ArticleClinical and experimental evaluation of new back-flow hydrodissection techniqueHirota, Atsushi MD1; Yasuda, Kazuomi MD2; Morita, Shinichi MD3; Okamoto, Fumiki MD4; Hoshi, Sujin MD4; Murakami, Tomoya MD4; Oshika, Tetsuro MD4,* Author Information 1Hirota Eye Clinic, Ibaraki, Japan 2Musashikoganei Sakura Eye Clinic, Ibaraki, Japan 3Tane Memorial Eye Hospital, Ibaraki, Japan 4Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan *Corresponding author: Tetsuro Oshika, MD, Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8575 Japan. E-mail: [email protected] Submitted March 11, 2019; revised April 29, 2019; accepted May 2, 2019.Figure: No Caption available.First author: Atsushi Hirota, MD Hirota Eye Clinic, Yamaguchi, Japan Journal of Cataract & Refractive Surgery: September 2019 - Volume 45 - Issue 9 - p 1280-1284 doi: 10.1016/j.jcrs.2019.05.016 Buy Metrics Abstract Purpose To assess the efficacy and safety of a new technique, back-flow hydrodissection. Setting Hirota Eye Clinic, Yamaguchi, and Department of Ophthalmology, University of Tsukuba, Ibaraki, Japan. Design Prospective case series and experimental study. Methods For back-flow hydrodissection, the irrigation line was connected to the aspiration port of an irrigation/aspiration handpiece using a female–female connector with the irrigation port open. The balanced salt solution was irrigated from the aspiration tip opening with constant pressure, hydrodissection was performed, and the excess fluid was evacuated via the sleeve lumen. In a clinical study, 200 eyes were randomly assigned to conventional hydrodissection with an irrigation cannula or back-flow hydrodissection. In experimental studies, intraocular pressure (IOP) fluctuation and fluid dynamics in the anterior and posterior chamber were evaluated in porcine eyes. Results The lens became freely mobile in the capsular bag in 99 (99%) of 100 eyes and in 96 (96%) of 100 eyes in the back-flow hydrodissection group and conventional hydrodissection group, respectively (P = .369). There were no between-group differences in any other surgery-related parameters, including surgical time and the complication rate. In porcine eyes, conventional hydrodissection induced a significantly larger increase in IOP than back-flow hydrodissection (P < .0001). Conventional hydrodissection immediately washed out fluorescein-stained ophthalmic viscosurgical device (OVD) from the anterior chamber, while there was little leakage of OVD from the eye with back-flow hydrodissection. The endoscopic view showed that conventional hydrodissection induced rapid and severe bulging of the posterior capsule; however, bulging was gentle and mild with back-flow hydrodissection. Conclusion Back-flow hydrodissection was safe and effective in disengaging the lens from the capsule, ensuring a freely mobile lens. © 2019 by Lippincott Williams & Wilkins, Inc.