Re: Abell et al.: Anterior Capsulotomy Integrity after Femtosecond Laser-Assisted Cataract Surgery (Ophthalmology 2014;121:17–24)
2014; Elsevier BV; Volume: 121; Issue: 7 Linguagem: Inglês
10.1016/j.ophtha.2014.02.014
ISSN1549-4713
Autores Tópico(s)Corneal surgery and disorders
ResumoRecently, Abell et al reported a high rate of anterior capsule tears with the use of the Catalys femtosecond laser for cataract surgery.1Abell R.G. Davies P.E.J. Phelan D. et al.Anterior capsulotomy integrity after femtosecond laser-assisted cataract surgery.Ophthalmology. 2014; 121: 17-24Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar Their experience is in sharp contrast with the experience of a global community of Catalys users. For this reason, I have collected data regarding the incidence of this complication from surgeons worldwide.The survey of Catalys users yielded a radial anterior capsule tear rate of 0.43% (38/8684). The data are from multiple surgeons in 5 countries (surgeons providing data in alphabetical order are Lisa Arbisser, Mark Blecher, Mark Cherny, William Culbertson, Burkhard Dick, James Gessler, Guenther Grabner, Jason Jones, David Loewy, Samir Melki, Johann Ohly, Rachel Owsiak, Julian Stevens, Jonathan Talamo, Shachar Tauber, and William Wiley).Abell et al report a rate of 1.87% (15/804). The rate for manual phacoemulsification cataract surgery is 2.32%, as reported from a summary of the literature in their paper.The authors state their concern that patient movement during treatment may partially explain their findings. In the Abell et al study, anesthesia was not used before treatment. Why was local or intravenous anesthesia not used before the laser treatment?The authors report that, in all laser cataract surgery cases, capsulotomies were completely cut with the laser. Inspection of the treated capsule and the removal technique are of paramount importance. Early recognition and management are key to preventing capsule tears. Successful capsule removal techniques after femtosecond laser exert tension toward the center of the capsule disc, such as continuous curvilinear capsulorrhexis or the central dimple down technique.2Arbisser L.B. Shultz T. Dick H.B. Central dimple-down maneuver for consistent continuous femtosecond laser capsulotomy.J Cataract Refract Surg. 2013; 39: 1796-1797Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar Any technique that exerts outward tension can potentially extend a defect peripherally, creating a radial tear. Capsule tears can also occur when the capsule is grasped or aspirated and removed directly out through the incision. Was the capsule ever removed directly with forceps or by aspiration with the phacoemulsification tip?A review of the cases reported from centers A and B provide an example of how widely results can vary between surgeons. In cases of anterior capsule tears, the posterior capsule tear rate was 12.5% at center A and 85% at center B. This is a remarkable difference. The other significant difference is the distribution of cases. If the laser capsulotomy strength is randomly incompetent, as proposed by the authors, then a fairly even distribution of cases would be expected. Note that 71% of cases with complications at center B occurred over 5% during that time period and all cases involved a posterior capsule tear as well. Were there new operative techniques or other new equipment used by the authors that might have contributed to the capsule tear incidence?As surgeons, we are dependent on the reliability of the laser systems we use. The authors acknowledge that differences in laser output or optic degradation may affect the consistency of the results. Environmental factors, such as particulate matter on the optics, can affect laser performance. At our institution, we noticed fibers from blankets and corrected the problem. Were the lasers used in the Abell et al study exposed to any particulate matter that might affect the optics or optical pathway, such as dust from construction, microfibers from linens, or other sources?The authors fail to make any substantiated clinicopathologic correlations. Random scanning electron microscope images are presented, but do not correlate clinical cases with pathology findings. They do demonstrate that the capsulotomy is not perfectly smooth at this high magnification. How these findings affect the strength of the capsulotomy is unclear and I agree that further study with human cadaver eyes and in vivo studies are needed.In conclusion, the rate of anterior capsule tears with the Catalys femtosecond laser users has been reported to be from 0% to 1.87%. Fortunately, these rates are within an acceptable range when compared with average phacoemulsification cataract surgery rates. Many surgeons feel that the strength of the laser cataract surgery capsulotomy is among the key factors allowing the use of techniques that place considerable force on the capsulotomy, such as capsule hooks, capsular tension rings, and capsule fixated intraocular lenses, such as the Tassignon lens. We must recognize that the perfect capsulotomy depends on multiple factors, such as patient selection, cornea clarity, identification of eye movement, and laser factors such as energy delivery and optic quality. This paper demonstrates the need for continued technology improvement within the industry and for independent evaluation by physicians. Recently, Abell et al reported a high rate of anterior capsule tears with the use of the Catalys femtosecond laser for cataract surgery.1Abell R.G. Davies P.E.J. Phelan D. et al.Anterior capsulotomy integrity after femtosecond laser-assisted cataract surgery.Ophthalmology. 