Imaging Pars Plana in Acute Anterior Uveitis: Association with Inflammatory Activity

To determine the association between pars plana thickness and disease activity in acute anterior uveitis.

Participants underwent anterior segment optical coherence tomography (AS-OCT) of the ciliary body using Topcon DRI-OCT Triton plus with an anterior segment adapter. Pars plana thickness was measured 3 mm posterior to the scleral spur in the nasal and temporal side. Patients received standard topical therapy and were followed longitudinally with repeat examination and AS-OCT imaging.

Forty nine eyes of 49 patients with anterior uveitis and 49 eyes of 49 healthy control were included in the analysis. The mean pars plana thickness was significantly greater in eyes with anterior uveitis compared to controls in both nasal (323.16 ± 81.14 µm vs 227.43 ± 56.68 µm; p < 0.001) and temporal side (354.48 ± 75.56 µm vs 235.31 ± 48.99 µm; p < 0.001). Supraciliary fluid (SCF) was detected in 59.2% of cases at baseline. Two or more than two step reduction in anterior chamber cell grade was documented in 24 eyes. It was associated with a significant decrease in nasal (313.18 ± 61.92 µm to 266.09 ± 64.95 µm; p < 0.001) and temporal pars plana thickness (362.39 ± 80.05 µm to 288.52 ± 74.03 µm; p < 0.001). Resolution of clinical activity was documented in 19 eyes. In this cohort, SCF was detected in 47.4% of eyes at baseline, declining to 10.50% at resolution.

Pars plana thickness may serve as a novel, non-invasive imaging marker that parallels longitudinal resolution in anterior uveitis.