Chloroquine and the eye

While most medicines can be taken without changing or damaging the eyes in any way, various medicines can affect the eyes and their functioning and a few can actually cause problems that threaten vision.  Chloroquine (Plaquenil) is one of these.

An interesting drug, Chloroquine is used most commonly in the treatment of arthritis, lupus and as an anti-malarial drug.  It is stored in high concentrations all over the body and is very slow to be eliminated.  Chloroquine has many systemic side-effects not related to the eye.  These are rare and include nerve weakness, hallucinations, psoriasis, and changes in hair color.

Chloroquine is especially attracted to the pigmented tissues of the eye, and eye complications are the most serious and worrisome of the drugs side effects.  They may occur any time after beginning therapy with the drug, but the longer the drug is taken the higher the chances of developing adverse reactions.  The retina and its adjacent tissues can exhibit characteristic changes that are recognizable during a comprehensive eye examination.  Blurred vision and defective color vision may be found early.  Visual field changes may also occur.  These are serious, permanent changes in vision.

Deposits of the drug may also be found in the cornea, but these are REVERSIBLE ... that is, they go away when the drug is stopped.  These deposits usually do not affect sight at all.

Regular eye exams (about every six months) are of great importance for all patients who are taking Chloroquine or Hydroxychloroquine.  At the earliest sign or symptom of possible vision change, the drug should be stopped, since patients who have ceased the drug have reported continued changes in vision.  With the newer forms of Chloroquine, these serious side effects have been reduced, but continued vigilance and regular exams are the only sure way to avoid potential problems with this class of drugs.