Purpose: To evaluate intra retinal morphological and macular thickness changes by using three dimensional optical coherence tomography before, 1 week and 1 month after intravitreal injection of Ranibizumab. Subjects and Methods: Twenty five eyes (10 eyes with wet type of age related macular degeneration (AMD), 10 eyes with diabetic macular oedema and5 eyes with central retinal vein occlusion) were treated with intravitreal Ranibizumab (Lucentis). The patients were diagnosed by fundus biomicroscopy, fundus photography, flourescein angiography, best corrected visual acuity before intravitreal injection of Ranibizumab. Optical coherence tomography by using spectral / Fourier domain three dimensional optical coherence tomography was done at base line, day 7 and month 1. Results: All eyes showed some degree of normalization of macular contour after intravitreal Ranibizumab. In age related macular degeneration group, the mean central macular thickness before injection was 516.9±48.9µm, at day 7 and month 1the mean central macular thickness was 357.3 ± 74.4 and 255.8 ± 34.9 respectively, the changes were statistically significant (P