Stepwise 900 µm to 1100 µm Microneedle Selection for Suprachoroidal Triamcinolone Acetonide

To describe real-world microneedle size use during suprachoroidal triamcinolone acetonide injection and identify patient-level factors associated with 900 µm vs 1100 µm microneedle requirement.

A retrospective study was performed of all eyes receiving suprachoroidal triamcinolone acetonide between November 2022 and May 2026 from a single provider at a tertiary referral center. The primary outcome was microneedle size requirement (900 µm vs 1100 µm) at the first injection. The secondary outcome was needle size transition on repeat injections among eyes initially injected with the 900 µm needle. Generalized estimating equations with patient-level clustering were used for the primary analysis. Safety outcomes were also assessed.

A total of 103 eyes from 88 patients were included, comprising 202 injections. Using a standardized stepwise approach of attempting the 900 µm needle at first injection in all eyes, 64 eyes (62.1%) were successfully injected, while 39 eyes (37.9%) required the 1100 µm needle. On multivariable analysis, self-identified Black race was independently associated with requirement of a 1100 µm needle (adjusted odds ratio, 8.59, 95% CI, 2.42-30.48; P < .001), robust across primary, multivariable, and sensitivity analyses. No other demographic or ocular variable was significantly associated with needle size. No adverse safety events were observed.

A stepwise approach beginning with the 900 µm needle is safe and effective for most patients and may optimize suprachoroidal drug delivery across a diverse patient population. Self-identified Black race is strongly and independently associated with requirement of a 1100 µm microneedle for suprachoroidal injection, potentially reflecting ancestry-related differences in scleral and suprachoroidal anatomy.