Advances in ocular drug delivery book extensively covers novel approaches for retinal drug delivery and ocular gene therapy. This treatise broadly explains the role of biodegradable polymers in ophthalmic drug delivery and importance of translational medicine in various ocular diseases. It showcases functional presence and importance of various ocular transporters in back of the eye for drug delivery. Several influx and efflux transporters are expressed in various ocular tissues. These transporters play an important role in ocular drug absorption. An update on applications of various particulate and colloidal formulations in ophthalmic research have also been discussed. Over the last two decades various biodegradable/nonbiodegradable polymers based controlled drug delivery systems have gained significant attention. These systems can carry large payload inside the polymer matrix and protect the molecules from the physiological environment. Polymeric drug delivery systems are beneficial in delivering sensitive therapeutic agents such as newly emerging protein drugs, which tend to exhibit short biological half-lives. This book reviews properties and applications of different biodegradable polymers utilized in controlled drug delivery systems. It also covers the growing interest and new advances in ocular gene therapy. In recent years dramatic increase in understanding of the pathophysiology of eye diseases at cellular and molecular level has opened a new platform for novel gene modulating molecules such as siRNA, oligonuleotides, aptamers and ribozymes. Different delivery options for macromolecules are also discussed. Basic principles of translational medicine and importance of ophthalmic translational research are discussed using examples of various ocular diseases. Each chapter is contributed by experts in their respective fields. It has been a pleasure working with all of the contributors. I would like to sincerely thank the authors for their concise summary and the publisher for patiently working with us to assemble this book.