Eyeworld

107 EW RESIDENTS September 2015 be helpful in determining wheth- er the cost-benefit ratio makes it worthwhile to pretreat dense lenses with the femtosecond laser. Despite these limitations, this study further supports the role of femtosecond la- ser pretreatment for dense cataracts, and we look forward to future stud- ies investigating long-term clinical outcomes in these patients. EW References 1. Shimmura S, Tsubota K, Oguchi Y, et al. Ox- iradical-dependent photoemission induced by a phacoemulsification probe. Invest Ophthal- mol Vis Sci 1992;33(10):2904–2907. 2. Murano N, Ishizaki M, Sato S, et al. Corneal endothelial cell damage by free radicals associated with ultrasound oscillation. Arch Ophthalmol 2008;126(6):816–821. 3. Augustin AJ, Dick HB. Oxidative tissue dam- age after phacoemulsification: influence of ophthalmic viscosurgical devices. J Cataract Refract Surg 2004;30(2):424–427. 4. Miyata K, Nagamoto T, Maruoka S, et al. Efficacy and safety of the soft-shell technique in cases with a hard lens nucleus. J Cataract Refract Surg 2002;28(9):1546–1550. 5. Abell RG, Kerr NM, Vote BJ. Toward zero effective phacoemulsification time using fem- tosecond laser pretreatment. Ophthalmology 2013;120(5):942–948. 6. Chylack LT, Wolfe JK, Singer DM. The Lens Opacification Classification System III. Arch Ophthalmol 1993;111(6):831–836. 7. Dick HB, Schultz T. On the way to zero pha- co. J Cataract Refract Surg 2013;39(9):1442– 1444. 8. Conrad-Hengerer I, Hengerer FH, Schul- tz T, Dick HB. Effect of femtosecond laser fragmentation of the nucleus with different softening grid sizes on effective phaco time in cataract surgery. J Cataract Refract Surg 2012;38(11):1888–1894. Contact information Tapino: Paul.Tapino@uphs.upenn.edu phacoemulsification of a moderately dense lens. The authors acknowl- edge the limitations of their study such as the non-randomized nature of the study and the same surgeon performing all of the operations (which leads to no interoperator variability but individual bias). However, they do not explain the method by which patients were assigned to either the femtosecond laser or conventional group. Final- ly, no endpoints measuring true clinical metrics were used, such as postoperative endothelial cell count, central corneal thickness, or visual acuity, which are the main concerns with increased phacoemulsification energy. Although there are statisti- cally significant differences in EPT when comparing the groups, it is not clear if this leads to any clinical difference to the patient. Given the high cost of acquiring a femtosec- ond laser, clinical endpoints would was no significant difference in the surgical time. However, the authors of this study were fortunate to have an operating room large enough to accommodate the femtosecond laser in the same room as the operating microscope, requiring only a rota- tion of the operative bed. In many surgical settings, the laser treatment would need to be performed in one room and then the patient would be transferred to another room housing the operating microscope. In these situations, a significant amount of surgical time would likely be added to the femtosecond-assisted cases. This study supports previous research demonstrating that the amount of phacoemulsification energy needed in cataract surgery can be significantly reduced with femtosecond laser pretreatment. In addition, it shows that pretreating a brunescent lens with the femto- second laser can lead to even less EPT compared to conventional with the femtosecond laser results in less EPT compared to conven- tional phacoemulsification of a softer, moderately dense lens. This finding may support a lower thresh- old to operate on brunescent lenses if a femtosecond laser is available. Although extracapsular cataract extraction (ECCE) is a viable tech- nique to remove dense lenses, it has disadvantages including decreased surgeon experience with the proce- dure, induced astigmatism, wound leaks, and prolonged visual recovery. In this regard, with femtosecond pretreatment, the phacoemulsifica- tion technique may still be applied to dense lenses instead of consider- ing ECCE. The second metric measured in this study, surgical time, found that dense, brunescent cataracts took significantly longer to remove compared to lenses of moderate density. However, when comparing femtosecond pretreated eyes to con- ventional phacoemulsification, there compared to standard cataract surgery From left to right: Anne Jensen, MD, Purak Parikh, MD, Aida Bounama, MD, Anita Kohli, MD, and Neepa Shah, MD Source: Scheie Eye Institute

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