Optical coherence tomography angiography for the diagnosis of granulomatosis with polyangiitis with serous retinal detachment: A case report

RATIONALE: Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease of unknown etiology. GPA affects multiple ocular tissues, most commonly the orbit, conjunctiva, cornea, and sclera. Retinal and choroidal manifestations are rare in GPA, but they often include choroidal neovascularization (CNV). PATIENT CONCERNS: A 36-year-old man was diagnosed with GPA. He had been taking oral steroid treatment for 8 years. He experienced disease recurrence and the dose of oral prednisolone was increased after steroid pulse therapy. Fundus examination showed small retinal pigment epithelial detachment and serous retinal detachment (SRD). Optical coherence tomography (OCT) revealed a protruded lesion inside the SRD. Fluorescein angiography (FA) showed a small, dot-shaped fluorescein leakage in the SRD, and indocyanine green fluorescein fundus angiography showed choroidal vascular hyperpermeability that was consistent with the hyperfluorescence seen with FA. We had to determine whether the protruded lesion inside the SRD was CNV secondary to the inflammation due to GPA or whether it was central serous chorioretinopathy (CSC)-like condition caused by high-dose steroid treatment. DIAGNOSES: We confirmed that the SRD was due to CSC but not CNV because the protruded lesion examined by B-scan OCT angiography (OCTA) showed no blood flow. INTERVENTIONS: We decided to reduce the dose of steroid. OUTCOMES: Since the reduction of steroids, no sign of worsening in the protruded lesions with SRD has been observed. LESSONS: We therefore propose the effectiveness of this advanced function of OCTA for the examination of blood flow signal images to detect CNV.