Q: Does laserarcs.com account for induced astigmatism coming from primary corneal incisions?
A: Yes, most definitely. Laserarcs was specifically designed to automatically factor in corneal astigmatism changes resulting from 2.4 to 2.6 mm horizontally located primary cataract incisions (femto created or hand cut). Our experience tells us 2.4 to 2.6 mm primary corneal incisions placed at +/- 10 degrees from 180 degree (horizontal) axis will induce around +0.2D of vertical astigmatism. Our studies show a slight difference in astigmatism induction between manual and femto incisions, but there’s not much difference. Laserarcs recommends tracking your outcomes and adjusting the surgeon factor if your personal primary incision induces more or less astigmatism than +0.2D.
We have also tinkered with 1.9 mm primary corneal incisions and smaller. As expected, induced astigmatism is even less with these sub 2.0 mm cuts however, we feel current phaco technology limits everyday use of these small incisions. When sub 2.0 mm becomes a reality, the easiest thing to do would be measure your new induced astigmatism and use the laser factor feature to adjust the nomogram. The laser factor is a very useful feature to personalize laserarcs for yourself.
Q: I always use the femtolaser to make my primary incision (always horizontal location). Sometimes the software of my laser will not allow an arcuate cut to be placed next to or on top of my primary incision. What should I do?
A: If primary or secondary incisions and planned arcuate incisions overlap by 15 degrees, we turn off the primary and/or secondary femto incisions and manually create these incisions posterior to the proposed arcuate cut(s). We allow the femtolaser to create the arcuate cuts because we feel astigmatism correction is more important (than entry incisions) for our cataract procedure. In the future, we hope this laser software limitation will be removed by laser manufacturers. If surgeons use 8 or even 9 mm optical zone, there is more than enough room to manually create primary or secondary incisions posterior to the arcuate cuts. That’s one of the main reasons we encourage an 8 mm optical zone (as opposed to 10 mm optical zone).
Q: I’m relatively new to femtosecond laser technology and I didn’t receive much guidance on astigmatism correction from the laser manufacturer. When I use your calculator, do I enter astigmatism data from topography, biometry, or manual keratometry? Many times, each instrument differs in the amount of astigmatism measured and axis location. How do I get the best results?
A: Surgical success depends on accurate pre-surgical measurements, consistent surgical planning, and clinical experience. Two instruments we feel are essential to accurate pre-surgical measurements are Zeiss’ ATLAS Corneal Topographer (Pathfinder II Package) and Haag-Streit’s LenStar Optical Biometer. Data from these instruments are correlated for accuracy and entered into the LaserArcs calculator app. LaserArcs calculator is a consistent surgical planning tool. The clinical experience part is up to you. We put together a flowchart to demonstrate our systematic approach.
Q: This nomogram is obviously based on your results with the femtolaser. How extensive is your database?
A: 5,000 laser assisted cataract procedures and counting. We received our femtolaser in October 2011 and laserarcs is currently in its third nomogram revision. We are very pleased with the accuracy of the current version and we feel you will be too. As more result data comes in, we will notify subscribers IF we need to make a major revision. We feel the easiest changes to the nomogram would probably be accomplished by adjusting the laser factor at this point.
Q: I’m concerned about HIPAA compliance. Does your website save any descriptive patient data?
A: No descriptive information is saved. In fact, you don’t even have to enter the patient name to generate a treatment result from the calculator. We feel the ‘patient name’ entry field is a nice addition should you choose to print the results page for your medical records. We have a legal team on retainer to ensure the upcoming surgery assistant program will also be HIPAA compliant.