Presence of free radicals in intracameral agents commonly used during cataract surgery.

BACKGROUND: Free radicals are known to cause cellular damage and are present in ophthalmic preparations. Corneal defence mechanisms are bypassed in intra-ocular surgery. We evaluated commonly used intracameral agents to ascertain the presence of free radicals and investigate the possibility of anterior segment and endothelial toxicity.

METHODS: Samples of 19 commonly used intracameral preparations were analysed for total free radical presence on an Instrument Laboratory IL600 using a Randox Kit for Total Antioxidant Status (RANDOX Laboratories Ltd, Crumlin, UK).

RESULTS: Free radical concentrations for the 19 intracameral agents ranged from 0 to 3.59 mmol/l, with median value of 0.34 mmol/l (mean value 0.933±1.19 mmol/l). Phenylephrine had the highest presence of free radicals, which were considerably higher than those for 0.5% hydrogen peroxide at all tested dilutions. Other notable results included cefuroxime (0.61 mmol/l), 2% undiluted lidocaine (0.34 mmol/l) and bevacizumab (0.59 mmol/l).

CONCLUSION: The results indicate that free radicals are present in intracameral surgical agents and some are in the order of 0.5% hydrogen peroxide. The risks of endothelial damage must be considered when using multiple intracameral preparations in complicated cataract surgery. Free radicals in intracameral preparations may be a contributing cause in cases of toxic anterior segment syndrome.