Role of anterior segment optical coherence tomography in scleral diseases: A review

Background Scleritis and episcleritis are an overlapping spectrum of diseases and accurate diagnosis is of utmost importance as the treatment and prognosis are vastly different. Predominantly a clinical diagnosis, the challenge lies in those cases with equivocal clinical features. Furthermore, clinical grading of scleritis is subjective and hence is neither very reliable nor reproducible. Existing modalities such as slit lamp examination and clinical photographs in scleritis describe macroanatomy but do not provide details on the microanatomy of the sclera. A recent adjusted algorithm for anterior segment optical coherence tomography (AS-OCT) imaging has improved the ability of this device to aid in the diagnosis of all the major forms of scleritis. Purpose To highlight the role of AS-OCT in delineating various anatomical forms of episcleritis and scleritis and explore this tool in monitoring disease course and response to therapy. Methods A comprehensive literature search was carried out in various medical databases using keywords AS-OCT and scleritis; AS-OCT and episcleritis; anterior segment imaging in scleritis; scleritis and episcleritis; Recent advances in anterior segment imaging. Original articles and novel reports describing the potential role of AS-OCT in the diagnosis and management of scleritis and episcleritis were included. Results After a thorough assessment, it was clear that published literature lacks guidelines for uniform interpretation and also for classification and follow-up in scleritis. We describe a uniform protocol for AS-OCT image acquisition, interpretation of images and list the advantages and limitations. Conclusions AS-OCT can be used to localize the level of scleral inflammation thus helping in the diagnosis of scleral inflammatory disease. It can be a valuable tool in studying progression.