Vocabulary List: None
Thresholds
In addition to a normal doctor schedule, some days will also have a Threshold schedule. Patients scheduled on the Threshold schedule will not see a doctor during their appointment, instead the OA running the threshold schedule that day will work with them to complete a series of tests after which they are free to leave. A doctor will later review these tests and contact the patient concerning their results.
These tests are called Thresholds, a more in-depth visual field test than the screening visual field they complete at their exam, and OCTs, a 3-D imaging of either their optic nerve or their macula.
How to determine which tests to perform
There are three main types of Thresholds and OCTs which can be performed.
Thresholds: Sita-Fast 30-2, Sita-Fast 24-2, and Sita-Fast 10-2
OCTs: RNFL, Mac, and Anterior
The majority of patients scheduled back for Threshold/OCT testing have a type of one of three families of diseases: Glaucoma, Macular Degeneration, and High Risk Medication use. Which of these diseases the patient has determines which type of Threshold/OCT is completed.
Glaucoma patients, in most instances, will complete a Threshold 24-2 and an OCT-RFNL
Macular Degeneration patients, in most instances, will complete a Thresh 10-2 and an OCT-Mac
High Risk Medications patients, in most instances, will complete a Thresh 10-2 and an OCT-Mac
-If a patient has more than one of these diagnoses, the diagnosis which has the request for testing listed in its plan determines the testing.
-If a patient does not have one of these diagnoses, then the test/tests to run will be specified in the plan of the diagnosis which is the reason they were brought back for testing.
Work Up
Workup up for a Threshold resembles most intermediate appointments.
1) Greet the patient, letting them know who you are and that you will be completing their testing.
2) Check visual acuity (monocular at distance only)
3) Review medications, allergies, and any updates to medical history.
4) Complete testing
5) Complete charting
6) Let the patient know that the doctor will review their testing and contact them about the results in about one week. Have the patient check out at front desk.
OCT
WHAT IS THIS TEST
Optical Coherence Tomography (OCT) is a painless and non-invasive imaging technique that takes a detailed picture of one of two possible structures in the back of the eye: the optic nerve or the macula. There are three different types of OCT tests: MAC, RNFL, and anterior seg. Instructions are below.
HOW TO DO THIS TEST
To turn on: Press button on front of machine (black square), wait to load. A screen will appear, with drop down, select Cirrus Operator and click okay. This will take you to the main screen to search or add a new patient to view previous OCT or acquire an image.
To turn off: exit out of programs, go to start menu and shut down computer, the computer will shut itself down without having to press the off/on button.
OCT RNFL:
Wipe off machine with alcohol swab.
If there is a previous OCT in the system the patient's last name should be entered into the computer under search. If it is a patient that has never had an OCT completed then select new patient, enter: patient name, date of birth, ID number, etc in the appropriate fields. Save the patient.
Once finding/adding the patient, highlight the name, and click acquire at the bottom right hand side.
Then select, Optic Disc Cube 200 x 200, for the right eye (choices are on the left side of the screen)
Have patient place chin on the left side first, and instruct them to focus on the "green snowflake" on the left side of the screen.
Adjust the chin rest with the arrows on the left top portion of the screen to get the pupil in line with the cross section. Make sure to get the pupil in focus, if out of focus, you can click, auto focus and the computer will auto focus the eye and the optic nerve below to get a sharper image.
The box on the left corner of the screen will show the optic nerve, line up the circular ring with the outer portion of the optic nerve by moving the entire box/circle in that field.
Once that is aligned make sure the wavelengths that appear on the right hand side within three different fields are also in focus and centered in their individual boxes, this can be done by pressing optimize.
Once all fields are adjusted appropriately without changing the other fields then click capture. Before selecting capture you may want to ask the patient to blink once, and hold their eye open focusing on the center of the green snowflake.
Once the image is captured. Remind the patient they can blink again. Then make sure on the rating scale in the center top portion of the screen it indicates a score of 6 or greater out of 10. If less, then click the button try again, if the image is a 6 or more out of 10 then click save.
Repeat steps 5-9 again for the right eye, you should always capture at least 2 images per eye.
Ask the patient to then place their chin on the right side of the chin rest, this time to obtain images for the left eye. Then select, Optic Disc Cube 200 x 200, for the left eye (choices are on the right side of the screen for the left eye) Then repeat steps 4-9; with exception of #4, patient's target will move to the right side of the screen for OS.
Once both eyes have been completed then click finish at the bottom right hand side of the screen, this will take you back to the main screen of searching for patients. Highlight the correct patient again, and this time click Analyze at the bottom right hand side. This will take you to the print out screen.
