User s Manual Color Vision Recorder version 4

Transcription

1 User s Manual Color Vision Recorder version 4

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3 COLOR VISION RECORDER version 4 USER S MANUAL Last updated: Feb 23,

4 Copyright Trademarks Disclaimer Copyright All Rights Reserved. This documentation and the accompanying software are copyrighted materials. Optical Diagnostics owns a number of unregistered Trademarks. These trademarks are extremely valuable to Optical Diagnostics and shall not be used by you, or any other person, without Optical Diagnostics express written permission. The trademarks include, but are not limited to the following: Color Vision Recorder and Aniseikonia Inspector. Optical Diagnostics has written this manual with care. However, Optical Diagnostics or its suppliers are not responsible for errors or omissions or for any consequences from application of the information in this manual and make no warranty, express or implied, with respect to the content of the manual. System requirements Computer hardware: Pentium II, 266MHz, 64 MB of RAM, USB port Operating system: Windows 98SE or higher Video board and monitor: Minimum resolution: XGA (1024 x 768) Number of colors: 16.7 Million colors (24 or 32 bits) Screen size 15 or higher A notebook/laptop is not recommended for testing Optical Diagnostics Eikvaren XE Culemborg The Netherlands Phone: info3@opticaldiagnostics.com Web: 4

5 Contents Contents Introduction Color deficiencies Color vision testing Program layout Overview Database Color calibration Color vision testing Farnsworth panel D15 test, Lanthony desaturated D15, and Farnsworth-Munsell 100-hue test Introduction Test setup Testing procedure Test results Dongle & Software updates Dongle Software updates...29 Index

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7 Chapter 1 Introduction 1 Introduction 1.1 Color deficiencies 1 Defective color vision can be either congenital or acquired. Reasons for an acquired color vision deficiency may be ocular pathology, intracranial injury, or excessive use of therapeutic drugs. The differences between congenital and acquired color deficiencies are laid out in Table 1.1. Table 1.1: Differences between congenital and acquired color vision deficiencies 1 Present at birth Congenital color vision defects Type and severity of the defect the same throughout life Type of defect can be classified precisely Both eyes are equally affected Visual acuity is unaffected (except in monochromatism) and visual fields are normal Predominantly either protan or deutan Higher incidence in males Onset after birth Acquired color vision defects Type and severity of the defect fluctuates Type of defect may not be easy to classify. Combined or non-specific defects frequently occur. Monocular differences in the type and severity of the defect frequently occur Visual acuity is often reduced and visual field defects frequently occur Predominantly tritan Equal incidence in males and females Classification of congenital color deficiencies Congenital color deficiencies are caused by inherited photopigment abnormalities. One, two, or three cone pigments may be missing or one of the three types of cones may contain a photopigment that differs significantly in spectral sensitivity compared to the normal photopigment. Table 1.2 shows the classification of congenital color deficiencies. 7

8 Table 1.2: Classification of congenital color vision deficiencies 1 Number of cone photopigments Type / Denomination Hue discrimination None Typical or rod monochromat Absent One Atypical, incomplete, or cone monochromat Absent Two Dichromat Protanope Deuteranope Tritanope Severely impaired Three (one abnormal) Anomalous trichromat Protanomalous Deuteranomalous Tritanomalous Mildly to severely impaired (continuous range of severity) Three Normal trichromat Optimum The terms protan, deutan, and tritan represent the color deficiencies involving the absence or abnormality of a single photopigment (dichromats and anomalous trichromats). Protan and deutan color deficiencies together are also named as red-green color deficiency. The prevalence of red-green color deficiency is much higher than that of the other types. Table 1.3 also shows that the prevalence of the red-green color deficiencies is much higher in men than in women and that deuternormal trichromatism is the most common color deficiency encountered. Table 1.3: Prevalence of the different types of red-green color deficiency in men and women 1 Type of color deficiency Frequency in men Frequency in women Protanopia 1% 0.01% Protanomalous trichromatism 1% 0.03% Deuternopia 1% 0.01% Deuternormal trichromatism 5% 0.35% Total 8% 0.40% The three types of congenital color deficiency (protan, deutan, and tritan) have their own specific color confusion characteristics. This can be represented by color confusion lines in the CIE color triangle as is shown in Fig The colors along these confusion lines may look the same to the color deficient person. For dichromats and severe anomalous trichromats colors that are far apart 8

