Anaesthesia for cataract surgery

Cataract surgery is the most frequent surgical procedure requiring anaesthesia in developed countries. It is performed mainly in elderly patients, who present with many coexisting diseases that induce subsequent hazards from general anaesthesia. Cataract anaesthesia is performed following various techniques of regional anaesthesia, which are detailed in this review. Needle block carries a low but real risk of complications, mainly because of needle misplacement. Correct teaching and training are mandatory to prevent complications. The main patient risk factor for inadvertent globe perforation is the presence of a myopic staphyloma. Retrobulbar block has been progressively phased out and replaced by peribulbar block, sub-Tenon's block (STB) or topical anaesthesia (TA). The requirement for very deep block with total akinesia has greatly decreased with the use of phacoemulsification for cataract surgery, allowing for use of TA or low-volume STB. However, non-akinesia techniques may give rise to impaired surgical conditions, which have the potential to result in surgical complications. A surgical approach to accessing sub-Tenon's space avoids needle block, but does not totally prevent complications. When deep anaesthesia is required, low-volume STB, performed using either the needle technique or a surgical approach, appears to be the technique of choice in terms of efficacy. Increasing the anaesthetic volume provides reproducible akinesia. Various local anaesthetics may be used, depending on their availability and respective properties. The most useful adjuvant to local anaesthetic is hyaluronidase.