Peripapillary microvasculature and retinal nerve fiber layer thickness in active and quiescent phases of intermediate uveitis

PURPOSE: Optic nerve head changes can be observed due to direct involvement or as a result of complications of intermediate uveitis (IU) and can lead to visual impairment. The purpose of this study was to investigate retinal nerve fiber layer thickness (RNFLT) and microvasculatory changes in the peripapillary region, and to determine their relationship with disease activity.
METHODS: This study was a cross-sectional analysis. The peripapillary RNFLT and radial peripapillary capillary (RPC) vessel densities (VDs) of IU patients, presented to our clinic between December 2017 and March 2023, were retrospectively analyzed using optical coherence tomography angiography (Avanti RTVue-XR; Optovue, Fremont, CA) and compared with healthy subjects.
RESULTS: Twenty-eight eyes with IU (12 in active, 16 in quiescent phase) and 23 healthy control eyes were included. Decreased RPC VDs were observed in the quiescent phase of IU compared with the healthy control group in the whole image, superior hemisphere, and inferior hemisphere areas (p=0.002, p=0.003, and p=0.007, respectively). Peripapillary VD values were reduced in the quiescent phase compared with the active phase and control eyes (p=0.013 and p=0.002, respectively). No significant differences were observed between the active and control groups (p>0.05 for all). Increased RNFLT was observed in the active phase compared with quiescent and control groups (p<0.001).
CONCLUSION: RNFLT increases during the active phase of IU due to possible inflammation in the peripapillary area, whereas vascular parameters do not change quantitatively. In the quiescent phase, the resolution of inflammation and possible permanent vascular changes may affect the vascular structure.

Keywords: Glaucoma, Intermediate uveitis, Optical coherence tomography, Vascular density