May 2015

 

CATARACT

 

FLACS simplifies black cataract cases


by Jason J. Jones, MD

 
 

Although it is difficult to objectively compare phaco time and energy with and without femto in these very dense nuclei, my sense is that both were considerably less in this case than they would have been had I been operating manually.

 

A 200-m treatment grid was used to effectively soften this very dense nucleus.

At the conclusion of this case, one can see the IOL nicely centered in the bag and a well-formed, round laser capsulotomy.

Source: Jason J. Jones, MD

Case demonstrates femtosecond laser can make emulsification of very dense nuclei safer and less stressful for the surgeon

Black cataracts are fairly unusual in most practices, but when we do encounter them, these very dense nuclei present distinct clinical challenges at nearly every step of the procedure, from the capsulorhexis to nuclear division and phacoemulsification. The amount of energy and fluid in the eye is considerably greater than in a normal case, increasing the risk of thermal injury and the degree of trauma and edema. I have now performed femtosecond laser-assisted cataract surgery (FLACS) in 2 black cataract cases and think that it is worth considering the use of our most advanced tools in complex situations like these. Here, I describe the second black cataract FLACS procedure I performed, including how I incorporated some lessons learned from the first case.

The patient was a 45-year-old male with a remote history of retinal surgery to his right eye. As a teenager, he had undergone repair of a penetrating injury from the spoke of a bicycle wheel. Following the surgery he reported having a gas bubble and was told that his eye healed well, but he did not recover good vision. Due to the already compromised vision in that eye, he had simply let the cataract progress. His presenting vision to me was light perception.

Using the Catalys femtosecond laser system (Abbott Medical Optics, AMO, Abbott Park, Ill.), I was able to obtain good quality imaging, which is by no means a certainty with such a dense nucleus. It is imperative to assess the imaging and make sure the surface fits are correct and safety zones are acceptable for the treatment to be safe. In this case, I could readily determine the surface fits were appropriate and correctly aligned so no adjustment was necessary.

Capsulotomy

The loss of red reflex in a black cataract case makes it very difficult to create the capsular opening. The imaging capabilities of the laser provided a significant advantage in being able to visualize the capsular surface. I generally prefer the scanned capsule function, which centers the capsulotomy based on an equator derived from the anterior and posterior surface fits. In this case, I felt more comfortable with centering on the dilated pupil with a 5.0 mm diameter capsulotomy.

Lens treatment

Lens softening and fragmentation is the next step of the laser procedure. I departed significantly from my typical FLACS approach. In my first experience using the Catalys in a black cataract, I had kept these parameters the same as my routine, but found softening the entire lens made it difficult to split it into segments. So in this case, I opted for a sextant cut, leaving a wide offset around the sextants so I had an area of untreated lens material where I could gain purchase and achieve good separation of the nuclear pieces. Within each sextant, I tightened the treatment grid from 350-m to 200-m cubes to increase the softening effect. I also increased the power setting for the anterior portion of the lens softening. Using the default settings in a typical case, the laser power decreases as it reaches the anterior portion of the nucleus. In this case, I had a much denser, more homogeneous lens, so it was more appropriate to continue at a higher power up through the anterior portion of the lens treatment.

In the OR

The laser had created a nice, round capsulotomy that lifted off easily. In routine cases, I have found capsulotomy with the Catalys system to be an extremely reliable part of the procedure, and this was no exception. One nice aspect of a pre-softened lens is that it is much easier to grasp the capsule on top of the dense nucleus with forceps or needle because I dont have rock hard anterior cortex right beneath the capsule. But because of the overall difficulty of the case, it was a great relief to get through this step with no radial tears or other issues. Hydrodissection was still challenging, as one would expect with any dense lens in either a manual or femto procedure. Without the red reflex to help identify the mobilization of the nucleus, I had to look for other cues, such as a rise in the capsule and gentle rotation of the lens. There seemed to be minimal cavitation, with very little gas escaping from the lens during hydrodissection and rotation.

Phaco

As one gets beyond the femto portion of the procedure, it is important to follow best practices for a very dense nucleus. I periodically recoated the endothelium with dispersive viscoelastic, was careful to achieve good cleavage of the nuclear pieces before attempting emulsification, and used a modulated pulse or nonlinear ultrasound modality to reduce the amount of energy delivered into the ocular environment. Although it is difficult to objectively compare phaco time and energy with and without femto in these very dense nuclei, my sense is that both were considerably less in this case than they would have been had I been operating manually. I implanted a Tecnis 1-piece monofocal IOL (AMO). On the first postoperative day, the cornea was fairly clear, with far less edema than I would normally expect in such a case. The patient ultimately had excellent recovery of vision, achieving 20/25 uncorrected vision in the presence of slight posterior capsular opacity, as well as mild epiretinal membrane. Femtosecond lasers allow us to enhance precision and predictability in the full range of nuclear densities. It is encouraging to me that when I most need technology to perform in a complex or challenging case such as the one described here, I can depend on it. A black cataract is never going to be an easy case, but the femtosecond laser certainly made it easier.

Editors note: Dr. Jones is in practice at Jones Eye Clinic in Sioux City, Iowa. He has financial interests with AMO.

Contact information

Jones
: jasonjonesmd@mac.com

FLACS simplifies black cataract cases FLACS simplifies black cataract cases
Ophthalmology News - EyeWorld Magazine
283 110
220 156
,
2016-07-08T15:40:38Z
True, 5