Experimental closed system surgical procedures and intraocular pressure fluctuation

Area of Science:

• Ophthalmology
• Surgical Science
• Animal Models

Background:

• Intraocular pressure (IOP) management is critical during ophthalmic surgery.
• Understanding IOP dynamics during different surgical procedures is essential for patient safety.

Purpose of the Study:

• To investigate intraocular pressure behavior during vitrectomy, phacofragmentation, and phacoemulsification in rabbits.
• To analyze the relationship between intraocular pressure and infusion pressure during these procedures.

Main Methods:

• Intraocular pressure was monitored in 24 rabbit eyes undergoing vitrectomy, phacofragmentation, or phacoemulsification.
• Procedures were categorized by instrument aspiration force (weak vs. strong).
• Continuous IOP measurement utilized a computerized polygraph with a vitreous chamber cannula.

Main Results:

• Mean intraocular pressure varied from 6 mmHg to 33 mmHg.
• Vitrectomy demonstrated the most significant IOP difference between weak and strong aspiration.
• Phacoemulsification exhibited the widest IOP fluctuations, with peaks nearing 50 mmHg under strong aspiration.
• Infusion pressure showed less variation than IOP, particularly at lower pressure levels.

Conclusions:

• Intraocular pressure fluctuations during the studied ocular surgeries were generally moderate.
• A positive correlation exists between higher aspiration pressure and increased intraocular pressure.
• Infusion pressure did not strongly correlate with intraocular pressure during these surgical procedures.