An overview of the structure and function of the retina and its relationship to the pigment epithelium, choroid and vitreous is provided. This section describes the major vitreoretinal disorders and appropriate diagnostic methods and treatment principles. Includes the management of age-related macular degeneration, diabetic macular edema, and venous occlusive disease chapter covering retinovascular disease associated with cardiovascular disease. An emphasis on imaging is demonstrated in this text with more than 175 images and ten surgical videos to illustrate common vitreoretinal procedures. Both print and eBook users have access to the videos. Separate chapters are devoted to age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity, including the latest imaging techniques and choroidal detail. Selected therapeutic topics include laser therapy and vitreoretinal surgery. Upon completion of Section 12, readers should be able to: *Select appropriate methods of examination and ancillary studies for the diagnosis of vitreoretinal disorders *Describe the principles of medical and surgical treatment of vitreoretinal disorders *Incorporate data from major prospective clinical trials in the management of selected vitreoretinal disorders Major revision: 2018-2019 Section chair: Colin A. McCannel, MD.