Evaluation of single-stage adjustable strabismus surgery under conscious sedation

To evaluate the feasibility and stability of ocular alignment after single-stage adjustable strabismus surgery (SSASS) performed under topical anesthesia.

Forty-five patients of concomitant exodeviations were randomized into three groups of 15 cases each and were operated with three different techniques: Group I - conventional surgery, Group II - two-stage adjustable suture technique with suture adjustment performed 6h postoperatively and Group III- SSASS under topical anesthesia and intravenous conscious sedation with midazolam and fentanyl. Intraoperative suture adjustment was done by giving a cross target to the patient on the ceiling at the end of the procedure. Surgical results were compared among the three groups at three months follow-up. Intraoperative hemodynamic parameters and patients' experience of the surgery (by questionnaire) were also compared.

Mean preoperative deviation for distance in Groups I, II, III was -41.67 prism diopter (pd) +/-9.0, -38.93 pd +/-11.05 and -41.87 pd +/-8.91 ( P =0.6) respectively. At three months, mean correction achieved for distance was +31.87 pd +/-11.71, +35.47 pd +/-10.86 and +42.80 pd +/-10.71 respectively which was significantly different between Group III and Group I ( P =0.03). Intraoperatively all hemodynamic parameters remained stable and comparable ( P =0. 5) in all groups. Intraoperative pain ( P < 0.001) and time taken for surgery ( P < 0.001) was more in the SSASS group. Amount of exodrift was 10-12 pd, comparable in all three groups ( P = 0.5).

SSASS, performed under topical anesthesia, is safe and has better outcomes than conventional recession-resection surgery for concomitant exodeviation. An overcorrection of about 10-12 pd is recommended to check the exodrift and achieve stable alignment.