucoma"
or "narrow angle glaucoma", the use of antihistamines
may trigger an attack of angle closure glaucoma. Basically, the
part of the eye that drains fluid becomes blocked and the pressure
within the eye will skyrocket. This is usually accompanied by pain,
blurred vision, eye redness, seeing rainbows around lights, and
even nausea or vomiting. Angle closure glaucoma is an emergency,
and vision can be permanently lost. Many people may be at risk for
angle closure glaucoma unknowingly. A recent study found that people
of Vietnamese descent may have increased risk for this type of glaucoma.
If in doubt, consult with an ophthalmologist who can determine if
it is safe to use antihistamines. For more information on glaucoma,
go to
Glaucoma.
Aspirin
Vitamin A has a reputation for being beneficial to the eye. The retina does need
a normal amount of vitamin A to properly function, and this amount can be
obtained with a well balanced diet without supplements. Large dosages of vitamin
A have NOT been shown to help to preserve vision in conditions which cause
retinal degeneration (such as retinitis pigmentosa). Large vitamin A intake can
be harmful, as it is stored by the body. One condition that can be caused by a
large intake of vitamin A (or of foods containing a large amount of vitamin A
such as liver) is "pseudotumor cerebi", which is an increase in the
pressure of the fluid around the brain (increased intracranial pressure). This
can cause visible swelling of the optic nerve within the eye, as well as
headache and visual disturbances.
Accutane
Accutane is commonly used to treat acne, and is known to cause dryness of mucous
membranes, and the eye is included. Symptoms of dry eye include the sensation
that something is in the eye, redness, burning, and even blurred vision.
Artificial tears and ointments may help. Accutane may also lead to temporary
visual disturbances and trouble with night vision.
Amitriptyline (Tri-cyclic antidepressants)
This class of medication including amitriptyline can have several ocular side
effects. They can cause a decrease in tearing, which can lead to dry eye
problems. They also can lead to a decrease in focusing ability (accommodation).
This temporary effect may cause difficulty with reading or even distance vision.
Finally, these medications may have a risk for causing acute angle closure
glaucoma, in those persons at risk for this type of glaucoma. Most people with
glaucoma have "open angle" glaucoma, and would have no problem with
taking these medication. Consult with your ophthalmologist is you are unsure.
For more information on this risk of glaucoma, see the section above under Antihistamines.
Antipsychotic medications
Many of these psychiatric medications can have risk for angle closure glaucoma
in those persons at risk for this type of glaucoma. Most people with glaucoma
have "open angle" glaucoma, and would not be at risk with taking these
medication. Consult with your ophthalmologist if you are unsure. For more
information on this risk of glaucoma, see the section above under Antihistamines.
Amiodarone
Amiodarone is a potent cardiac medication with a common ocular side effect which
rarely gives any symptoms. A person taking this medication will develop a
whorl-like pattern on the surface of the cornea over a period of time. Rarely
this may interfere with vision or cause glare symptoms. The condition is
reversible.
Recently, an association between amiodarone and optic neuritis or optic
neuropathy has been made. This has prompted the manufacturer of Cordarone
(amiodarone) to revise the Warnings section of this medication's prescribing
information. It now states that cases of optic neuritis and/or optic neuropathy
have been reported in patients receiving this drug, and that the problem could
develop at any time during the use of the drug. It has NOT been clearly
established that the drug causes the optic nerve problem, but if there are any
changes in vision or peripheral vision then an prompt ophthalmic examination
should be performed. Regular ophthalmic examination is recommended for patients
receiving amiodarone.
Chloroquine
This is an anti-malarial drug also rarely now used in arthritic conditions.
Currently, Plaquenil (hydroxychloroquine) is more commonly used in arthritis,
with fewer side effects. Chloroquine can cause degeneration of the optic nerve.
It can also cause a retinal degeneration which can lead to blind spots in the
vision, reduced colour vision, and blurred central vision. The risk of retinal
problems may be related to the total cumulative amount of chloroquine taken
over time. See the section on Plaquenil below for more
information on this potential retinal problem.
Cimetidine
This anti-ulcer medication can rarely lead to angle closure glaucoma in people
susceptible to this type of glaucoma. Most people with glaucoma have "open
angle" glaucoma, and would not be at risk with taking these medication.
Consult with your ophthalmologist if you are unsure. For more information on
this risk of glaucoma, see the section above under Antihistamines.
Chlorpromazine (Thorazine)
Thorazine, a psychiatric medication, taken in large dosages can lead to
pigmentation of the conjunctiva, cornea, and eyelids. A pigmentary retinal
degeneration can also occur. Cataract is also possible. This drug is in the
class of drugs known as "phenothiazines", and Mellaril (thioridazine)
can have similar side effects.
Chlorpropamide
This diabetic medication can rarely cause a degeneration of the optic nerve.
Digitalis
This cardiac drug can cause a few ocular symptoms, such as glare
symptoms and seeing halos around light. In cases of over dosage of
digoxin, the vision may become yellowish. This is important since
the blood level of digoxin needs to be monitored and may fluctuate
for different reasons.
