Preface

The causative agents of type 1 and type 2 diabetes differ, but the main dysfunction by which they inflict damage to the human body is the same: hyperglycemia. Other systemic factors such as hypertension, lipid levels, and genetics also contribute to the effects diabetes has on individuals afflicted with this condition. Our ability in health care to control these factors has improved, but still those with diabetes too often suffer from kidney disease, neuropathy, amputation, and diabetic retinopathy. It is expected that in 20 years' duration nearly all those with diabetes will exhibit some diabetic retinopathy. In some patients, it will progress to blindness.

Currently, the only treatment available in the early stages of diagnosis and treatment of dia‐ betes to control diabetic retinopathy is management of the above-listed systemic factors. Di‐ abetic retinopathy is a slow process beginning with early damage to retinal vasculature and retinal ganglion cells. Often, years of damage to the diabetic retina occurs before it progress‐ es to a level where our current treatments of diabetic retinopathy play a role. Pan-retinal photocoagulation has stood the test of time helping reduce the risk of blindness, but it leaves the patient with reduced vision, especially at night. Injections of anti-VEGF agents have shown to be effective in many cases of diabetic macular edema. In addition, they have dem‐ onstrated effectiveness in treating proliferative diabetic retinopathy; however, many ques‐ tions remain regarding the wisdom of using anti-VEGF agents for extended periods of time on these relatively young individuals.

The number of those diagnosed with type 2 diabetes in both developed and developing countries has sky-rocketed. It is expected that the prevalence of individuals with type 2 dia‐ betes will continue to increase. Healthcare systems in these countries struggle to screen those at risk of diabetic retinopathy who have either type 1 or type 2 diabetes.

This book covers topics addressing imaging processes currently available in the development stage for screening of diabetic retinopathy. It also covers potential biomarkers that may be used to identify those at risk. Further, new pathways which can lead to diabetic retinopathy are identified.

We are grateful to those contributors who have labored to make this book a reality. We would also like to thank the staff at InTech, especially Marina Dusevic, Publishing Process Manager, who helped us through this process. It is our hope that this book will serve as a resource for clinicians, scientists, and public health workers by expanding knowledge on di‐ abetic retinopathy, as well as offering insights into the screening modalities, which might help those developing the condition. Further, it is also our hope that this book will offer illumination into the early mechanisms of diabetes and help us identify targets that, if ad‐ dressed early enough, might prevent us from ever having to use our present treatment pro‐ cedures.

> **Jeffery G. Grigsby** Vision Health Specialties, Midland, Texas, USA College of Optometry, University of Houston, Houston, Texas, USA Texas Tech University Health Science Center, Midland, Texas, USA

> > **Andrew T.C. Tsin** Department of Biomedical Sciences University of Texas Rio Grande Valley, School of Medicine Edinberg, Texas, USA

**Introduction**

**Section 1**

**Section 1**