9 on the confusion lines are confused, while mild and moderate anomalous trichromats only confuse colors that are closer together on the confusion lines. protan deutan tritan Figure 1.1: Schematic representation of the CIE color triangle with the confusion lines for protan, deutan, and tritan defects. Besides the different color confusion characteristics for protan, deutan, and tritan defects, there is also a difference in the relative luminous efficiencies. While in normal observers the maximum sensitivity occurs at a wavelength of 555 nm, in protanopia the maximum sensitivity occurs at about 535 nm and there is a marked reduction in sensitivity above 600 nm (a shortening of the red end of the spectrum). The shift in maximum sensitivity in deuternopia and tritanopia is less pronounced (maximum sensitivity in deuternopia is at 565 nm and tritanopia at 555 nm). Tritanopes have reduced sensitivity at the blue end of the spectra. The relative luminous efficiency of anomalous trichromats falls in between that of the trichromats and the corresponding dichromats. Classification of acquired color deficiencies Acquired color vision deficiencies have been classified similar to congenital color vision deficiencies with two types of red-green deficiencies and one type that is tritan-like. Table 1.4 shows general characteristics and associations with ocular conditions for the three types of acquired color deficiencies. As also mentioned in Table 1.1, acquired color deficiencies are less easy to classify than congenital color vision deficiencies. The detection and classification of an acquired color vision deficiency may be an important diagnostic aid. Furthermore, the changes in color vision are frequently used to monitor ocular pathology and to assess treatments. Note that if an acquired color vision deficiency is expected or evaluated, the testing should always be done monocularly. 9

10 Table 1.4: Classification of acquired color deficiencies 1 Classification Characteristics Association Type 1 red-green Type 2 red-green Type 3 tritan Similar to protan deficiency displaced relative luminous efficiency to short wavelengths Similar to deutan deficiency but with greater reduction in short wavelength sensitivity a) Similar to tritan deficiency but with displaced relative luminous efficiency to short wavelengths Progressive cone dystrophies Retinal pigment epithelium dystrophies Optic neuritis Central serous chorioretinopathy Age-related macular degeneration b) Similar to tritan deficiency Rod and rod-cone dystrophies Retinal vascular disorders Peripheral retinal lesions Glaucoma Autosomal dominant optic atrophy 1.2 Color vision testing 1,2 The purpose of color vision testing is to identify, classify, or grade a color vision deficiency. The reasons for looking into someone s color vision capabilities may be to evaluate fitness for a certain occupation (congenital and acquired color deficiencies) or as a diagnostic aid (acquired color deficiency). Different tests are usually designed to perform a different function. The general notion is that no one color vision test is all-fulfilling. If a complete and accurate diagnosis is required, it is necessary to use a battery of tests. The gold standard in color vision testing are the anomaloscopes. These devices are based on the principle of color matching. For example, a mixture of red and green is matched to a yellow color. Depending on the mixture ratio of the red and green, a patient can be diagnosed in type and severity. Also a distinction between anomalous trichromats and dichromat can be made. Anomaloscopes are relatively costly and require a skilled and knowledgeable operator. Therefore. they are rarely found outside research and teaching institutes. Screening (identification) In the screening process the question is simply if there is a color deficiency present or not. Since the prevalence of protan and deutan defects is by far the highest in congenital color deficiencies, most screening color vision tests only identify these red-green deficiencies. A screening test for acquired color vision deficiencies would have to be designed to detect both red-green as well as blue-yellow deficiencies. Screening of color vision deficiencies is usually done with so called pseudoisochromatic plates of which the Ishihara test probably is the most well-known. In these kind of tests, the 10

11 subject has to identify an object (e.g. numeral, letter, or symbol) of a certain color(s) in a background of another color(s). A color deficient subject will fail the test if the colors of the object and background lie on a corresponding confusion line and the colors are close enough together. Contour and luminance cues are usually suppressed by using a (random) dot diagram and an equal average object and background luminance. Type diagnosis (classification) The aim of type diagnosis is to distinguish between protan, deutan, and tritan defects. For occupational fitness purposes, it might be especially important to detect the difference between protan and deutan defects. That is, protans have the additional handicap that red colors are not detected as well because of the reduced sensitivity on the red end of the spectrum. In acquired color vision deficiencies it might be important to differentiate between the red-green and tritan defects because of the possible underlying condition (see Table 1.4). Besides using an anomaloscope, diagnosing the type of color deficiency can be done with specially designed pseudoisochromatic plates (e.g. HRR test) or with arrangement tests (e.g. Farnsworth panel D15 and the Lanthony desaturated D15). In arrangement tests, the subject is offered a series of colors that need to be sorted either into a sequence (usually based on hue) or into groups (most often grays versus colors). The advantage of arrangement tests is that they are less designed for specific confusion lines, so they may classify all congenital types (protan, deutan, and tritan). Furthermore they are particularly useful for the examination of acquired color deficiency because non-specific defects can be identified and changes with time recorded. Severity diagnosis (grading) The severity of an anomalous trichromat may be graded as mild, medium, and strong. Doing a severity diagnosis may be especially important in congenital color vision deficiencies. That is, in certain professions a mild defect may be completely acceptable, while a strong defect would be unacceptable. Grading can again be done with an anomaloscope, specially designed pseudoisochromatic plates (e.g. HRR test), or arrangement tests. With an arrangement test like the Farnsworth panel D15, a distinction between medium and strong defects may be made based on the number of crossings. If a subject passes the Farnsworth panel D15 test, but fails the Lanthony desaturated (which has smaller color differences), this subject is likely to have a mild defect (see table 3.1). References 1. Birch J, (1993). Diagnosis of Defective Colour Vision. Oxford University Press. Oxford. 2. Dain SJ, (2004). Clinical colour vision tests. Clinical and Experimental Optometry, 87,

