Comparison of intravitreal preservative-free triamcinolone versus posterior sub-tenon triamcinolone acetonide injection for bevacizumab-resistant diabetic macular edema

BMC Ophthalmol. 2024 Jan 19;24(1):25. doi: 10.1186/s12886-024-03291-2.

Abstract

Background: Triamcinolone acetonide (TA) is administered as an intravitreal or posterior sub-Tenon's capsule injection, as treatment for diabetic macular edema (DME). The intravitreal use of TA is limited because commercially available triamcinolone acetonide contains benzyl alcohol, a neurotoxic preservative. Few studies have compared effects of preservative-free intravitreal TA (IVTA) and posterior sub-Tenon capsule TA (STTA) injections for DME. Thus, herein, we compared the effectiveness of preservative-free IVTA and STTA for treatment of bevacizumab-resistant DME.

Methods: In this retrospective cohort study, bevacizumab-resistant DME was defined as a lack of response to at least three consecutive intravitreal bevacizumab (IVB) injections. Changes in mean central macula thickness (CMT), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) between IVTA and STTA groups were compared at baseline and at 1, 2, and 3 months after treatment.

Results: Forty eyes from 40 patients were included in this study. In the IVTA group, the mean CMT improved significantly from 400.2 ± 144.42 μm at baseline to 288.35 ± 151.74 μm at 3 months after treatment (p = 0.01). Similarly, in the STTA group, the mean CMT improved significantly from 446.65 ± 120.74 μm at baseline to 382.9 ± 113.58 μm at 3 months after treatment (p = 0.009). The mean BCVA of the IVTA group also 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 after treatment (p = 0.089). Similarly, the mean BCVA of the STTA group improved, from 0.6 ± 0.36 logMAR at baseline to 0.54 ± 0.35 logMAR at 3 months after treatment (p = 0.094).

Conclusion: Given that IVTA and STTA demonstrated statistically equivalent anatomical and functional effects in patients with bevacizumab-resistant DME, the less invasive STTA may be considered the preferred treatment approach for the management of bevacizumab-resistant DME.

Trial registration: Retrospectively registered.

Keywords: Bevacizumab-resistant; Diabetic macular edema; Sub-tenon’s capsule injection; Triamcinolone acetonide.

MeSH terms

  • Bevacizumab / therapeutic use
  • Diabetes Mellitus*
  • Diabetic Retinopathy* / complications
  • Glucocorticoids
  • Humans
  • Intravitreal Injections
  • Macular Edema* / etiology
  • Retrospective Studies
  • Treatment Outcome
  • Triamcinolone Acetonide

Substances

  • Triamcinolone Acetonide
  • Bevacizumab
  • Glucocorticoids