Hydrodissection does not require instruments specific to bimanual phaco. A flat Pearce canula will enable the surgeon to perform the two stages of this important aspect of the procedure, namely: the cleavage between the capsule and the cortex, and rotation of the nucleus within the bag.
However, self-sealing microincisions impose precautionary extraction of part of the viscoelastic agent before hydrodissection so as to prevent excess pressure within the bag when injecting BSS.
In fact, BSS in the bag, which would be blocked by the viscous agent prevented from exiting the anterior chamber by the leak-proof incisions, can bring about a rupture by excess pressure in the posterior capsule, whose thickness is only 5 microns.
When the Pearce canula is introduced into the anterior chamber, gently depressing the posterior edge of the incision and injecting BSS into the chamber will enable gentle evacuation of part of the viscous agent.
The Pearce canula should then be properly placed under the capsulorhexis canopy and slightly lifted to create a small tent under the anterior capsule to facilitate the progress of the BSS. The progression of the posterior hydrodissection wave does not require injection of a significant quantity of BSS and the cleavage between the cortex and the capsule can be performed more easily due to the pressure within the chamber caused by the leakproof incisions. To separate the equatorial and anterior cortex, the practitioner exercises pressure on the crystalline dome with the canula to cause the BSS exiting from the capsular bag to rise.
Before completing the hydrodissection, the surgeon verifies that the nucleus rotates properly within the bag by placing the end of the canula at 3 o’clock on the edge of the rhexis and then turning the nucleus with a rotating movement . If the nucleus should not turn, the surgeon must restart the hydrodissection procedure in another quadrant.
Some practitioners add hydrodelineation by BSS injection on the equatorial edge of the nucleus to release it from the epinucleus so as to preserve a cushioning of protective cortex for nuclear phacoemulsification. This results in a characteristic bronze-coloured ring. This alternative is very useful to perform phaco-chop in order properly to identify the instrument placement area. Hydrodelineation outlines the diameter of the adult nucleus (golden colour) of the epinucleus. It is within the epinucleus that the chopper will be operated for the horizontal chop. The larger the epinucleus, and the smaller the adult nucleus, the easier it will be to place the chopper.