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13 Chapter 2 Program layout Overview Program layout The main window of the software is shown in Fig On the left is the patient database. A new patient can be added by clicking the button Add new patient. A color vision test can then be started by following the steps 1, 2, and 3 on the upper right side of the main window: 1. Verify that the correct patient is selected 2. Choose which eye(s) is going to be tested 3. Start test to be performed. Note that if the screen has not been color calibrated, this should be done before starting to test the patients. Calibrating the screen is done by selecting the menu option Tools Color calibration. After a test is performed (for specifics on the different tests, see the next chapters), the results window for this test will be opened. If this window is closed again, you will see that the test just performed is added to the Previous examinations of the selected patient table on the lower right side of the main window. The results window of any previous test can be opened by simply double-clicking on this test in the Previous examinations of the selected patient box. By clicking the Patient history graph button, a graph will be shown in which a color confusion parameter is plotted against the date of the color vision tests. This is particularly useful to evaluate the development of an acquired color deficiency. Note that any changes in a results window need to be confirmed when exiting the results window. This allows you also to undo the changes, which was not possible in earlier versions. Also note that to remove a patient or test result from the database, simply select the patient or test result and press the Delete key on the keyboard. Figure 2.1: Main window of the software 13

14 2.2 Database The database of the Color Vision Recorder consists of a folder (directory) with separate files for the different patients. The default folder is C:\Program Files\Color Vision Recorder\database. The currently selected database folder can be found in the lower-left corner of the main window of the program (see Fig. 2.2). Warning: Do not make any changes to the separate database files, as this may make the files unreadable for the Color Vision Recorder. Figure 2.2: The current patient database folder can be found in the lower left corner. New database To create a new database a new empty folder needs to be created. This can be done by selecting the menu item File New database. This option will create a new folder and assigns the current patient database folder (see Fig. 2.2) to this newly created folder. Open database If you want to change the current patient database folder, then select the menu item File Open database. Append database If you have multiple Color Vision Recorder databases and would like to add them together, then you can use the menu item File Append database. With this function you have to select a database folder that will be appended to the currently selected (see Fig. 2.2) folder. Before you append a database to the current database, it is recommended that you first make a backup of the current database (see next page). When a database is appended the patients of both databases are compared to each other. If the last name, first name, date of birth, and patient ID number of a patient is the same in both databases, then the patients will be considered the same patient and the results will be merged. In that case the results of the two patients are also compared (including test date and time, etc.) and if they are exactly the same only one copy of this specific test result is saved. Reset database authorization file To avoid data handling conflicts, the software monitors with a database authorization file which application/computer is using the database. If another computer/application is already working 14

15 with the data of a certain patient, you will notice that it is not possible to access that patient data. If the software was not properly closed (e.g. with a power failure), it might be that the database authorization file becomes corrupted. Usually this will automatically be restored, the next time you use the software again and close properly. However, in the unlikely event that you keep getting the message: You cannot select this patient, because the patient is already selected on a different computer/application, you can reset the database authorization file to solve the issue. Create backup file It is good practice to regularly make a backup of your database. Since the database is a folder with many files, the menu item File Create backup file will gather all these files and combine them into one larger backup file. Restore backup file Select the menu item File Restore backup file to restore a backup file. This function will append (see above) the database of the backup file to the currently selected database. Export database If someone wants to analyse the color vision data that was gathered and calculated by the color vision recorder further, they can export the data to a comma delimited text file (.cvs). Such a file can for example be opened by spreadsheet programs such as Excel. 2.3 Color calibration In conventional pseudoisochromatic and arrangement tests the intended colors are obtained by specific pigmented dyes and a light source with a specific spectrum. In the Color Vision Recorder the colors are represented by the intended color coordinates. To convert these color coordinates into the actual colors on the computer monitor, the monitor must be color calibrated. This should be done each time the settings (e.g. contrast, brightness, color temperature, or gamma) of the monitor are changed, the monitor is replaced, and at regular intervals to account for color changes due to aging of the monitor. So instead of having to purchase a new test (or light source) when the colors of the caps become inaccurate Figure 2.3: The currently used monitor calibration file can be found in the menu item File Options. due to the interaction with light (aging discoloration) or from contact dirt, you now only have to recalibrate the monitor. 15

