The following is a summary of “Comparison of intravitreal preservative-free triamcinolone versus posterior sub-tenon triamcinolone acetonide injection for bevacizumab-resistant diabetic macular edema,” published in the January 2024 issue of Ophthalmology by Jeon et al.

While Triamcinolone acetonide (TA) tackles diabetic macular edema (DME) through both intravitreal and sub-Tenon capsule injections, its intravitreal use faces limitations due to preservatives, prompting comparison of preservative-free intravitreal TA (IVTA) and sub-Tenon capsule TA (STTA) for DME treatment.

Researchers conducted a retrospective study to compare the efficacy of preservative-free IVTA and posterior STTA in treating bevacizumab-resistant DME.

They investigated bevacizumab-resistant DME, characterized by an inadequate response to a minimum of three consecutive intravitreal bevacizumab (IVB) injections. It compared alterations in mean central macula thickness (CMT), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) between the intravitreal triamcinolone acetonide (IVTA) and posterior sub-Tenon capsule triamcinolone acetonide (STTA) groups at baseline, 1, 2, and 3 months post-treatment.

The result showed that 40 eyes from 40 patients were enrolled. In the IVTA group, the mean CMT significantly improved from 400.2 ± 144.42 μm at baseline to 288.35 ± 151.74 μm at 3 months post-treatment (P=0.01). In the STTA group, the mean CMT also significantly improved from 446.65 ± 120.74 μm at baseline to 382.9 ± 113.58 μm at 3 months post-treatment (P=0.009). The mean BCVA in the IVTA group showed improvement, decreasing from 0.75 ± 0.55 logarithm of the minimum angle of resolution (logMAR) at baseline to 0.625 ± 0.50 logMAR at 3 months post-treatment (P=0.089). Similarly, the mean BCVA in the STTA group improved, changing from 0.6 ± 0.36 logMAR at baseline to 0.54 ± 0.35 logMAR at 3 months post-treatment (P=0.094).

Investigators concluded that for equivalent effectiveness in treating bevacizumab-resistant DME, less invasive STTA emerged as the preferred option over IVTA. 

Source: bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-024-03291-2