Configure Settings
Once you have downloaded the Phorcides program and opened it for the very first time, click on the “Tools” at the top.
Then select “Settings”.
Optical Character Recognition (OCR)
If you would like to have Phorcides try to read patient data from your Contoura planning screen to save you time typing this information in yourself, then next to UseOCR type True.
MnOCRConfidence should be set for 20.
You can always change these settings or turn off the OCR later if you choose.
NOTE: Alcon’s Contoura Laptop currently provides a low resolution image of the Contoura treatment data page. Because of this, Phrocides optical character recognition is prone to errors. The OCR saves the user time but requires that the user be vigilant in checking that all data has been entered correctly.
Alcon WaveLight SP3 vs SP4
Before you start you need to decide if your Alcon Wavelight laser is running on SP3 or SP4 software.
How can you tell? Easy.
Examine how your Alcon Contoura planning laptop screen looks like. Then in Phorcides, select your version.
Obtaining the topographic treatment maps
Use the Alcon Contoura planning laptop as you normally would for a patient.
Remove the Vario scans you do not want to use.
Move forward on the Alcon software until you reach the treatment page. (see next slide)
Set the Modified Sphere and Cylinder both to zero.
This will give you the pure topographic treatment map.
Place a USB drive into the Alcon Contoura planning laptop.
Hit the keys Ctrl P. This will allow you to save a copy of this page to the USB.
Do this for each patient and each eye for that surgical day.
When done, bring that USB to the computer using Phorcides.
After Installation
When Phorcides was installed on your computer, it created four folders on your desktop.
Place the JPEG image files of the topographic treatments you calculated on the Alcon Contoura planning laptop into the “Patient Topo Exams” file.
Phorcides will automatically take you there when you click the “Open Image” button. Find the patient and the eye that you want to work with. Double click that file.
Your First Treatment
You are now ready to plan your first treatment.
In the upper right-hand corner select the “Open Image” button.
Phorcides is now displaying the patient information you selected. ID, DOB, and Name of Patient are displayed. The correct eye has been selected.
Phorcides has entered as much data as it can. Again, Alcon provides us with a poor resolution image, so our OCR is limited in its accuracy. We hope Alcon will solve this issue soon.
Boxes in light yellow need you to review them for accuracy. Boxes in bright yellow need you to enter the data in manually.
Go to the first yellow box. When you click this box you will notice that a blue outline surrounds the box above that contains the information you need. Phorcides is helping to lead you along.
Type the value found in the blue outlined box into the bright yellow box you are working in. When done hit “tab” and Phorcides will take you to the next box that needs to be filled.
Notice that the topographer anterior corneal negative cylinder and the topographer posterior negative cylinder have been entered for you. Notice also these boxes are white. They are always 100% correct. You don’t need to adjust them. They come directly from your Pentacam or Galilei G4.
You need to add the micron values for the max (maximum) tissue ablation and the cen (center) ablation. These values also come from the Alcon Contoura planning image. A copy of these values is provided to you by Phorcides. Type in the max (red arrows) and the cen (green arrows) into the data boxes.
Once all data has been correctly entered and you have confirmed each entry for accuracy hit the ”Analyze” button in the lower right corner (blue arrow).
Talus Processing
This next step is known as Talus Processing. Remember that we use the shorthand “talus” to refer to raised topographic abnormalities. Phorcides has automatically identified the most important, highest micron talus. This is the area in light purple that has been circled and identified with a number 1.
If you are satisfied with the analysis you can simply click the Calculate Treatment button.
Final Page and Save
Phorcides is displaying the final page. It is showing you the Clinical (Manifest) refraction, the Measured astigmatism, and the Phorcides Recommended treatment based on all calculations.
The sphere is correct, having been modified by three factors. First, the change in astigmatism magnitude from the clinical to the manifest. Second, the topographical treatment effect on the sphere. Third, a nomogram has been applied.
The recommended cylinder and axis should be correct. Hit the Save button in the upper right corner.
Please remember that the medical professional using this software must still use their clinical judgement to reach a final decision on what treatment should be used on the patient. Phorcides is an advisory software tool.
Also note that the Measured sphere provided by Alcon is gibberish. It is not a real number and should be ignored (yellow arrow).
When you hit the “Save” button in the upper right corner, Phorcides will lead you to the folder it created on your desktop named “Phorcides Results”. This conveniently saves all of your treatments in a single place. The treatments can be printed and brought into the laser treatment room so that you can compare it to the treatment screen for each eye.
Once you have saved your work, Phorcides leads you back to the first screen so you can begin your next treatment. Phorcides was designed to make the surgical process as efficient as possible.
Click on the Open Image button and select your next eye for analysis.
