ASRS 2018: Instrumentation Symposium

Zachary Bodnar, MD
Vitreoretinal Surgery Fellow
Byers Eye Institute, Stanford University

The instrumentation symposium was moderated by Carl Awh, MD and Raymond Iezzi, MD.

Kevin Blinder, MD presented initial experiences with hypersonic vitrectomy. The Vitesse is a novel single lumen vitrectomy hand-piece with an ultra-rapidly vibrating needle tip. It offers the potential advantage of a longer duty cycle and higher cut rate with less vitreous traction. Following an initial animal safety study in 4 pig eyes, the authors conducted a prospective two-surgeon non-randomized consecutive case-control study. Vitrectomy was performed on 64 eyes using the hypersonic cutter and 24 controls using a pneumatic guillotine cutter for a variety of preoperative diagnoses. The log files from the Stellaris Elite vitrectomy system, which was used for each case, were examined. Notably, hypersonic vitrectomy cases had lower vacuum settings (159 mmHg vs 463 mmHg) but overall operative time was similar. Two surgical complications occurred in the Vitesse group: 1 superficial scoring of an acrylic IOL and 1 iatrogenic break in detached retina. As mentioned during other ASRS sessions, damage to the IOL optic during posterior capsulectomy may be a disadvantage of the current hypersonic vitrector design. Dr. Blinder showed some excellent videos demonstrating the effectiveness of the Vitesse at removing retained lens material and silicone oil.

Dr. Blinder

Non-pharmacologic anesthesia using ultra-rapid cooling of the ocular surface was presented by Cagri Besirli, MD, PhD. Dr. Besirli and colleagues have developed a handheld device that can cool the ocular surface in order to attenuate nerve conduction and provide anesthesia for intravitreal injections. They conduced a prospective randomized study comparing standard of care anesthesia (either lidocaine gel or subconjunctival lidocaine) vs the cooling device at varying temperatures and duration of contact. The primary outcome was immediate post injection pain, and the secondary outcome was post injection pain 4 hours after treatment. Both patients with neovascular AMD and DME were enrolled.

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Dr. Besirli

Visual analogue pain scores on a scale from 1-10 were similar (2.3 for standard of care group and 2.16 for focal cooling) at -10 degrees C immediately after injection. A dose response trend was noted with improved pain scores in proportion to cooling treatment duration. The 4-hour post-treatment pain scores were less for the cooling group than the standard of care group, but the difference was not statistically significant. In addition, there was an average of 4.5 minutes of time saved per procedure in the cooling group.

The final presentation came from Dr. Robert Gizicki on evolving trends in practice patterns of North American Vitreoretinal Surgery Fellows from 2010-2016. He presented trends in responses to the Annual Fellows Forum survey of 150 questions regarding practice pattern in AMD, DR, ROP, vitreoretinal interface disease, retinal detachment, vitreoretinal surgery and future practice plans. The response rate to the survey ranged from 80 – 90% over the years with the majority were from academic centers. One notable trend is that the use of fluorescein angiography for diagnosis of neovascular AMD has decreased in favor of OCT-alone over the course of the study. Approximately 60% of fellows report using bevacizumab as their first line treatment for neovascular AMD, but the proportion of fellows using aflibercept has increased markedly in recent years. Unsurprisingly, the use of focal laser for central DME has declined to negligible levels as anti-VEGF has been increasingly adopted. Most respondents do not feel that OCT angiography can replace fluorescein angiography, at this time. The number of fellows reporting exposure to ROP screening and treatment has remained stable. Fellows report increasing experience in ILM peeling in ERM and macular hole surgery. Additionally post-operative face-down positing times after macular hole surgery have decreased, now averaging 2-3 days.

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Dr. Gizicki