16 The Color Vision Recorder s color calibration is based on the standards set by the International Color Consortium (ICC). By default the program assumes the monitor to be compatible with the srgb standard of the ICC, i.e. the color space of the average (CRT) monitor. The current calibration file used by the program can be found and changed in the menu item Tools Options (see Fig. 2.3). To create a specific color calibration file for your monitor, you have the choice of two methods: 1. Use the software (visual) monitor calibration tool of the Color Vision Recorder which is executed by selecting the menu-item Tools Color calibration. 2. Use a hardware monitor calibration tool such as X-Rite s MonacoOptixXR or GretagMacbeth s EyeOneDisplay. In general, it is believed that a hardware calibrator provides a better absolute color calibration. However, it is unclear at this point if a hardware calibration provides a significant improvement on the color vision testing accuracy compared to the visual method. Visual monitor color calibration When the menu item Tools Color calibration is selected, the window of Fig. 2.4 appears. The color calibration consists of 6 steps: 1. Initial settings In this first step it is described that you should A) set the color depth to 24 or 32 bits (16.7M colors). This ensures that the color resolution is high enough. In case of an LCD monitor, it is also recommended to set the screen resolution to the display s native resolution Figure 2.4: Starting screen of the color calibration to avoid interpolation artifacts. B) Turn off the monitor s power saving mode and turn on the monitor/computer at least 0.5 hours before doing color vision test. This ensures that the monitor is warm and provides consistent colors. C) When calibrating, make sure the room lights are dimmed. This ensures that the subject perceives light predominantly from the monitor and not from the possibly interfering surroundings. 2. Color temperature In the second step you are asked to set the color temperature or white point of the monitor to preferably 6500K. If 6500K is not an option then another temperature could also be used. Just make sure to enter the color temperature in section B of this step. 16

17 3. Brightness / Contrast In the third step you are asked to optimize the brightness and contrast setting of the monitor. The optimum settings ensure that the luminance of the monitor is (just) not clipped for low and high pixel values and therefore different shades of grey/white are just discernable. The brightness and contrast implementation of some newer LCD displays may be different (and also more intuitive) from that of the conventional CRT displays. For these displays the visibility of the central circles in the boxes do not seem to change much when changing the brightness and contrast setting. In those cases, choose the default or 50% values for the brightness and contrast. 4. RGB colors In the fourth step the color coordinates of the three primary colors (Red, Green, and Blue) of the monitor should be set. By default the color coordinates of the srgb standard are assumed (i.e. the color coordinates of a typical monitor). Since the coordinates of the RGB colors can differ slightly between different monitors, there is also the option to add the color coordinates of your custom monitor. This is done by clicking the button Add a specific monitor (see Figure 2.5: RGB colors step of the color calibration procedure. Fig. 2.5). In the (unlikely) event that you have obtained the color coordinates directly, you can enter them by hand. However, there is also the possibility to extract the color coordinates from a generic color calibration file of your monitor. By clicking the button Copy data from an existing ICC file, you can obtain the RGB color coordinates that are encapsulated in such a file. Many manufacturers post generic color calibration files (i.e. drivers with extension.icm or.icc) of their monitors on their website. If you have difficulties locating this file, please send us an (see contact information at: with your monitor brand and type and we will try to locate it for you. Note that in order to make such an RGB values request for your monitor, you will need to be registered (see Help Registration). 5. Gamma In the fifth step of the calibration process the gamma of the monitor is set. The gamma is a parameter that says something about how the screen luminance changes as a function of pixel value. By default only a white visual target is shown with a solid center bar and two striped patterns on the side. By adjusting the slider bar below the visual target, the luminance of the 17