Troubleshooting
Because Alcon currently provides us with a low resolution image from the Contoura planning laptop, the OCR sometimes makes mistakes reading numbers and certain letters.
The most common error when reading a patient’s name is confusing Y and V. Notice in this case the Y has been read as a V. Because of this the Pentacam or G4 data has not been found.
Simply correct the letter and Phorcides will go back and find the correct file and data for you, entering the numbers automatically.
Advanced Features
You can allow Phorcides to find and choose the most significant talus for you. You can simply hit Calculate Treatment and be done. This is simpler and does lead to excellent results.
However, we have built in more advanced tools if you want to have more control over the talus analysis. This is an option but not mandatory.
A standard talus is meant to mirror the size of one “wing” of a plus cylinder WFO treatment. When using your mouse to select a talus or portion of a talus, try to draw a size similar to the standard.
The Phorcides software will automatically encircle the entire area of a talus. It will then find the geometric center and make this the axis for the talus. For a standard size talus this works fine but in this example one talus is very broad. We need to adjust for this. So click the “clear talus” button.
You now have a “clean slate” to work with. Begin selecting standard size talus sections of the large talus. (see next section)
Use your mouse to draw a line around a standard size talus. For each standard talus section you select, you must assign it a height value. Since this section is made up of the lightest purple you would select 100%.
Continue until all areas of talus have been accounted for. Then hit “calculate treatment” and you are done.
Again, Phorcides is designed to find the most optically significant talus on each cornea. But sometimes a user might want to select a talus that is lower in height, less optically significant, but still present. In this example Phorcides has identified the light purple highest talus. But there is an area in dark red that we may want to include as well.
Use your mouse to draw a line around the talus you want to include.
Phorcides will ask you what height you want to assign to the talus. Look at the color bar on the right. Find the color that most closely approximates the center of your talus. Then click the button that corresponds to this value.
Notice that Phorcides has listed two taluses now. The first, given the number 1, was automatically selected by the software. The second was manually entered by the user.
Once you are done, hit the Calculate Treatment button.
There is another very powerful tool to help you in your talus analysis. This is the Talus Finder slide. In this example, Phorcides has found 3 significant taluses. You could simply move forward with the calculation at this point. But not all 3 of the taluses are exactly at the maximum 100% height. Let’s refine the analysis a bit.
Use your mouse to grab the blue arrow on the Talus Finder slide. Move it to the right. You will see the software adjust the analysis of the taluses in real time. We have moved the blue arrow until only the very highest talus is auto-identified. The slightly lower taluses are not being auto-identified.
Now use your mouse to draw a line around the talus you want to identify. Assess it a height percentage. This circled talus appears to be composed of darker purple so it is given a height of 80%.
Now use your mouse to draw a line around the final third talus. Assess it a height percentage. This circled talus appears to be composed of a mix of lighter and darker purple so it most closely matches a height of 90%.
Don’t swipe left. Moving the Talus Finder slide to the left picks up too much “noise”, making the analysis unreliable.
Our studies show that eyes with these features that are treated with Contoura in the usual manner end up with residual astigmatism post-operatively. You have two choices. You can proceed with a normal WFO treatment. However, our studies show that WFO treatment of these eyes leads to a 20% enhancement rate. A second option is to split the treatment into two. The first treatment is with a Contoura treatment that is designed to create a cornea with no talus and no anterior astigmatism. Then the surgeon uses a second card and immediately treats with a WFO treatment to create anterior astigmatism that balances the calculated internal astigmatism. The IR (iris recognition) data obtained on the Vario can only be used for one treatment. It is important to use the IR (iris recognition) with the Contoura treatment and not the WFO. In our research thus far, this more complicated approach leads to good results in these unusual eyes. Phorcides has your back, it will not lead you astray.
Vectors
Because in ophthalmology we work in optical vectors, from zero to 180 degrees, the vectors are displayed in this format instead of on a 360 degree vector plot. The legend in the lower right corner lists what each colored vector represents. The green vector is the total corneal astigmatism, correctly combining the anterior and posterior astigmatism into one vector. The purple vector is the combined optical vector of all taluses. The red vector is the internal astigmatism. The black vector represents the final recommended treatment.
In the lower left corner you can choose to add a vector displaying the manifest refraction astigmatic vector.
This was all designed to give the user a quick visual explanation of why the measured astigmatism differs from the manifest astigmatism. It also gives one a visual recognition of why the treatment cylinder magnitude and axis may differ from manifest and measured. Here we see why the patient is asking for less MRx astigmatism than measured – the talus vector is 90 degrees away from the corneal astigmatism, reducing its optical effect.
Adjusting Targeted Spherical Outcome
The default targeted sphere is set to zero, plano.
The user may opt to target slight hyperopia in a young patient or myopia for monovision.
This can be done by entering in the desired final refraction here.
