Background: In recent years, there has been a major change in the provision of LA for cataract surgery. Sub-Tenon's, topical and topical-intracameral LA techniques have become common. This study was set up to assess the safety of these 'newer' LA techniques in routine practice.
Aims: (i) to obtain an estimate of the frequency of use of the various LA techniques for cataract surgery in the United Kingdom (UK), (ii) to estimate the incidence of severe adverse events associated with each LA technique, and (iii) to document the types of severe adverse events associated with each LA technique.
Methods: A prospective, observational study of routine practice in the UK, lasting for 13 months in 2002-2003. The study was done through the British Ophthalmic Surveillance Unit (BOSU), which runs a proven system of case ascertainment for studies of rare conditions in ophthalmology. Each month, BOSU wrote to all senior UK ophthalmologists, asking if they have seen any cases 'potentially sight-threatening or life- threatening complications of LA for cataract surgery'. Details of these cases were obtained by sending a questionnaire to each respondent. To estimate the actual usage of LA and the various LA techniques, another questionnaire was mailed to all ophthalmologists on the BOSU database, at the mid-point of the survey.
Results: Overall, cataract surgery done under the National Health Service comprised 4.1% general anaesthesia, 92.1% LA without sedation, and 3.9% LA with sedation. An estimated 375,000 LA's were given for cataract surgery during the survey period. Usage of the different LA techniques was: 30.6% peribulbar, 3.5% retrobulbar, 42.6% sub-Tenon's, 1.7% sub-conjunctival, 9.9% topical and 11.0% topical-intracameral LA. 'Potentially sight-threatening complications' were mostly reported in association with retrobulbar and peribulbar techniques, with 26 cases of globe penetration or perforation, 16 of which had a poor visual outcome. 'Potentially life-threatening' complications were reported with all techniques except topical/intracameral LA. Eight 'neurological' complications, consistent with brainstem anaesthesia, were reported: 7 occurred with peribulbar or retrobulbar LA. Poisson regression analysis gave strong evidence that rates vary with technique (p < 0.0001 for 'potentially sight-threatening' complications, p = 0.03 for 'neurological' complications). Because of likely under-reporting, it is probable that further complications occurred during the survey period.
Conclusions: This large prospective survey of routine practice found a lower rate of reported serious complications with sub-Tenon's, topical and topical- intracameral LA, when compared with retrobulbar and peribulbar techniques. It provides further evidence that these 'newer' techniques may be preferable for routine cataract surgery.
- Local anaesthesia complications
- Peribulbar anaesthesia
- cataract surgery
- sub-Tenons anaesthesia
- topical anaesthesia