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Technique eases removal of subincisional cortex
A surgeon says he has not had complications or compromises of the anterior or posterior capsule after more than 100 cases.
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The introduction of femtosecond lasers in the arena of cataract surgery has improved the reproducibility of some of the surgical steps, simplified the management of very hard nuclear cataracts and advanced the field from a technological aspect. With continued improvement, it may contribute to the advancement of the quality of vision over time. Currently, femtosecond laser-assisted cataract surgery offers initial surgical corneal incisions, laser capsulotomy and lens fragmentation, and it may be used for peripheral corneal planned incisions to decrease or eliminate pre-existing corneal astigmatism.
Image-guided laser-assisted phacoemulsification is a historic milestone in cataract surgery. This is an amalgamation of OCT and femtosecond laser technology for cataract surgery. Although the cornea is readily accessible, the lens position and orientation differ from patient to patient. Hence, precise three-dimensional imaging capability is a required minimum for safe and proper femtosecond laser-assisted cataract surgery.
Laser application in cataract surgery dates back to the 1970s, when Krasnov used laser phacopuncture for soft cataracts. In 1987, Peyman and Katoh used Er:YAG laser on the lens nucleus, causing photoablation. Nagy performed the first femtosecond laser-assisted cataract surgery in 2008 in Budapest, Hungary. Since its introduction, continued technological advances have made the procedure more efficient and surgeon friendly. It offers a precise self-sealing corneal incision, a circular, strong, reproducible capsulorrhexis and advanced phacofragmentation, and it provides yet another option when dealing with challenging cases such as very hard cataracts, subluxated cataracts with zonular compromise, cataracts with partial anterior chamber vitreous prolapse, intumescent complete white cataracts, and combined cataract and Fuchs’ dystrophy.
Subincisional cortex removal may be somewhat challenging in some cases. In this column, Dr. D’Ambrosio describes his surgical technique to assist in this aspect of femtosecond laser-assisted cataract surgery.
Thomas “TJ” John, MD
OSN Surgical Maneuvers Editor
Francis A. D'Ambrosio
Since the advent of extracapsular cataract surgery, one of the more challenging aspects has been cortical removal after nuclear extraction. In the original extracapsular cataract surgery and early phacoemulsification, the capsulotomy was large, and it was somewhat easy to get to the cortex for cortical removal. However, with the advent of the continuous curvilinear capsulotomy, which is necessary for stable in-the-bag IOL placement, it was harder to get at and remove all the cortex, particularly the subincisional cortex.
Early on, hydrodelineation, which was used to separate the nucleus from the cortex, was employed to help free up and remove the nucleus. However, studies began to show that it was in the act of cortex removal that the higher incidence of capsular tears occurred. To counteract this difficulty, techniques were developed to aid in freeing up the cortex from the capsular bag. This usually involved injecting balanced salt solution through a 27- or 30-gauge cannula between the anterior capsular rim and the posterior capsular bag. This fluid wave would break the cortical-bag adhesions and facilitate its removal with irrigation and aspiration. This was done before hydrodelineation, so the fluid wave would travel posteriorly and not migrate to the path of least resistance, the previous hydrodelineated nuclear-cortex space.
The problem with laser-assisted cataract surgery is that during the process of nuclear softening, the cortex-nuclear bonds are broken, so when hydrodissection is attempted, there is an incomplete breakage of the cortex-bag adhesions. This is especially problematic for the subincisional cortex as well as with a smaller, perfectly round capsulorrhexis.
I am presenting a technique that works around this problem. I currently use the Catalys laser system (Abbott Medical Optics) for my laser cataract removal. However, this technique applies to all laser systems and can also be used during regular phaco surgery.
Figure 1. Following nucleus removal with I&A following femtosecond laser treatment, the cortical plate remains.
Figure 2. A diamond-dusted ball syringe with balanced salt solution is used to break through the posterior plate to free up the cortex.
Figure 3. Using the same J-hook that was used for the hydrodelineation, hook under the lip of the posterior plate while injecting balanced salt solution in the fornix area.
Figure 4. Using standard I&A the cortex comes easily out of the capsular bag.
Images: D’Ambrosio FA
The technique
The technique comes into play after the laser has been performed and the capsulorrhexis and lens softening have been completed. Viscoelastic is injected into the anterior chamber, and the capsulotomy flap is removed. The next step is removal of the nuclear material with or without first performing hydrodelineation. After the nucleus has been removed, you will be presented with an outer nuclear and/or cortical shell that is still adherent to the capsular bag. Next, by using a bulb-shaped posterior capsular polisher (25-gauge Jensen capsular polisher, Katena) on a 3 cc syringe with balanced salt solution, the surgeon is able to gently rub against the center of the cortical shell while injecting balanced salt solution to break open the center of this area. While injecting the balanced salt solution, the capsular polisher is advanced while sweeping in a left-to-right fashion, advancing toward the fornix area. This will simultaneously polish the posterior capsule and start freeing up the cortex adhesions all the way through to the fornix of the capsular bag. Using a J-shaped cannula (30 gauge, Anodyne Surgical) on a 3 cc syringe filled with balanced salt solution, the surgeon will then hook the cannula under the cortex plate where the original plate was broken open with the bulb syringe. This is usually in the middle of the posterior cortical plate. As the balanced salt solution is injected, the cannula is advanced proximally toward the subincisional bag fornix. The cannula is gently swept left to right as it is advanced, injecting balanced salt solution all along. This will free up the subincisional cortex all the way to the fornix, and you will often see the cortex start floating toward the center of the pupillary margin.
At this point, standard cortical clean-up is performed. All the cortex is now freed from the bag adhesions and will easily be removed without risk of violating the posterior capsular bag. This greatly facilitates the removal of the cortex, which has been one of the more difficult learning curves of laser cataract surgical techniques. I have used this technique in more than 100 cases and have found it to be safe and effective without any complications or compromises of the anterior or posterior capsule.
References:
Abell RG, et al. J Cataract Refract Surg. 2015;doi:10.1016/j.jcrs.2014.06.025.Blumenkranz MS, et al. Am J Ophthalmol. 2014;doi:10.1016/j.ajo.2014.03.013.
Chee SP, et al. Am J Ophthalmol. 2015;doi:10.1016/j.ajo.2015.01.016.
Krasnov MM. Br J Ophthalmol. 1975;doi:10.1136/bjo.59.2.96.
Moshirfar M, et al. Middle East Afr J Ophthalmol. 2011;doi:10.4103/0974-9233.90129.
Peyman GA, et al. Int Ophthalmol. 1987;10(4):245-253.
For more information:
Francis A. D’Ambrosio Jr., MD, can be reached at D’Ambrosio Eye Care, 100 Powder Mill Road, Acton, MA 01720; email: drfran@dambrosioeyecare.com.Edited by Thomas “TJ” John, MD, a clinical associate professor at Loyola University at Chicago and in private practice in Oak Brook, Tinley Park and Oak Lawn, Ill. He can be reached at tjcornea@gmail.com.
Disclosure: D’Ambrosio and John report no relevant financial disclosures.