Eyeworld

EW REFRACTIVE 98 October 2017 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer presbyopia ultimately resulting from the loss of lens elasticity with age. However, the proof of successful presbyopia "correction" is ultimately in the results. Dr. LiVecchi explained that one of the more interesting and prom- ising surgical approaches to presby- opia is the use of corneal implants. There are currently several variations of corneal implants that take advan- tage of completely different mecha- nisms of action to achieve multifo- cality and/or increase the depth of field. There are others coming that are just around the corner. The KAMRA inlay (AcuFocus, Irvine, California) is a 5 micron thick, 3.8 mm diameter disc, with a 1.6 mm central pinhole aperture that is implanted into the cornea of the non-dominant eye, blocking out peripheral light rays and improving depth of focus for near vision. The polyvinylidene fluoride device has 8,400 microperforations that vary slightly in size, to ensure circulation of fluids and nutrient distribution. The dominant eye does not get the implant, which allows it to maintain Surgeons are warming up to the notion of choosing a safe, efficient, and reversible option such as corneal inlays to satisfy the visual expectations of presbyopic patients M ounting interest in cor- neal inlays, a surgical solution for presbyopia that involves restoring near vision without compromising distance visual acuity, may reflect the growing excitement of 21st century patients to finally be able to cast off their glasses and see the world as they once could, from near and far. Meanwhile, inlays are making big strides in popularity among eye surgeons as well, thanks to their reliable refractive outcomes, quick and uncomplicated implanta- tion, and reversibility. According to John T. LiVec- chi, MD, FACS, assistant clinical professor of ophthalmology, Drexel University College of Medicine, Philadelphia, presbyopia is the final frontier in eye surgery. In a pre- sentation that he gave at the 2017 ASCRS•ASOA Symposium & Con- gress, Dr. LiVecchi explained that this "holy grail" represents the final obstacle that surgeons need to clear to provide an ever-aging population with excellent near, intermediate, and distance vision. Dr. LiVecchi thinks that as innovations continue to progress, the answers to presby- opia will come into reach. Presbyopic numbers rising Presbyopia is complete by the time most of us turn 50 years of age, leav- ing us with "zero" accommodative ability. It is "inevitable, dramatic, and frustrating," Dr. LiVecchi said. With 12% of the world's population currently older than 60 years of age, the prediction is that 2 billion peo- ple will be presbyopic by 2020. The challenge for eye doctors is finding the best approach to take. Surgeons can choose between surgical (pseudoaccommodative) or dynamic approaches to the prob- lem. Surgical procedures include presbyLASIK, LASIK, LASEK, PRK, monovision, corneal implants, and multifocal IOLs, while dynamic solutions include procedures such as accommodative IOLs, lens filling optics, presbydrops, presbydrop lens softening, femto lens softening, and scleral procedures like incisions and scleral bands. It is up to every eye doctor to weigh the risks and benefits for his or her patients and choose accordingly. Theories of accommodation The surgeon's choice may largely depend on the accommodative theo- ry that makes the most sense to him or her. Dr. LiVecchi is an advocate of Schachar's idea and theory that says ciliary muscle contraction increases tension on the zonules, resulting in equatorial stretching that causes the lens to change shape, adding power to the central lens, which results in accommodation. In contrast, Helm- holtz proposed that the zonules relax during accommodation, with Corneal inlays: Moving us closer to the holy grail –4.17 D in Group A and –3.78 D in Group B. The mean preoperative pa- chymetry was 535.18 μ and 533.24 μ, respectively. The mean lenticule thickness was 86.38 μ in Group A, and the mean ablation depth was 53.48 μ in Group B. Seven patients had a residual error >0.5 D in Group A as opposed to three in Group B. 26 eyes in Group A and 32 eyes in Group B achieved better than 6/6. The improvement in higher order aberrations was significantly better in Group B as compared to Group A (p=0.04). Conclusion: Excellent visual outcomes were obtained with both SMILE and combined topo-guided and wavefront-optimized laser ablation techniques. The excimer group had fewer eyes with residual error and more eyes with improvement in best corrected visual acuity and better aberration profile. Dr. Hofmeister: Since SMILE is relative- ly new, there aren't many head to head comparisons of SMILE vs. LASIK. As we gain more experience with SMILE, comparisons such as these will be im- portant in helping surgeons decide what role each technique will have in their practice. EW Editors' note: Dr. Hofmeister has no financial interests related to her comments. The views and opinions expressed by Dr. Hofmeister are her own and do not necessarily reflect the official position of the U.S. Navy, Department of Defense or Federal Government. Contact information Hofmeister: elizabeth.m.hofmeister.mil@mail.mil Best continued from page 97 Presentation spotlight KAMRA inlay Source: Perry Binder, MD Raindrop inlay Source: ReVision Optics Flexivue Microlens Source: Presbia

• Blank Page
• Blank Page (1)