Study: Intraocular corticosteroids best for treating complications of chronic inflammatory eye condition

(Image Credit: AdobeStock/Pixel-Shot)

According to data from a clinical trial funded by the National Eye Institute (NEI), continued treatment with corticosteroid injections improved vision in people with persistent or recurrent uveitis-related macular edema better than two other therapies.

When compared with methotrexate or ranibizumab intravitreal (in-the-eye) injections, the corticosteroid treatment achieved greater reductions in retinal swelling and was the only therapy in the study that improved vision, according to a National Institutes of Health news release. Results from the MERIT study (NCT02623426) were published today in the journal Ophthalmology. NEI is part of the National Institutes of Health.¹

“Prior to this study, we didn’t know the best treatment for persistent or recurrent macular edema, a major cause of vision loss in people with uveitis,” Douglas A. Jabs, MD, Johns Hopkins Bloomberg School of Public Health, and chairman of the study, said in the news release. “This trial strongly indicates that repeat intraocular corticosteroid injections are superior to either intravitreal injections of methotrexate or ranibizumab.”

The first treatment for uveitis-related macular edema focuses on the control of inflammation and reduction of the fluid under the retina, according to the news release. While some patients achieve this goal with oral corticosteroids, most patients with macular edema also need intraocular corticosteroid injections. A dexamethasone intraocular implant one option ophthalmologists often turn to.

According to the NHS, intraocular corticosteroids can raise pressure inside the eye, creating a risk factor for glaucoma. The study also noted that the intraocular corticosteroids can also lead to cataract.¹

The NHS news release noted that the team of researchers looked at 3 treatments for uveitis-related macular edema: an additional intraocular corticosteroid injection, an injection of the anti-vascular endothelial growth factor (anti-VEGF) drug ranibizumab, or an injection of the anti-inflammatory drug methotrexate. Anti-VEGF injections are used to treat age-related macular degeneration, as well as macular edema due to other causes, such as diabetic retinopathy. Earlier, small pilot studies suggested that ranibizumab injections and the anti-inflammatory effects of methotrexate might help reduce uveitis-related macular edema.

Uveitis is inflammation of the eye originating in the uvea, which includes the iris, ciliary body, and choroid. (Image courtesy of NEI/Lesley Earl)

The NHS reported the clinical trial enrolled 194 participants (225 study eyes) with well-controlled uveitis but persistent or recurrent macular edema. Sixty-five participants received a dexamethasone corticosteroid, 65 participants received methotrexate, and 64 participants received ranibizumab. The study took place at 33 clinical centers, located across the United States, the United Kingdom, Australia, and India. All participants had previously received at least one intravitreal corticosteroid injection for uveitis-related macular edema.

“The injection schedules for each group were based on how each treatment is generally used in clinical practice,” the NHS noted in the release. “The corticosteroid group participants received 1 dexamethasone implant injection at baseline and, if the macular edema had not resolved, another injection at 8 weeks. The methotrexate group received 1 injection at baseline, then repeat injections at 4 and 8 weeks if macular edema did not resolve. The ranibizumab group received injections at baseline, 4 weeks, and 8 weeks, even if their macular edema resolved.”

Moreover, the NHS noted in its release that all 3 groups demonstrated a reduction in retinal swelling after 12 weeks, with the reduction being the greatest in the dexamethasone group compared to the other 2 (35% reduction for corticosteroid; 20% for ranibizumab; 11% for methotrexate).

The NHS also noted in its release the corticosteroid group was the only group that showed improvement in vision, nearly 5 letters—about 1 row on an eye chart. This group did have more occurrences of mild increases in intraocular pressure, but rises to high levels were infrequent (<10%) in all three groups.

“Intraocular corticosteroid treatment remains the most effective therapy for uveitis-related macular edema,” Nisha Acharya, MD, University of California San Francisco, the lead author of the study, said in the NHS news release. “The vision gains in participants who received the corticosteroid treatment were very promising.”

According to the NHS, the study was funded by NEI, and Allergan and Genentech provided a portion of the dexamethasone implants and ranibizumab, respectively.

Reference:

1. The Multicenter Uveitis Steroid Treatment Trial (MUST) Research Group. “Intravitreal therapy for uveitic macular edema – ranibizumab vs methotrexate vs the dexamethasone implant: The MERIT Trial Results.” Ophthalmology, June 13, 2023.