Malaria drug may help treat eye inflammation in ocular sarcoidosis
Study: Treatment allowed some patients to reduce reliance on corticosteroids
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The antimalarial medication hydroxychloroquine may help treat uveitis, a type of eye inflammation, in some people with ocular sarcoidosis, a study reports.
Specifically, over half of the 42 people with sarcoidosis-related uveitis (SAU) responded to hydroxychloroquine, sold under the brand names Plaquenil and Sovuna, with generics available.
This allowed some participants to reduce their reliance on prednisone or other corticosteroids, anti-inflammatory medications that can cause serious side effects with prolonged use.
Hydroxychloroquine “may represent a promising therapeutic option that warrants further comparative investigation,” researchers wrote.
The study, “Hydroxychloroquine in the treatment of sarcoidosis-associated uveitis and idiopathic uveitis,” was published in the Journal of Ophthalmic Inflammation and Infection by a team of researchers in France.
Malaria drug used to suppress inflammation in autoimmune diseases
Sarcoidosis is marked by the formation of masses of inflammatory cells, called granulomas, that can develop in various tissues throughout the body. Symptoms can vary broadly depending on where these masses form.
When the disease affects the eyes, it is called ocular sarcoidosis. One of its main manifestations is uveitis, or inflammation of the uvea — the eye’s middle layer, which includes the colored iris and supplies blood to the retina, the light-sensitive layer at the back of the eye.
Doctors can classify SAU depending on whether inflammation occurs in the front (anterior), middle (intermediate), or back (posterior) part of the uvea. Panuveitis refers to inflammation that affects the entire uvea.
Corticosteroids, including those applied directly to the eye and those taken orally or via injectable medications, which affect the whole body, are a mainstay of SAU treatment. While these can substantially reduce inflammation, they can also cause serious side effects, so patients and doctors prefer to limit their dosage. Supplemental medications may help reduce reliance on corticosteroids.
Hydroxychloroquine, a medication initially developed to prevent and treat malaria, a parasitic infection, is now mainly used to suppress inflammation in autoimmune and inflammatory diseases such as sarcoidosis.
The therapy “has demonstrated immunomodulatory effects in several [whole-body] diseases, including sarcoidosis,” the researchers wrote.
55% of patients successfully responded to treatment
In a small prior study from the same research team, hydroxychloroquine showed some signs of efficacy in SAU. With extended use, antimalarials like hydroxychloroquine can sometimes harm the eyes, but this risk is lower for people who use the medications for less than five years.
To further investigate the therapeutic potential of hydroxychloroquine in SAU, the researchers retrospectively analyzed data from 42 people with SAU who were seen at a single center and given the medication for at least six months.
Patients’ mean age was 52.8 years at the time of their uveitis diagnosis. Most started hydroxychloroquine as an addition to oral prednisone or other treatments because their uveitis remained uncontrolled.
Hydroxychloroquine was given for a median of 24.5 months (about two years). At the last visit while on treatment, 55% of participants had successfully responded to hydroxychloroquine treatment.
A successful response was defined as controlled inflammation, a relatively low dose of prednisone or other treatments, and no discontinuation of hydroxychloroquine due to side effects.
Higher response rates were observed among patients with anterior SAU (70%) and intermediate SAU (77%). However, the number of participants in each group was small, making it difficult to generalize these findings.
his study suggests that HCQ can control [eye] inflammation, preserve visual acuity, decrease the median prednisone dose required, and reduce the incidence rate of flares in certain types of SAU.
Overall, the median dose of oral prednisone dose was significantly reduced from 10 mg/day at study’s start to 4 mg/day at the last visit. Five SAU patients (12%) were able to discontinue prednisone.
Changes in vision were also assessed.
“Although HCQ [hydroxychloroquine] did not improve visual acuity, it did help stabilize it, suggesting a positive effect in limiting vision loss,” the team wrote.
Because most participants received hydroxychloroquine for less than two years, many didn’t undergo detailed screening for potential medication-related eye damage. Among those who did, 5% showed signs of such damage.
Hydroxychloroquine treatment was also associated with a lower rate of disease flares, or temporary periods of worsening inflammation. Some flare-ups turned into relapses, or flares that needed a modification in treatment. Nearly half of patients (42%) did not experience a flare, and at last visit, 24% of participants had at least one relapse.
“This study suggests that HCQ can control [eye] inflammation, preserve visual acuity, decrease the median prednisone dose required, and reduce the incidence rate of flares in certain types of SAU,” the researchers wrote.
Among the study’s limitations, the team noted its retrospective nature, small sample size, and lack of a control group for comparison. Without complete data on hydroxychloroquine-related eye damage, it was also challenging to assess the safety of the treatment.
“Further and longer-term studies are needed to confirm that HCQ could be a safe therapeutic option without affecting the visual prognosis,” the researchers concluded.
