Moran CORE

Open source ophthalmology education for students, residents, fellows, healthcare workers, and clinicians. Produced by the Moran Eye Center in partnership with the Eccles Library

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Hydrodissection and Hydrodelineation

Home / Ophthalmic Surgery / Lens and Cataract Surgery

Title: Hydrodissection and Hydrodelineation
Author (s): Troy Teeples, MSIV, Nikko Ronquillo, MD, Tara Hahn, MD, Jeff Pettey, MD
Photographer: Troy Teeples, MSIV University of Utah School of Medicine
Date: 8/8/2018
Keywords/Main Subjects: Hydrodissection, hydrodelineation, cataract surgery

Brief Description: Hydrodissection is a technique used to free the lens from the capsular bag to facilitate easier extraction. Hydrodelineation is a similar technique performed with the goal of separating the epinucleus and endonucleus.


Hydrodissection is a vital step in cataract surgery in which the lens capsule is separated from the lens cortex with the use of a balanced salt solution (BSS). When properly performed, the lens will be freely mobile and detached from its surrounding capsule, facilitating an easier extraction during phacoemulsification. In addition, an effective hydrodissection will allow for an easier cortical clean up, thus reducing the risk of capsular rupture during cortical extraction.

Hydrodelineation is a technique similar to hydrodissection, where BSS is used to separate the outer epinuclear shell from the central endonucleus. The purpose of hydrodelineation is to temporarily maintain the epinuclear shell, which acts as a protective shield in which to confine the ultrasonic energy emitted during phacoemulsification of the endonucleus. In addition, the remaining epinuclear shell keeps the capsule on stretch, preventing the bag from unexpectedly coming forward, occluding the phaco tip and tearing.

Description of Technique:

Hydrodissection is performed after creation of the capsulorhexis. A Chang canula is attached to a syringe filled with a balanced salt solution (BSS), inserted into the eye, and then directed 180-degrees from the main incision. It is then gently placed under the anterior capsule and advanced forward ensuring visualization of the tip. The anterior capsule is gently lifted, and the cannula is pointed towards the lens equator, taking care as to not puncture the capsule or damage the zonules. Gentle, continuous irrigation of BSS generates a fluid wave which cleaves the cortex from the posterior capsule. A fluid wave will cause the lens to slightly bulge upwards from the pressure exerted by the BSS. Using the canula, the central portion of the lens is carefully depressed, forcing the fluid trapped posteriorly to escape and resulting in further disrupting the equatorial cortical-capsular adhesions. A successful hydrodissection is demonstrated when the nucleus can be rotated easily by the canula.

Hydrodelineation is also performed after creation of the capsulorhexis. This step most often follows hydrodissection but may also be performed without hydrodissection. A Chang canula is placed in the nucleus, angled downward and forward toward the central plane of the nucleus until the nucleus starts to move. When the nucleus starts to move the endonucleus has been found. The canula is then directed tangentially to the endonucleus and a tract is carefully created using the canula itself, into which BSS is gently and steadily injected. The fluid will follow the path of least resistance, cleaving the epinucleus from the endonucleus. A successful hydrodelineation will result in a golden ring or dark circle around the endonucleus, signifying a circumferential division of the nucleus.

Faculty Approval by: Jeff Pettey, MD
Identifier: Moran_CORE_25251
Copyright statement: Copyright Teeples, ©2018. For further information regarding the rights to this collection, please visit:
Disclosure (Financial or other): None

Easy; One-Step; and Consistent Hydrodissection Technique

Home / Ophthalmic Surgery / Lens and Cataract Surgery

Title: Easy; One-Step; and Consistent Hydrodissection Technique
Author: D. Brian Kim, MD, Professional Eye Associates, Dalton, Georgia
Date: 7/14/2016
Keywords/Main Subjects: Cataract surgery; Lens fragmentation techniques; lens disassembly techniques; phacoemulsification; phaco chop
Secondary CORE Category: Ophthalmic Surgery / Lens and Cataract Surgery
Diagnosis: Cataract
Brief Description: This lecture is intended to teach techniques for hydrodissection of the lens during cataract surgery. 
Format: video
Series: AECOS Lecture Series 2016
Identifier: Moran_CORE_23285
Copyright statement: Copyright 2017. Please see terms of use page for more information.