• An instrument to assist in resection surgery consists of a telescoping hook within a second hook that can be spread a calibrated distance. Its primary purpose is to maintain a constant tension and an accurate measure of tendon length during suture passage. Additionally, the grooved distal hook supports the needle and protects the globe from needle trauma.
Lingua RW, Lee W. A Caliper-Hook for Strabismus Surgery. Arch Ophthalmol. 1989;107(9):1387. doi:10.1001/archopht.1989.01070020457055