The new versus the old: local anaesthesia techniques examined

A survey of British Ophthalmologists has found that there is a lower rate of serious complications after cataract surgery if sub–Tenon's, topical and topical–intracameral local anaesthesias are used rather than the 'older' retrobulbar and peribulbar techniques.

Tom Eke of the Norfolk & Norwich University Hospital and John Thompson from the University of Leicester, UK, conducted a prospective, observational study of routine practice in the UK for 13 months during the 2002 - 2003 period. The study was done through the British Ophthalmic Surveillance Unit (BOSU). Each month BOSU contacted all senior UK ophthalmologists asking for recent cases of 'potentially sight–threatening or life threatening complications of local anaesthesia for cataract surgery'.

The results showed that cataract surgery, conducted within the National Health Service (NHS), comprised 4.1% under general anaesthesia, 92.1% with local anaesthesia without sedation and 2.9% with local anaesthesia and sedation. Approximately 375,000 local anaesthesias were given for cataract surgery during the survey period. Of these, 30.6% used the peribulbar technique, 3.5% retrobulbar, 42.6% sub–Tenon's, 1.7% sub–conjunctival, 9.9% topical and 11% topical–intracameral local anaesthesia.

The largest number of potentially sight–threatening complications were reported in association with the retrobulbar and peribulbar technique. Twenty–six cases of globe penetration or perforation, 16 of which resulted in a poor visual outcome, were reported. Potentially life–threatening complications were reported with all techniques except for topical and intracameral local anaesthesias. Eight neurological complications were reported, seven of which occurred after peribulbar or retrobulbar anaesthesia.

The authors believe that the study demonstrates that newer techniques, such as sub–Tenon's, topical and topical–intracameral anaesthesia, offer a more favourable safety profile than more traditional methods.