Ephedrine
This stimulant can lead to pupillary dilation and may give risk
for angle closure glaucoma in people susceptible to this type of glaucoma.
Oestrogens
Estrogens are commonly used in post-menopausal women for symptoms
related to oestrogen deficiency, and their use has also been associated
with a decreased risk for heart disease and hip fracture. A recent
study suggests that oestrogen use in post-menopausal women may give
a protective effect against the formation of cataract (the nuclear
sclerotic type of cataract).
5-Fluoro-Uracil (5-FU)
This cancer chemotherapeutic agent can lead to scarring and closure
of the tear drainage system (nasolacrimal obstruction). This commonly
leads to spontaneous tearing.
Ethambutal
This agent used in the treatment of tuberculosis can rarely lead
to a degeneration of the optic nerve.
Haldol
This psychiatric sedative medication can lead to decreased tear
production, decreased focusing ability, pupillary dilation, and may
give risk for angle closure glaucoma in people susceptible to this
type of glaucoma. See the section discussing Tricyclic
Antidepressants for more information on these side effects.
Indomethacin
This anti-inflammatory medication can rarely lead to whorl-like
changes on the surface of the eye (cornea). This rarely causes any
visual symptoms.
Isoniazide
This agent used in the treatment of tuberculosis can rarely lead
to a degeneration of the optic nerve.
Minocycline, which is a drug similar to tetracycline, is commonly
used orally in the treatment of acne and rosacea. Recently reported
is a pigmentation of the white of the eye (sclera) which can occur
with the use of this drug. It is typically a blue-gray discoloration,
but may also be black or brownish. It may be worse in areas exposed
to sunlight. This is also true with the similar skin pigmentation
which can occur with the drug, as well as fingernail and tooth discoloration.
If the abnormal pigmentation is recognized quickly, discontinuation
of the drug may allow the skin, eye, etc. to return to their normal
appearance.
Nalidixic Acid
Tis medication is one of several that can be associated with the
development of increased pressure of the fluid around the brain, or
"pseudotumor cerebri". This can lead to headache, visual
changes, and a visibly swollen optic nerve.
Nasal Steroids (spray)
Inhaled steroids for asthma have been recently implicated as causing
glaucoma, in susceptible people (note, this is "open angle glaucoma".)
Niacin, Niacinamide
These drugs may lead to a cystic swelling of the retina known as
"cystoid macular edema". Blurred and distorted vision are
common with this.
Oral Contraceptives
Oral contraceptives, or birth control pills, can lead to numerous
ocular problems. Migraine headaches may be caused by this. Also, increased
pressure of the fluid around the brain (pseudotumor cerebri) can occur,
leading to headache, visual changes, and a swollen optic nerve. Finally,
certain retinal vascular problems may be caused or worsened by oral
contraceptives.
Plaquenil is a drug used as an anti-inflammatory medication which
is helpful in certain rheumatological conditions such as rheumatoid
arthritis or lupus. It is similar to chloroquine, an anti-malarial
agent, which also has much more potential toxicity. Plaquenil can
rarely cause a retinal problem involving the central visual area,
or macula. In dosages usually used, there is usually no problem with
the retina. Nevertheless, it is recommended to have an eye examination
at least once a year to look for signs of toxicity. Visual changes
may include blurred vision, decreased color vision, distorted vision,
blind spots in the vision, and halos around lights. Monitoring the
vision between examinations with an "Amsler grid" make help
an individual to pick up a problem with the vision early. The retina
may take on a specific appearance when it is being adversely affected
by plaquenil. Discontinuing the drug at the earliest sign of toxicity
may help to prevent visual loss. Generally, however, visual loss from
this medication is almost unheard of, and it may have less potential
ocular toxicity than other medications that may be used.
Quinine
Quinine can rarely cause difficulty with night vision, or seeing
in the dark. If taken by pregnant women, it can lead to "optic
nerve hypoplasia" in the foetus, which is a birth defect characterized
by an under-developed optic nerve.
Rifabutin
This medication is used as a preventive treatment for "mycobacterium
avium", which is an infection that can occur in HIV positive
people. It has been shown to cause intra-ocular inflammation (iritis
or uveitis) in some people.
Scopolamine Patch
This is a patch often placed behind the ear to help which motion
sickness, or sea-sickness. Scopolamine is a potent dilating agent,
with the pupillary dilation lasting 3 to 5 days. When used normally,
this ocular side effect is not usually seen. However, if the patch
is broken open or cut, and the contents are inadvertently rubbed into
the eyes, this pupil dilation could occur. A loss of focusing ability
also occurs with the dilation.
Steroids (Prednisone)
- Oral or intravenous steroids are commonly used especially during
attacks of asthma or emphysema, and as an anti-inflammatory agent
with arthritis. It is also used after organ transplantation. Short
term use of steroids normally does not cause eye problems, but long
term chronic use may lead to two possible complications. One complication
is glaucoma. Certain predisposed individuals exhibit a rise in eye
pressure with the use of steroids, usually after 3 to 4 weeks. This
includes oral and IV steroids as well as eye drop steroids. The glaucoma
is treatable using medication or rarely surgery, and the pressure
usually returns to normal if steroids can be stopped.
