Phorcides for Contoura
Phorcides was developed by Dr. Mark Lobanoff.
Dr. Lobanoff became interested in LASIK during his residency at Emory University. Following residency he completed a LASIK/Refractive Surgery Fellowship at the University of Minnesota. He is a Howard Hughes Research Scholar. Dr. Lobanoff has been performing LASIK for 2 decades and has treated thousands of eyes with Contoura.
What is Phorcides?
Phorcides is a software program that uses geographic imaging software to analyze the topographic treatment for an eye in Contoura. Added to this data is information from the anterior and posterior corneal astigmatism taken from a Scheimpflug topographer. Advanced algorithms are used as is vector analysis and differential geometry. The result is that the program calculates the perfect sphere and cylinder treatment for Contoura for the surgeon. It works for all eyes, even those that differ greatly between manifest and measured. Early results show patients have better outcomes than the FDA Contoura clinical trials and better results than WFO. It is not a nomogram, rather it is something far more advanced and a paradigm shift in how LASIK treatments are calculated. Phorcides is an artificial intelligence to guide the surgeon. Other advantages are automatic data input directly from a G4 or Pentacam, ensuring there is no chance for data entry errors by a human. Safeguards are built in to correctly identify the correct patient and the correct eye, eliminating possible identification errors.
Phorcides for Contoura
Finally, Clinical Decision Support Software to Help Surgeons Calculate Contoura Treatments!
When Contoura, topographic-guided LASIK, was released by Alcon in 2017 it was advised that surgeons should calculate treatments based on the patient’s manifest refraction. This was what surgeons had always done previously and thus it made sense. However, Contoura treats corneas differently than any other prior technology, correcting topographical irregularities on the corneal surface. These topographic irregularities have an optical effect and contribute to the manifest refraction seen at the phoropter. By ignoring the refractive effect of eliminating the topographic irregularities, surgeons were not getting patient visual acuity results as good as they would want. If the topographic irregularities were large, the astigmatic axis resulting from treating just the manifest could result in large errors.
An effort was then taken to treat completely off of the measured anterior corneal astigmatism, the topography-modified refraction or TMR. Developed by Dr. John Kanellopoulos, this brilliant insight led surgeons to realize the importance of correcting the complete anterior corneal measured astigmatism if you are to correct the anterior corneal topographic irregularities as well. The results of TMR were better than treating off of the manifest when using Contoura. However, there were cases in which treating the full TMR led to the astigmatic axis being flipped after surgery. In other cases, residual astigmatism remained that kept patients from their best vision.
Seeing the results of TMR, some surgeons began to treat 50% of the difference between the manifest and the measured astigmatism. This technique was appealing in its simplicity and being conservative it would not result in a flipped axis in most cases. However, this technique is at its heart a “guess” at what the best astigmatic axis and magnitude should be. It was felt that there was a better answer out there, one that was based on logic, mathematics, and optical physics. It was this objective that led to the birth of the Phorcides software.
What Does the Name Phorcides Mean?
In Greek mythology there were 3 wise sisters, known as the Phorcides. These sisters shared one eye among them that they would pass around to one another in order to see. Phorcides software is the “eye” shared among refractive surgeons that allows them to “see” the correct treatment.