Background Plication is an alternative tightening procedure to resection. In monkeys, plication has been shown to preserve anterior segment circulation compared with full-tendon tenotomy, but this is unconfirmed in humans.

Purpose To evaluate anterior segment circulation by iris angiography before and after strabismus surgery in humans.

Methods Prospective, blinded study of 14 patients (mean age (SD), 58.6 (14.3)) undergoing plication and/or full tendon tenotomy (resection or recession) from August 2013 to March 2014. Eight patients (mean age (SD), 59.0 (13.3)) underwent plication of one muscle with or without recession of a second muscle on the same eye and six patients (mean age (SD), 58.2 (16.8)) underwent tenotomy of one to two muscles on the same eye. Preoperative and postoperative iris angiograms were compared for changes in perfusion by a masked examiner. In patients undergoing binocular surgery, one eye was chosen preoperatively to be the study eye.

Results Postoperative iris filling defects were present in four patients (67%) after tenotomy and one patient (12.5%) after plication (p=0.09). Of the seven total vertical rectus muscles operated (three tenotomies and four plications), filling defects were present after three tenotomies and one plication (100% vs 25%; p=0.14). Of the 13 total horizontal rectus muscles operated (eight tenotomies and five plications), filling defects were present after one tenotomy and none of the plications (13% vs 0%; p=0.99).

Conclusions Rectus muscle plication spares the ciliary vessels and may be considered a safer alternative to resection for patients at risk for anterior segment ischaemia, especially when surgery involves a vertical rectus muscle.