Optical Coherence Tomography in Vitreomacular Disorders

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Optical Coherence Tomography (OCT) is part of the routine examination of all vitreomacular disorders. Spectral domain technology has provided images with better resolution, which are also easier to interpret reliably. In most of these pathologic cases, it is now possible to visualize the status of the posterior hyaloid, its connection to the retinal surface, and its thickness and reflectivity. OCT plays an essential role in the diagnosis and preoperative assessment of macular holes. In impending macular holes, it shows minute irregularities of the foveal curvature, and/or tiny intrafoveal tractional retinal cysts. In full thickness macular holes, OCT clearly shows defects in the retinal tissue and allows full thickness macular holes to be distinguished from macular lamellar holes or pseudoholes. The quality of the OCT scan profiles also allows accurate measurement of macular hole diameter, which is a major indicator of the chances of successful surgery and may affect the choice of surgical technique. Furthermore, OCT allows assessment of the quality of macular hole closure. Although the presence of epiretinal membranes may also be diagnosed on red-free and blue reflectance photographs, OCT has the advantage of showing the degree of retinal thickening in the fovea, as well as the presence of any intrafoveal cysts or vitreomacular traction. Diagnosis of the vitreomacular traction syndrome has also been greatly facilitated by the use of OCT, which shows, more clearly than ultra sound or biomicroscopy, the elevation of the foveal surface due to the focal traction of a thick and hyper-reflective posterior hyaloid. Finally, OCT has allowed the identification of myopic foveoschisis, a hitherto unknown but relatively common complication related to myopic staphyloma. This vision - threatening complication may benefit from surgery, depending on its OCT characteristics. In conclusion, although OCT is still a technique in evolution, but it already provides invaluable information on vitreomacular disorders and plays an essential part in their diagnosis and management.