Objective: To evaluate differences in pain, photophobia, retinal and optic nerve function in test eyes given intracameral lidocaine compared with control eyes given intracameral saline after phacoemulsification under topical anesthesia.
Design: Prospective paired-eye intervention study with random treatment allocation.
Participants: Thirty eyes of 15 patients underwent cataract surgery in both eyes under topical anesthesia.
Intervention: The first eye of each patient was randomly assigned to either 0.5 ml preservative-free 2% intracameral lidocaine or 0.5 ml of intracameral sterile saline. Within 5 months, the second eye automatically received intracameral saline if the first eye received intracameral lidocaine or vice versa.
Main outcome measures: The duration of surgery was recorded. Immediately after surgery, each patient was asked to evaluate the degree of pain and photophobia experienced during surgery using a nominal scale. In addition, in five patients, electroretinography (ERG) and visual evoked response (VER) were performed within 1 week before surgery, immediately after surgery, and 1 day after surgery. Amplitudes and latencies were calculated.
Results: There was no difference in the duration of surgery comparing test eyes given intracameral lidocaine with control eyes given sterile saline (P = 0.81). There was no significant difference in the level of pain reported when comparing test eyes given intracameral lidocaine with control eyes (P = 1.00). None of the patients reported any significant difference in photophobia between their two eyes (P = 1.00). When comparing ERG measurements, test eyes given intracameral lidocaine did not show any significant decrease in ERG amplitudes or prolonged latencies compared with control eyes. When comparing VER measurements, test eyes given intracameral lidocaine did not show any increase in P1 latencies compared with control eyes (P = 0.31). When evaluating all postoperative ERG results 1 day after surgery, there was a suggestion of improved cone function.
Conclusions: Although intracameral lidocaine does not depress retinal or optic nerve function, the addition of intracameral lidocaine to topical anesthesia during phacoemulsification does not significantly reduce intraoperative pain or photophobia.