Superior subconjunctival anesthesia versus retrobulbar anesthesia for manual small-incision cataract surgery in a residency training program: a randomized controlled trial

Abstract

Pipat KongsapDepartment of Ophthalmology, Prapokklao Hospital, Chanthaburi, Thailand; Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandPurpose: To evaluate the effectiveness of subconjunctival anesthesia as compared to retrobulbar anesthesia for pain control during manual small-incision cataract surgery (MSICS) performed by third-year residents.Design: A randomized, controlled trial.Patients and methods: A total of 150 patients undergoing routine cataract surgery were randomly assigned to receive either subconjunctival anesthesia (group 1, n = 75) or retrobulbar anesthesia (group 2, n = 75). Third-year residents performed MSICS using the modified Blumenthal technique. Subconjunctival anesthesia was administered by injecting 2% xylocaine with adrenalin into the superior conjunctiva, and retrobulbar anesthesia by injecting 2 mL of 2% xylocaine with adrenalin into the retrobulbar space. We studied the following variables: intraoperative pain score rated on a 100-point visual analog scale (VAS), operative time, and injection and operative complications.Results: A mean age of 69 vs 70 years, an operative time of 47.1 (SD, 9.9) min vs 47.7 (10.9) min, and a median (interquartile range) pain score of 40 (range, 20–70) vs 40 (range, 20–50) were observed in the subconjunctival and the retrobulbar groups, respectively. The injection complication of subconjunctival hemorrhage was significantly higher in the subconjunctival group (25.3%) compared to the retrobulbar group (1.3%). The operative complication rate between groups was not different (P > 0.05).Conclusion: Both, superior subconjunctival anesthesia and retrobulbar anesthesia were effective during MSICS when used in a residency training program.Keywords: subconjunctival anesthesia, retrobulbar anesthesia, cataract surgery, small-incision cataract surgery, visual analog scale, pain score