Effect of Peribulbar Anesthesia with and Without Adrenaline on Retinal Thickness in Patients Undergoing Elective Cataract Surgery

BACKGROUND: The toxic effect of local anesthesia on the retina has been previously investigated in animal studies but not in humans. OBJECTIVES: The objective of this study was to clarify the effect of local anesthesia with lidocaine versus local anesthesia with lidocaine with extra administration of adrenaline on the retinal layer thickness measured by optical coherence tomography (OCT) in patients indicated for elective cataract surgery. METHODS: This is a randomized controlled trial conducted on 60 patients indicated for elective cataract surgery under local anesthesia with lidocaine. Thirty participants received local anesthesia with lidocaine 2% with extra administration of adrenaline (adrenaline group), and 30 participants received local anesthesia with lidocaine 2% only (control group). The retinal thickness was measured for all participants preoperatively and one week postoperatively using OCT. RESULTS: The OCT findings showed statistically significant decreases postoperatively in superior (P value = 0.028), inferior (P value = 0.017), and average (P value = 0.021) retinal thickness in the adrenaline group. Moreover, there were statistically significant decreases postoperatively in superior (P value = 0.032), inferior (P value = 0.046), and average (P value = 0.028) retinal thickness in the control group. Comparing the adrenaline and control groups for the OCT findings, there was no statistically significant difference between the groups regarding the decreases in superior (P value = 0.325), inferior (P value = 0.642), and average (P value = 0.291) retinal thickness. CONCLUSIONS: Local anesthesia with lidocaine significantly decreased the retinal thickness. The extra administration of adrenaline to lidocaine did not affect the post-anesthetic changes in the retinal thickness.