Dr. Theodore Rabinovitch On NTEC’s New Lenstar Technology:
It’s important to remember that the bar regarding patient expectations about their vision after surgery is continually being raised. When I started doing surgery a three decades ago we were really happy if we achieved outcomes of 20/40-20/60 uncorrected. Now, patients can even be 20/20 and can be unhappy if things are not just perfect.
So, we have to make sure that the ocular surface is in good condition and one of the biggest things is to make sure there is no dry eye and to make sure patients have not had their eyes open too long when testing them, leading to poor pictures.
Over the last year, we have switched to the Lenstar LS 900.
We have found that to be very helpful. Lenstar has automated tracking, so once the technician gets the eye lined up it basically takes over and, as a result, we get good pictures.
It’s very good because it has all of the major formulas incorporated into it, which makes it a lot easier to do our calculations. In particular, it has the 4th generation formulas of Barrett which has been shown to be highly accurate even for higher myopic and hyperopic patients. For Toric patients, it integrates the posterior astigmatic effect on total astigmatism. Also, it has the Hill-RBF formula that Warren Hill developed with its higher order math analysis which gives us the potential to get our patients to within ½ diopter of Plano.
It’s interesting that we think we are getting great results but when we actually look at our own data we are not as close as we think. As we do more and more multifocal IOLs we really cannot have any refractive error left, which means we have to get the sphere perfect and the cylinder perfect. With the Lenstar we are able to tell if we have good images and it gives us not only axial length and highly accurate K readings, it also gives us anterior chamber depth, lens volume, white to white, pachymetry and even angle kappa which are essential for the newer lenses on the market.
On top of that, we can even add a cone to the machine if you want to get topography. It gives us the ability to do Toric planning with all the Toric formulas. This is really helpful because if you don’t treat astigmatism it’s like giving someone glasses without treating the cylinder – we need to get both the sphere and the cylinder on target.