VISCOAT through defect
9.4 Vitreous Detection with Triamcinolone
If vitreous is suspected to be already present in the anterior chamber, inject diluted (approx. 10×) triamcinolone in the anterior chamber to “stain” vitreous. If vitreous is detected, this should be removed by careful anterior vitrectomy to prevent traction to the retina.
9.4.1 Lens Emulsification in the Safe Zone
Prior to any emulsification, it is safer to bring the nuclear pieces to a safe position into the anterior chamber far enough from the capsule rupture and the vitreous. This can be achieved by a manual technique and/or injection of viscoelastic behind the nucleus (Fig. 9.3). It makes no sense to jeopardize a complicated posterior capsular rent case by manipulating and emulsifying the lens material in the close proximity of the capsule break. Once the lens is brought up into the anterior chamber, one can reinject more dispersive viscoelastic to reinforce the dispersive viscoshield barrier. Emulsification of nuclear fragments should be performed at a very low flow setting to limit the removal of the viscoelastic barrier as much as possible as previously stated (Fig. 9.4). The vacuum should be very moderate to reduce the occlusion break surge response. I reiterate that it is essential to have a dedicated verylow fluidics program. The dispersive viscoelastic barrier which serves as a very effective protection for preventing nucleus to go down and vitreous to come upward, remains very much intact with very low aspiration flow and a very moderate vacuum setting. Alternative protective measures have been described such as sheets glides and early IOL injection as a scaffold to keep the nucleus in the anterior chamber. But, with a very early posterior capsular rent, these techniques are not applicable. The dispersive viscoelastic barrier + very low fluidics strategy is useful in all stages of a complicated case. Torsional ultrasound settings can remain normal because of the lack of repulsion. With longitudinal ultrasound, power settings should be limited and duty cycle (percentage ultrasound on time) decreased to a level at which the lens pieces are no longer repelled from the phaco tip. Longitudinal ultrasound modulation with greatly decreased duty cycle is mandatory in a very low-flow program.
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