18 solid center bar is changed. The slider bar should be adjusted such that the luminance of the central bar equals that of the average luminance of the striped bars. To view the average luminance of the striped bars, you will need to move back from the monitor or squint your eyes (so you do not see the separate stripes anymore). In case you are using an LCD screen, there are three things to note: Firstly, the white visual target assumes that all colors will have the same gamma, but for some LCD screens this is not quite correct. In that case check the checkbox RGB colors separately and determine the gamma of each color separately (if this is difficult to do for one of the colors, e.g. the blue color, then it is still better to use the white visual target). Secondly, LCD screens are more affected when the viewing angle to the screen changes. Therefore, if you move away from the monitor to set the gamma, make sure that the viewing angle stays the same as what will be used during the actual color vision testing. If there is a significant viewing angle dependence and/or non-uniform light distribution across the screen, there may also be a color non-uniformity across the screen. This could affect the accuracy of the test. Thirdly, if the screen resolution set in the display properties does not equal the native resolution of the LCD screen, then an interpolation takes place and the striped bars on the sides of the gamma image may not be black and white but may also contain gray. In that case it is probably difficult to make a reliable seting for the gamma. It is recommended to change the resolution to the native setting of the LCD screen. Changing the resolution can be done by right clicking somewhere on the desktop and selecting properties. Next, select the Settings tab where you will find the resolution setting. If it is not possible to make a gamma setting (the range of the slider bar does not seem large enough), then you should find out if the monitor itself has a gamma setting. Set the gamma of the monitor to off, default or close to 2.2. If the gamma of the monitor is changed, you should first redo the Brightness/Contrast (step 3) settings again, before retrying to set the gamma in step Save The last step is to actually create the color calibration file. This is done by clicking the button Save as and Finish. Besides creating the color calibration file, the program automatically also will use this newly created color calibration file for its color presentations as can be seen in the menu item Tools Options (see Fig. 2.3). 2.4 Color vision testing In the introduction it was mentioned that if a complete and accurate color vision diagnosis is required, it is usually necessary to use a battery of tests. Currently the Color Vision Recorder contains three color vision tests: The Farnsworth panel D15, the Lanthony desaturated D15, and the Farnsworth-Munsell 100-hue test. These tests are usually not used for screening of 18

19 (congenital) color deficiencies, but they have more the function of diagnosing the type and severity of the color deficiency. They are also particularly suited for identifying and keeping track of an acquired color vision deficiency. A logical sequence to carry out color vision testing could be for example: Screen the subject for red-green color deficiencies with for example the Ishihara test or SPP (Standard Pseudoisochromatic Plates) test. 1 Do the Farnsworth D15 test. If the subject fails this test, then the subject s color deficiency ranges from medium (a couple of crossings) to strong (many crossings). If the Farnsworth test is passed (but the screening test was failed), then the subject is most likely mildly color deficient. In that case do the Lanthony D15 test to determine the type of the color deficiency. Note that if the subject is suspected of having an acquired color deficiency the eyes should be tested separately. Testing for congenital color deficiency can be done with both eyes together. 1 Currently there is no typical screening test in the Color Vision Recorder. However, if there is enough interest, we intend to design and include such a test. Note that the Color Vision Recorder is setup modularly and that a new test could be obtained as an add-on. 19

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21 Chapter 3 3 Farnsworth panel D15 test & Lanthony desaturated D15 test, and Farnsworth-Munsell 100-hue test Farnsworth panel D15 test, Lanthony desaturated D15 test, and Farnsworth-Munsell 100-hue test 3.1 Introduction The Farnsworth panel D15, Lanthony desaturated D15, and Farnsworth-Munsell 100-hue (FM- 100) test are hue discrimination or arrangement tests. The conventional (i.e. not software) tests consist of moveable Munsell colored caps (discs) and fixed reference cap(s). The patient s task is to identify the cap that most closely resembles the reference cap(s) in color and to place it next to the reference cap. Next, from the remaining moveable caps the patient needs to identify the cap that most closely resembles the cap that was just placed next to the reference cap, etc. This process is repeated until all moveable caps are placed in color order. Both the Farnsworth and Lanthony D15 test provide information about the type and severity of a color deficiency. The difference between the tests is that the colors of the Lanthony test are less saturated. Since the colors in these arrangement tests encircle white, this means that the color differences between the Lanthony test caps are smaller than those of the Farnsworth test. Consequently, the tests diagnose a different severity of color deficiency (see Table 3.1). In general, the D15 tests can be administered to subjects of approximately age 5 and older. Table 3.1: Difference between the Farnsworth and the Lanthony D15 test pass/fail levels Test Color deficiency severity PASS level Color deficiency severity FAIL level Farnsworth panel D15 normal mild medium medium strong Lanthony desaturated D15 normal mild mild medium strong The FM-100 test also provides information about the hue discrimination ability, both for color normals as well as color deficient people. 21

