Changes of intraocular pressure during experimental vitrectomy.

Area of Science:

• Ophthalmology
• Surgical Technology
• Biomedical Engineering

Background:

• Accurate intraocular pressure (IOP) management is crucial during pars plana vitrectomy.
• Vitrectomy devices display infusion pressure, but its correlation with actual IOP requires validation.
• Understanding factors influencing IOP during surgery can optimize patient outcomes.

Purpose of the Study:

• To compare the displayed infusion pressure of a vitrectomy device with the actual IOP during pars plana vitrectomy.
• To evaluate the impact of variable parameters on actual IOP during vitrectomy surgery.

Main Methods:

• Porcine eyes were used to measure actual IOP with a digital manometer during vitrectomy.
• Vented gas forced infusion (VGFI) and gravity infusion systems were employed.
• Actual IOP was analyzed based on varying infusion fluid volumes and parameters like cutting rate, vacuum pressure, and VGFI settings.

Main Results:

• Vitrectomy device settings and gravity system pressure strongly correlated with actual IOP (r=0.99, p=0.0001).
• Actual IOP decreased significantly as infusion fluid volume reduced below 125 ml.
• Cutting rate, VGFI setting, and vacuum pressure were identified as factors affecting actual IOP.

Conclusions:

• The infusion pressure displayed by vitrectomy devices accurately reflects actual IOP in porcine models.
• Infusion fluid volume and adjustable parameters critically influence IOP during vitrectomy.
• Optimizing vitrectomy system parameters can enhance surgical safety and efficacy for vitreoretinal diseases.