Association of OCT angle recess width with IOP response after intravitreal triamcinolone injection

A circumferential pretrabecular anatomical structure, the angle recess (AR), can be imaged with anterior segment ocular coherence tomography. AR's utility to predict ocular hypertension after intravitreal triamcinolone injection was assessed.

All intravitreal triamcinolone injection recipients from 2002 to 2005 with high-resolution anterior segment ocular coherence tomography images had AR width (between the anteriormost prominence of the iris root and posterior cornea) measured by masked physicians using the caliper function of Stratus ocular coherence tomography. Intraocular pressures (IOPs) from 1 month before to 6 months after the injection were compiled for IOP rise (Δ) and maximal IOP (max), categorized as "minimal" (IOPmax < 21 mmHg and/or IOPΔ ≤ 5 mmHg), "moderate" (IOPmax 21-29 mmHg and/or IOPΔ 6-14 mmHg), or "severe" (IOPmax ≥ 30 mmHg and/or IOPΔ ≥ 15 mmHg). Linear regression and analyses of variance were applied.

Twenty-six eyes satisfied the entry criteria, with 11 (42%) eyes demonstrating minimal, 11 (42%) moderate, and 4 (15%) severe IOP responses. The corresponding (mean ± SEM) AR widths were: 326 ± 31.5 μm, 281 ± 22.0 μm, and 138 ± 20.3 μm, respectively. Highly significant AR width differences existed between moderate and severe responders and between minimal and severe responders (both P < 0.004); 5 of 6 patients with IOP ≥ 29 mmHg had AR < 200 μm.

These findings indicate that a potentially clinically useful relationship exists between AR width and IOP elevation accompanying intravitreal triamcinolone injection. Anterior segment screening could become a beneficial extension of ocular coherence tomography for retinal practices.