Globe stability during simulated vitrectomy with valved and non-valved trocar cannulas

Figures & data

Figure 1 Photographs showing (A) temporary globe collapse under open-cannula conditions and (B) reinflation of the eye after non-valved cannulas are occupied while working under air.

Figure 2 Experimental setup of the fluid-filled plastic eye model.

Abbreviations: BSS, buffered saline solution; DAQ, data acquisition.

Figure 3 Intraoperative view of a valved (left) and a non-valved (right) cannula in a rabbit cadaver eye.

Figure 4 Experimental setup for evaluating vitreous incarceration in rabbit and porcine cadaver eyes.

Figure 5 Intraoperative image of a rabbit cadaver eye.

Note: The encircled area indicates the region of interest (ROI) 2 mm in diameter centered around each cannula. The percent vitreous incarceration was calculated for the area within the circle.

Table 1 Intraocular pressure (mmHg) in the air-filled model

	Two cannulas occupied	One cannula occupied	Unoccupied conditions
Non-valved cannula
23-gauge	29.4	5.2	1.8
25-gauge	29.8	6.8	2.6
27-gauge	29.5	7.3	3.0
Valved cannula
23-gauge	28.4	28.4	28.6
25-gauge	29.4	29.4	28.9
27-gauge	29.3	29.6	29.9

Note: The intraocular pressure setting was 30 mmHg.

Figure 6 Fluid-filled plastic eye model: change in IOP, taking the 25-gauge cannula as an example.

Notes: (A) Non-valved trocar cannula, one port open. (B) Non-valved trocar cannula, two ports open. (C) Valved trocar cannula, one port open. (D) Valved trocar cannula, two ports open.
Abbreviation: IOP, intraocular pressure.

Figure 7 Vitreous incarceration in rabbit cadaver eyes.

Figure 8 Vitreous incarceration in porcine cadaver eyes.

Abbreviation: ga, gauge.