Recent testing of hydroxychloroquine to treat COVID-19 has been a mixed bag so far. With few other treatment options available, however, doctors are willing to try out this particular drug, which has been highly touted by the Trump administration.

What can’t be ruled out is the damage the drug could inflict on one’s eyes after prolonged use. 

Hydroxychloroquine is a drug that helps regulate and improve your immune system’s ability to fight off infection, and is often used to treat malaria and autoimmune diseases like lupus or rheumatoid arthritis. According to the Johns Hopkins University Lupus Center, the drug has been shown to improve an array of symptoms, such as muscle and joint pain, skin rashes, inflammation of the heart and lung linings, fatigue and fever. 

What has been known after six decades of use is that hydroxychloroquine can have dangerous side effects—namely eye injury. In fact, although it is safe for most of the public to use, the drug has been shown to cause some sort of eye damage, minor or major, in up to 7 percent of patients. 

More specifically, tests have proven that hydroxychloroquine can harm your retina, eventually causing partial or full blindness. According to the American Academy of Ophthalmology, between 1 and 2 percent of patients have developed retinal problems during a five-year course of hydroxychloroquine treatment. 

Hydroxychloroquine retinopathy can cause the destruction of macular rods and cones, with the sparing of foveal cones. The drug binds to melanin, which then accumulates in the retinal pigment epithelium and can remain there for long periods of time. Retinal pigment epithelium is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells. As the drug is directly toxic to retinal pigment epithelium, cellular damage and atrophy are often seen. 

Because of these alarming findings, doctors have recommended that people get regular eye exams when they’re taking the drug.

The related drug chloroquine is sold under the brand name Aralen, while hydroxychloroquine is sold under the brand name Plaquenil. Hydroxychloroquine is more commonly prescribed because it causes fewer and less serious side effects than chloroquine. Both drugs are available as generics. 

Hydroxychloroquine is generally considered safe for treatment of malaria and autoimmune diseases, and an estimated 90 percent of people won’t experience any side effects if they take the drug.

Ethen Kim Lieser is a Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV.

Image: Reuters