Optical Coherence Tomography (IMAGE) Columbia University Irving Medical Center Caption The Optical Coherence Tomography (OCT) imaging revealed the loss of outer segments in foveal cone cells in the "optical gap" of a patient with ATF6A defects. Credit Courtesy of the Laboratory of Dr. Stephen Tsang, Columbia University Medical Center Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.