Vitreous dynamics: Vitreous flow analysis in 20-, 23-, and 25-gauge cutters

Octaviano Magalhaes, Lawrence Chong, Charles DeBoer, Prashant Bhadri, Ralph Kerns, Aaron Barnes, Sophia Y Fang, Mark Humayun

Research output: Contribution to journalArticlepeer-review

56 Scopus citations


PURPOSE: To evaluate porcine vitreous flow and balanced saline solution (BSS) flow rates in different vitrectomy systems. METHODS: Porcine vitreous was obtained within 24 hours of slaughter. A high-speed (2 samples/s) balance, precise to 0.01 g, was used. Variable cut rates and vacuum pressures were analyzed in vitreous and BSS. The vitreous was labeled with glass microspheres and triamcinolone acetonide. A high-speed (400 frames/s) camera was used to record cutting for each condition. RESULTS: For all cutters, there was no vitreous flow at zero cut rates (off). In 25-gauge cutters, at 500 mmHg of vacuum, the electric cutter produced higher average flow rates at high cut rates (600 cpm, 0.004 mL/s, and 1500 cpm, 0.013 mL/s) than pneumatic, which demonstrated a decreased flow at speeds higher than 1000 cpm (1000 cpm, 0.015 mL/s, and 1500 cpm, 0.006 mL/s). The percentage of vitreous flow rate/BSS flow rate in different aspiration and cut rates showed an ascending curve. This demonstrates evidence of flow obstruction in 25- (all cut rates), 23- (all cut rates), and 20-gauge (all cut rates). Flow obstruction and surge movements were seen in the high-speed videos. CONCLUSIONS: The vitrectomy systems each illustrate different performances of vitreous removal. The physical characteristics of vitreous resulted in nonuniform flow in all vitreous cutters.

Original languageEnglish (US)
Pages (from-to)236-241
Number of pages6
Issue number2
StatePublished - Feb 2008
Externally publishedYes


  • Instrumentation
  • Surgery
  • Vitrectomy
  • Vitreoretinal surgery
  • Vitreous body

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems


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