Risk factors for failing sub-Tenon's triamcinolone acetonide for uveitic macular edema.

Background: Sub-Tenon's triamcinolone acetonide (STA) is less effective than intravitreal corticosteroids in the treatment of uveitic macular edema (ME), but does have some relative advantages, including substantially lower cost and decreased risk of post-injection ocular hypertension. It would be useful for clinicians to know which eyes may respond well to STA and not necessarily require intravitreal therapy. The objective of this study is to identify risk factors for failing STA for the treatment of uveitic ME.

Main body: A retrospective cohort study was performed. Medical records were reviewed of patients who underwent STA for the treatment of uveitic ME between January 1, 2013, and July 31, 2022, at the University of Colorado Hospital. Uveitic ME was defined by a central subfield thickness (CST) greater than 320 μm or the presence of intra-retinal cystoid spaces on optical coherence tomography (OCT), or by the presence of petaloid macular leakage on fluorescein angiography (FA). Data collected included age, race/ethnicity, sex, history of diabetes mellitus, anatomic classification of uveitis, use of corticosteroids, use of immunomodulatory therapy, presence of intra-retinal fluid on OCT, CST on OCT, and presence of petaloid macular leakage on FA. STA failure was defined as the need for additional therapy within 12 weeks of STA due to persistent or worsening uveitic ME. One hundred eighty eyes from 131 patients were included. Forty-two eyes (23.3%) were considered treatment failures. In univariate and multivariable analysis, higher baseline CST was associated with a higher likelihood of failing STA (OR 1.17 for each 30 μm increase in CST, P = 0.016).

Conclusions: STA, while not as potent as intravitreal corticosteroids for the treatment of uveitic ME, was still an effective therapy, particularly for patients with lower baseline CST. Given its lower side effect profile and cost compared to intravitreal treatments, clinicians could consider STA as an initial treatment for mild uveitic ME.