Ten randomised controlled trials (RCTs) were eligible for inclusion. In addition, there were 4 case-control or cohort studies, 5 case series or case reports, and 13 experimental studies on animals.
Effectiveness. One RCT compared peribulbar anaesthesia and combined topical and intracameral anaesthesia. The trial found that patients who received intracameral lidocaine 1% reported more pain during surgery and post-operatively.
The studies reached different conclusions about the effectiveness of intracameral anaesthesia as an adjunct to topical anaesthesia. Three RCTs reported that the adjunct of intracameral lidocaine 1% decreased pain at various points during and after the surgery, compared with groups receiving topical anaesthesia and placebo intracamerally.
Four RCTs showed a minimal difference in pain control between intracameral lidocaine and placebo when they were used as topical anaesthesia. The evidence from studies using different designs was limited.
One RCT comparing intracameral bupivacaine 0.5% and lidocaine 1% found no significant difference in pain between the two groups.
Corneal toxicity.
Three RCTs examined post-operative endothelial cell counts in the short term. Compared with controls, preservative-free lidocaine 1% caused no change in the endothelial cell counts. There was also no difference between the lidocaine and control groups in terms of the blood-aqueous barrier permeability at 1 month.
The authors also reported the results from animal studies.
Retinal toxicity.
One RCT showed no long-term effect of intracameral anaesthetic on retinal cells. The authors also reported the results from animal studies.