OSN Technology and Equipment Workshop presentation: Coaxial illumination

Uday Devgan

The following excerpt is from a presentation by Uday Devgan, MD, FACS, at the 2009 OSN Technology and Equipment Workshop on coaxial illumination.

Uday Devgan, MD, FACS:

So, seeing is believing. The sunrise from the top of Mt. Haleakala in Maui, it was an amazing sunrise. I love the picture because it's a sunrise that I've never seen before. And, oh, by the way, my name, Uday, in Hindi means sunrise, so I figured it was apropos. So, seeing is believing.

I do mostly private practice, but I do spend 1 day a week teaching the UCLA residents and pulling my hair out. But it's always a lot of fun.

I work with a lot of companies, but I've never worked with Zeiss before. I purchased two Lumera (Carl Zeiss Meditec) scopes in our ASC about a year ago and really enjoy them. We did a live surgery event for the Academy with the Zeiss Lumera scope. So, I really liked the scope, even before talking to anyone from Zeiss.

The reason why I liked it was because of the type of illumination you get. I've always liked the optics. In the past, I'd always just purchase a used scope. To me it was a no-brainer. I got my 10-year-old Zeiss scope and it was a good deal. But with this new scope with this SCI, the sterile coaxial illumination, and the Xenon lighting, there was significantly better contrast brightness, a very even image, better depth, better comfort and a great red reflex.

Microscope lighting is actually not a very exciting topic, but I'll tell you briefly the differences. Normally in a scope there is paraxial lighting. It's offset by a couple of degrees. It gives you good depth perception, but a poor red reflex. You have to move that eye just the right angle to hopefully catch a glimpse of the red reflex. So the light beams come right down, but they are offset from monocular.

Coaxial light is in order to see the retina better, to get that better red reflex bouncing off the retina. So, in the path of your two oculars, the light is 0° offset. It's actually the same axis of your oculars. And you get a really superb red reflex. So, cases like a prior RK, the incisions are absolutely just highlighted. They light up. And prior LASIK, there is the rhexis edge. There is the LASIK flap edge.

So, there is paraxial lighting; when the patient looks up they see the one light. There is coaxial lighting. And you can actually have a combination of both. In fact, you can dial in any combination of coaxial, paraxial or both. In most situations I do both, but sometimes I'll switch to just the coaxial to get a better red reflex.

Xenon lighting. We like it because that has the same kind of profile as sunlight. In your cars, if you've got a newer model — particularly a European car, a Mercedes, BMW, Audi, Porsche, whatever — they've got Xenon lights. And you know it's a huge difference at night.

There are five zones of the ReZoom (Abbott Medical Optics) lens. It's stuff you haven't seen before; at least, I hadn't. Doing an IOL exchange, or the multiple rings of the ReStor (Alcon), they are just very plainly easy to see. And then throughout the whole procedure I have a great red reflex. It helps to visualize things like this rhexis edge, etc.

So, here is a tough case. The patient has four RK incisions and has a decentered lens, with silicone oil droplets on the lens. And thanks to coming to meetings like this, I've learned all of the fun tricks of how to exchange these and put new ones in. Using that Siepser technique, which is so incredibly clever, to suture the lens in place. If you haven't tried this yet, just read the Siepser article or Osher's modification of the knot. It's just a fun, fun day in the OR to do this. It's kind of like solving a puzzle. It's like the Rubik's cube, except I can actually solve this one.

At the end, we remove the viscoelastic from the eye. I know you are asking yourself, you're saying, "Geez, c'mon. How often do you do lens exchanges?" Well, I do them frequently. Maybe that's a bad sign for my judgment skills.

In regular cases, it's truly where this scope shines. So, forget the fancy cases. How about a routine case, seeing the rhexis? When I turn on the SCI reflex — wow! — it goes from an absolutely dark, dark-looking eye to superb red reflex, using just the stereo coax illumination. If the patient is getting an accommodating lens, I'm going a large rhexis. And I just wouldn't have the confidence to do this big, large rhexis in this eye if I didn't have this lighting. So, it's also reduced my use of these trypan blue dyes tremendously. And where there are studies showing that these trypan blue dyes cause some capsule fragility, it makes me feel a little bit better.

How about zonular insertion points? Sometimes I am surprised that the zonules insert more anteriorly than I would have anticipated. And that's why I'm going around sometimes trying to make this huge capsulorrhexis to put in an accommodating lens, and sometimes I'll get stuck in the zonules. Well, in this case, we didn't get stuck in the zonules. We did okay.

Torque alignment marks. I learned this technique from Byron Stratus, a really bright guy. He said, "Make anterior stromal puncture marks at the correct axis. And then all you've got to do is line up the puncture marks with the torque IOL marker and you are done." When we line up the lens, it's just such an easy reflex to see.

How about centration of multifocal lenses? While I don't implant a lot of diffractive multifocals, I do some. And here it's just so easy to line them up. You can actually see the rings. Without it, good luck - impossible to see. But with the SCI, the coaxial illumination, you can see all of the detail.

And finally, fixing the details of phakic lens surgery. I do a lot of phakic IOLs, and when I implant these phakic lenses, I like to have a loose fill of viscoelastic. I like to see the spaghetti strands. I don't like a very thick, cohesive film, because then it's hard to remove. So, as I'm putting in OcuCoat (Bausch & Lomb), nice loose spaghetti. That's kind of the way I like it in the eye. Then for me it's easy to remove it at the end of the case. I want to be gentle in removing it. In a young, phakic person, I don't want to slam the lens.

So, for me it was just an incredibly novel and new way of seeing things. It's just things I haven't seen before.

If you do get a chance, by the way, you absolutely have to do that sunrise over Haleakala. It's absolutely beautiful.

If you remember just one thing from my talk, because usually in my talks I can only remember one thing, it's just that seeing is believing. Truly there is a huge difference in the illumination. And for me, it changed the way I do surgery. And if you give it a test drive, you may feel the same way.

The OSN Technology and Equipment Workshop is a showcase of the clinical benefits of new surgical and diagnostic equipment, surgical instruments, software, vision testing and contrast sensitivity testing systems. Step beyond the brochures, bring the products in the exhibit hall to life, and hear surgeons' clinical impressions of the newest equipment and instrumentation. This workshop will allow attendees to interact with surgeon users and manufacturers.