Intraocular pressure changes after peribulbar injections with and without ocular compression

Transconjunctival approach to peribulbar block

As increasing numbers of anesthetists perform eye block anesthesia, thorough understandings of peribulbar injection techniques are important for safe practice. There is uncertainty in the literature regarding the optimum needle length, entry point, volume of injectate, and use of single vs double-injection techniques. A modified technique of peribulbar block anesthesia is presented, which offers increased safety, simplicity, low cost, and little change to instrumentation.

Single injection peribulbar anaesthesia. Total upper eyelid drop as an end-point marker

A prospective, observer blinded study on 51 patients undergoing cataract surgery was conducted to assess Total Upper Eyelid Drop as a new end-point marker to single injection peribulbar block. At present, no such clinical marker exists to stop clinicians injecting more than necessary volumes of local anaesthetic and therefore to prevent dangerous increases in intra-ocular pressure. Using this technique, satisfactory ocular akinesia was achieved in 90% of eyes 10 min after injection. Operating conditions were satisfactory in 98% of cases. The mean (range) volume injected was 9.1 (4-15) ml. The mean increase in intra-ocular pressure immediately after injection was 6.9 mmHg, decreasing to 0.7 mmHg after 5 min without the application of ocular compression. We found a negative correlation between the increase in intra-ocular pressure and the volume of injection (p < 0.002), which has never previously been reported. We conclude that Total Upper Eyelid Drop is a reliable endpoint marker for producing satisfactory operating conditions for cataract surgery while minimising increases in intra-ocular pressure and its use may therefore avoid the risks associated with ocular compression.