Hydroxychloroquine, otherwise known as Plaquenil, is a commonly prescribed medication for systemic lupus erythematosus (or simply lupus), rheumatoid arthritis, and other inflammatory or dermatologic conditions.
It is also being researched for its application in diabetes, heart disease and cancer therapy. Unfortunately, the use of this medication has some ocular side effects that can cause permanent vision loss.
If you have been prescribed this medication, our optometrist may be monitoring you to ensure that there are no toxic effects to the back of your eye. Read on to learn more about what they will be looking out for and how.
A full eye examination is important to determine if there is any underlying disease already present that may be exacerbated by the medication. It is also important to be checking the health of the eyes overall on an annual basis.
An annual screening is recommended for patients on the medication longer than five years to rule out or manage side effects.
There are also changes at the front of the eye resulting from the use of hydroxychloroquine that should be monitored by our optometrist, like pigmentation in the cornea.
At this exam, our optometrist may also inquire about a variety of risk factors, such as other medical conditions (i.e. kidney problems), use of other drugs or medications, and the length and dosage of hydroxychloroquine prescribed.
Other significant risk factors may also be noted such as Asian descent and higher weight.
An OCT measures and assesses the health of the nerves at the back of the eye. It is these nerves that are damaged with the use of hydroxychloroquine.
The scans completed are assessed by our optometrist to determine if there is any loss of nerve fibers or changes in the macula, which is the center of the nerves responsible for clarity in your central vision.
The test is conducted by having you sit in front of a machine, with your chin and forehead resting against it. A painless and quick scan will then be completed and the results will be interpreted by our optometrist.
Repeating this test annually is important, as it allows our doctors to determine if there is any progression in the disease and loss of nerve fibers.
Your visual field is the extent to which you can see into your periphery. Damage to the nerves at the back of the eye will affect your visual field and completing this test will allow our optometrist to determine the extent of the damage functionally.
Often, it is the center of vision that is affected.
This test is often conducted using a machine that requires your active participation. While seated in front of the visual field test, you will need to press a button to indicate when a light blinks in the periphery.
The most important aspect of the test is to ensure that you are always staring at the fixation target at the center of the visual field testing screen, as this ensures the results are accurate and reliable. Repeat completion of this test allows our doctors to determine if there is any worsening of the side effects.
In order to assist in tracking the changes, a photo of the back of the eye may also be taken. This is a great way to assess not only for changes from the medication but also for other pathology that may also be occurring.
This test is a quick procedure that involves a bright flash upon image capture, one eye at a time.