Clinical and experimental evaluation of new back-flow hydrodissection technique

To assess the efficacy and safety of a new technique, back-flow hydrodissection.

Hirota Eye Clinic, Yamaguchi, and Department of Ophthalmology, University of Tsukuba, Ibaraki, Japan.

Prospective case series and experimental study.

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.

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.

Back-flow hydrodissection was safe and effective in disengaging the lens from the capsule, ensuring a freely mobile lens.