A 58-year-old Japanese man with diabetes presented with blurred vision in his right eye. His intraocular pressure was 53 mm Hg and the peripheral anterior synechia index was around 20%. The anterior segment optical coherence tomography (OCT) angiography image showed that the iris neovascularization was marked around the pupil in the superficial layer (Figure, A; green shading).1 Anterior segment OCT angiography using a swept-source OCT system enabled the visualization of physiological radial vessels in the stroma, even in a brown eye (Figure, A; red shading). Panretinal photocoagulation was administered immediately and completed in 3 separate installments over 1 month. An intravitreal ranibizumab injection was administered 2 weeks later. By 1 month after the beginning of panretinal photocoagulation, the iris neovascularization had mostly diminished (Figure, B; green shading) and the patient’s intraocular pressure had decreased to 19 mm Hg with ocular hypotensive drops; however, the physiological radial vasculature in the deep layer showed little change (Figure, B; red shading).