Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Scholarly Journal of Medicine, Vol. 2(4) pp. 51-56 June, 2012 Available online at http:// www.scholarly-journals.com/SJM ISSN 2276-7134 ©2012 Scholarly-Journals Full Length Research Paper Estimating proptosis by digitalized exophthalmometry in children and teenagers with thyroid diseases Jurate Jankauskiene and Dalia Jarusaitiene Eye Clinic, Medical Academy, Lithuanian University of Health Sciences Accepted 31 May, 2012 Objective of the present study was to construct a device for digital Hertel measurement of eye protrusion, to use it in practice and measure proptosis in children and teenagers with thyroid diseases. There was developed the system for the measurement of eye protrusion using Hertel exophthalmometer, video camera and personal computer (PC). Measurements of proptosis were done in children and teenagers with thyroid diseases. The difference between the right and left eyes was not significant. Proptosis in patients was significantly higher than in control group. Digitalization of eye bulging measurements is important for accurate assessment of proptosis, to compare results of measurements and to monitor progress of the disease. Key words: exophthalmometry - thyroid diseases - proptosis. INTRODUCTION In people with thyroid diseases may occur Graves’ ophthalmopathy and ocular signs in any age but Graves’ ophthalmopathy are most frequently in the third to fifth decades of life. Ophthalmopathy may cause diplopia, decreased ocular motility, exposure keratitis, compressive optic neuropathy. Severe ophthalmopathy develops in men. Severe ocular signs (vision-threatening exposure corneal, optic nerve problems) require surgical decompression. Orbit is an osseous pyramid which contains orbital soft micro tissues and the eyeball. Due to the increased volume or orbital contents the retro bulbar pressure rises and pushing the globe forward causing proptosis. Exophthalmos is abnormal protrusion of the eye ball and may be a sign of many severe orbital diseases such as orbital tumor, thyroid eye disease (Graves’ ophthalmopathy), orbital varix, arteriovenous fistula, collagen vascular disease, infections, inflammations, pseudo tumor, prolapse of cranial contents into the orbit and congenital cranial - orbital defects, spheroidal meningioma, lymphoma. Exophthalmometry measures the relationship between the orbital rim and the anterior cornea surface (Tsai et al., 2006). Exophthalmometry, the Corresponding author e-mail: [email protected] quantitative assessment of the position of the globe in the orbit, is a clinically useful measurement and has become a routine examination for any patients with suspected orbital disease, especially is important in thyroid eye disease or Graves’ ophthalmopathy because proptosis may be main sign in these diseases (Stan et al., 2012). The orbital involvement in Graves’ disease is characterized by lymphocytic infiltration and edema of the retro bulbar tissues, resulting in marked swelling of extraocular muscles and orbital fat. Normal value of ocular protrusion is different in various nations and is very important to differentiate from pathological proptosis levels. GE Krassas (2007) showed that normal values depend on type of exophthalmometer, age and gender. Traditionally, in the absence of other clinical signs, orbital pathology of one eye is suspected when exophthalmometric values are outside of the normal range or when there is more than 2 mm difference between the eyes. Autoimmune hyperthyroidism is the most common cause of juvenile thyrotoxicosis in children and teenagers. Eha et al. (2010) revealed that in children and teens Graves’ ophthalmopathy is less common than in adults. Chan et al. (2002), Durairaj et al. (2006), Krassas (2004, 2005) showed that eye clinical picture in children is less well defined than in adults. Normal values of proptosis for children under the age of 11 years were reported by Nucci et al. (1989). 1 Jankauskiene and Jarusaitiene 52 Proptosis values were very variable. Wong and Cheng (2001) revealed that Graves’ disease in childhood is increased. Shibayama et al. (2005) showed increase of thyroid-stimulating antibodies and thyrotropin-binding inhibitory immunoglobulin in children with Graves’ disease. Exophthalmometry measurements of childhood Graves’ ophthalmopathy tend to increase with age (Gerber et al. (1972). Sleep and Manners (2002) noted that variation of the readings of Hertel exophthalmometer was seen between instruments from different manufacturers. Hertel exophthalmometry difficulty is mainly caused by the low sensitivity and reproducibility. There are some digitalized techniques to measure eyelid positions, photographic measurements in patients (Rubin (2005), Edwards et al. 2004). No such information about digitalization of exophthalmometer