Select an image for both eyes by clicking on one image of Optic Disc Cube 200 x 200 for each eye in the upper center section. Then select the print out option for OCTRNFL which is on the upper right hand side labeled ONH and RNFL OU Analysis.
Once the images populate, click the print icon on the far upper right hand side of the screen.
This will take you to the print out screen, then click file on the upper left hand side, and select print, once the print box populates, click print again. The images will print at the pretest printer in color.
OCT MAC:
Wipe off machine with alcohol swab.
If there is a previous OCT in the system the patient's last name should be entered into the computer under search. If it is a patient that has never had an OCT completed then select new patient, enter: patient name, date of birth, ID number, etc in the appropriate fields. Save the patient.
Once finding/adding the patient, highlight the name, and click acquire at the bottom right hand side.
Then select, Macular Cube 512 x 128 the first option, for the right eye (choices are on the left side of the screen)
Have patient place chin on the left side first, and instruct them to focus on the center of the "green snowflake" in the middle of the screen.
Adjust the chin rest with the arrows on the left top portion of the screen to get the pupil in line with the cross section. Make sure to get the pupil in focus, if out of focus, you can click, auto focus and the computer will auto focus the eye and the optic nerve below to get a sharper image.
The box field on the left corner of the screen will show the macular area, make sure the green cross section is in the center of the box (it should not require any movement, it should already be in the center of the box in that field)
Once that is aligned make sure the wavelengths that appear on the right hand side within three different fields are also in focus and centered in their individual boxes, this can be done by pressing optimize. You should also ensure the indentation of the wavelengths has the center line of each box directly cutting through the center of the indentation to ensure the image will be centered for the most accurate results.
Once all fields are adjusted appropriately without changing the other fields then click capture. Before selecting capture you may want to ask the patient to blink once, and hold their eye open focusing on the center of the green snowflake.
Once the image is captured. Remind the patient they can blink again. Then make sure on the rating scale in the center top portion of the screen it indicates a score of 6 or greater out of 10. If less, then click the button try again, if the image is a 6 or more out of 10 then click save.
Repeat steps 5-9 again for the right eye, you should always capture at least 2 images per eye.
11. Ask the patient to then place their chin on the right side of the chin rest, this time to obtain images for the left eye. Then select, Macular Cube 512 x 128 the first option, for the left eye (choices are on the right side of the screen for the left eye) Then repeat steps 4-9.
Once both eyes have been completed then click finish at the bottom right hand side of the screen, this will take you back to the main screen of searching for patients. Highlight the correct patient again, and this time click Analyze at the bottom right hand side. This will take you to the print out screen.
Select an image for each eye individually by clicking on one image of Macular Cube 512 x 128 for each eye in the upper center section. Then select the print out option for OCTMAC which is on the upper right hand side labeled Macular Thickness.
Once the image populates for one eye, click the print icon on the far upper right hand side of the screen.
This will take you to the print out screen, then click file on the upper left hand side, and select print, once the print box populates, click print again. The images will print at the pretest printer in color.
Then repeat steps 13-15 for the left eye.
Threshold
WHAT IS THIS TEST
A threshold visual field measures the integrity of the visual pathway from the eyes to the occipital cortex, the part of the brain we use to see. In addition, it is a test to determine if any of the nerves in the back of the eye have been injured by too much pressure inside your eye. This specialized test is one way to monitor whether blind spots are developing in your field of vision from glaucoma or damage to the optic nerve. There are many reasons this test may be necessary for our patients: monitoring risk factors for glaucoma or macular degeneration, monitoring for changes in the macula secondary to use of high-risk medications, head injuries, or drooping eyelids are just a few of the reasons our doctors may recommend this test and repeat it at regular intervals.
HOW TO DO THIS TEST
To turn on: press button on side of threshold on top by monitor, and turn on button behind printer to turn on printer.
To turn off: press button by monitor and press button behind printer.
Generally when performing a threshold you will perform a SITA FAST 24-2, occasionally you will perform other types of thresholds; if different it should be notated in the plan for the testing to be performed at the visit. Other types commonly performed include; SITA STD 24-2, SITA FAST 10-2 or C-40 Screening; there are other options on the machine as well.
This test requires no CL wear or spectacle wear. Please ensure that CL wearers take CL’s out prior to the start of the testing; after getting entering visual acuities.
Complete steps 1-5 prior to bringing the patient back for testing.
1. First you must select the type of VF-Threshold you will be performing. For a “normal” threshold select SITA FAST 24-2 (unless otherwise specified)
2. Then it will have you select an eye in which will be tested first, select right eye; unless the doctor specifies otherwise.
