Corticosteroids Show Efficacy Against Diabetic Macular Edema

New research presented at the American Society of Retina Specialists 2020 (ASRS 2020) Virtual Sessions might add to the list of therapies aimed at treating diabetic macular edema (DME).

A team, led by Madison Kerley, BA, compared the efficacy and adverse effects of triamcinolone acetonide and dexamethasone in a real-world setting to treat diabetic macular edema and determined which corticosteroid is more effective in the long-term management of the disease.

To treat diabetic macular edema, clinicians often administer corticosteroids when laser photocoagulation and anti-VEGF agents become ineffective. Triamcinolone acetonide is an injection administered every 3 months, while dexamethasone is an implant that can last up to 6 months.

In the retrospective study, the investigators examined 40 eyes from 32 patients treated for DME at a tertiary care center. Of the eyes treated, 24 were treated triamcinolone 2-4 mg and 16 with dexamethasone 0.7 mg implant. Each patient was followed for up to 12 months.

In addition, some patients continued to receive anti-VEGF injections after steroid injections, which was determined by clinical judgment. The median age in the triamcinolone group was 60 and 65 in the dexamethasone group.

The investigators sought main outcome measures of changes in best corrected visual acuity (BCVA), intraocular pressure (IOP), number of IOP medications used, and central macular thickness (CMT), as well as time to the next treatment of any kind.

The baseline mean BCVA was 20/60 for triamcinolone and 20/37 for dexamethasone (P = 0.003), but neither group achieved a statistically significant improvement in BCVA after 1 month.

The mean IOP at baseline was 15.2 mmHg in the triamcinolone group and 15.9 mmHg with the dexamethasone group. This increased by 2.9 and 0.2 mmHg at 1 month, respectively (P = 0.04).

The mean CMT at baseline was 438 mm for the triamcinolone and 430 mm for dexamethasone, which decreased by 103 mm and 47 mm at month 1, respectively (P = 0.068).

For patients who received additional treatments of any kind, the mean time to next treatment was 19 weeks for triamcinolone and 22 weeks for dexamethasone (P = 0.32).

“Both triamcinolone and dexamethasone show anatomical efficacy in treating DME,” the authors wrote. “Triamcinolone appears to have somewhat better efficacy at one month but at the expense of a slightly poorer IOP profile. Because of the retrospective nature of this study, it is unclear if the dexamethasone implant has a longer duration of efficacy based on these data.”

As of 2015, there were 285 million people worldwide with diabetes mellitus, a third of which diagnosed with diabetic retinopathy. DME represents the leading cause of vision loss in patients with non-proliferative diabetic retinopathy, which is characterized by vascular leakage that exceeds the capacity of retinal dehydration mechanism.

Currently, there are only 3 intravitreal corticosteroids approved for DME.

The study, “A Retrospective Comparison of Dexamethasone to Triamcinolone Acetonide in the Treatment of Diabetic Macular Edema,” was published online by ASRS 2020.