Emergency (****); * (*): *-* This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com 121 Emergency (2014); 2 (3): 121-124 ORIGINAL RESEARCH Diagnostic Accuracy of Ultrasound in Detection of Traumatic Lens Dislocation Seyed Hossein Ojaghi Haghighi1, Hamid Reza Morteza Begi1, Raana Sorkhabi2, Mohammad Kazem Tarzamani3, Golshan Kamali Zonouz1*, Akram Mikaeilpour4, Farzad Rahmani1 1. Department of Emergency Medicine, Tabriz University of Medical Sciences, Tabriz, Iran 2. Department of Ophthalmology, Tabriz University of Medical Sciences, Tabriz, Iran 3. Department of Radiology, Tabriz University of Medical Sciences, Tabriz, Iran 4. Department of Cardiology, Tabriz University of Medical Sciences, Tabriz, Iran Abstract Introduction: Traumatic eye injuries (TEI) involved about 3% of cases referred to the emergency departments of developing countries. Lens dislocation is one of the critical cases of ophthalmic emergencies. The present study was aimed to evaluate the diagnostic accuracy of ultrasonography in detection of traumatic lens dislocation. Methods: In this cross-sectional study the findings of ultrasonography and orbital computed tomography (OCT) of head and face trauma patients, referred to Imam Reza hospital, Tabriz, Iran, from July 2013 to June 2014, have been compared. The sensitivity, specificity, positive and negative likelihood ratio, positive and negative predictive value, and accuracy of ultrasonography were calculated. Cohen's kappa coefficient was presented to assess the agreement of ultrasonography with OCT findings. Results: One hundred thirty patients with the mean age of 35.4±18.0 were evaluated (75.4% male). Sensitivity and specificity of ultrasonography were 84.6% (95% Cl: 53.7- 97.3) and 98.3% (95% Cl: 93.3- 99.7), respectively. In addition, positive and negative likelihood ratio were calcu- lated 49.5 (95% Cl: 12.3-199.4) and 0.15 (95% Cl: 0.04- 0.56), respectively. Cohen's kappa coefficient of 0.83 (95% Cl: 0.66-1.0; p<0.0001) was representative of excellent agreement of these two tests. Conclusion: The find- ing of this project was representative of 84.6% sensitivity, 98.3% specificity, and 96.9% accuracy of ultrasonog- raphy in detection of traumatic lens dislocation. It seems that in cases, which OCT is not possible, ultrasonogra- phy, could be an acceptable option to assess traumatic eye injuries. Key words: Ultrasonography; diagnostic techniques; ophthalmological; lens subluxation; eye injuries, trauma Cite this article as: Ojaghi Haghighi SH, Morteza Begi HR, Sorkhabi R, et al. Diagnostic accuracy of ultrasonography in detection of traumatic lens dislocation. Emergency. 2014;2(3):121-4. Introduction:1 raumatic eye injuries (TEI) involved about 3% of cases visited in emergency departments (ED) of developing countries (1). It is estimated that trauma causes blindness and visual impairment in many referees of ophthalmic emergency (2). Most of these injuries are hard to diagnose in initial ED assess- ment. On the other hand, more frequent examinations to detect injuries maybe hazardous for the patient (3). Orbital computed tomography (OCT) scan, magnetic resonance imaging (MRI), ultrasonography, and slit- lamp are introduced as the most important imaging tools to evaluate TEI (4-8). Although MRI presents high accurate and quality images, it is an expensive and time-consuming test, which is not accessible in all *Corresponding Author: Kamali Zonouz Golshan; Emergency Medicine De- partment, Imam Reza Hospital, Tabriz University of Medical Sciences, Golgasht Avenue, Tabriz, Iran, Tel/Fax: 00984113352078 E-mail: G.Kamali.Z@gmail.com Received: May 2014; Accepted: June 2014 emergency centers. Optical methods are cost effective and easy to use, but they have a low accuracy in evalua- tion of injuries to optical structures such as sclera, pu- pil, and cornea, as well as hemorrhage. While ultraso- nography, known as a non-expensive, accessible, and safe method, has a high accuracy in evaluation of inju- ries to optical structures (3). When the patient is non- cooperative for fundoscopic tests or suffers from severe edema, chemosis, or hyphema, eye ultrasonography can present valuable and useful information to the physi- cian (9). But, it should be mentioned that diagnostic accuracy of ultrasonography is highly dependent to op- erator proficiency and it is not reliable in detecting parenchymal injuries (10). Lens dislocation is one of the critical cases of ophthalmic emergencies referred to partial or complete dislocation of eye lens from its nat- ural location to posterior chamber. Trauma is one of the most common reasons of lens dislocation (11). The fast diagnosis of such an injury can be greatly help improv- T mailto:G.Kamali.Z@gmail.com This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com Ojaghi Haghighi et al 122 ing the patients' outcomes. Diagnostic accuracy of ultra- sonography in assessment of traumatic lens dislocation is evaluated in a few studies. Whereas some of investi- gations suggested OCT as an accurate method (12), oth- ers consider ultrasonography as a valuable diagnostic tool in detection of lens dislocation, especially in lack of OCT (13-16). However, the low number of studied sam- ples in this field is the critical limitation. Therefore, the present study was performed to evaluate the diagnostic value of ultrasonography versus OCT in traumatic lens dislocation. Methods: Study design and setting: In this cross-sectional study the findings of ultrasonog- raphy and OCT of multiple trauma patient with head trauma, referred to Imam Reza hospital, Tabriz, Iran, from July 2013 to June 2014, have been compared. Data collection and ultrasonography was done by an emer- gency medicine specialist. OCTs (as a gold standard tool) were interpreted by a radiologist who was blind to the aim of study. The protocol of the present project was studied and confirmed by the ethical committee of Tabriz University of Medical Sciences. All researchers adhered the Helsinki declaration during the study. The study protocol did not have any interference with treatment process and no danger threatened patients. The collected forms were anonymous and for each pa- tient an especial code registered. Before the study, pa- tients filled the personal consent form. Participants In this study, multiple trauma patients with TEI were entered. Patients with irregularity of the globe contour, and lack of ability to cooperate for imaging were ex- cluded from the study. Sample selection was sequential- ly. For determining of the sample volume, the least needed samples were achieved 121 persons noticing to at least 93% sensitivity of ultrasonography to detect TEI, 15% prevalence (12), 95% confidence interval (α=0.05), 90% power (β= 0.1), and maximum error of 1% (d= 0.01). Measurements The emergency medicine specialist was prospectively assessed demographic data (age, sex, and trauma mechanism), clinical symptoms of each patient, and registered them in data gathering form. Then, the pa- tients underwent eye ultrasonography by a trained emergency medicine specialist. Ultrasonography was done using bedside machine (GH Healthcare; LOGIQ 200, PRO series; Korea) with 10 MHz micro-convex lin- ear transducer in sagittal and transverse plane and closed eye technique with water-soluble gel. Then pa- tients referred to ED radiology unit for performing OCT. The findings of OCT was interpreted by a radiologist blind to the goal of study and recorded. OCT was done using a Toshiba Asteion 16 slices scanner with consid- ering the one-millimeter distance between image slices. Both ultrasonography and OCT was performed in re- cumbent position. Statistical analysis Data were entered to SPSS version 21.0 and imaging findings reported as the frequency and percentage. For evaluating the quality of ultrasonography receiver op- erating characteristic (ROC) curve was drown and final- ly sensitivity, specificity, accuracy, positive likelihood ratio, negative likelihood ratio, positive predictive val- ue, and negative predictive value calculated. Cohen's kappa coefficient was presented to assess the agree- ment of ultrasonography with OCT findings. P<0.05 was considered as a significant level. Results: 130 patients with the mean age of 35.4±18.0 were en- tered to the study (75.4% male). Five patients (3.8%) had systolic blood pressure below 90 and 32 ones Table 1: Clinical and demographic characteristics of studied patients  Clinical characteristic Frequency (%) Gender Male 32 (24.6) Female 98 (75.4) Hypotension No 125 (96.2) Yes 5 (3.8) Glasgow Coma Scale 14-15 74 (56.9) 9-13 35 (26.9) 3-9 21 (16.2) Mechanism Pedestrian 20 (15.4) Car (driver) 51 (39.2) Motorcycle (driver) 36 (27.7) Falling 8 (6.15) Intentional injuries 7 (5.4) Other 8 (6.15) Visual accuracy Normal 57 (43.85) Abnormal 8 (6.15) No cooperation 65 (50.0) Laceration No 73 (56.15) Yes 57 (43.85) Ecchymosis No 17 (13.1) Yes 113 (89.9) Eye bleeding No 128 (98.5) Yes 2(1.5) Globe Rupture No 124 (95.4) Yes 6 (4.6) Periorbital edema NO 67 (51.5) Yes 63 (48.5) This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved. Downloaded from: www.jemerg.com 123 Emergency (2014); 2 (3): 121-124 (24.6%) suffered from tachycardia. GCS of 21 patients (16.15%) was below nine and in 