Intraocular lidocaine in phacoemulsification: an endothelium and blood-aqueous barrier permeability study

Abstract

Objective: To evaluate the effects of intraocular lidocaine hydrochloride (HCI) on the corneal endothelium and of blood-aqueous barrier (BAB) permeability in ultrasound phacoemulsification.

Design: Nonrandomized, comparative trial.

Participants: Sixty patients who underwent uneventful, single-surgeon, clear cornea phacoemulsification were studied prospectively.

Methods: Sub-Tenon's anesthesia was administered to 30 patients (group 1), and intraocular lidocaine hydrochloride was administered to an additional 30 patients (group 2). An endothelial study of at least 120 cells per patient, using a noncontact specular microscope and a digital image analysis system, was performed before surgery and 1 month after surgery. Blood-aqueous barrier permeability was evaluated preoperatively and postoperatively (48 hours, 1 week and 1 month) using a laser flare meter.

Main outcome measures: Endothelial parameters (cell density, hexagonality, and coefficient of variation in cell area) and BAB permeability.

Results: No significant differences were found between groups when comparing the postoperative changes produced in endothelial cell density (95% confidence interval [CI], 0.46, 4.7; P = 0.10), hexagonality (95% CI, -2.5, 3.5; P = 0.72), and coefficient of variation in cell area (95% CI, -8.3, 4.6; P = 0.57). A multivariate study detected no significant differences in mean flare values between groups during follow-up (P = 0.40). No clinically significant differences were found between mean preoperative and 1 month postoperative flare values in either group.

Conclusions: The recovery of BAB permeability 1 month after surgery seems to suggest that no additional inflammation was induced by intraocular lidocaine HCI. The fact that no differences in postoperative changes in endothelial parameters were found between groups indicates that no further corneal endothelial damage (other than that caused by surgical manipulation) was incurred. According to our results, intracameral lidocaine HCI appears to be safe for the average phacoemulsification patient in the absence of ocular pathologic conditions.