is available in the literature. Objective of the present study was to construct a device for digital Hertel measurement of eye protrusion and measure proptosis in children and young adults with thyroid diseases. MATERIALS AND METHODS Hertel exophthalmometer was used to measure the eyeball protrusion out of the orbit (eye’s level of proptosis) to determine its position along the sagittal axis. Doctor sits opposite the examined person at ocular level during the evaluation. The doctor asks the examined person to look straight ahead, to keep the head still and wide open eyelids aperture. The mirrors of the exophthalmometer with millimeter scales for the left and right measuring halves are calibrated so that the zero mark on the scale is located in the plane of the resting points of exophthalmometer rims. In order to measure proptosis the resting points of exophthalmometer are placed against the temporal orbital rims. The corneal axes are reproduced on the mirrors; the mirror images appear at equal distance behind the mirrors and therefore fall on the rulers. Apparatus is constructed so that the eye axes coincide with the ruler in eye axis. The instrument is maneuvered using both hands and firmly propped first against the right-hand orbital wall on the temporal side. Apparatus which measures from the lateral orbital rim has an unavoidable error: the greater the pressure over the lateral orbital rim and the longer this pressure is maintained, the more the soft tissues over the lateral orbital rim are compressed. An error of 0.5 to 1.0 mm can easily be produced by long pressure. In order to investigate the exact proptosis, examiner should be able to determine accurately the relative position of the two orbits in the skull, the frontal plane of the skull, the relative positions of the two lateral orbital rims, the measurements of the length, width, height, capacity of each orbit, an axis through the lateral orbital rim vertical to the frontal plane (which axis is, after all, a function of the frontal plane). Such an axis would be parallel to the visual line with "eyes front." These measurements are determined not accurately and data of exophthalmometry are not enough right. Measurement error can be reduced by increasing stability and reducing the human factor, in determining the parallelism of the distances. We propose the use of simple and non-invasive digital image analysis to estimate exophthalmometric parameters of children and young people with thyroid diseases. It was decided to increase the stability of the system with Hertel exophthalmometer consolidation into metal structure. Digital video camera was added to this construction (figure 1), this allowed to see the results of measurements of the Personal Computer (PC) screen and save them in digital form. Digitalized measurement system includes: a) Hertel exophthalmometer; b) Horizontal floating part of the device for consolidation of video camera and selection of position in order to photograph the results of Hertel exophthalmometer of the left and right eyes; c) Regulated part of the device for patient's face consolidation and for fixation of position of Hertel exophthalmometer. d) Video camera and personal computer. Experiments Experiments were done with web camera CNRWCAM820. This is 2.0 Mega pixel high quality tube style USB webcam. It features a five-layer glass lens with a viewing angle of 70 degrees, face tracking software, a digital zoom function and an automatic brightness adjustment, white balance and color compensation. It can be positioned stably on a flat surface. The CNRWCAM820 is compatible with all Windows versions available. Images saved as JPEG files. The camera and Hertel exophthalmometer were positioned at eye-height. Measurements were taken in a well illuminated room, with subjects seated in an upright position with the head erect. Subjects were asked to look at a distance fixation target, framing the face centrally, using a video camera (figure 2). The reading was taken as the distance between a point on the temporal orbital rim, the deepest palpable point on the angle, and the apex of the cornea. Both the right eye and left eye readings were taken sequentially without removing the instrument from the orbital rims. Measurements for the right and left eyes were averaged for each subject and measured in millimeters (mm). Video camera through the USB connector connects to the personal computer. At the display of computer are visible mirror of Hertel exophthalmometer with the ruler and lateral view of the patient’s eyeball. Using the Web 2 Scholarly J. Med. 53 Figure 1. The device for measurement of proptosis Figure 2. Quantification of eye bulging (proptosis) using Hertel exophthalmometer and video camera Camera photographing function, the image can be saved in 1600 * 1200 resolution