Abstract: Objective To observe the image features of swept-source optical coherence tomography (SS-OCT) in patients with idiopathic posterior scleritis at different disease stages. Design Retrospective case series. Participants A total of 27 patients with idiopathic posterior scleritis diagnosed at Beijing Tongren Hospital from September 2018 to February 2021 were included in the study. Among them, 14 patients were bilateral involved and other 13 patients were unilateral involved. A total of 41 affected eyes were selected as the study group, and other 13 eyes were selected as the control group. Methods Disease staging was conducted based on the clinical manifestations of the enrolled patients. The active stage was defined as the period from the onset of symptoms to the stabilization stage. The stabilization stage was defined as the disappearance of patient discomfort complaints, discontinuation of medication, or use of the minimum maintenance dose of oral glucocorticoids (5-10 mg/day) and/or immunosuppressants (oral methotrexate 7.5 mg per week or lower doses). The recurrence stage was defined as the reappearance of symptoms and/or re-diagnosis of active posterior scleritis after the stabilization stage. All patients underwent SS-OCT examination at the initial visit, 1 and 2 weeks, and at 1, 3, 6, and 12 months after treatment. The abnormal features of the retina and choroid, as well as the thickness of the retinal and choroidal layers in the posterior pole of SS-OCT images, were compared among different stages. Main Outcome Measures The abnormal signs of retina and choroid showed by SS-OCT and their resolving time, thickness of retinal and choroid. Results Abnormal signs observed using SS-OCT in the active stage (n=41) included retinal folds in 23 eyes (56.10%), subretinal fluid in 11 eyes (26.83%), punctate hyperreflectivity in the retina and/or choroid in 35 eyes (85.37%),  RPE wave-like change in 11 eyes (26.83%), optic disc and/or macular edema in 25 eyes (60.98%), and choroidal structural abnormalities in 12 eyes (29.27%). These abnormal signs could occur simultaneously in different or the same regions of the fundus in the same patient. The choroidal thickness in the macular fovea of the eyes in the stabilization stage (n=41) was (245.923±6.829) μm, which was significantly lower than that in the active stage (n=41) (405.640±40.629) ?滋m (P=0.001). Compared with the stabilization stage, the choroidal thickness in the eyes in the recurrence stage (n=12) (354.917±62.034 ?滋m) increased again (P=0.001). Conclusion Abnormal imaging signs including punctuate hyperreflectivity in retina and/or choroid, increased choroidal thickness could be seen in active idiopathic posterior scleritis, while the choroidal thickness decreased significantly during stabilization stage and re-increased during recurrence stage. (Ophthalmol CHN, 2024, 33: 107-113)

Key words:  posterior scleritis, swept-source optical coherence tomography