This is a single center, single arm, open label observational trial of patients undergoing EGD. The primary objective of this clinical trial is to evaluate the ability of physicians to position the NvisionVLE Optical Probe to acquire an image of an area of the esophagus to identify and discriminate abnormal areas of tissue from normal.

Inclusion Criteria:

• Males and females over the age of 18 years.
• Patients presenting for an EGD.
• Ability to provide written, informed consent.
• Females who are able to become pregnant, are willing to take a pregnancy test.

Exclusion Criteria:

• Patients on anticoagulation undergoing high risk procedures in accordance to ASGE guideline for the management of antithrombotic agents for endoscopic procedures (2009)*.

• Patients with esophageal varices that preclude biopsies.

• Presence of an esophageal mass that precludes full distention of the balloon from the NvisionVLE catheter.

• Patients with esophageal strictures that would prevent adequate expansion of the balloon from the NvisionVLE catheter.

• Patients with known inflammatory disease, esophageal tears or ulcers, which prohibit full distention of the balloon from the NvisionVLE catheter.

• Patients with known eosinophilic esophagitis.

• Patients that are pregnant.

• Patients with a history of hemostasis disorders**.

  • Patients on anticoagulation undergoing low risk procedures are not excluded. ** Hemostasis disorders will include, but will not be limited to: patients with hemophilia or other congenitally acquired clotting factor deficiencies, patients with cirrhosis with coagulopathy, patients known to have thrombocytopenia (<100,000 plt/ul) and individuals with von Willibrand's disease or other known platelet malfunction disorders.

Males and females >18 years of age undergoing esophagogastroduodenoscopy (EGD).