JPEG / BMP file format. The distance between the lateral orbital walls can then be read from the upper side of the scale at the display of personal computer; this distance can be noted for future reference (figure 3). The examiner measures proptosis in each eye by looking into the mirror (which has a millimeter scale 3 Jankauskiene and Jarusaitiene 54 Figure 3. An example of digitalized result of proptosis measurement marked on it) with one eye and moving the head horizontally. The examiner can determine the position of the corneal apex of the patient from the millimeter reading and compare the resulting measurements to normal values in order to determine if further testing or treatment is needed. Physiologically, there are also certain differences in the degree of proptosis in each eye. For basic measurement in this construction the distance between the lateral orbital rim and corneal apex axis was measured. Under normal conditions, the distance between the apex of the cornea and the orbital wall is approximately 17 mm. This value should only be regarded as a statistical average, from which there may well be upward or downward deviations. Image analysis is the extraction of meaningful information from images; mainly from digital images by means of digital image processing. Because proptosis causes clinically perceived distortions in orbital architecture, digital photographs can also be used to detect and quantify these changes in eyeball protrusion measurements. Noninvasive standardized digital exophthalmometry allows reliable ocular documentation and clinical assessment in thyroid diseases or orbital pathology, with regard to orbital changes. Saving of the results provides new opportunities: to collect measurements for each patient, perform image analysis, compare results of measurements and monitor progress of the disease, dynamics of the changes after the treatment. The system gives us reproducibility and repeatability of the results. Proptosis was measured in 45 children and teenagers with thyroid diseases and 39 persons of the control group. Statistical analysis Statistical analysis was conducted using statistical SPSS software package (Version 16.0). The following statistical characteristics were expressed as a mean value and standard deviation (SD). The statistical difference between patients and control groups was tested with the Student’s t-test. For groups with abnormal distribution Mann-Whitney U test for independent samples was used. A p value less than 0.05 was considered statistically significant. RESULTS Mean age of patients was 10.60±3.77 years, range from 4.5 to 18 year, there were 40 girls and 5 boys. Mean age of persons of the control group was 10.83±4.46 years, range from 5 to 18 year. The measurements included exophthalmometry of the right and left eyes. No individual had greater than 1 mm difference between eyes. Table 1 shows the mean (± standard deviation) measurement of the right eye was 17.89 ± 1.77 mm, ranging from 15.5 to 22.0 mm. Exophthalmometric values for patients had a mean of the left eye was 17.73±1, 4 Scholarly J. Med. 55 Table 1: The mean (±SD) of exophthalmometry in children and teenagers with thyroid diseases Subjects Patients Mean+SD(mm) Control group Mean+SD(mm) P value Right eye 17.89 ± 1.77 14.54 ± 1.34 0.001 64 mm and ranged from 15 to 21.5 mm. The difference on exophthalmometry between the right and left eyes was not significant (Table 1). Mean of proptosis in patients was significantly higher (p<0.001) than in control group (right eye mean was 14.54±1.34 mm, ranging from 12.5 to 16 mm), (left eye mean – 14.42±1.20 mm, ranging from 13 to 16.5). DISCUSSION There are some methods for interpretation the exophthalmometric readings: absolute exophthalmometry, relative exophthalmometry and comparative exophthalmometry (Comer, 1991). Absolute exophthalmometry is method when we compare exophthalmometric levels to known normal level of exophthalmometry. Relative exophthalmometric data are the data of the comparing of the right and left eyes exophthalmometry measurements. Comparative exophthalmometry is comparing exophthalmometric values with time. There are some factors which influence exophthalmometric readings: the doctor uses not the same exophthalmometer at the time, different designs of exophthalmometers. Using the Hertel exophthalmometry we may compare the unilateral and simultaneous bilateral measurement of the globe position (Ameri and Fenton, 2004). According to the configuration of the osseous orbit and various nations, races, a value of 14 mm might be pathological whereas 20 mm might be normal. Exophthalmometric data may vary according to age, gender, height, weight, body mass index, ethnicity orbital parameters and refraction (Beden et al., 2008, Kashkouli et al., 2003, Smolders et al., 2004). Continuous