Anterior segment optical coherence tomography in modern ophthalmic diagnostics

Since the 1990s, tomography examination techniques in ophthalmology have undergone significant development. Optical coherence tomography (OCT) plays a crucial role in the differential diagnosis of retinal pathologies, however, this non-invasive technique that operates with infrared light is also excellent for imaging the anterior segment of the eye. The former time-domain tomographies have been replaced by spectral-domain and swept-source types, which are less sensitive to eye movement and capable of higher resolution. In addition to reconstructed cross-sectional images, its micrometer-resolution imaging provides quantitative data from the ocular surface to the lens. Its fields of application include the examination of the ocular surface, corneal opacities, degenerations, and dystrophies. In the diagnosis of corneal pathologies, the advantage is that it provides reliable data not only on the anterior but also on the posterior curvature, thus on the true total refractive power of the cornea, as well as on its thickness. It can also be used for early keratoconus screening. It is also excellent for follow-up after corneal surgeries (refractive surgery, corneal transplantation). In addition, it is an accurate and reliable technology in the diagnosis of glaucoma and intraocular lens calculation. One of its latest applications is its integrated form in the operating microscope, which assists the surgeon during intervention. Another innovative form is the non-invasive angiographic examination of the anterior segment.