This month we will discuss some facts about the medication Hydroxychloroquine and its effects on the eyes.
What is Hydroxychloroquine? How does it work and what is it used for?
Hydroxychloroquine is a medication that has been used for many years. The medication works to lower the inflammation caused by the body’s own immune system. Originally, it was used in the treatment and prevention of malaria.1 Now, it is primarily used for the treatment of inflammatory conditions including lupus, rheumatoid arthritis, and Sjogren syndrome.2
What does the medication do to the eyes?
It is well known that the medication can cause damage to the retina. The majority of these cases occur over many years of use and with high doses of the medication every day. The medication collects in the layers of the retina and causes toxicity to it. It specifically affects the macula, the area of the retina that controls the central vision. When this happens, patients may have blurry vision, distorted vision, or hazy vision.
What testing is done to determine if there is toxicity?
A comprehensive exam is done to check the vision and look at the retina. Ophthalmologists look for a specific pattern of the macula called a bull’s eye maculopathy. There are several photos that help in the diagnosis including ocular coherency tomography (OCT), and autofluorescence (AF). The OCT shows the area where the medication collects and has caused damage. The AF shows the disruption of this retinal layer by highlighting specific proteins in it. Below are photos of someone with the bull’s eye maculopathy. The first photo is how we see the eye on exam and the second is the autofluorescence. The arrows point to the ring-shaped area that is affected.
Fundus photo of toxicity. Image Source3
Autofluorescence photo of toxicity. Image Source3
A visual field test can also be done to test the vision in the macular region. To aid in the diagnosis, an electroretinogram (ERG) is occasionally performed. This test looks at the cells in the macula to determine if they are functioning properly.
Patients who are on this medication are routinely checked once or twice a year to find any signs of toxicity. The goal is to find early signs even if the patient has no symptoms.
What are the treatments of toxicity?
Currently, there are no proven treatments for the toxicity. If it is discovered, the medication must be stopped immediately. Even if the medication is stopped, vision can continue to worsen. Therefore, it is imperative to get testing done and see an ophthalmologist regularly to look for any changes on exam even if there are no visual symptoms.
What about Hydroxychloroquine and COVID-19?
Currently, there are no studies showing the benefit of taking the medication to treat or prevent the virus. There are some reports of its use and improvement in patients with coronavirus. However, these reports present a limited number of cases and it is unknown if the drug alone helped patients recover. The medication is not approved by the FDA for routine treatment or prevention of the coronavirus.4 The FDA has allowed for the drug to be used in the treatment of some very severe cases but more clinical trials are needed to determine if the medication truly is beneficial in treatment of the virus. Therefore, we do not know of any effects on the eyes with such a short course of treatment.
Ultimately, it is important to prevent the spread of the virus. Please avoid close contact with others who are sick or may be infected, minimize travel and exposure to yourself and others, avoid touching your face, and wash your hands often or use hand sanitizer if soap and water are unavailable.
There is still a lot to learn about this virus. Please keep up to date with the information posted on the following websites and other medical sources:
- Centers for Disease Control and Prevention
- World Health Organization
- American Academy of Ophthalmology
- American Medical Association
We understand this is a difficult time for everyone, so we hope you all stay safe and healthy during this time. Please feel free to call or email our office if you have any questions or concerns.
Return next month for a discussion on a new topic!
References:
- Porter, D. (2020). What is Plaquenil? Retrieved from https://www.aao.org/eye-health/drugs/what-is-plaquenil. [return]
- Marmor, M et al. (2016). Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy (2016 Revision). Retrieved from https://www.aao.org/clinical-statement/revised-recommendations-on-screening-chloroquine-h. [return]
- This work is a derivative of “File:1746-1596-5-20-1-l.jpg” by “Doctors:Xiaoyun Ma, Liang Yan, Linping He Dongyi He, Hao Lu from Shanghai, China”, used under CC BY 2.5. This image is licensed under CC BY 2.5 by Gupta Eye Center LLC. [return]
- U.S. Food and Drug Administration. (2020). Coronavirus Disease 2019 (COVID-19) Frequently Asked Questions. Retrieved from https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/coronavirus-disease-2019-covid-19-frequently-asked-questions. [return]