screenings are more useful than individual measurements. Mourits MP et al. (2004) showed that there was no dependence on age in healthy individuals and in Graves' patients’ adults. Measurements depended on sex (in males were bigger measurements). Fledelius and Stubgaard (1986) revealed that eye position changes during growth and adult life and exophthalmometry, interpupillary distance, orbital distance measurements may vary. Image Processing with Image J was used in biomedical and clinical practice (Abramoff et al. 2004). New magnetic resonance imaging methods are used in diagnosis and differential diagnosis of Graves’ ophthalmopathy and other orbital diseases (Roshdy et al., 2010). FruehandFrueh (2007) Left eye 17.73 ± 1,64 14,42 ± 1.20 0.001 P value 0.33 0.09 performed an analysis of Hertel exophthalmometer Geometry and revealed that exophthalmometers should be used with the narrowest feasible base and the examiner should be consistently positioned as far from the reflecting surface of the instrument as possible. Chang et al. (1995) compared results between the Hertel and Luedde instruments. There was no statistically or clinically significant difference between measurements taken with the Luedde as compared with the Hertel instrument. The Luedde exophthalmometer has a number of advantages over the Hertel exophthalmometer, and represents a simple, inexpensive and equally reliable means of evaluating clinically the anteroposterior position of the eye in the orbit. Sleepand Manners (2002) showed variability in exophthalmometry measurements taken with different manufacturers of exophthalmometers. This study suggested that the same instrument should be used for each examination to minimize error caused by variation between instruments. It is useful for measurements in dynamics of the conservative and surgical treatment of patients. We have found quite marked proptosis in children and teenagers with thyroid diseases in comparison with control group. Our data correspond with findings of other authors. Liu et al. (1996) and Uretsky et al. (1980) found persisting proptosis in children. The exophthalmometric values we obtained can either serve as a diagnostic guide or be used to monitor progress of orbital disease via serial measurements. A larger image at the display, the possibility to calculate data, close to the routine measurement, more accurate, we get digital image, set up a data base of personal measure and document proptosis, monitor the dynamics of measurements, acceptable for medical and scientific tasks. Serial proptosis exams are required to monitor disease progress and response to therapy. Computational image editors can display and analyze digital images, and digital image pixels can be quantified and measured. These properties allow the use of digital image analysis systems to estimate external ocular modifications, several differences between controls and patients with orbit diseases that can be observed with digital image. Practitioners may also need to know exophthalmometry measurements. The effective measurement of exophthalmometric parameters could lead to an objective estimation of the effects of therapeutic interventions. It is a more sensitive way than Hertel exophthalmometer 5 Jankauskiene and Jarusaitiene 56 itself. When performing clinical or experimental trials, the increase in sample size, the number of pictures per eye, or even the use of a video camera for selecting the more representative picture can reduce any interference with accurate measurements. Careful standardization of light, framing, zoom and position remains the key factor for accurate orbital measurements. Availability, noninvasiveness, ability to transfer and display make digital exophthalmometry a suitable method for clinical documentation and clinical trials and scientific investigations. Digital photographs can also be easily stored and reemployed in future studies. Digital exophthalmometry can be used to objectively estimate exophthalmometric parameters for patients with thyroid diseases in clinical practice. Examples of image analysis techniques in different fields include: 2D and 3D object recognition, image segmentation. This will further work in this direction. CONCLUSIONS A new method for the measurement of eye protrusion using Hertel exophthalmometer, video camera and PC has been studied and tested. It would lend itself to accurate and convenient use in clinical practice. Measurements of proptosis were recorded in children and teenagers with thyroid diseases. The difference between the right and left eyes was not significant. Proptosis measurements in patients was significantly higher (p=0.001) than in controls. Digitalization of proptosis measurements is suitable method for clinical documentation, monitoring disease progression and status of exophthalmos after