Clinical Study Assessment of Anterior Segment Changes in Pseudophakic Eyes, Using Ultrasonic Biomicroscopic Imaging, after Pars Plana Vitrectomy with Silicone Oil or Gas Tamponade Erkan Ünsal, Kadir Eltutar, Belma Karini, and Osman KJzJlay Istanbul Research and Training Hospital, 34098 Istanbul, Turkey Correspondence should be addressed to Erkan ¨ Unsal; erkanunsal@gmail.com Received 30 March 2016; Revised 19 April 2016; Accepted 24 April 2016 Academic Editor: Sang Beom Han Copyright © 2016 Erkan ¨ Unsal et al. Tis 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. Objective. To evaluate the morphological changes of the anterior segment using ultrasonic biomicroscopy (UBM) imaging in pseudophakic patients who underwent pars plana vitrectomy (PPV) with silicone oil or gas (C 3 F 8 ) internal tamponade agent injection. Method. Tis prospective study included pseudophakic patients with planned PPV, divided into two groups according to internal tamponade agent: those in which silicone oil was used ( = 27, Group 1) and those in which gas (C 3 F 8 ) was used ( = 24, Group 2). UBM measurements were performed in the supine position before and one week afer surgery. Results. In patients of Group 1, postoperative trabecular meshwork-ciliary process distance (T-CPD) and iris-ciliary process distance (I-CPD), according to preoperative values, were found to be statistically signifcantly reduced, and postoperative mean value of scleral thickness (ST) and intraocular pressure (IOP), according to preoperative value, was found to be statistically signifcantly increased. In patients of Group 2, postoperative mean values of anterior chamber depth (ACD), ciliary body thickness (CBT), T-CPD, I-CPD, and IOP, according to preoperative values, were found to be statistically signifcantly reduced. Preoperatively, in Group 2 patients, according to Group 1 patients, TIA and IOP were found to be statistically signifcantly increased. Preoperative and postoperative IOP between the measured parameters with UBM showed no statistically signifcant correlation. Conclusions. Gases cause more morphological changes in the anterior segment structures. It is thought that complications such as increased intraocular pressure can be seen more frequently for this reason. 1. Introduction Ultrasound biomicroscopy (UBM) technology uses high- frequency ultrasound to produce images of the anterior segment in high resolution. Anterior segment structures, including the crystalline lens, ciliary body, and lens zonules, can be morphologically assessed and quantitatively measured by using this in vivo noninvasive imaging technique. Te reported repeatability of UBM measurements is good if the measurements are performed by the same experienced observer [1–4]. UBM has been investigated regarding the repeatability of measurements, accuracy, and precision [5– 7]. Several publications have reported that intraobserver reproducibility is high for all the measurements performed using this technique, but interobserver reproducibility is poor [3, 7, 8]. Te main reason for this variability is the quality of the received image. In addition, the variability in the measurement analysis should not be underestimated. Te main reasons underlying this variability are the diferences in the selection of the frame to be measured and the detection of the location of the scleral spur. Terefore, the comparison of the measurements before and afer any attempt should be performed by the same observer. Tus, in our study, pre- and postoperative UBM measurements were performed and compared by a single observer. In many vitreoretinal diseases, PPV is considered the standard surgical approach. Gases and silicone oil are used frequently as internal tamponade agents. Following PPV surgery, many complications can be encountered, a number of which are related to the anterior segment. UBM can reveal changes in the anterior segment due to complications in the postoperative period [9–16]. Among these changes are Hindawi Publishing Corporation Journal of Ophthalmology Volume 2016, Article ID 8303792, 8 pages http://dx.doi.org/10.1155/2016/8303792