Laser-assisted cataract surgery (LACS) has continued to evolve since its introduction in 2009.1 The addition of laser technology to a cataract procedure enhances precision through the creation of a tailored architecture for the principal wound, a perfectly sized and round capsulorrhexis centered on the capsular bag, and nucleus fragmentation allowing phacoaspiration with minimal use of ultrasound energy.2 Several laser platforms have been commercialized for LACS, each with its own particular features.
In June 2014, l’Institut de l’Oeil des Laurentides was one of the first clinics in Canada and the first in the province of Quebec to offer LACS using the Catalys laser (Abbott Medical Optics) for routine cataract surgery. Having more than 1 year of experience performing immediate sequential bilateral cataract surgery (ISBCS), we felt confident offering immediate sequential bilateral LACS to our patients as well. This article details our method, results, and conclusions garnered from nearly 1 year’s experience performing this procedure.
Our ambulatory surgery center is equipped with three operating rooms. The femtosecond laser facility is installed in a central room, with two adjoining phaco rooms to optimize surgery times. While the surgeon performs the femtosecond laser preparation in one room, the nurses ready the previously laser-prepared patients in the two adjoining rooms.
Most of the nine surgeons in our group elect to perform capsulotomy and lens fragmentation with the laser in both eyes in one sitting, using two different liquid optics interfaces from the same lot. The patient is then transferred to the next room, where cataract surgery is completed by wound creation or completion if required, followed by lens aspiration with minimal phaco energy, and, finally, IOL implantation. The surgeon then moves to the next room either to perform the next femtosecond laser preparation or to complete the surgery of another laser-prepared patient. As with conventional ISBCS, all substances and supplies are from two different lots for each eye of the same patient, and the instruments used come from two separate sterilization cycles.
incidence of complications
Between October 2014 and May 2015, we removed a total of 2,501 cataracts. Of this total, 1,469 patients (59%) elected to be operated on with the femtosecond laser, and 1,142 patients (46%) opted for immediate sequential bilateral LACS. Table 1 lists the complications encountered during this period.
Our data suggest that the incidence of posterior capsular rupture tended to be higher with LACS (14 of 1,469 = 1%) compared with the incidence observed during conventional surgery (seven of 1,032 = 0.7%). Radial anterior capsule tears that often extended to the posterior capsule were more prevalent with all forms of LACS (six occurrences with LACS vs zero with standard cataract surgery). We observed nine (0.78%) posterior capsular ruptures while performing immediate sequential bilateral LACS, of which eight occurred during the operation on the second eye.
Our study demonstrated a tendency toward a higher incidence of radial anterior capsule tears in the LACS group. Upon retrospective analysis, we noted that radial anterior capsule tears occurred most often during the first few months of using the femtosecond laser. In the past few months, Health Canada approved the Catalys software version cOS3, and we optimized our capsulotomy parameters based on the parameters that Shachar Tauber, MD, presented at the 2015 annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS).3 Since then, we acquired the latest software and adjusted our capsulotomy parameters to an incision depth of 400 μm, a horizontal spot spacing of 5 μm, a vertical spot spacing of 10 μm, and a pulse energy of 4 µJ. Use of these parameters seems to have solved this problem, with less tag formation and more free-floating caps. Nevertheless, as reported by Abel et al,4 the higher incidence of anterior capsule tears observed with LACS remains a concern.
In performing immediate sequential bilateral LACS, we noted that complications seemed to occur more frequently during second-eye surgery; we speculate that this may be due to the successfully treated first eye causing a feeling of overconfidence in the surgeon’s mind, leading to subsequent complication in the second eye. In this series, when a complication occurred in the first eye, the surgeon always successfully completed second-eye surgery.
One or Two sittings?
The question arises whether femtosecond laser preparation should be performed in one sitting or two because, once the capsule is opened and the nucleus is fragmented, there is no turning back. This exposes the surgeon to bypassing the recommendations of the International Society of Bilateral Cataract Surgeons (iSBCS): that is, not to perform second-eye surgery if there is a complication in the first eye.5
I have elected to complete the cataract procedure in the first eye before performing the femtosecond laser preparation of the second eye (two sittings), whereas the eight other surgeons at our center have chosen to complete the femtosecond laser preparation of both eyes in one sitting before bringing the patient to the other room to perform aspiration of the fragmented nucleus and IOL implantation. There were no differences between these two ways of ordering the surgery, with an overall complication rate of 22 of 988 cases (2.2%) in the one-sitting group and three of 154 cases (1.9%) in the two-sittings group. Other forms of less severe complications were distributed evenly between groups, including one case of toxic anterior segment syndrome (TASS) in each group, LACS and conventional. One patient with Fuchs dystrophy underwent immediate sequential bilateral LACS and developed bilateral corneal edema that persisted for 6 months, with a slow recovery to 6/7.5 UCVA in each eye.
