Vitreous humor thermodynamics during phacoemulsification.

Area of Science:

• Ophthalmology
• Surgical Science
• Biomedical Engineering

Background:

• Cataract surgery often involves phacoemulsification and pars plana vitrectomy (PPV).
• Intraocular temperature dynamics during these procedures are not well-established.
• Understanding vitreous humor temperature is crucial for patient safety and surgical outcomes.

Purpose of the Study:

• To establish baseline vitreous humor temperature during combined phacoemulsification and PPV.
• To quantify temperature variations during phacoemulsification.
• To compare intraocular vitreous temperature with systemic (sublingual) temperature.

Main Methods:

• Prospective, interventional, and comparative study design.
• Inclusion of patients undergoing combined phacoemulsification and PPV for cataract and vitreous hemorrhage.
• Exclusion of cases with posterior capsular rupture.
• Vitreous temperature measurement using a thermoprobe via PPV trocar at multiple time points.
• Sublingual temperature measurement post-surgery; room temperature recorded.

Main Results:

• Seventeen patients were included; mean sublingual temperature was 36.5°C.
• Mean total vitreous temperature was 31.47°C; mean baseline vitreous temperature was 33.04°C.
• Significant difference between sublingual and baseline vitreous temperatures (P < 0.000).
• Significant temperature decrease from baseline during phacoemulsification (P < 0.000 for surgical step, P = 0.003 for time).

Conclusions:

• Vitreous humor is significantly hypothermic compared to systemic temperature.
• Phacoemulsification causes a significant decrease in vitreous humor temperature.
• Findings highlight the thermal impact of phacoemulsification on the eye.