35 ones (26.9%) with- in 9-13 (Table 1). The most common mechanism of ac- cident in the patients was related to car (39.2%), mo- torcycle (27.7%), and pedestrian accidents (15.4%), respectively. OCT evaluation has detected 13 cases (10%) of trau- matic lens dislocation. The findings of ultrasonography in 11 cases were compatible with OCT with two false negative cases, while two false positive were found by ultrasonography. The area under the ROC curve of ul- trasonography in traumatic lens dislocation was achieved 0.9145 (95% Cl: 0.81-1.0) (Figure 1). Sensitiv- ity and specificity of ultrasonography were 84.6% (95% Cl: 53.7-97.3) and 98.3% (95% Cl: 93.3- 99.7), respec- tively. Positive and negative likelihood ratio of this di- agnostic test in detection of lens dislocation were calcu- lated 49.5 (95% Cl: 12.3-199.4) and 0.15 (95% Cl: 0.04- 0.56), respectively (Table 2). Cohen's kappa coefficient of 0.83 (95% Cl: 0.66-1.0; p<0.0001) was representa- tive of excellent agreement of these two tests. Discussion: The findings of the present study showed 84.6% sensi- tivity and 98.3% specificity of eye ultrasonography in detection of traumatic lens dislocation. The accuracy of this diagnostic test was 96.9%. Based on these results, it seems that in cases, which OCT is not possible, ultra- sonography, could be an acceptable alternative for evaluation of lens dislocation. There are a few study assessed the diagnostic value of ultrasonography in detection of lens dislocation. Imran et al. revealed that sensitivity and specificity of ultraso- nography are 75% and 97.9% in diagnosis of lens dislo- cation, respectively (12). Blavis and colleagues by study of 61 patients observed two cases of lens dislocation both of which was detected by ultrasonography (13). The trivial difference between previous studies and the present project could be due to operator-dependent of ultrasonography. On the other hand, reaching a certain diagnosis is time consuming and ophthalmic consult- ants are not present in all hospitals. All of these issues maybe lead to delay in detection and management whereas eye ultrasonography can be helpful in such situations. However, eye ultrasonography has not yet common in ophthalmic clinicians. In addition, eye ultra- sound transducers for eye ultrasonography are differ- ent from common transducers applied in the ED (13). In addition, it should be mentioned that clinical evaluation of patients with TEI is painful and not possible in many cases. Although there is no information regarding the negative effect of entered energy by high frequency ultrasonog- raphy on eye structures, more investigation is required in this area. One of the limited studies in this field re- vealed that using ultrasonography with frequency of 10 to 60 MHz did not have any destructive effects on visual field and histological findings. But, the recent study showed that using ultrasonography causes to increase the internal temperature of eye (17). However, re- searchers expressed that this test should be used pre- ciously until finding appropriate solutions to the above problems. Conclusion: The finding of this project was representative of 84.6% sensitivity, 98.3% specificity, and 96.9% accuracy of ultrasonography in detection of traumatic lens disloca- tion. It seems that in cases, which OCT is not possible, ultrasonography, could be an acceptable option to as- sess traumatic eye injuries. Acknowledgments: Authors would like to say thanks to all patients and stuffs of the emergency department of Imam Reza hos- pital for their contribution. This article has been written in terms of the residency thesis registered in Tabriz University of Medical Sciences. Conflict of interest: None Table 2: Diagnostic accuracy of ultrasonography in detection of traumatic lens dislocation  Value Rate (95% CI) Sensitivity 84.6 (53.7-97.3) Specificity 98.3 (93.3-99.7) Positive predictive value 84.6 (53.7-97.3) Negative predictive value 98.3 (93.3-99.7) Positive likelihood Ratio 49.5 (12.3-199.4) Negative likelihood Ratio 0.15 (0.04-0.56) Accuracy 96.9 (93.9-99-9) CI: confidence interval. 0 .0 0 0 .2 5 0 .5 0 0 .7 5 1 .0 0 S e n si ti v it y 0.00 0.25 0.50 0.75 1.00 1 - Specificity Area under ROC curve = 0.9145 Figure 1: The receiver operating characteristic (ROC) curve of ultrasonography in detection of traumatic lens disloca- tion.  This open-access article distributed under the terms of the Creative Commons Attribution NonCommercial 3.0 License (CC BY-NC 3.0). Copyright © 2014 Shahid Beheshti University of Medical Sciences. All rights reserved. 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