Topical anaesthetic strabismus surgery
Reviewed by Fiona Rowe

This prospective observation study was undertaken with 16 symptomatic diplopia patients (15 male, one female) from various causes. All underwent single stage adjustable strabismus surgery (SSASS) under topical anaesthesia. Mean age was 28.12 years (range 19-65) and all had a primary symptom of diplopia: six exotropia, six esotropia, two vertical strabismus and two combined. Four underwent single muscle surgery, 10 had 2-muscle surgery of recession and plication, one had recession and advancement of a previously recessed muscle and one had recess / resect on a single muscle. Ten had diplopia after the planned surgery and underwent intraoperative adjustment under topical anaesthesia. Patients with esotropia became ortho for the horizontal strabismus and <6PD for the vertical element, if any. Patients with exotropia had 100% success on day one but reduced to 83.33% success at one month (one patient became exo) and with further reduction of success to 66.67% at three months with exo drift for two patients. Thus, the authors consider that surgery should aim for overcorrection in exo cases to avoid drift. Only one eso case had overcorrection but the patient could fuse and was therefore observed. All tolerated the topical anaesthesia well. The authors conclude that best outcomes are obtained for esotropia and vertical strabismus, but a drift is seen for exo cases over follow-up periods. Many required intraoperative modification of the planned surgery to address persistent diplopia. They found SSASS to be safe and well tolerated but acknowledge the small sample size of their study.

Evaluation of single stage adjustable strabismus surgery (SSASS) under topical anesthesia in patients with symptomatic diplopia.
Ganesh SC, Rao SG, Narendran K.
STRABISMUS
2020;29(2):215-22.