Sub-Tenon's anaesthesia: an efficient and safe technique.

AIM: To evaluate sub-Tenon's anaesthesia as an alternative to peribulbar anaesthesia. METHODS: 109 consecutive patients listed for various eye operations (including cataract, trabeculectomy, and vitrectomy) under peribulbar anaesthesia were operated on under sub-Tenon's anaesthesia instead. After topical anaesthesia a buttonhole was fashioned through the conjunctiva and Tenon's capsule 10 mm posterior to the limbus. 1.5 ml of lignocaine 2% was then delivered to the posterior sub-Tenon's space using a blunt cannula. The surgical procedure was performed immediately after the completion of the anaesthetic procedure. Chemosis, conjunctival haemorrhage, degree of akinesia, and pain scoring were analysed. RESULTS: There were no anaesthesia related complications. The administration of the block was painless for 99.1% of the patients. In all, 97.3% reported no pain during surgery. There was no akinesia when assessed just after the completion of the block and akinesia was limited when assessed after surgery. Chemosis and conjunctival haemorrhage were frequent but caused no intraoperative problems. CONCLUSION: Sub-Tenon's anaesthesia is an efficient and safe anaesthetic technique. It is a good alternative to peribulbar anaesthesia.

Surgically induced astigmatism with superior and temporal incisions in cases of with-the-rule preoperative astigmatism.

PURPOSE: To evaluate surgically induced astigmatism (SIA), postoperative astigmatism, and uncorrected visual acuity (UCVA) after cataract surgery with superior corneal, superior scleral, and temporal corneal 4.0 mm sutureless incisions in cases of preoperative with-the-rule (WTR) astigmatism. SETTING: Hopital des Quinze-Vingts, Paris, France. METHODS: This prospective evaluation included patients having phacoemulsification with foldable lens implantation through a 4.0 mm incision. Patients with preoperative WTR astigmatism were randomly assigned to 1 of 3 incisions: superior corneal (Group 1), superior scleral (Group 2), or temporal corneal (Group 3). All patients had autokeratometry preoperatively and postoperatively (1 day, 1 week, 1 month, 1 year). Surgically induced astigmatism using the vector method, postoperative astigmatism, and UCVA (patients whose spherical equivalent was with +/- 1 diopter) were evaluated. RESULTS: Ninety patients were included in the study; there were 30 in each incision group. One year postoperatively, Group 1 had 1.52 diopters (D) of SIA and 1.36 D of postoperative astigmatism; 53.5% of patients had a UCVA of 20/32 or better, Group 2 had 0.69 D of SIA (P < .05) and 0.67 D of postoperative astigmatism (P < .05); 82.7% of patients had a UCVA of 20/32 or better (P < .05). Group 3 had 0.69 D (P > .05), 0.98 D (P < .05), and 79.3% (P > .05), respectively. CONCLUSIONS: In this study, the superior corneal incision produced significant SIA, leading to high postoperative astigmatism and poor UCVA. The scleral and temporal incisions produced minimal SIA and good UCVA.