Late Spontaneous Intraocular Lens Dislocation To Anterior Chamber In A Patient With Rheumatoid Arthritis

Spontaneous intraocular lens (IOL) dislocation is a rare but serious complication following cataract surgery. The purpose of this case report is to describe a rare complication of nontraumatic IOL dislocation and prolapse into the anterior chamber in the setting of an autoimmune disorder.

Cornea, Anterior Segment and Refractive Surgery service of National Ophthalmology Unit, Guatemala, Central America.

A 67 yo patient presented with one-week history of spontaneously onset blurred vision. He denied history of trauma and had medical history of dry eye disease, uncontrolled rheumatoid arthritis and cataract surgery. Posterior capsular rupture was managed and sulcus PMMA IOL was implanted. At one year postoperative follow-up, BCVA was 20/20 but 4 years later it was MM  in the left eye, and a complete dislocated IOL in the anterior chamber was observed. Endothelial cell density revealed 2549/mm2, Rheumatoid Factor was 64 IU/ml. After informed consent, dislocated IOL extraction and iris claw IOL implantation was performed. BCVA was 20/200 at one month follow up.

Late dislocation of an IOL into anterior chamber is primarily associated with trauma. Few similar cases to ours have been reported, most of them, in eyes with zonular weakness.

The lens zonule complex connect the lens to the smooth muscle fibers of the ciliary body. Rheumatoid arthritis has been associated to higher levels of Smooth Muscle Antigens due to IgG-antibodies. Pro-inflammatory cytokines and toll-like receptor (TLR)-4 are recognized as important mediators. Rheumatoid factors are directed against the Fc region of IgG. Our patient had very high levels of RF.

As an immune-privileged tissue, the lens is protected of immunogenic inflammation. However, there is circulation of immune cells from the vascular-rich ciliary body along the zonule fibers. Several signaling proteins like TLR4 could be involved in this migration.

These findings suggest that the zonules can act as a conduit for immune cells and directly participate in the immune response of the lens. Therefore, comprehending the mechanism of immune cells migration along the zonules to the capsular bag can deepen our understanding of zonular weakness, cataract formation, lens fibrosis and provide a potential cause of dislocation of an IOL due to anterior displacement of iris-lens diafragm.

There still remains much to learn about the function of zonules in lens immunity, especially in the setting of autoimmune diseases such as rheumatoid arthritis. Collaborative efforts between ophthalmologists and rheumatologists, as well as patient compliance to treatment, are essential to improve outcomes.