22 3.2 Test setup In the Color Vision Recorder the conventional D15 and FM-100 tests are simulated. At the top the caps will need to be positioned according to color order. The moveable caps are positioned randomly in the box below. Viewing angle If an LCD screen is used as a monitor, the subject should view the screen straight-on (i.e. at central viewing angle). The reason is that the brightness and color of the screen may look different when not looking straight-on, possibly giving clues on how to pass the test. Distance to the screen The individual cap diameters should subtend an angle of approximately 1.5 to ensure that observations are made with the rod-free retinal area. His means that, depending on the monitor size, the distance to the screen should be approximately 60 cm (2 feet). Especially for LCD screens it is recommended to make sure that the patient keeps this relatively large viewing distance, because a larger viewing distance helps to limit the viewing angle between the left and right side of the screen. Ambient lighting To avoid a color contrast reduction due to ambient light reflecting of the monitor, it is recommended that the ambient lights are dimmed when doing the color vision measurements. 3.3 Testing procedure Moving the caps As mentioned in the introduction, the patient s task is place the moveable caps in an order according to color. In the Color Vision Recorder there are basically two ways to move the caps: Clicking on the caps: If the cap is in the box, then left-clicking on it will move the cap to the next available position in the top row. If the cap is in the top row, then clicking on it will move the cap back to the box. In the FM-100 test it is also possible to right-click on a cap to move the cap to next available position next to the right reference cap. Dragging the caps: A cap in the box can be dragged (i.e. keeping the left mouse-button down on top of a cap and moving the mouse) to the next available position in the top row. Similarly, a cap can be moved out of the top row by dragging it into the box. NOTE that caps can also be dragged in between cap positions in the top row (either coming from the box or from another position in the row). This is useful for a patient to know when doing the test, because it allows for easy adjustments to the color order. 22

23 Numbering the caps It is possible to number the caps during a test. This is achieved by pressing the keys n, c, or r with the following meanings: n: No numbering: the default testing mode r: Random numbering: random two digit numbers are placed in the caps. The idea is that the random numbers can be useful in case a subject cannot handle the mouse well and the administrator has to do this. Note however that there has not been any research yet to verify that adding the numbers does not affect the test results. c: Correct numbering: the caps are numbered according to the correct color order. 3.4 Test results Figures 3.1 and 3.2 show a screenshots of the test results window of the D15 tests and FM-100 test. Part of the data in this window can still be changed. Note that if changes are made to the data in the results window, the program will ask if you want to save these changes when exiting the results window. General test data At the top-left part of the results window, there is some general test data such as the patient name, test date/time, eye(s) tested, and test duration. Except for the patient name, all of these data can be changed by clicking (left mouse button) on the results. This is particularly useful when you are entering data of a previously performed conventional test. For the FM-100 tests behind the test duration there are also 4 percentage numbers. These show the fractions of the time that the patient spend on each of the 4 boxes. Comments In this box the administrator can enter additional data about this specific test. There are 14 lines of text that can be written (nearly the whole box). Results diagram In the results diagram of the D15 tests, the D15 horse-shoe diagram is drawn. This diagram is a graphical presentation of the caps order. For a color normal subject who will not make any errors or just one or two small errors (e.g. switching two adjacent numbers), the blue line will follow the circumference of the diagram. Depending on the test and the severity of color deficiency (see also Table 3.1), a color deficient person may make several or many large errors (crossings) in the horse shoe diagram. The type of color deficiency (protan, deutan, or tritan) is determined from the horse shoe diagram by evaluating in what direction the crossings are made. The three different types of color deficiency have their own confusion axes in the horse-shoe diagram, which are represented by the dashed lines. For example, in Fig. 3.1 the crossings are clearly made along the deutan axis. 23

24 In the results diagram of the FM-100 test, a polar or linear graph of the Kinnear error score is drawn. By clicking on the graph or the View ++ button, the graph is enlarged. Clicking the button Options on top of the results diagram shows the options for the results diagram, such as: graph type (polar or linear), graph scaling (auto or fixed), visibility of the confusion axes (center cap) according to Dain and Birch (1987), Dain-Birch normalization (dividing each error score by the mean score of the test, i.e. TES/85), and the application of an averaging filter (default width of 21 as also used by Dain and Birch (1987)). Figure 3.1: Screenshot of a results window of a D15 test Figure 3.2: Screenshot of a results window of an FM-100 test 24

