Research Article Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography Anna I. Dastiridou, 1 Xiaojing Pan, 1,2 ZhouYuan Zhang, 1 Kenneth M. Marion, 1 Brian A. Francis, 1,3 Srinivas R. Sadda, 1,3 and Vikas Chopra 1,3 1 Doheny Image Reading Center, Doheny Eye Institute, Los Angeles, CA 90033, USA 2 he Ailiated Hospital of Medical College, Qingdao University, Qingdao, Shandong 266003, China 3 Department of Ophthalmology, David Gefen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA Correspondence should be addressed to Vikas Chopra; vchopra@doheny.org Received 26 January 2015; Accepted 13 March 2015 Academic Editor: Marcel N. Menke Copyright © 2015 Anna I. Dastiridou et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. To compare the efects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA) measurements obtained with spectral domain optical coherence tomography (SD-OCT). Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1) pupil constricted under standard room lighting, (2) physiologic mydriasis in a darkened room, and (3) postpharmacologic mydriasis. Inferior angle Schwalbe’s line-angle opening distance (SL-AOD) and SL-trabecular-iris-space area (SL-TISA) were computed for each eye and pupillary condition by masked, certiied Reading Center graders using customized grading sotware. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87 ± 0.31 mm and 0.33 ± 0.14 mm 2 , respectively; decreased to 0.75 ± 0.29 mm ( < 0.01) and 0.29 ± 0.13 mm 2 ( < 0.01), respectively, under physiologic mydriasis; and increased to 0.90 ± 0.38 mm ( < 0.01) and 0.34 ± 0.17 mm 2 ( = 0.06) under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle. 1. Introduction Anterior segment optical coherence tomography (OCT) has evolved as a new method of imaging the anterior segment. Together with gonioscopy and ultrasound biomicroscopy, it can help in the evaluation and measurement of the anterior chamber angle (ACA) [1, 2]. Early OCT devices, like Visante (Carl Zeiss, Meditec, Dublin, CA, USA), utilized time- domain technology, which provided good visualization of scleral spur but relatively poor localization of Schwalbe’s line. he development of spectral domain (SD) OCT provides a faster scan speed and higher resolution imaging of ACA and allows for better visualization of the termination of Descemet’s membrane (Schwalbe’s line (SL)) and the tra- becular meshwork [3–6]. he noncontact nature of OCT can also be advantageous over gonioscopy and ultrasound biomicroscopy in assessing angle anatomy and quantifying the ACA dimensions, since it avoids the inadvertent disrup- tion of the ACA anatomy by the instruments. Additionally, the light levels during the OCT examination can be accu- rately adjusted, whereas this cannot always be controlled in gonioscopy. As a result, OCT imaging of the anterior segment is a useful tool for angle imaging in clinical practice and can aid in understanding the pathophysiology of angle closure glaucoma [7, 8]. Hindawi Publishing Corporation Journal of Ophthalmology Volume 2015, Article ID 845643, 6 pages http://dx.doi.org/10.1155/2015/845643