Using the second instrument peripheral corneal incision in phacoemulsification as a blow-off valve

Area of Science:

• Ophthalmology
• Surgical Innovation

Background:

• Phacoemulsification is a common cataract surgery technique.
• Postoperative intraocular pressure (IOP) spikes can occur after phacoemulsification.
• The architecture of secondary instrument incisions may influence IOP dynamics.

Purpose of the Study:

• To evaluate the transient increase in intraocular pressure following phacoemulsification.
• To determine if peripheral corneal incision design affects postoperative IOP.
• To assess aqueous humor egress through different corneal incision types.

Main Methods:

• 42 patients undergoing phacoemulsification were randomized into perpendicular or oblique peripheral corneal incision groups.
• Intraocular pressure was measured preoperatively and at 3, 6, 12, and 18 hours postoperatively.
• Seidel's test assessed aqueous release from incisions; unoperated eyes served as controls.

Main Results:

• A significant IOP rise was observed in both groups at 6 hours (mean 10.95 mmHg).
• Perpendicular incisions showed a significant difference in IOP compared to oblique incisions at 12 hours.
• Seidel's test was positive in 63.6% of perpendicular incisions versus 15% of oblique incisions.

Conclusions:

• Post-phacoemulsification IOP elevation peaks around 6 hours, necessitating timely pharmacological intervention.
• Perpendicular peripheral corneal incisions may act as a 'blow-off valve,' potentially mitigating IOP spikes.
• Oblique incisions tended to be water-tight, with less aqueous release compared to perpendicular incisions.