At the 2026 ASCRS meeting, Eric D. Donnenfeld, MD, FACS, of OCLI Vision, presented during the "Advanced Astigmatism Management to Achieve the Best Refractive Cataract Surgery Outcomes" session. Here, he shares some key takeaways with Ophthalmology Management. The below transcript has been edited for clarity. 

Hello everyone. My name is Eric Donnenfeld. I'm here at ASCRS and I'm talking about astigmatic keratotomy now more than ever. Why is astigmatism correction important? That's almost a rhetorical question. It has visual, occupational, and economic repercussions. Surgical correction is preferable to spectacles because of meridional magnification. While I do love toric lenses for higher amounts of cylinder, for lower amounts of cylinder, limbal relaxing incisions have become the mainstay of my practice. Residual astigmatism is the rate-limiting step for many patients who have cataract surgery, especially multifocal IOLs where they are extremely affected by astigmatism. So, there are a lot of ways of performing limbal relaxing incisions, but I basically do them simply at the slit lamp. They can be done in the OR as well. And we have a nomogram that I designed 20 years ago. It's called LRI Calculator. It's had over 10 million hits. It uses what's called a Donnenfeld Nomogram. 

And it basically goes from a half diopter correction with 1 incision up to a diopter and a half of a correction with 2 incisions. And by doing these small incisions, you can really improve quality of vision. It's safe, it's simple, and it's cost effective. That website is a very easy website to go to, and it will give you a display of an eye. All you have to do is put down where you make your incision, what the preexisting keratometry is, and it will show you exactly where you need to place an incision to resolve this problem. I also have designed a diamond knife called the Donnenfeld Diamond Knife that's meant to be used at the slit lamp. And I love using that slit lamp modification in that my experience is when you lie a patient down flat, it becomes an operation. If you do it at the slit lamp where they're sitting up, similar to a YAG laser, it's much less invasive and the patient feels it's more of a procedure rather than an operation.

I was involved in the original use of the femtosecond [laser] to do astigmatic keratotomies. Stephen Slade, MD, and I did the first incisions about 15 years ago, and we've now automated these incisions so that limbal relaxing incisions can actually be done now with a laser, with the accuracy and safety of using a laser. In addition to that, this can use vector analysis and you can actually take the preexisting anterior cylinder, the posterior cylinder, put it in the surgically induced cylinder, and it will give you a very accurate representation of where the astigmatic incisions should be done with the femtosecond laser. This registration system has really been crucial in that when you take the cylinder preoperatively when the patient is sitting up, there can be cyclotorsion when the patient lies down. So having a registration system, which is what you have with many of the femtosecond lasers, really improves the accuracy of the laser dramatically. And we have a nomogram that we published on femtosecond astigmatic keratotomies as well.

Finally, I'd just like to talk a little bit about penetrating LRIs, which is my newest interest. And this is a very simple process of using a keratome; we use sizes ranging from 2.7 mm to 3 mm to 3.3 mm. And when you're doing cataract surgery, simply place 1 incision for small amounts of cylinder or paired incisions for larger amount of cylinder in the axis of the existing cylinder. And a penetrating incision is similar to a primary wound incision. Everyone can do it. It's cost effective, it's economical, it's simple, and you can correct up to a diopter of cylinder by simply placing these incisions at the desired axis of your procedure. So they're easily performed, they don't gape, they can treat low levels of cylinder, and they're really an inexpensive way to perform refractive cataract surgery.

In conclusion, astigmatic keratotomies, whether they be diamond knife limbal incisions, femtosecond astigmatic keratotomies, or penetrating incisions have become part of my surgical armamentarium. And I think you'll find that using these technologies will dramatically improve patient satisfaction and uncorrected visual acuity. Thank you very much.