LAUSR

OBJECTIVE To optimize the flanged belt-loop technique of scleral fixation through biomechanical testing and report clinical outcomes of resultant modifications. DESIGN Experimental study. METHODS The force to disinsert flanged polypropylene suture from human cadaveric sclera was assessed using a tensile testing machine and compared to the breaking strengths of 9-0 and 10-0 polypropylene. The effects of modifying suture gauge (5-0, 6-0, 7-0 or 8-0), amount of suture cauterized (0.5 or 1.0mm), and sclerotomy size (27-, 30-, 32-, 33-gauge) were investigated. Belt-loop intrascleral fixation using 6-0 and 7-0 polypropylene with 30- and 32-gauge needles respectively was performed in 5 patients. MAIN OUTCOME MEASURES Flanged suture disinsertion force in cadaveric sclera. RESULTS The average force to disinsert a flange created by melting 1.0mm of 5-0, 6-0, 7-0 and 8-0 polypropylene suture from human cadaveric sclera via 27-, 30-, 32- and 33-gauge needle sclerotomies was 3.0 ± 0.5N, 2.1 ± 0.3N, 0.9 ± 0.2N and 0.4 ± 0.1N respectively. The disinsertion forces for flanges formed by melting 0.5mm of the same gauges were 72-79% lower (p < 0.001). In comparison, the breaking strengths of 9-0 and 10-0 polypropylene were 1.0 ± 0.2N and 0.5 ± 0.0N. Belt-loop fixation using 6-0 and 7-0 polypropylene with 30- and 32-gauge sclerotomies demonstrated good outcomes at 6 months. CONCLUSIONS The flanged belt-loop technique is a biomechanically sound method of scleral fixation using 1.0mm flanges of 5-0 to 7-0 polypropylene paired with 27-, 30- and 32- gauge sclerotomies. In contrast, 8-0 polypropylene and 0.5 mm flanges of any suture gauge will likely be unstable with this technique.