Intraocular pressure rise during 25-gauge vitrectomy trocar placement.
OBJECTIVE
Small-gauge vitrectomy has been used to treat various vitreous and macular pathologies. Trocar/cannula insertion may raise intraocular pressure (IOP) to the point it might become detrimental to the eye, especially in the setting of open-globe trauma and eyes with severe vascular compromise. We propose to determine the magnitude of this IOP rise and its possible implications.


METHODS
Three different settings were designed to measure IOP rise during trocar placement for 25 ga vitrectomy (TSV); water-column manometry was performed during trocar placement in pig eyes. Electronic applanation tonometry was recorded in human eyes undergoing 25-ga vitrectomy for macular pathology during trocar placement, and wound behavior was recorded during trocar placement in harvested dog eyes with a previously sutured corneal wound.


RESULTS
The pressure recorded during trocar placement was 57.5 mmHg in pig eyes and 63.7 mmHg in human eyes. Sutured corneal wounds in dog eyes showed wound leakage and tissue incarceration during trocar insertion.


CONCLUSIONS
The 25-ga vitrectomy system may have limited usefulness in the setting of open-eye trauma and compromised bloodflow, due to the elevated pressures reached during trocar placement.
Dalma-Weiszhausz
José
J
Retina Service, Asociación para Evitar la Ceguera en Mexico, Vicente Garcia-Torres #46, Coyoacan, México DF, Mexico. jose@dalma.org
Gordon-Angelozzi
Maximiliano
M
Ustariz-Gonzalez
Orlando
O
Suarez-Licona
Ana Maria
AM
D000818:Animals; D004285:Dogs; D015807:Eye Injuries, Penetrating / Q000150:complications; D006801:Humans; D007429:Intraocular Pressure; D008866:Microsurgery; D009798:Ocular Hypertension / Q000209:etiology*; D013552:Swine; D014821:Vitrectomy / Q000009:adverse effects* / Q000295:instrumentation