![]() ![]() Segmentation algorithms capable of specifically segmenting the anterior iris surface could compensate for the ambiguity in eyes with light iris color. The purpose of this review is to summarize the current OCTA application to the anterior segment of the eye, with emphasis on how to use it to assess iris vascular changes in anterior uveitis. OCTA finds fertile soil in inflammatory eye diseases as vascular changes in the iris, retinal, and choroid are the core sites of the pathophysiology of eye inflammation. The past 3 years have witnessed an explosion in the application of this imaging method to vascular retinal diseases, and only recently more and more studies are sprouting on OCTA in uveitis. ![]() This is a technique that creates images of capillary networks by comparing the amount of light returned from static and mobile targets without the need for intravenous dye administration. The most relevant step forward of OCT has been its evolution from assessing the morphology of a tissue to studying its functional component, through optical coherence tomography angiography (OCTA). Since its advent at the end of the last century, optical coherence tomography (OCT) has constantly evolved as far as resolution and sensitivity are concerned. In addition, OCTA can depict neovascularization of the iris secondary to proliferative diabetic retinopathy. This review aims to establish the current application of OCTA to anterior segment disorders of the eye, with an emphasis on exploring its use in iris vessel dilation seen in various forms of iritis, as a predictive factor for further episodes of inflammation. Additional studies including different iris pathologies are needed to determine the most optimal scanning parameters in OCTA of the anterior segment. Fine, clinically invisible iris vessels can be visualized by OCTA in the very early stages as well as in the regressed stage of NVI. In both OCTA and fluorescein angiography, iris pigmentation causes vasculature imaging blockage, but OCTA provides more detailed iris vasculature images. OCTA for imaging of the iris vasculature in health and disease is highly dependent on iris pigmentation. In addition, OCTA gives qualitative vessel density values that can be compared pre- and post-anti-inflammatory treatment. OCTA can determined iris vessel filling defects or their flow increase, when present, secondary to inflammatory conditions. Anterior segment OCTA allows analysis of iris vasculature and 3-D reconstruction of the normal iris vessels. At the same time, it can detect changes in conjunctival and limbal vascularization and thus can be applied to pseudo-inflammatory conditions such as pterygium. OCTA can successfully delineate corneal vessels with substantial image quality. OCTA, currently designed as a retinal vascular imaging system, has been recently adapted for anterior segment and showed good potential for successful imaging of the conjunctiva, the cornea, and the iris. With an increased number of papers on how to interpret optical coherence tomography angiography (OCTA) findings in uveitis, the aim of this review is to assess its efficacy for the quantitative monitoring of structural and functional changes in inflamed conjunctiva and iris vessels in patients with acute anterior uveitis and iris neovascularization. ![]()
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