the conservative and surgical treatment, it may take part in clinical trials and scientific investigations. REFERENCES Abramoff, MD, Magalhães, PJ, Paulo J, Ram, SJ, Sunanda, J (2004) Image Processing with Image J. Biophotonics Int., 11(7): 36-42. Ameri, H, Fenton, S (2004) Comparison of unilateral and simultaneous bilateral measurement of the globe position, using the Hertel exophthalmometer. Ophthal. Plast. Reconstr. Surg., 20(6): 448–51. Beden, U, Ozarslan, Y, Oztürk, HE, Sonmez, B, Erkan, D, Oge, I 2008 Exophthalmometry values of Turkish adult population and the effect of age, sex, refractive status, and Hertel base values on Hertel readings. Eur. J. Ophthalmol., 18(2): 165–71. Chan, W, Wong, GW, Fan, DS, Cheng, AC, Lam, DS, Ng, JSK (2002) Ophthalmopathy in childhood Graves’ disease. Br. J. Ophthalmol., 86:740–42. Chang, AA, Bank, A, Francis, IC, Kappagoda, MB (1995) Clinical exophthalmometry: a comparative study of the Luedde and Hertel exophthalmometers. Aust. NZ. J. Ophthalmol., 23(4): 315-8. Comer, GW (1991) Exophthalmometry. Chapter 37. In: Clinical Procedures in Optometry (eds J. B.Eskridge, J. F.Amos and J. D.Bartlett), J.B. Lippincott Co., Philadelphia, PA, 350–57. Durairaj, VD, Bartley, GB, Garrity, JA (2006) Clinical features and treatment of Graves’ ophthalmopathy in pediatric patients. Ophthal. Plast. Reconstr. Surg., 22: 7–12. Edwards, DT, Bartley, GB, Hodge, DO, Gorman, CA,. Bradley, EA (2004) Eyelid position measurement in Graves' ophthalmopathy: reliability of a photographic technique and comparison with a clinical technique. Ophthalmol., 111(5): 1029-34. Eha, J, Pitz, S, Pohlenz, J (2010) Clinical features of pediatric Graves orbitopathy. Int. Ophthalmol., 30:717–21. Fledelius, HC, Stubgaard, M (1986) Changes in eye position during growth and adult life as based on exophthalmometry, interpupillary distance, and orbital distance measurements. Acta Ophthalmol., 64(5): 481–86. Frueh, WT, Frueh, BR (2007) Errors of single-mirror or prism Hertel exophthalmometers and recommendations for minimizing the errors. Ophthal. Plast. Reconstr. Surg., 23(3): 197-201. Gerber, FR, Taylor, FH, DeLevie, M, Drash, A, Kenny, FM (1972) Normal standards for exophthalmometry in children 10 to 14 years of age: relation to age, height, weight, and sexual maturation. J. Pediatr., 81: 327–29. Kashkouli, MB, Beigi, B, Noorani, MM, Nojoomi, M (2003) Hertel exophthalmometry: reliability and interobserver variation. Orbit, 22(4): 239–45. Krassas, GE (2004) Treatment of juvenile Graves’ disease and its ophthalmic complication: the European way. Eur. J. Endocrinol., 150: 407–14. Krassas, GE (2007) Childhood Graves’ orbitopathy. In: Wiersinga, WM, Kahaly, GJ (eds) Graves’ orbitopathy—a multidisciplinary approach. Karger, Basel, pp 221–28. Krassas, GE, Segni, M, Wiersinga, WM (2005) ChildhoodGraves’ ophthalmopathy: results of a European questionnaire study. Eur. J. Endocrinol., 153: 515–21. Liu, GT, Heher, KL, Katowitz, JA, Kazim, M, Moazami, G, Moshang, T (1996) Prominent proptosis in childhood thyroid eye disease. Ophthalmol., 103: 779–784. Mourits, MP, Lombardo, SH, van der Sluijs, FA, Fenton, S (2004) Reliability of exophthalmos measurement and the exophthalmometry value distribution in a healthy Dutch population and in Graves' patients. An exploratory study. Orbit, 23(3): 161-8. Nucci, P, Brancato, R, Bandello, F, Alfarano, R, Bianchi, S (1989) Normal exophthalmometric values in children. Am. J. Ophthalmol., 108: 582–84. Roshdy, N, Shahin, M, Kishk, H, El-Khouly, Sh, Mousa, A, Elsalekh I ( 2010) Role of new magnetic resonance imaging modalities in diagnosis of orbital masses: A clinicopathologic correlation. Middle East Afr. J. Ophthalmol., 17(2): 175-79. Rubin, PA (2005) Eyelid position measurement. Ophthalmol., 112(7): 524-25. Shibayama, K, Ohyama, Y, Yokota, Y, Ohtsu, S, Takubo, N, Matsuura, N (2005) Assays for thyroid-stimulating antibodies and thyrotropinbinding inhibitory immunoglobulins in children with Graves’ disease. Endocrinol. J., 52: 505–10. Sleep, TJ, Manners, RM (2002) Interinstrument variability in Hertel-type exophthalmometers. Ophthal Plast Reconstr Surg., 18(4): 254-7. Smolders, MH, Graniewski-Wijnands, HS, Meinders, AE, Fogteloo, AJ, Pijl, H, De Keizer, R.J (2004) Exophthalmos in obesity. Ophthalmic Res., 36(2): 78–81. Stan, MN, Garrity, JA, Bahn, RS (2012) The evaluation and treatment of Graves ophthalmopathy. Med Clin North America, 96(2): 311-28. Tsai, CC, Kau, HC, Kao, SC, Hsu, WM (2006) Exophthalmos of patients with Graves' disease in Chinese of Taiwan. Eye, 20(5): 569–73. Uretsky, SH, Kennerdell, JS, Gutai, JP (1980) Graves’ ophthalmopathy in childhood and adolescence. Arch Ophthalmol., 98: 1963–4. Wong, GW, Cheng, AC (2001) Increasing incidence of childhood Graves’ disease in Hong Kong: a follow-up study. Clin. Endocrinol., 54: 547–50. 6