3. This will then take you to the patient information screen, if there is previous information from another patient, select clear patient data. Then begin entering the current patient’s information; Patient last, first name, date of birth
4. Calculate the lenses needed for the testing. Ignore any cyl power of -1.00 or less; include any cyl of -1.25 or more. The resultant sphere power would simply be the result of adding +3.00 to the sphere power. However, if the resultant of +3.00 to the sphere power results in a trial lens of +0.50 to -0.50, then no sphere lens is required
5. After calculating the trial lenses for the test, pull the loose lenses from the lenses case and place the lenses in the holder in the machine for OD first. Go ahead and keep the lenses for OS with you until they are needed, so that you do not need to pull them while the patient is in the room waiting to complete the testing.
6. Then click proceed on the bottom right hand corner of the screen to initiate the test to the testing screen.
7. At this time you should go and get the patient
8. Prior to beginning the testing get the patient’s entering VA’s
9. If the patient is wearing CL’s have them take them out at this time, if spectacles are being worn, have the patient take them off for testing
10. Clean off the equipment in front of the patient, then have the patient place the eye patch over the left eye (when beginning with right eye; vice versa if you begin with the left eye). At this time you should also hand the patient the button for the test.
11. Direct the patient to place their chin on the left side first. Upon placing their chin there you will align the patient’s eye with cross cursor on the screen while also ensuring that the lens (when applicable) is close enough to the patients eye so that it does not obstruct their view of the screen and for best vision; since the lenses replace eyewear and CL’s for the testing.
12. Then once the patient is aligned you will select start, a box will appear asking you to initialize gaze giving you the options of start or cancel; at this time you will instruct the patient to: “Go ahead and focus your attention on the orange light in the center of the screen, and now I will have you blink a couple times and then hold your eye open for a moment while I get a quick pupil measurement,” then select start on the box that populated. This will initialize the patient’s gaze for the testing; this allows for tracking eye movement during the test in order to ensure the test is reliable. Once it initializes make sure you let the patient know they may blink as normal.
13. After that is complete another box will pop up at this time before selecting start you instruct the patient on what they will be doing during the testing. State: “During the test you will focus on the orange light in the center of the screen, all around the screen you will see flashes of light, some will be bright and others will be dim, whenever you see the flashes of light you will click the button. I may have to move your chin around occasionally throughout the test to make sure you are aligned with the camera. The test can last any where from 3 to 6 minutes. If you need me to pause the test at any time, please let me know. Any questions?” Then once they reply, select start and tell the patient, “You may begin.”
14. The patient will then continue testing with the right eye. While the patient is testing with the right, make sure that you are paying attention to their eye on the screen, if they are looking around, kindly remind them to stay focused on the orange light in the center and not to look at the lights as they flash. Also while they are testing, this is a good time to fill out the necessary information in the paper chart or EHR in regards to their visit for the day (this is discussed in training)
15. Once the patient has completed the right eye the machine will beep and a box will appear asking you if you would like to save. Direct the patient to go ahead and sit back and at this time click save.
16. Next, instruct the patient to cover the other eye (left eye) and if a different lens is needed for the left eye, this is the time to exchange the lenses in the holder on the threshold. Once the machine finishes saving select, “test other eye” this will take you back to the testing screen. Have the patient place their chin on the right side now. Then align the patients eye with the tracking (refer to steps 10-11)
17. After that is complete another box will pop up at this time before selecting start instruct the patient: “You are going to do the same thing again, remain focused on the orange light in the center and whenever you see the flashes of light you will click the button.” Click start then state, “you may begin.” Remember to make sure that you are paying attention to their eye on the screen, if they are looking around, kindly remind them to stay focused on the orange light in the center and not to look at the lights as they flash.
18. Once the patient has completed the left eye, you will hear the machine beep and the save option will pop up in a box. Ask the patient to sit back, and click save. Once the patient sits back at this time you should gather the equipment (patch, button and lenses) and put them away.
19. Once it saves, click the print icon on the right hand side. Once the print screen comes up select “print all selected items,” For some patients “not enough qualified exams exist to perfrom GPA for the right/left eye” may appear. Select “print classic SFA”. The test will print each eye individually for OD and OS for all thresholds excluding C-40 screenings; C-40 screenings will print OD and OS on the same page.
20. Import the document into the patient’s EHR screen under the appropriate tab (Test Sum). Right click in the large images box to the right and select import. Click desktop from the left menu. Double click Threshold folder. Double click VF. The files are by date, with the most recent test at the top. Double click the patient’s name. Under Files of Type, select TIF images. Double click on the appropriate eye. Click Save. Repeat on other eye.
THRESHOLD LENS POWERS
In a effort to keep the threshold and C-40 appointments moving as efficiently as possible, below is a quick cheat sheet to help determine the needed lens powers for the test.