Cataract is another complication. The typical steroid induced cataract
develops on the back surface of the lens in the eye, and is called
a "posterior subcapsular cataract". This can be a rapidly
forming and very visually significant type of cataract, often causing
much glare disability. Once cataract forms, it cannot be reversed,
although surgery can remove the cataract and restore the vision.
Tamoxifen
This medication is often used after breast cancer treatments. It
can lead to crystalline deposits in the retina and cornea in some
cases.
Tetracycline
Tetracycline is a commonly used antibiotic. It has a property whereby
the oil gland secretions become more thinned. Thus, it is commonly
used in cases of acne. It also can thin the oil secretions of the
"Meibomium glands" in the eyelids. This can help prevent
stye formation and can help with inflammation of the eyelid (blepharitis).Tetracycline has also been shown to rarely lead to increased intracranial
pressure (pseudotumor cerebri), which can cause headache, blurred
vision, and blind spots in the vision.
Thioridazine (Mellaril)
This is a psychiatric medication in the same class as chlorpromazine
(thorazine). In cases of high chronic dosages, it can lead to reduced
night vision and blind spots in the vision. Retinal pigmentary changes
and "brownish" vision can also occur.
Alcohol (Ethanol)
In spite of the numerous medical complications of chronic alcohol
abuse, the eyes are relatively spared from complications. Acute intoxication
with alcohol can lead to temporary blurred vision, pupil dilation,
eye redness, double vision, and difficulty focusing. Chronic alcohol
abuse can lead to what is thought to be a nutritional degeneration
of the optic nerve. This could result in permanently reduced vision,
blind spots in the vision, and reduced colour vision. Short term consumption
of alcoholic beverages may be a trigger for migraine headache. In
some cases, people may experience the visual aura (flashing jagged
shimmering lights) of migraine without developing the headache. Other
chemicals found in wine or beer may also trigger migraine.
Tobacco
While tobacco itself is not a drug, nicotine is a drug found in
tobacco and is quite addictive. Nicotine itself probably does not
cause ocular damage. However, other chemicals found in smoked tobacco
materials have been shown to lead to ocular complications:
- Cataract. Studies have proven that smoking
tobacco increases the risk of cataract formation in men, and increases
the risk of cataract surgery in women.
- Macular degeneration. Studies have shown that
smoking tobacco increases the risk for macular degeneration in
men and women. This can lead to a rapid irreversible loss of vision.
- Vascular disease. Smoking tobacco is known
to contribute to arteriosclerosis, or hardening of the arteries,
along with high cholesterol and hypertension (along with other
factors as well). This arteriosclerosis may contribute to vascular
problems of the eye such as vein occlusions, artery occlusions,
and optic nerve damage. These are serious eye problems which often
lead to substantial loss of vision.
- Nutritional optic nerve degeneration. Tobacco
is often implicated along with alcohol (in combination) as to
causing a nutritional degeneration of the optic nerve.
Amphetamines use can lead to a reduced focusing ability and dilation
of the pupil. With this dilation comes a risk for acute angle-closure
glaucoma. In this glaucoma, the eye pressure becomes suddenly extremely
elevated, leading to eye pain, redness, blurred vision, loss of vision,
seeing rainbows around lights, nausea, and vomiting. Angle closure
glaucoma is a serious eye emergency. Amphetamines otherwise can lead
to hallucinations during usage.
Cocaine has been reported to potentially lead to corneal ulceration.
These ulcers are sometimes sterile, and sometimes infected with bacteria.
It is not fully understood why this occurs, except that cocaine is
a potent eye anaesthetic. Thus, with the eye numb, damage can occur
unknowingly leading to the ulceration. Once the anaesthetic effect
wears off, the eye can become very painful with blurred vision. This
problem can lead to scarring that can cause permanent vision loss.
Cocaine has also been shown to lead to an occlusion of the arteries
in the retina. This leads to rapid and often irreversible loss of
vision.
Intravenously injected drugs
The injection of drugs directly into the veins can lead to deposits
of talc or other "cutting agents" forming in the retina.
This can lead to loss of vision, and larger particles can potentially
block the retinal circulation altogether, with a rapid and severe
loss of vision.
Marijuana
The use of marijuana can lead to eye redness and dilated pupils.
It can also cause visual hallucinations. More controversial is the
use of marijuana as a helpful drug in the lowering of eye pressure
in glaucoma. There is a scarcity of good studies demonstrating this
pressure lowering effect, but apparently it does exist. However, marijuana
is a poor choice as a drug for glaucoma for several reasons: It has
a short duration of action, and must be taken (smoked) every 2 to
4 hours to maintain the effect. Many glaucoma drugs (eye drops) are
more effective at lowering pressure in the eye and only have to be
taken ONCE at day. Furthermore, smoking is a poor drug delivery system.
Depending on how deeply one inhales and on the potency of a given
marijuana cigarette, the dosage of actual pressure lowering medication
is variable. Finally, marijuana has numerous side effects, including
impairment of thought processes and lung disease.