There are some undeniable advantages to performing femtosecond laser preparation of both eyes in one sitting, especially in a patient with reduced mobility. The patient flow is more harmonious; however, care must be taken because, after fragmenting the lens in both eyes, the patient is almost blind and needs help transferring from one chair to the next. This is not a problem when femtosecond laser preparation is performed in two sittings, but, in this scenario, time is lost moving the patient back and forth, and patients sometimes complain about the numerous displacements they undergo. One patient in the two-sittings group was so nauseated that we decided to abort second-eye surgery.
In the consensus opinion of our group, the decision of whether to perform femtosecond laser preparation in both eyes in one sitting or two should be left to the surgeon. If the surgeon feels he or she has the capacity to reassure the patient and to go on performing second-eye surgery after having had a complication in the first eye, he or she can proceed with this approach. Our experience has been favorable with both approaches, as the complication rate has been equal in both groups. Moreover, a complication in both eyes has not occurred to date.
In fact, after a complication in the first eye, we suggest going on and operating on the second eye while the reason for the complication is still fresh in the surgeon’s mind. Having the second eye operated without complication is somewhat reassuring for the patient because he or she can at least see well in one eye. On the contrary, aborting the second eye after having had a complication in the first eye can raise the patient’s anxiety level.
In our group of unilaterally operated patients, some experienced a complication in their first-operated eyes. In this subgroup, three patients decided not to have second-eye surgery. Indeed, there is no guarantee that a complication will not occur during second-eye surgery, even if we elected to postpone the surgery after a complication in the first eye. If we had operated sequentially on both eyes in this situation, the patients would have at least had one successfully operated eye.
We observed one case of TASS in one eye (the second-operated eye) in the immediate sequential bilateral LACS group. We also had one case of TASS in the conventionally operated group. In both cases, after thoroughly verifying each step of the sterilization cycle and the surgeries themselves, we could not identify the cause. We did not encounter any cases of endophthalmitis.
In Quebec, the ophthalmic community is accepting of ISBCS, as the fee for second-eye cataract surgery has only recently been increased to 90% of the value for first-eye surgery. Performing ISBCS has also gained popularity in our patient population because of its convenience. With ophthalmologists having a large territory to cover—and patients sometimes needing to travel up to 500 km to have cataract surgery—patients appreciate the ability to reduce their number of visits. Adding the use of the femtosecond laser was an additional incentive for adoption of a same-day surgery approach.
Immediate sequential bilateral LACS is a safe and convenient approach to cataract surgery. Because there is a learning curve for mastering the femtosecond laser technique, we would recommend that surgeons acquire enough experience that they feel as comfortable with LACS as with manual cataract surgery before attempting to perform immediate sequential bilateral LACS. The decision of whether to perform femtosecond laser preparation in one sitting or two can then be based on the surgeon’s preference. We feel that having a complication in the first eye should not be considered a contraindication to operating on the second eye with the patient’s consent. n
The author thanks Sébastien Gagné, MD, FRCSC; Dan Samaha, OD, MSc; Isabelle Vanier, Inf; and Caroline Lavoie-Fleury for their help in the completion of this article.
1. Nagy Z, Takacs A, Filkorn T, Sarayba M. Initial clinical evaluation of an intraocular femtosecond laser in cataract surgery. J Refract Surg. 2009;25:1053-1060.
2. Conrad-Hengerer I, Hengerer FH, Schultz T, Dick HB. Effect of femtosecond laser fragmentation on effective phacoemulsification time in cataract surgery. J Refract Surg. 2012;28:879-883.
3. Tauber S. Clinical comparison of effect of sub-one second femtosecond laser capsulotomy on capsulotomy irregularities. Paper presented at: the ASCRS/ASOA Symposia and Congress; April 17-21, 2015; San Diego.
4. Abell RG, Darian-Smith E, Kan JB, Allen PL, Ewe SYP, Vote BJ. Femtosecond laser-assisted cataract surgery versus standard phacoemulsification cataract surgery: outcomes and safety in more than 4000 cases at a single center. J Cataract Refract Surg. 2015;41:47-52.
5. ISBSC website. ISBSC General Principles for Excellence in ISBCS 2009. http://isbcs.org/research-reviews/isbcs-general-principles-for-excellence-in-isbcs-2009/. Accessed July 2, 2015.
Laurent Lalonde, MD, MSc, FRCSC
• Research Director, l’Institut de l’Oeil des Laurentides, Quebec, Canada
• Member of the Ophthalmology Service, Centre de Santé et des Services Sociaux, Canada
• Financial disclosure: Consultant (Abbott Medical Optics)