Ignore any cyl power of 1.00 or less; include any cyl of -1.25 or more. The resultant sphere power would simply be the result of adding +3.00 to the sphere power. However, if the resultant of +3.00 to the sphere power results in a trial lens of +0.50 to -0.50, then no sphere lens is required.
Examples:
Rx of -5.25 -0.75 x 017 would get a lens power of -2.25
Rx of -1.25 -2.00 x 089 would get a lens power of +1.75 -2.00 x 089
Rx of +1.25 -1.00 x 012 would get a lens power of +4.25
Rx of -2.75 -0.25 180 wouldn’t need any lens at all (using a lens power of +0.50, +0.25, -0.25 or -0.50 might be more disruptive to the reliability of the test than no lens at all.
Please make sure to notate in the notes section of the VF tab what specific lens powers were used on each eye.
Charting for Thresholds
Add a new chart for the day and select the “Threshold” Layout.
On the Hx/Meds tab:
1) Forward the Review of Systems.
2) Add any new mediations/allergies, and update any changes to medical history.
On the Workup tab:
1) Record info provided by (patient, patient and parent)
2) ADD or forward as the chief complaint the diagnosis which is the reason the patient returned for testing.
3) Enter monocular visual acuity for distance.
4) Enter the type of visual field (Sita Fast 24-2, Sita Fast 10-2), if performed.
On the Exam Tab:
1) Forward the diagnosis in which the plan requests that the patient return for Threshold testing (this diagnosis will match the chief complaint)
2) After opening the diagnosis, switch the order number to “1” and record in the plan “(whichever tests were performed) only today. Sent to-do to (whichever doctor reviewed last round of testing; see below) for review”
Send the to-do to whichever doctor reviewed previous testing.
On the Testing Tab:
1) Add an entry for each test performed (Monocular entries for Visual Fields unless using the Octopus; OU entry for OCT-RFNL; Monocular entry for OCT-Mac and anterior)
Search for the testing by typing “VF” into the “Test” box for visual fields and “OCT” for OCTs. Then use the drop down to select the appropriate test (this should auto-populate “location” and “eye”). Select the correct diagnosis, put in that day’s date for “Ordered” and “Performed” (leave “Report” and “Reviewed” empty), select the doctor who will review the testing for “ordered by” and your initials for “performed by”.
On the Routing Tab:
1) If a visual field was performed check “Visual Field 92083”
2) If an OCT was performed check either OCT-RFNL 92133, OCT-MAC 92134, or OCT-ACA 92132 depending on which was performed
3) put none in the glasses and contacts box (unless the patient needs to meet with an eyewear stylists for either of theses).
4) use the Threshold Flowchart (see below) and paste the appropriate conclusion into the “Additional Notes for Optician” box.
How to use the Routing Flowchart
There is a Threshold tab on the Routing Flowchart which is accessible in the OA helpful things folder on the desktop. This MUST be used for every appointment on the Threshold Schedule! The Flowchart, just like the screening photos and fundus photos flowchart asks a series of two questions. Depending on the answers to these questions, you will be led to one of four possible conclusions which you simply copy and past into the “additional notes for optician” box on the routing.
Question #1 Do we take the patient’s medical insurance?
The patient’s insurances are listed in the middle table on their demographic page. As long as there is a medical insurance listed without an expiration date (and there is not an alert saying that it is an insurance we do not take), then we take the patient’s medical insurance. In this example the patient has AETNA for their medical insurance (see below)
Question #2 Does pt have PEC or DEP and an appropriate diagnosis
PEC and DEP are subsets of certain VSP plans that assist in coverage for certain types of medical testing (including Thresholds and OCTs). If a patient has VSP it will be listed as “eyefinity” without an expiration date on their insurance page and there will be a pulled authorization (titled VSP eligibility) in the Referral Sources table. However, not all VSP patients have PEC or DEP. To verify if a VSP patient has PEC or DEP we must open up their most recent authorization to view their benefits. Double click on the most recent authorization in the Referral Sources table. A window will open up; click on “View Elig/Auth” to view the benefits page.
If the patient has Primary Eyecare or Diabetic Eyecare Plus, it will be listed under Patient Coverage (see example below). If the patient does not have either program it will not be listed.
If the patient has PEC or DEP, you must also verify that the diagnosis which is the reason they were brought back for Threshold testing is one that PEC and DEP accept. Most Glaucoma, Macular Degeneration, and Diabetic Diagnoses are accepted. To verify if the patient’s diagnosis is accepted, compare it to the listed ranges of acceptable codes on the right side of the Threshold Flowchart.
In the above examples, the patient returned for Threshold testing because they were being monitored for POAG-B (H40.013). This diagnosis falls within the acceptable range for Glaucoma diagnoses. They also had Aetna medical and DEP, leading us to the bottom left conclusion of the flowchart which is then copied and pasted to the routing.
