Retinal optical coherence tomography: past, present and future perspectives.

Optical coherence tomography (OCT) has undergone substantial changes since its first use in the 1990s. Although the first generation of OCT systems heralded a new era in the non-invasive diagnostic options in ophthalmology, they did not reveal much detail. Later devices offered more information and helped in the diagnosis and treatment of a variety of pathological conditions, primarily of the retina. With today's spectral-domain type models ophthalmologists are offered a comprehensive tool with the opportunity for early diagnosis and precise monitoring of patients with retinal and glaucomatous pathologies. However, as experience with these new devices grows and demands by clinicians and researchers rise, further improvements need to be addressed. Future developments in the improvement of the transverse resolution and extension of the penetration depth are to be expected. New modalities such as polarisation sensitive OCT (PS-OCT) or Doppler OCT are now in use and promise additional insights in the properties of physiological and pathological tissue. While PS-OCT reveals further detail in alterations of the retinal pigment epithelium, Doppler OCT gives additional information about blood flow measurements. With these and further new developments, OCT will continue to be an invaluable instrument in the armamentarium of modern ophthalmology.