Background To evaluate intraocular pressure (IOP) using the application of a novel liquid patient interface for femtosecond laser-assisted cataract surgery with the FEMTO LDV Z8.
Methods IOP was evaluated in enucleated porcine eyes prior, during and after the application of the Femto LDV Z8 liquid patient interface (Ziemer Ophthalmic Systems, Switzerland) using intracameral cannulation (n=20), intravitreal cannulation (n=20), rebound tonometry (n=20) and indentation tonometry (n=20). Pressure was assessed prior vacuum, during vacuum (30 s, 1 min, 2 min, 3 min) and after releasing the vacuum (1 min and 2 min). Two groups with different predefined vacuum levels (350 mbar, 420 mbar) were investigated.
Results Mean intracameral pressure (±SD) increased during vacuum application from 20 mm Hg to 52.00 mm Hg (±6.35mm Hg; p=0.005) and 45.18 mmHg (±4.34 mm Hg; p=0.005) for the 420 mbar and the 350 mbar vacuum levels, respectively. Mean intravitreal pressure increased from 20 mm Hg to 25.60 mm Hg (±9.85 mm Hg; p=0.058) and 28.10 mm Hg (±2.54 mm Hg; p=0.059) for the 420 mbar and the 350 mbar vacuum levels, respectively. Pressure values from indentation and rebound tonometry were in between intracameral and intravitreal values. Mean intracameral IOP was 18.1% higher (p=0.019) in the 420 mbar group compared with the 350 mbar group.
Conclusion During vacuum application of the liquid patient interface of the Femto LDV Z8 for femtosecond laser-assisted cataract surgery, IOP values were higher in the anterior chamber compared with the intravitreal pressure measurements. The higher predefined vacuum level (350 mbar vs 420 mbar) resulted in significant higher intracameral IOP.
- intraocular pressure
- lens and zonules
- treatment lasers
- experimental – laboratory
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Contributors ME contributed to the design, interpretation, and experimental procedure and wrote the first draft. KTB contributed to the design, interpretation, and experimental procedure and made revisions to the manuscript. SM contributed to experimental procedure, made revisions to the manuscript and conducted statistical analysis. PS, KJ, KB and A-MS contributed to the design and interpretation of the experimental data and made revisions to the manuscript.
Funding This work was supported by Ziemer Ophthalmic Systems AG, Port, Switzerland. The authors received material support for the femtosecond laser procedure by Ziemer Ophthalmic Systems AG, Port, Switzerland.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.