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Purpose: To describe the changes seen on optical coherence tomography angiography [OCTA] in patients with PIC following immunosuppressive therapy.Methods: We reviewed serial OCTA scans from five consecutive PIC patients (5 eyes) with at least 3 months of follow-up, who underwent imaging before and after immunosuppressive therapy. Using ImageJ, superficial and deep retinal vasculature were analyzed for vessel area and foveal avascular zone. Choriocapillaris layer was analyzed for flow signal loss.Results: Five out of five patients received an orbital floor triamcinolone acetonide injection as the initial treatment for periods of activity. Mean choriocapillaris (CC) flow void area obtained after immunosuppressive therapy was significantly lower than the mean CC flow void area obtained prior to treatment (Pre-treatment: 0.270 vs Post-treatment: 0.144; p = .0068). In 2 out of 2 patients with longitudinal visual field testing, CC flow voids were spatially associated with visual field defects, and immunosuppressive therapy was associated with reduced CC flow void area and improved visual function.Conclusion: OCTA can detect alterations in choriocapillaris flow. Longitudinal follow-up demonstrates a centripetal restoration of choriocapillaris flow in response to immunosuppressive therapy. OCTA may be a useful adjunct for monitoring and evaluating treatment of PIC.

The type III intermediate filament (IF) proteins vimentin and desmin are sequentially overexpressed in stromal myofibroblasts over the period when fibrosis sets in after corneal injury. Prior findings have revealed vimentin-deficient mice are significantly protected from corneal fibrosis after alkali injury, which has implicated this IF protein as an important regulator of corneal fibrosis. It has remained as yet unproven whether desmin contributes in any significant manner to corneal fibrosis. Here we have employed desmin-deficient (Des KO) mice in the corneal alkali injury model and show that injured Des KO mice develop fibrosis and show similar levels of corneal opacity at 14 days post-injury as wild type (WT) mice and retain this phenotype even at 30d post injury. Des KO corneas from injured mice show upregulation of vimentin and alpha-smooth muscle actin expression to equivalent levels as WT corneas, illuminating that desmin deficiency does not interfere with myofibrobast differentiation. Employing the small molecule withaferin A (WFA), an inhibitor of vimentin, we show that WFA treatment causes the decrease in steady state levels of vimentin and serine 38 phosphorylated vimentin, the latter a biomarker associated with corneal fibrosis, and improved corneal clarity through blockade of myofibroblast differentiation. To investigate further the mechanism of fibrosis in desmin deficiency, we examined keratin 8 expression in the epithelium, and found reduced levels of this cytokeratin in injured Des KO corneas compared to WT corneas. This finding also corroborates the decrease of cell proliferation in injured Des KO corneas compared to that in WT corneas. The fibrotic phenotype of Des KO corneas also features abundant vascularization, further exemplifying the magnitude of corneal pathology. Together, these findings illuminate that desmin does not contribute significantly to corneal fibrosis in this injury model.