Subluxation of suture-fixated posterior chamber intraocular lenses a clinicopathologic study

To report the occurrence of subluxation of suture-fixated posterior chamber (PC) intraocular lenses (IOL) and elucidate the mechanisms involved.

Prospective clinicopathologic study.

A single 10-0 Prolene suture explanted from a patient who experienced subluxation of his PC-IOL, 11.5 years after placement. Furthermore, multiple 10-0 Prolene sutures and PC-IOLs used for iris fixation were studied as controls.

Scanning electron microscopy (SEM) was used to analyze the surface of the explanted suture. In addition, randomly selected 10-0 Prolene sutures cut with Vannas scissors and cut with the positioning holes of a randomly selected PC-IOL identical to that implanted in the patient's eye were examined as controls. Finally, the positioning holes of several randomly selected, iris-fixated PC-IOLs were studied using SEM with particular attention to surface quality and edge finish.

Presence of any signs of suture degradation, the character of the cut edge of the suture, as well as the characteristics of the positioning holes of the PC-IOLs.

Scanning electron microscopy of the explanted suture revealed sharply cut edges, without significant degradation of the suture, and no intact loop. Scanning electron microscopy of the control suture cut with a PC-IOL demonstrated a similarly cut edge. The positioning holes of the examined PC-IOLs had a sharp edge, and some also had an imperfect finish.

We conclude that the surface properties of the positioning holes lead to cutting of the suture, and subsequent subluxation of the PC-IOL.