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Enlarge ImageThomson Test Chart 2000 Pro & Remote Control
Wednesday, August 23, 2006
Thomson Test Chart Software
In the mid 90s, a team of optometrists and vision scientists at City University led by Professor David Thomson set about developing the software to exploit new developments in computer and display technology to provide eye care professionals with a powerful new set of tools for vision assessment in the consulting room.
Test Chart 2000 was launched in January 2000 after extensive beta-testing and evaluation. The program provided a cost-effective and extremely versatile alternative to back-illuminated charts and projectors and the response from clinicians was immediate and enthusiastic. Within three years, the program was used by over 600 optometrists, ophthalmologists, orthoptists and others.
During this time the program evolved and many new features were added in response to feedback from users. Test Chart 2000 PRO builds on the success of Test Chart 2000 and offers the eye care professional an unrivalled battery of vision assessment tools for the consulting room.
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Snellen charts: The Snellen chart remains the most popular chart design among some clinicians. A range of different optotypes can be displayed in Snellen format including British, Sloan, Sheridan-Gardner, Landolt Cs, Tumbling Es, Lea symbols, Lea numbers and Kaye pictures. A single row or column can be shown and a range of cursors are available to isolate specific letters or rows |
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LogMAR charts: The LogMAR chart is a superior design to the Snellen chart and has been used in research laboratories for many years. An increasing number of clinicians are making the switch and it is likely that this chart format will become the standard in years to come. A wide range of optotypes can be displayed in LogMAR format. A single row or column can be shown and a range of cursors and available to isolate specific letters or rows. | |
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Single letter charts: It is sometimes easier to show a single letter, particular when dealing with children and those with learning difficulties. The size of the letter can be changed in 0.1 logMAR steps and crowding bars can be added. A wide range of optotypes can be displayed in single letter format |
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Contrast Sensitivity Charts: Test Chart 2000 PRO includes a Pelli-Robson type test of contrast sensitivity. Patients are required to read triplets of letters with decreasing contrast. The minimum contrast required for the patient to read 2 out of the 3 letters is recorded as the contrast sensitivity. This measurement is partivular valuable for patients with cataracts and various neurological conditions such as glaucoma. | |
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Cross-cyl targets: A range of targets are included for use during the cross-cylinder test. Targets include rings and dots of different sizes, which may be shown singly or in pairs. |
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Fan and block test: The fan and block test remains a useful test for identifying and correcting astigmatism. | |
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Duochrome tests: The duochrome test provides a rapid method for assessing patients’ refractive status. Test Chart 2000 PRO allows various targets and optotypes to be presented against a duochrome background. |
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Phoria tests: Test Chart 2000 includes targets for use with the Maddox rod and a test for associated phoria. | |
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Associated Phoria tests: The patient views the bars through the red/green spectacles provided. The bars are moved until they appear to be aligned and a measure of the associated phoria in prism dioptres is displayed on the screen. |
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Fixation disparity tests: Test Chart 2000 PRO includes an improved fixation disparity test which requires the use of red and green spectacles (provided). The unique design ensures good binocular lock and stable accommodation. | |
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Worth 4 dot test: The Worth 4 dot provides a quick check for suppression. In this implementation the patient wears red / green spectacles (provided) and is asked how many dots the can see. 4= binocular, 3 = Left suppression, 2= Right suppression. |
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Stereopsis: At last - a distance stereopsis test. Use random dot stereograms to asssess steropsis. Dynamic generation of stereograms allows the disparity of the images to be adjusted to provide an accurate assessment of stereopsis. Generate shapes or letters | |
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Vernier acuity has been shown to be useful in assessing the potential vision of patients with cataracts. Simply measure the minimum displacement require for the patient to detect that the two bars are mis-aligned. |
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Fixation targets: Test Chart 2000 PRO includes over 200 different images for fixation including photographs, cartoons and a selction of spots and crosses. The images are arranged in groups and a slide-show of the images within a group may be shown during retinoscopy or opthalmoscopy for example. Add your own images by simply dropping them into a directory. | |
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Task images: Patient having problems seeing the TV or reading teletext? Why not show them these images on the test chart. Use the task images supplied with Test Chart 2000 PRO or add your own images by simply dropping them into a directory |
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UK number plate tests: The "number" plate test remains the only statutory test of vision required for driving in the UK. Test Chart 2000 is capable of exactly replicating a series of front and rear number plates using the exact fonts and character spacing. The number plates can also be presented against a variety of backgrounds to simulate real world conditions. | |
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Polarised screen: A polarised screen option is available for Test Chart 2000 PRO. The screen is mounted in front of the monitor and polarises small areas of the screen in orthogonal directions. The patient views the screen through a polarised visor. This enables a range of binocular vision tests to be carried out (see below). |
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Polarised fixation disparity: This test is carried out in conjunction with the polarised screen. The two nonius markers are seen by the left and right eyes respectively while the rest of the screen is seen binocularly. | |
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Polarised traffic lights: This test is carried out in conjunction with the polarised screen. Amber is seen binocularly while red and green are seen by the right and left eyes respectively. This provides a quick test for suppression. |
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Polarised binocular balancing: This test is carried out in conjunction with the polarised screen. The right eye see the letters at the top, the left eye see the letters at the bottom while the central letters are seen binocularly. Binocular balancing made simple! | |
Remote Controls
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Two infra-red control systems are available for Test Chart 2000: Standard and Dynamic. Both systems allow complete control of all aspects of the program from distances of up to 10m. The IR receiver module plugs into a USB port of the computer. This unit is extremely sensitive and will pick up the IR signals from the handset from anywhere in the consulting room even if the handset is not directed towards the sensor.
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The Standard Remote handset has been designed specifically for Test Chart 2000 PRO. The ergonomic design fits comfortably in the hand and the buttons give subtle tactile feedback. The most commonly used buttons come easily to hand and the layout is simple and intuitive. All aspects of the program can be controlled using the handset - you can even point at individual letters on the test charts. |
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The Dynamic Remote unit uses a high resolution touch-sensitive screen to provide an intuitive visual interface giving complete control of all the functions provided by Test Chart 2000. The system also exploits the high resolution screen to provide a series of near vision tests | |
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All of the tests in Test Chart 2000 can be selected by tapping the appropriate icon on the screen. Having selected a test mode, the screen changes to show the options relating to that test mode. This makes it very easy for those unfamiliar with the system to access all the features of the program. The illuminated screen is also ideal for use in a darkened consulting room. |
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In addition to controlling Test Chart 2000, the dynamic remote incorporates a range of near vision tests. The patient simply holds the unit at the normal reading distance and views the tests on the screen. For example Near acuity ... | |
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Fixation disparity ... |
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Amsler charts ... | |
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Task images .. and much more. |
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The Dynamic Remote comes with a cradle for recharging the unit and a full instruction manual. “This innovative product puts you in complete control in the consulting room” | |||