2014; 121: 17-24Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar Their experience is in sharp contrast with the experience of a global community of Catalys users. For this reason, I have collected data regarding the incidence of this complication from surgeons worldwide. The survey of Catalys users yielded a radial anterior capsule tear rate of 0.43% (38/8684). The data are from multiple surgeons in 5 countries (surgeons providing data in alphabetical order are Lisa Arbisser, Mark Blecher, Mark Cherny, William Culbertson, Burkhard Dick, James Gessler, Guenther Grabner, Jason Jones, David Loewy, Samir Melki, Johann Ohly, Rachel Owsiak, Julian Stevens, Jonathan Talamo, Shachar Tauber, and William Wiley). Abell et al report a rate of 1.87% (15/804). The rate for manual phacoemulsification cataract surgery is 2.32%, as reported from a summary of the literature in their paper. The authors state their concern that patient movement during treatment may partially explain their findings. In the Abell et al study, anesthesia was not used before treatment. Why was local or intravenous anesthesia not used before the laser treatment? The authors report that, in all laser cataract surgery cases, capsulotomies were completely cut with the laser. Inspection of the treated capsule and the removal technique are of paramount importance. Early recognition and management are key to preventing capsule tears. Successful capsule removal techniques after femtosecond laser exert tension toward the center of the capsule disc, such as continuous curvilinear capsulorrhexis or the central dimple down technique.2Arbisser L.B. Shultz T. Dick H.B. Central dimple-down maneuver for consistent continuous femtosecond laser capsulotomy.J Cataract Refract Surg. 2013; 39: 1796-1797Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar Any technique that exerts outward tension can potentially extend a defect peripherally, creating a radial tear. Capsule tears can also occur when the capsule is grasped or aspirated and removed directly out through the incision. Was the capsule ever removed directly with forceps or by aspiration with the phacoemulsification tip? A review of the cases reported from centers A and B provide an example of how widely results can vary between surgeons. In cases of anterior capsule tears, the posterior capsule tear rate was 12.5% at center A and 85% at center B. This is a remarkable difference. The other significant difference is the distribution of cases. If the laser capsulotomy strength is randomly incompetent, as proposed by the authors, then a fairly even distribution of cases would be expected. Note that 71% of cases with complications at center B occurred over 5% during that time period and all cases involved a posterior capsule tear as well. Were there new operative techniques or other new equipment used by the authors that might have contributed to the capsule tear incidence? As surgeons, we are dependent on the reliability of the laser systems we use. The authors acknowledge that differences in laser output or optic degradation may affect the consistency of the results. Environmental factors, such as particulate matter on the optics, can affect laser performance. At our institution, we noticed fibers from blankets and corrected the problem. Were the lasers used in the Abell et al study exposed to any particulate matter that might affect the optics or optical pathway, such as dust from construction, microfibers from linens, or other sources? The authors fail to make any substantiated clinicopathologic correlations. Random scanning electron microscope images are presented, but do not correlate clinical cases with pathology findings. They do demonstrate that the capsulotomy is not perfectly smooth at this high magnification. How these findings affect the strength of the capsulotomy is unclear and I agree that further study with human cadaver eyes and in vivo studies are needed. In conclusion, the rate of anterior capsule tears with the Catalys femtosecond laser users has been reported to be from 0% to 1.87%. Fortunately, these rates are within an acceptable range when compared with average phacoemulsification cataract surgery rates. Many surgeons feel that the strength of the laser cataract surgery capsulotomy is among the key factors allowing the use of techniques that place considerable force on the capsulotomy, such as capsule hooks, capsular tension rings, and capsule fixated intraocular lenses, such as the Tassignon lens. We must recognize that the perfect capsulotomy depends on multiple factors, such as patient selection, cornea clarity, identification of eye movement, and laser factors such as energy delivery and optic quality. This paper demonstrates the need for continued technology improvement within the industry and for independent evaluation by physicians. Anterior Capsulotomy Integrity after Femtosecond Laser-Assisted Cataract SurgeryOphthalmologyVol. 121Issue 1PreviewTo compare the incidence of anterior capsular tears after femtosecond laser-assisted cataract surgery (FLACS) versus phacoemulsification cataract surgery (PCS) and to assess the ultrastructural features of anterior capsulotomy specimens (FLACS and PCS) using electron microscopy. Full-Text PDF Author replyOphthalmologyVol. 121Issue 7PreviewWe thank Dr. Scott for his interest and response to our manuscript.1 A “sharp contrast” is suggested between our findings and their survey of a “global” community of selected Catalys users. Retrospective surveys are known to introduce selection and reporting bias. The ophthalmic community deserves higher level analysis of femtosecond laser. Neither comparative manual phacoemulsification cataract surgery anterior capsule (AC) tear rate nor objective measure of cataract grade (mean, 2.9 Pentacam nuclear densitometry in our cohorts) were provided, which allowed limited conclusions on the safety and benefits of laser cataract surgery (LCS) over phacoemulsification cataract surgery in their hands and patient case mix to be drawn. Full-Text PDF
Referência(s)