RCOphth guideline: Hydroxychloroquine and Chloroquine Retinopathy: NEW screening recommendations February 2018
2 March 2018
The new guideline on screening for hydroxychloroquine and chloroquine retinopathy is written in response to evidence from the United States that shows that hydroxychloroquine retinopathy is more common than previously recognised. Implementation of the guideline’s recommendations will prevent iatrogenic visual loss. The new guideline also makes recommendations regarding the techniques and timing of baseline and follow-up screening tests for both hydroxychloroquine and chloroquine retinopathy.
Hydroxychloroquine is a medicine that is effective in treating various long-term inflammatory disorders of the joints and skin. In general, hydroxychloroquine is a safe and cost-effective medication, particularly when compared to newer anti-inflammatory medicines which can more significant adverse effects on the body. However, some patients taking hydroxychloroquine, or a similar medication called chloroquine, can suffer permanent loss of vision due to the harmful long-term effect of hydroxychloroquine on the retina. The retina is the light sensitive layer at the back of the eye which allows light to be sensed and relayed to the brain so that an image is perceived or “seen” by an individual. This condition where hydroxychloroquine can affect the retina and vision when taken for a long period of time is called “hydroxychloroquine retinopathy”.
Hydroxychloroquine retinopathy becomes more likely the longer any individual is taking the medication. The disorder is rarely seen within the first five years of treatment, but becomes more common with a longer duration of use. Between 20 and 50% of people taking hydroxychloroquine for more than 20 years may have some signs of hydroxychloroquine retinopathy. Overall, 7.5% of individuals taking hydroxychloroquine for more than five years may have some signs of retinal damage detected on specialized tests.
If advanced, hydroxychloroquine retinopathy can cause symptoms of loss of peripheral vision, and then in later stages, central vision can become affected too. If hydroxychloroquine retinopathy is advanced, it can result in permanent loss of sight in both eyes that can impact quality of life and activities such as driving and reading. It is unlikely that all the visual field will be lost, even in advanced hydroxychloroquine retinopathy. However, once hydroxychloroquine retinopathy results in noticeable loss of vision, the damage to the retina is permanent and often continues to get worse even if the medication is stopped.
It is possible to detect early signs of hydroxychloroquine retinopathy using specialized techniques that can look at layers of the retina with photographs of the eye, and by visual field testing. Visual field testing is tested by an individual pressing a button when they see a light on a specialized type of eye test. These tests, when taken together, can detect early signs of hydroxychloroquine retinopathy before the condition is noticed by an individual (before it causes symptoms) and therefore are able to detect the condition at a much earlier stage.