Optical coherence tomography ( OCT) is a new technique in the diagnosis of eye diseases uses a lowr coherence interferometry to give optical sections in ocular tissues. The principle of OCT by using infrared Diode laser, is based on analysis the time of light delay from optical signals that have been reflected from ocular tissues such as the retina. It has the advantage of being non invasive, non contact, comfortable and well tolerated by the patient. It does not require dye injection or radiation exposure. OCT can be used as well as an adjunctive diagnostic tool for imaging of selected macular diseases including macular holes , macular edema, age- related macular degeneration central serous chorioretinopathy , epiretinal membranes and other retinal diseases. OCT is also of great value in the early diagnosis of glaucoma and the early detection of glaucomatous progression using direct measurement of peripapillary nerve fibre layer thickness.