Eyeworld

Reporting from the 2017 American Academy of Ophthalmology (AAO) annual meeting, November 11–14, New Orleans EW MEETING REPORTER 96 laser patterns warrants further inves- tigation, Dr. Krueger said, of what would be an "externally noninvasive procedure." Editors' note: Dr. Krueger has finan- cial interests with LENSAR (Orlando, Florida). Dr. Durrie has no financial interests related to his presentation. Barraquer Lecture The Barraquer Lecture in the In- ternational Society of Refractive Surgery symposium was delivered by Scott MacRae, MD, Rochester, New York, who spoke about refractive indexing. Dr. MacRae described how refractive indexing with a femtosec- ond laser could provide an abla- tion-free, noninvasive approach to correcting refractive error, higher order aberrations, and presbyopia at the level of the cornea, IOL, or contact lens. Unlike changing shape or cur- vature to affect refractive change, refractive indexing induces the change segmentally within the same size media. The energy used by the femtosecond laser to change the refractive index is 2.5 nJ, which is significantly below the damage threshold (the lowest laser pulse en- ergy for cutting a femtosecond flap, for example, is 150 nJ). The spot size is also only about 1 micron. Refractive indexing of the cor- nea has been researched in animal models with human trials to begin within the next 2 years, Dr. MacRae said. It has also shown to be safe and effective in IOLs in vivo. Quoting the namesake of the lecture, Jose Barraquer, MD, Dr. MacRae said "imagine a world with- out glasses." With this technology and advancements that are to come, "I think we can do it," he said. Dr. MacRae envisions the creation of a portable, noninvasive refractive laser that could be brought into underserved communities around the world to permanently correct refractive error through refractive indexing. EW Editors' note: Dr. MacRae has no finan- cial interests related to his presentation. needed to dislocate the haptic in flanged fixated vs. non-flanged. The Yamane flanged technique showed a seven-fold higher force required to disinsert the haptic. Editors' note: Dr. McCannel has finan- cial interests related to his presentation. Dr. Todorich has no financial interests related to his presentation. Symposia focuses on presbyopia Daniel Durrie, MD, Overland Park, Kansas, shared information that "you can apply in your practice immediately when you go home" without any additional equipment. This, Dr. Durrie said, is educating your patients on dysfunctional lens syndrome (DLS), which describes the different stages of lens aging and how it affects vision. Stage 1 DLS generally occurs between 42 and 50 years old when the lens starts to stiffen, the patient loses focusing power, and higher order aberrations develop. Stage 2 occurs when there is loss of accom- modation, light scatter formation, and decreased contrast sensitivity and night vision. Stage 3 is the development of a full cataract with poor visual quality. Explaining to your patients the continuum of lens aging and the stage of DLS they might have is easy to do and appreciated by patients, helping them better understand the options for their DLS stage. A separate category covered the possibility of femtosecond alteration of either an IOL in vivo or the intact crystalline lens. Ronald Krueger, MD, Cleveland, described safety and efficacy research that has been done using a laser to create patterns on the crystalline lens to allow for ac- commodation. Studies have shown that it doesn't induce a visually significant cataract, while showing an improvement in distance vision, depth of focus, and accommodation. At this point, Dr. Krueger said accommodation restoration is at least theoretically possible and is a clinically promising femtosecond laser treatment. The absence of cataracts and significant symptoms and early clinical success with new Research presented by Colin McCannel, MD, Los Angeles, de- scribed the final visual acuity versus the amount of visual acuity im- provement in epiretinal membrane surgery. Historically, surgery was recommended if visual acuity was 20/70 or worse or in the presence of severe metamorphopsia. In gen- eral, Dr. McCannel said epiretinal membrane peeling resulted in two lines of visual acuity improvement, but patients' overall visual acuity was still poor with unsatisfactory functional vision. Forty-seven patients met the study's inclusion criteria to assess whether earlier surgical intervention resulted in better outcomes. Eyes 20/30 or better were grouped as "early indication for PPV," 20/40 to 20/50 were "contemporary indica- tion for PPV," and 20/60 or worse comprised the "historical indication for PPV" group. Overall, the amount of improve- ment was limited and eyes with worse vision preoperatively saw larger improvements than eyes with better vision. However, better final visual acuity was achieved with ear- lier surgery in eyes with better pre- operative visual acuity. Dr. McCan- nel said epiretinal membrane peel surgery might be better performed at earlier indications to optimize long- term visual function. Bozho Todorich, MD, Royal Oak, Michigan, described research on the structural analysis and long- term outcomes of sutureless intras- cleral haptic fixation (ISHF) of IOLs. Concerns with ISHF techniques, Dr. Todorich said, include haptic stretch or breakage as well as lens position, stability, and visual outcomes. To address these concerns, ISHF was performed on cadaver eyes in a wet lab and high resolution pho- tographs were taken after the eyes were sectioned at the equator to study the anatomy. No ciliary body process touch was observed, and there was minimal stretch in the op- tic-haptic junction (most stretching was at the haptic tip). Dr. Todorich and co-investiga- tors also tested the Yamane dou- ble-needle flanged ISHF technique in cadaver eyes and measured the force December 2017

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