Hook and loop fastener on loose prisms assists in measuring ocular deviation

It is difficult to hold a pair of loose prisms in one hand. Doing so can lead to inaccuracy, which worsens with large-angle exotropia or vertical deviations. The authors applied a self-adhesive hooked Velcro (Velcro Sticky Back Tape, Velcro USA Inc., Manchester, NH) strip to the base and the top of loose prisms. They applied the complementary looped Velcro to a wooden bar. As a result, a pair of prisms could be suspended horizontally and/or vertically while being held in one hand. Forty consecutive patients undergoing strabismus surgery without adjustable sutures were retrospectively studied to evaluate the accuracy of this method. Clinical use confirmed its ease and convenience. Of 19 patients with exotropia and 15 patients with esotropia (mean ages 41.9 and 15.7 years, respectively; mean deviations 44.7 and 49.8 D, respectively), 4 patients with abducens paralysis, and 2 patients with trochlear palsies, 1 surgery achieved less than 10 D of residual deviation in all but 2 (5.9%). This simple, inexpensive system can assist with the clinical evaluation of ocular deviation.