25 Caps order At the bottom left part of the results window, the numbered caps order is shown. Here you can also change the order of the caps by clicking and dragging, similar to the way the caps are moved in the actual test. Furthermore, holding down the right mouse button and moving the mouse over caps will have the same effect as left-clicking these caps. The feature that the caps order can be changed in the results window has been implemented so the software can also be used as a scoring-only tool. Diagnosis The main diagnosis of the color vision test consists of two parts: a pass/fail diagnosis (automatic, pass, fail, undetermined) a type of color deficiency diagnosis (automatic, protan, deutan, tritan, unclassified, NA) By default the diagnosis for both parts is set to automatic. In this mode a suggestion is made by the software (see below). Note, however, that it is the physician s responsibility to do the final diagnosis. The final diagnosis can be made by clicking on the buttons and selecting the appropriate items. Automatic diagnosis D15 tests The automatic diagnosis of the D15 tests is based on the amount and type of crossings/errors. A crossing means that two adjacent caps are numbered at least 4 places apart (e.g. cap 6 and cap 1/2/10/11/12/etc). A small error means that two adjacent caps are numbered less than 4 places apart (e.g. cap 6 and cap 3/4/8/9). If two adjacent caps are more than one number apart, but it provides the smallest color difference at that point in the caps order, then it is not considered a crossing or error (e.g. in an order R, 1, 2, 4, 3, 5, 6, cap 4 is assigned a small error, but cap 5 is not because after cap 3 the next closest color left in the box will be color 5). In order to pass a D15 test, the criteria in the automatic diagnosis is that a maximum of one crossing or two small errors may be present. The test is assumed to be failed if there are more errors. To determine the type of color deficiency each crossing/error is classified as either a small error or a protan, deutan, tritan, maybe protan, maybe deutan, maybe tritan, maybe protan/deutan, or unresolved crossing. Next, it is determined if either the (pure) protan, deutan, or tritan crossings are more present than the other two. If one of the types of (pure) crossings is indeed more present than the others, then all the appropriate maybe crossing are assigned to that type. Also, small errors in the direction of the identified type will no longer be considered as errors anymore. Finally, a protan, deutan, or tritan type is diagnosed if there are now at least two crossings in that direction and there is a maximum of two small errors or one crossing in another direction. An automatic diagnosis is also made when not all caps are placed in the caps order. However, in that case the diagnosis will be shown in between brackets. 25

26 Automatic diagnosis FM-100 test The pass/fail part of the automatic diagnosis of the FM-100 test is based on the Total Error Score and the age-dependent pas/fail criteria from Kinnear and Sahraie (see below). If the test is failed, the type part of the automatic diagnosis is based on the Vingrys and King-Smith score (see below). Bowman score Bowman published a method for quantitative scoring of D15 tests in 1982 [Acta Ophth. 60: , 1982], which is based on sum of the color differences between all adjacent caps in the final order. This resulted in the so-called total color difference score (TCDS). Later this scoring parameter was converted in the Color Confusion Index (CCI), which is the TCDS divided by the TCDS of a perfect caps arrangement. Tip: The quickest way to see if a subject made any errors in the caps arrangement is to see if the CCI value equals In 1984 Bowman et al. evaluated the effect of age on the CCI for subjects with normal color vision. Based on this data also the Age Corrected Color Confusion Index (AC-CCI) is calculated in the software. This parameter is only available for a patient age between 10 and 70 years. Total error score and Kinnear and Sahraie diagnosis The error scores of the FM-100 test are calculated based on the absolute difference in cap numbers of the adjacent caps minus 2. For example, say somewhere in the first box a cap order of 4, 5, 6, 8, 7, 9, 10 is found. The error score at the position of cap nr 5 is: abs(5-4) + abs(5-6) 2 = 0. The error score at the position of cap nr 6 is: abs(6-5) + abs(6-8) 2 = 1, etc. The Total Error Score (TES) is the sum of the error score on all 85 positions. There are two ways to calculate the TES: across boxes and within boxes. Across boxes means that the reference (also called anchor) caps are not taken into account in the analysis. The calculation of the error scores assume that the cap orders of the differened boxes are stuck together. For example, if box 1 ends with the caps 18, 19, 20, 21 and box 2 starts with 24, 22, 23, 25, 26, then the error score for the last cap position of the first box is abs(21-20) + abs(21-24) 2 = 2. If the within boxes calculation method is checked, then the end cap positions are calculated with the cap nr of the reference caps. In the example above, the TES within boxes would become: abs(21-20) + abs(21-22) 2 = 0. The software also provides two Total Partial Error Scores (TPES), one for the red-green (RG) axis and one for the blue-yellow (BY) axis. For the RG axis the error scores for cap positions and are summed, while for the BY axis the error scores for cap positions 1-12, 34-54, and are summed. Kinnear and Sahraie published normative TES data for normal observers as a function of age [Br J Ophth 86: , 2002]. Based on these pass/fail criteria the software also provides a pass/fail diagnosis. 26

