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

Abulon DJ, Charles M, Charles DE - Clin Ophthalmol (2015)

Bottom Line: With two open ports, the IOP dropped to 20%-30% of set infusion pressure, regardless of infusion pressure and IOP compensation.The IOP was maintained in valved cannulas when one or two ports were left open, regardless of IOP compensation settings.External observation of rabbit eyes showed vitreous prolapse through non-valved, but not valved, cannulas.

View Article: PubMed Central - PubMed

Affiliation: Global Medical Affairs, Alcon Laboratories, Inc., Lake Forest, CA, USA.

ABSTRACT

Purpose: To compare the effects of valved and non-valved cannulas on intraocular pressure (IOP), fluid leakage, and vitreous incarceration during simulated vitrectomy.

Methods: Three-port pars plana incisions were generated in six rubber eyes using 23-, 25-, and 27-gauge valved and non-valved trocar cannulas. The models were filled with air and IOP was measured. Similar procedures were followed for 36 acrylic eyes filled with saline solution. Vitreous incarceration was analyzed in eleven rabbit and twelve porcine cadaver eyes.

Results: In the air-filled model, IOP loss was 89%-94% when two non-valved cannulas were unoccupied versus 1%-5% when two valved cannulas were unoccupied. In the fluid-filled model, with non-valved cannulas, IOP dropped while fluid leaked from the open ports. With two open ports, the IOP dropped to 20%-30% of set infusion pressure, regardless of infusion pressure and IOP compensation. The IOP was maintained in valved cannulas when one or two ports were left open, regardless of IOP compensation settings. There was no or minimal fluid leakage through open ports at any infusion pressure. Direct microscopic analysis of rabbit eyes showed that vitreous incarceration was significantly greater with 23-gauge non-valved than valved cannulas (P<0.005), and endoscopy of porcine eyes showed that vitreous incarceration was significantly greater with 23-gauge (P<0.05) and 27-gauge (P<0.05) non-valved cannulas. External observation of rabbit eyes showed vitreous prolapse through non-valved, but not valved, cannulas.

Conclusion: Valved cannulas surpassed non-valved cannulas in maintaining IOP, preventing fluid leakage, and reducing vitreous incarceration during simulated vitrectomy.

No MeSH data available.


Related in: MedlinePlus

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.
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f5-opth-9-1745: 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.

Mentions: Twelve porcine cadaver eyes were prepared in the same way as the rabbit eyes. For each test in each eye, the same size cannulas were used. Two valved trocar cannulas were inserted at the 4 and 6 o’clock positions for the endoilluminator and infusion cannula, respectively. For side-by-side comparisons of vitreous incarceration, one valved cannula was inserted at the 8 o’clock position and one non-valved cannula at the 10 o’clock position. The infusion pressure was set to 30 mmHg, and 0.04 cm3 of pure triamcinolone was injected through the sclera between the 8 o’clock valved cannula and 10 o’clock non-valved cannula (Figure 5), using a 30-gauge marked needle to yield the same depth in each test.


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

Abulon DJ, Charles M, Charles DE - Clin Ophthalmol (2015)

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.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590688&req=5

f5-opth-9-1745: 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.
Mentions: Twelve porcine cadaver eyes were prepared in the same way as the rabbit eyes. For each test in each eye, the same size cannulas were used. Two valved trocar cannulas were inserted at the 4 and 6 o’clock positions for the endoilluminator and infusion cannula, respectively. For side-by-side comparisons of vitreous incarceration, one valved cannula was inserted at the 8 o’clock position and one non-valved cannula at the 10 o’clock position. The infusion pressure was set to 30 mmHg, and 0.04 cm3 of pure triamcinolone was injected through the sclera between the 8 o’clock valved cannula and 10 o’clock non-valved cannula (Figure 5), using a 30-gauge marked needle to yield the same depth in each test.

Bottom Line: With two open ports, the IOP dropped to 20%-30% of set infusion pressure, regardless of infusion pressure and IOP compensation.The IOP was maintained in valved cannulas when one or two ports were left open, regardless of IOP compensation settings.External observation of rabbit eyes showed vitreous prolapse through non-valved, but not valved, cannulas.

View Article: PubMed Central - PubMed

Affiliation: Global Medical Affairs, Alcon Laboratories, Inc., Lake Forest, CA, USA.

ABSTRACT

Purpose: To compare the effects of valved and non-valved cannulas on intraocular pressure (IOP), fluid leakage, and vitreous incarceration during simulated vitrectomy.

Methods: Three-port pars plana incisions were generated in six rubber eyes using 23-, 25-, and 27-gauge valved and non-valved trocar cannulas. The models were filled with air and IOP was measured. Similar procedures were followed for 36 acrylic eyes filled with saline solution. Vitreous incarceration was analyzed in eleven rabbit and twelve porcine cadaver eyes.

Results: In the air-filled model, IOP loss was 89%-94% when two non-valved cannulas were unoccupied versus 1%-5% when two valved cannulas were unoccupied. In the fluid-filled model, with non-valved cannulas, IOP dropped while fluid leaked from the open ports. With two open ports, the IOP dropped to 20%-30% of set infusion pressure, regardless of infusion pressure and IOP compensation. The IOP was maintained in valved cannulas when one or two ports were left open, regardless of IOP compensation settings. There was no or minimal fluid leakage through open ports at any infusion pressure. Direct microscopic analysis of rabbit eyes showed that vitreous incarceration was significantly greater with 23-gauge non-valved than valved cannulas (P<0.005), and endoscopy of porcine eyes showed that vitreous incarceration was significantly greater with 23-gauge (P<0.05) and 27-gauge (P<0.05) non-valved cannulas. External observation of rabbit eyes showed vitreous prolapse through non-valved, but not valved, cannulas.

Conclusion: Valved cannulas surpassed non-valved cannulas in maintaining IOP, preventing fluid leakage, and reducing vitreous incarceration during simulated vitrectomy.

No MeSH data available.


Related in: MedlinePlus