Evaluating the Variation of Intraocular Pressure With Positional Change During Colorectal Laparoscopic Surgery:...

Area of Science:

• Ophthalmology
• Surgical Anesthesiology
• Colorectal Surgery

Background:

• Perioperative visual loss after colorectal surgery occurs at an incidence of 1.24 per 10,000 in the US.
• Elevated intraocular pressure (IOP) from extreme Trendelenburg positioning is a suspected cause of reduced optic nerve perfusion.

Purpose of the Study:

• To evaluate the impact of Trendelenburg tilt angle and duration on IOP.
• To assess IOP changes during laparoscopic colorectal procedures.

Main Methods:

• Fifty patients undergoing laparoscopic colorectal surgery were enrolled.
• Intraocular pressure (IOP) was measured hourly and during table tilts using a Tonopen XL tonometer.
• Correlation between Trendelenburg degree and IOP was analyzed, comparing right-sided (Group 1) and left-sided (Group 2) procedures.

Main Results:

• A strong positive correlation (r=0.78) was found between the degree of Trendelenburg tilt and IOP increase.
• Group 2 (left-sided procedures) experienced greater mean tilt (19° vs 10°) and higher IOP increase (15 mm Hg vs 9 mm Hg) compared to Group 1.
• Longer surgery durations were noted in Group 2 (268 min vs 142 min).

Conclusions:

• A significant correlation exists between elevated IOP and the degree of Trendelenburg tilt in laparoscopic colorectal surgery.
• The findings are clinically relevant for prolonged surgeries and patients with pre-existing glaucoma.
• Monitoring IOP during Trendelenburg positioning is recommended.