Management Of An Intraoperative Surprise In A Case Of Pmma Iol Subluxation

To present a challenging case of Polymethyl methacrylate (PMMA) intraocular lens (IOL) dislocation diagnosed intraoperatively and corrected via anterior chamber with posterior iris fixation. 

Department of Ophthalmology, Prof. Doutor Fernando Fonseca Hospital, Lisbon, Portugal

We present a 78-year-old male with history of cataract surgery more than 15 years ago, with implantation of a single-piece PMMA IOL. He came to the emergency room complaining of blurred vision in the right eye (OD) three days before. He denied eye trauma or other triggers and his left eye vision was good. On biomicroscopy, the IOL was subluxated inferiorly but, there were no apparent signs of pseudoexfoliation, the intraocular pressure (IOP) was normal, and the fundus observation was unremarkable. The patient was urgently referred to the cataract surgery department and the immediate preoperative observation showed a haptic capture over the pupil into the anterior chamber. Intraoperatively, with the patient under general anaesthesia, surprisingly we noted a complete dislocation of the PMMA IOL into the anterior vitreous. Since the IOL haptic was visible, the decision was to carefully “fish” the IOL via anterior chamber with a microforceps using gentle manoeuvres and an anterior central vitrectomy was performed. Due to the size and rigidity of the IOL, we fixed it to the posterior iris with polypropylene sutures and finished the surgery with a peripheral iridectomy. The result was a very well positioned IOL but, on the next day, we noted an inferior optic capture over the pupil. Given the absence of inflammation and IOP elevation, we decided to watch it closely. After one month, the capture resolved, supposedly spontaneously, and his best-corrected visual acuity was 0,66. 

IOL subluxations are a surgical challenge because there can always be an intraoperative surprise and change the initial plan. Some cases like this require unusual approaches using non-consensual manoeuvres. The anterior chamber approach to a dislocated IOL can be an option when there is no retina specialist immediate support, there is good visualization of the IOL and high suspicion of liquified vitreous. In this case, the visual outcomes were good, and no complications were observed. Nevertheless, close follow-up is important to avoid changes in the surgical outcome.