This article is more than 5 years old. Information may no longer be current.
Top five fact vs. fiction analysis of femtosecond laser cataract surgery
Dispelling myths may help the premium surgeon decide on whether to add a laser to his or her armamentarium.
Click Here to Manage Email Alerts
More than 3 million Americans undergo cataract surgery each year, with more than half of them older than 65 years. Cataract surgery as we know it today is one of the safest and most commonly performed surgeries in the United States. The challenges faced by ophthalmologists are higher expectations from our patients because cataract surgery today is treated like refractive surgery and the financial pressures of obtaining advanced technology to meet these expectations.
Our newest armamentarium of technology includes advanced IOLs (aspheric, toric, multifocal, accommodating), femtosecond lasers (limbal relaxing incisions, clear corneal incisions, anterior capsulotomy, lens fragmentation) and intraoperative wavefront aberrometry. Recent surveys show that only 2.5% of ophthalmologists are performing femtosecond laser-assisted cataract surgery (as of the first quarter 2013), although a significant percentage wants access to the technology. Obviously, the financial burden involved with femtosecond laser cataract surgery is making it difficult for many surgeons to pull the trigger on this technology. There are also many misconceptions among ophthalmologists on femtosecond laser technology, so I present my top five fact vs. fiction analysis to help the premium surgeon decide on making this surgical change to his or her armamentarium.
1. Anterior capsulotomy is superior with femtosecond: FACT
It is known that a 4-mm capsulotomy results in longer postoperative effective lens position than a 6-mm capsulotomy, and inconsistent capsulotomy size can lead to inaccurate effective lens position and post-surgery refractions. The industry standard perfect capsulotomy depends on position, size, and “free-floating” or complete pattern with insignificant or no capsular/cortical tags. In one study, 95.9% of capsulotomies were free-floating or complete, whereas nearly 100% of capsulotomies showed insignificant or no tags. Several clinical studies, both in vitro and in vivo, indicate that capsulotomies created with the femtosecond laser are significantly more precise in size and reproducibility and that a continuous curvilinear capsulorrhexis created with a femtosecond laser results in a more stable refractive result with less IOL tilt and decentration than a manual capsulorrhexis.
2. Femtosecond lens fragmentation reduces effective phacoemulsification times/corneal insult: FACT
While the use of ultrasound phacoemulsification has made the cataract operation relatively safe, application of prolonged ultrasound power within the eye does carry the risk of corneal endothelial injury. Using rabbit eyes, Murano et al studied the oxidative stress and cellular necrosis effect of ultrasound oscillations in the anterior chamber and concluded that corneal endothelial cell damage was caused by free radicals associated with ultrasound oscillation within the anterior chamber. Similarly, Shin et al showed that increasing ultrasound time and energy had a direct relationship to endothelial cell injury. Clinically, in my experience, my average effective phacoemulsification time using the Stellaris system (Bausch + Lomb) after Lensar (Lensar) fragmentation of a LOCS III graded cataract was reduced from 4.3 seconds to 0.86 seconds, with clearer corneas seen even as early as postoperative day 1. Advanced optical coherence tomography and Scheimpflug imaging with modern femtosecond laser systems allows for fragmentation of even black and mature cataracts and further lessens phacoemulsification duration in the anterior chamber.
3. Femtosecond astigmatic correction delivers superior outcomes compared with manual astigmatic incisions: FICTION
Although femtosecond laser astigmatic incisions are easier to create than those with a manual diamond or steel blade, there is still no clear-cut evidence on better efficacy. However, with iris registration and guidance systems such as Verion/LenSx (Alcon), Cirle/Victus (Bausch + Lomb), Cassini/TrueVision/Lensar and Callisto (Carl Zeiss Meditec) to make the femtosecond laser process markerless and less dependent on cyclorotation, efficacy will improve. Corneal incisions in general are typically limited to 1.5 D of cylinder correction and more susceptible to regression effects inherent to corneal tissue healing changes. Nevertheless, femtosecond astigmatic incisions provide an effective option in the lower cylinder powers.
4. Patients lack acceptance of femtosecond laser technology: FICTION
Recent surveys have shown that up to 22% of all cataract surgeries are performed using femtosecond laser technology. The limiting factor in the overall femtosecond laser cataract volume is more related to surgeon access than patient acceptance. As more surgery centers bring femtosecond lasers into the mix, the numbers will rise. Mobile access through Sightpath and other companies such as Precision Eye Services will have a larger impact than expected in the overall increased usage of femtosecond laser-assisted cataract surgery. My personal patient conversion rate to laser-assisted cataract surgery is averaging 70%, mostly due to my approach that femtosecond laser is the surgeon’s tool and choice, and patients choose whether to wear glasses or not postoperatively.
5. Femtosecond laser-assisted cataract surgery slows down our efficiency: FICTION
Every premium surgeon needs to decide on the proper OR flow and efficiency when incorporating femtosecond laser technology. In a multiple OR room setup (three or more rooms), having the femtosecond laser in its own clean room may be the best option to limit flow issues. In my setting, I have all the technology in one OR room, including intraoperative aberrometry with ORA (WaveTec), and utilize Lensar due to its ability to keep the patient on the same bed under the laser or during phacoemulsification and IOL implantation to save time and space. The minimally added time to perform laser-assisted cataract surgery — 2 to 3 minutes on average — saves time on the back end, especially with difficult complex cataracts involving pseudoexfoliation, intraoperative floppy iris syndrome risk, past trauma or extremely dense cataracts. In my hands, OR efficiency is unchanged, but efficacy and improved outcomes for my patients have been enhanced with laser-assisted cataract surgery.
Stay tuned for next month’s Premium Channel column — continuing education for the premium surgeon: is the glass half empty or half full?
References:
Abell RG, et al. Clin Experiment Ophthalmol. 2013;doi:10.1111/ceo.12025.
Conrad-Hengerer I, et al. J Cataract Refract Surg. 2012;doi:10.1016/j.jcrs.2012.07.023.
Filkorn T, et al. J Refract Surg. 2012;doi:10.3928/1081597X-20120703-04.
Friedman NJ, et al. J Cataract Refract Surg. 2011;doi:10.1016/j.jcrs.2011.04.022.
Kránitz K, et al. J Refract Surg. 2011;doi:10.3928/1081597X-20110623-03.
Kránitz K, et al. J Refract Surg. 2012;doi:10.3928/1081597X-20120309-01.
Market Scope. October 2014.
Murano N, et al. Arch Ophthalmol. 2008;doi:10.1001/archopht.126.6.816.
Nagy ZZ, et al. J Refract Surg. 2011;doi:10.3928/1081597X-20110607-01.
Roberts TV, et al. Ophthalmology. 2013;doi:10.1016/j.ophtha.2012.10.026.
Shin YJ, et al. Arch Ophthalmol. 2009;doi:10.1001/archophthalmol.2009.39.
Uy HS, et al. Curr Opin Ophthalmol. 2012;doi:10.1097/ICU.0b013e32834cd622.
For more information:
Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Avenue, Suite L, Lake Villa, IL 60046; 847-356-0700; email: mjlaserdoc@msn.com.
Disclosure: Jackson is a consultant to Bausch + Lomb, Marco Ophthalmic, Lensar and i-Optics.