THE TORQUE AND TILT GAMBLE

Purpose: To analyze possible suture configurations at the haptics of p osterior chamber intraocular lenses (IOLs) and estimate the resulting tilt. Setting: King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia.Methods: Using a plastic cylinder with two pairs of hole s drilled on opposite sides and an IOL with eyelets in the haptics, we determined possible suture configurations and analyzed them for net t orque on the IOL haptics that would result in tilting of the optic. Re sults: We identified 64 combinations of regular and countless combinat ions of irregular suture configurations. Among the 16 most likely comb inations, only 4 were torque-free (or torque neutral), 2 caused maximu m tilt, and 10 induced some tilting. Theoretically, torque could be el iminated by radial suture placement, but this is anatomically undesira ble, and by positioning the eyelet perpendicular to the haptic, but th is is technically difficult. Longer suture bites tended to lessen the torsion on the haptic but increased the risk of the suture looping aro und the free end of the haptic. Conclusion: Surgeons using scleral fix ation of a posterior chamber IOL should be aware of the possibility of inducing tilt and should aim for symmetrical suture configurations at the two haptics.