Intraocular Pressure Control in Vitreoretinal Surgical Systems

Area of Science:

• Ophthalmology
• Surgical Technology
• Biomedical Engineering

Background:

• Maintaining stable intraocular pressure (IOP) is critical during vitrectomy.
• Current systems like the Enhancing Visual Acuity (EVA) system use automatic infusion compensation (AIC).
• The Constellation Vision System offers integrated intraocular pressure (IOP) control.

Purpose of the Study:

• To compare the efficacy of the Constellation Vision System with IOP control against the EVA system with AIC.
• To evaluate IOP stability during simulated vitrectomy in a closed eye model.

Main Methods:

• A simulated closed eye model was used with a vitrectomy probe and infusion cannula.
• The Constellation and EVA systems were tested at vacuum settings of 250, 450, and 650 mmHg.
• Intraocular pressure (IOP) was measured before, during, and after vitreous removal and fluid replacement.

Main Results:

• The Constellation system maintained target IOP (30±2.5 mmHg) 63% to 93% of the time across vacuum settings.
• The EVA system maintained target IOP only 16% to 23% of the time.
• At 650 mmHg vacuum, EVA showed a significant IOP increase during vitreous removal (44.62±1.24 mmHg) compared to Constellation (30.99±0.66 mmHg).

Conclusions:

• The Constellation Vision System with IOP control demonstrates superior performance in maintaining stable IOP during simulated vitrectomy.
• The EVA system with AIC struggled to maintain target IOP under dynamic fluid conditions.
• Constellation's IOP control offers enhanced stability for vitreoretinal surgery.