27 Vingrys and King-Smith score Vingrys and King-Smith published a quantitative scoring method for the D15 and FM-100 tests based on a vector analysis of the color differences between adjacent caps [IOVS 29:50-63, 1988]. This analysis results in the following three factors that are shown in the diagnosis frame of the D15 results window: C-index: The confusion index quantifies the degree of color loss. A score of 1.00 means a perfect arrangement of the caps. S-index: The selectivity index quantifies the amount of polarity or lack of randomness in the cap arrangement. Confusion angle: The confusion angle is associated with the type of color defect. In a population study, Vingrys and others determined what diagnosis might be made based on the values of the C-index, S-index, and the Confusion angle. This diagnosis is also shown in the results window. The pass/fail parameter is only available for a patient age of up to 55 years. Previous examinations In this table, the same tests are shown as in the Previous examinations of the selected patient table on the lower right side of the main window (see Fig. 2.1). This table allows you to quickly browse through the different results of the same patient. Note that an examination can be removed from the database by pressing the Delete key on the keyboard. By holding down the shift key when pressing the delete key, you will not be asked if you are sure you want to delete the examination. Printing To print the results of a D15 or FM-100 test, select the menu-item File Print of the Results window. In the File menu also a Print Preview function is present which allows you to view the output of the print function before it is actually printed. Copying Under the menu-item Edit of the D15 or FM-100 results windows, you can copy two images to the clipboard: 1) the results diagram or 2) the whole results window. These copy functions are implemented in case you would like to paste the results in another (e.g. word) document. 27

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29 Chapter 4 Dongle & Software updates 4 Dongle & Software updates 4.1 Dongle To protect agains unlawful copying of the software, the Color Vision Recorder uses a dongle. This is a file (software dongle ) or USB stick (hardware dongle) that needs to be present when running the software. This dongle also contain information such as a possible expiration date or the authorized software functions/modules. The advantage of the hardware dongle above the software dongle is that the hardware dongle allows the user to run the software on different computers as long as the dongle is attached to that computer. A software dongle can only be used on one specific computer (when replacing the computer, the dongle and therefore the software will no longer work). Updating the dongle By selecting the menu-item Help Dongle, it is possible to update the information contained on your dongle. This might be necessary if you, for example, purchased an additional software module or if the expiration date needs to be changed. The procedure to update a dongle is: 1. You make a request for an update using the tool in the dongle update window. 2. If you agree to the terms of the update, Optical Diagnostics will prepare an update code to be downloaded. 3. After Optical Diagnostics notified you that the update code is available for download, you can click the Download new dongle button and the updated dongle will be installed. 4.2 Software updates The frist time the software is run, you can choose to have the software connect to Optical Diagnostics website each time the software is started to check if you are running the latest version of the software. In case there is a new version, the software will either guide you how to update the software for free (if it is a minor update), or how to update the software license first (if it is a major update). To check manually for updates, go to Help Check for updates. To enable/disable the default checking each time the software start, go to Tools Options. 29

30 Index Backups...15 Color calibration...15 Brightness/Contrast...17 Color temperature...16 Gamma...17 Initial settings...16 LCD screens note...18 RGB colors...17 Save...18 Color confusion lines...8 Color vision deficiencies...7 Acquired...7, 9, 10 Congenital...7, 8 Prevalence...8 Protan, deutan, and tritan...8, 9 Color vision testing Anomaloscope...10 Arrangement tests...11 General...10 Gold standard...10 Pseudoisochromatic plates...10 Screening...10 Severity diagnosis...11 Type diagnosis...11 Using the Color Vision Recorder...18 Contents...5 Copyright...4 D15 and FM-100 tests...21 Differences between Farnsworth and Lanthony..21 Test procedure...21, 22 Moving the caps (clicking and dragging)...22 Numbering the caps...22 Test results...23 Bowman score...26 Caps order Comments Copying Diagnosis Diagnosis (automatic) General test data Printing Results diagram Vingrys and King-Smith score Test setup Ambient lightning Distance to screen Viewing angle Database Add new patient Append Backups Delete a patient or test result Export New Open reset authorization file Disclaimer... 4 Dongle Hardware vs. software Updating Index Notebook/laptop... 4 Optical Diagnostics... 4 Relative luminous efficiencies... 9 Software updates System requirements... 4 Trademarks

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