Intraoperative eye position after sub-Tenon's anesthesia for cataract surgery.

BACKGROUND: To evaluate the incidence and extent of ocular deviation associated with sub-Tenon's anesthesia. METHODS: Seventy-five consecutive patients undergoing routine phacoemulsification with sub-Tenon's anesthesia at the Eye Unit, Royal Gwent Hospital, were prospectively enrolled in this observational case series. The exclusion criteria were patients taking warfarin, or patients with preexisting ocular motility disorders, allergy to local anesthetics, or previous surgery for squint or retinal detachment. Eleven patients were subsequently excluded from the study group as they required additional anesthesia blocks before measurements were taken for ocular deviation. We injected 5 mL of a local anesthetic mixture of 2% lignocaine and 7.5 mg/mL levobupivacaine in the sub-Tenon's space in the inferonasal quadrant. Ocular deviation was assessed objectively by means of the Krimsky test. Forced duction tests were performed before and after anesthesia. RESULTS: Hyperdeviation was documented in 49 (77%) eyes, exodeviation in 62 (97%), and hypodeviation in 6 (9.4%). No esodeviations were documented. Only 2 patients were orthophoric after anesthesia. Mean vertical deviation was 4.4 prism dioptres (PD) (SD 4.7 PD, 95% CI 3.2-5.5 PD, range 0-14 PD). Mean horizontal deviation was 19.5 (SD 9.6, 95% CI 17-22, range 0-50) PD. Forced duction test revealed no mechanical restriction before or after anesthesia. INTERPRETATION: This study suggests that there is an appreciable ocular deviation with sub-Tenon's anesthesia. Intraoperative ocular deviation may make certain procedures more difficult; therefore, we recommend a low threshold for an additional corrective block administered before surgery to rectify the deviation.

Sub-Tenon's anesthesia with aspirin, warfarin, and clopidogrel.

PURPOSE: To review the frequency of hemorrhagic complications with sub-Tenon's anesthesia in patients on aspirin, warfarin or clopidogrel. SETTING: St. James's University Hospital, Leeds, United Kingdom. METHODS: Data were collected prospectively for patients having elective phacoemulsification under sub-Tenon's anesthesia. Seventy-five patients were on aspirin, 65 were on warfarin, and 40 were on clopidogrel. Seventy-five patients on no anticoagulants were used as the control group. No changes in the anticoagulant regimen were made prior to surgery. RESULTS: No sight-threatening hemorrhagic complications were noted, and no surgery was postponed or cancelled due to an anesthesic complication. Subconjunctival hemorrhage occurred in 19% in the control group, 40% in the clopidogrel group, 35% in the warfarin group, and 21% in the aspirin group. The warfarin and clopidogrel groups had the highest incidence of subconjunctival hemorrhage (P<.05). The incidence of hemorrhages involving more than 1 quadrant was highest in these 3 groups; however, this did not achieve statistical significance (P = .37, Fisher exact test). CONCLUSION: Data from this study support the continued use of anticoagulant agents among routine users during cataract surgery using a sub-Tenon's block.