Retinal vascularity, nerve fiber, and ganglion cell layer thickness in thyroid eye disease on optical coherence tomography angiography.

Purpose: To compare the retinal vascularity, peripapillary vascularity, nerve fiber layer thickness and ganglion cell layer thickness between active, inactive thyroid eye disease (TED) and healthy eyes.

Methods: Retrospective comparative cross-sectional cohort study. Patients with TED, active and inactive on the VISA score, and healthy eyes were included. All patients underwent optical coherence tomography angiography with detailed demographic and clinical data capture. Using automated software, retinal and peripapillary vascularity index, nerve fiber layer thickness, and ganglion cell layer thickness were calculated and were compared between the groups.

Results: Twenty-four eyes with active TED, 102 eyes with inactive TED and 52 healthy eyes were included. Independent sample t test was used to compare parametric data and Mann-Whitney test to compare non-parametric data. The age and gender were comparable across groups. The peripapillary vascularity index (26.82 ± 4.13 versus 34.92 ± 5.08, = .002) and the macular vascularity index (20.32 ± 2.5 versus 31.21 ± 3.89, < .0001) were reduced in active TED eyes versus inactive eyes. Macular vascularity index was comparable in the inactive versus the healthy eyes. The RNFL thickness was increased in the active TED eyes versus the inactive eyes (45.11 ± 18.3 versus 35.55 ± 7, = .03) and active versus healthy eyes (45.11 ± 18.3 versus 36.28 ± 7.89, = .03). Ganglion cell layer thickness between all three groups was comparable.

Conclusion: Decrease in peripapillary and macular vascular density and increase in RNFL thickness are seen in active TED compared to inactive TED and healthy eyes. In disease inactivity, these parameters are comparable to healthy eyes.