Ab externo trabeculectomy performed under topical anesthesia supplemented by conscious sedation

Ab externo trabeculectomy (AET) is the most common surgical procedure to treat glaucoma; topical anesthesia supplemented by conscious sedation is one of the diverse anesthetic methods to perform such type of surgery. The efficacy and safety of using topical anesthesia supplemented with conscious sedation for performing trabeculectomy were assessed in this prospective study.

Twenty-six eyes of 26 consecutive patients underwent trabeculectomy under the effect of topical anesthesia and sedation. All cases were prospectively assessed during five different intra-operative times in which the degree of pain was measured using a visual analog scale (VAS).

One patient was excluded from the study due to excessive somnolence. Performing the iridectomy caused less tolerance (p = 0.03) but with acceptable scores according to the VAS (score 2 = minimal and tolerable pain; p = 0.02), followed by conjunctival closure (nonsignificant p values). The entire procedure did not cause either moderate to extreme pain (scores 4 and 5 of the scale, respectively) in any of the patients. Levels of pain, blood pressure, heart rate, and oxygen saturation were compared among the different intra-operative times. No statistically significant (p >0.05) differences were demonstrated. Eighty percent (n = 4) of the patients with green or blue iris had symptoms during the surgery, but this was of borderline statistical significance (p = 0.053). No ocular or systemic side effects appeared related to the reported anesthesia regime.

Topical anesthesia associated with conscious sedation seems to be efficacious and safe and can be recommended for performing trabeculectomy.