Instructions for using the DXDT Engineering and Research Retina Health Monitoring System

© Copyright 2011, Christopher Hekimian
dxdthelp@dxdtengineering.com
www.dxdtengineering.com

This system is designed to replace the paper Amsler grid prescribed for home use by many eye care professionals. Use of this system in no way replaces the services and skills of an Eye Care professional.  Please consult with an eye care professional regularly for optimal eye health.

Concept: The DXDT Quantitative Retina Test Grid employs a computer-enabled Amsler grid to characterize blind spots and distortions in vision due to retinal abnormalities.  The user is provided with a modified Amsler grid that can be resized as desired.  Any prescribed eyewear should be used during the test. The user selects which eye to test first and covers (or closes) the other one throughout the testing process. The user positions themselves a comfortable (and repeatable) distance from the computer monitor. The user uses the system to systematically identify blind spots in the field of view and to “correct” for retina-imposed distortions using mouse click and drag operations. The user then calculates the score for the test with the touch of a button and commits the data to a database that can be used to track trends in retina health. 

Made for use at home, the system contains many warnings and prompts to avoid data irregularities. The user should read them at first and then over time may want to “click through” them.

First Use: 

Profiles: The first time the system is used the user should start the program, click through the initial information block, and then click the RESET button to free the program from the default user profile. The user profile will associate a specific grid size, color scheme and center “X” size, for each user. The user should sit comfortably a fixed distance from the computer and vary the size of the grid using the slider beneath the grid. The user should also check the OPTIONS menu to try different color schemes for the grid. Once comfortable settings have been determined, the SAVE feature will allow the profile to be saved.   Use the form controls to identify a place to save your profile (a .ret file).  By default, the profile will save to the thumbdrive that contains the program.  You may save the .ret file to your desktop for easy access if you intend to e-mail it later. Enter a name for your profile in the text box and double click in the box. Check the “Make Default “ box so the profile will be loaded automatically with each use. Then click OK.  All subsequent tests using that profile should be done at the same distance from the same computer and using the same size grid in order to ensure that the collected test data remains valid.

Saving Images:
The Quantitative Retina Test Grid is capable of saving .bmp images of eye test results.  If you wish to save the images, use the ADMIN choice in the OPTIONS menu to establish a location to save those files.  Also, when you are committing data to the data log after each test, the ADMIN button on the “Specify Right or Left Eye” form will need to be checked.

Testing Concept: The user should close one eye and focus on the center dot in the grid. Retinal abnormalities may be manifest in the wavy lines or in vertexes in the grid that disappear.  The user should practice clicking and dragging the vertices so as to straighten the wavy lines while focusing on the center "X". The UNDO button will undo a single click and drag or blindspot drop operation. The user should also practice moving the mouse down each vertical line of the grid, from left to right, and stopping on each vertex. The user should practice using each eye.  

It is likely that it will take several initial test runs to get used to the system and get used to using the drag and drop operations while maintaining focus on the center dot.  Analysts will consider this learning curve when interpreting results. 

Continued Use: 

Blind spots: The recommended method for using the system is to begin by identifying blind spots.  This is done by starting at the upper left hand corner of the grid and working down each vertical line in the grid and jiggling the mouse pointer over each vertex in the grid. If the mouse pointer cannot be seen by the user while the user maintains focus on the center dot, then the user should jiggle the mouse over an increasingly larger area until the approximate size of the blind spot is known. Then the user can focus on the blind area, place the mouse pointer on the upper leftmost corner of the blind area, right click on the mouse pointer and drag the mouse to trace the shape of the blind spot. Please use simple shapes. Complex blindspot shapes should be made from overlapping simple shapes. The computer will require a few seconds to fill in the shape that you drew. Note that the UNDO button can be used to erase the dot that has just been placed. The complete grid should be processed in this way for the eye under test.

The system has a dynamic noise feature that is accessible through the NOISE selection on the OPTIONS menu tab.  The noise option allows for blind spots to be identified against a moving noise background.  Healthy parts of the retina will see the noise flickering while parts of the retina impaired by blind spots will appear “quiet” and there will be no flickering.

Retinal Aberrations: After blind spots have been mapped, the user should work from left to right to click and drag vertices carefully, to correct the bends and waves that the retinal aberrations cause in the vertical lines. The vertices that are impacted by blind spots may be omitted in the test. The more the user learns to carry out the click and drag operations while focusing on the center dot, the easier the process will become.  A similar process is repeated for the horizontal rows.  

Scoring: When the process is complete, press the SCORE button to determine the average deviation between the clinically corrected grid and the starting, master grid.  Press the COMMIT button to enter the score into the user profile. The user will be required to identify the eye that was tested and then press OK.  Repeat the entire test process for the other eye as required.

Alternate profiles can be loaded using the LOAD feature.  There is no limit to the number of profiles that can be initiated using the SAVE feature but only one can be the default profile that loads automatically when the program is started.

NOTE: Consistency is desirable over perfection. If the user can create a consistent improvement to the grid using click and drag operations then the data over time will be useful. If the user gives up because it wasn’t possible to create a perfect looking grid, then no useful data will be collected.

Eye Trainer:  An off-macula visualization training tool is being provided at no cost with the the Quantitative Retina Test Grid.  The training tool is accessible through the EYE TRAINER menu tab on the Quantitative Retina Test Grid.  This tool is intended to assist the patient in learning to use the healthier parts of the retina (identified using the Quantitative Retina Test Grid) that may be offset from the center of vision, to read with.  This system contains its own instruction sheet.

For Help: E-mail the developer at dxdthelp@dxdtengineering.com. Ensure that the term EYE TEST appears in the subject line.

Multiple User License:  Contact the developer at dxdthelp@dxdtengineering.com to inquire about purchasing the rights to use this system for multiple users.