Dislocated Intraocular Implants

Cataract surgery is one of the most common and successful surgical procedures performed today. Over the past decade, the risk of severe complications has decreased with advances in surgical instruments and techniques. In the procedure, the cataract (cloudy lens) is removed, and a clear intra-ocular (in-the-eye) lens is placed. Rare complications include intra-ocular lens (IOL) dislocation, where the lens moves out of place.

Symptoms

The most common symptom of a dislocated IOL is a change in vision. The degree to which vision is affected will depend on the severity of the dislocation.

• Blurring

• Double vision

• Seeing the edge of the lens implant

IOL dislocation can also lead to other complications such as retinal detachment, bleeding, intra-ocular inflammation, macular edema, glaucoma, and corneal edema.

Causes

During most cataract surgery procedures, the IOL is placed inside the capsular bag, a sack-like structure in the eye that previously contained the cloudy lens. In some situations, this extremely thin capsular bag or the fibers that hold it in place rupture and the IOL support is compromised.

Dislocation of the IOL can occur days to years after surgery and can be a result of factors during the original surgery, trauma to the eye, or diseases that affect the stability of the capsular bag.

Risk Factors

• Trauma
• Prior vitreoretinal surgery
• Pseudoexfoliation syndrome (a condition that causes instability of the capsular bag where the IOL is placed)

• Certain connective tissue disorders
• Inflammation in the eye (uveitis)

Treatment – Lens Exchange

Probably the most common procedure done for a dislocated intraocular lens is a lens exchange. The offending IOL is removed from the eye and a new lens is placed in the eye. If there is some capsule left in the eye that will support a larger IOL then a posterior chamber lens can be placed in the eye. If their is not capsular support adequate for a posterior chamber lens, then an anterior chamber IOL like the one in this photo can always be placed in front of the iris. In addition, there are a few useful techniques where a posterior chamber IOL can be placed into an eye without capsular support. A posterior chamber IOL can be clipped to the iris, sutured to the iris, sutured to the sclera or the haptics of the IOL can be tunnelled into the sclera. All of these options are reasonable depending on the state of the cornea, iris, and capsule.

Treatment Choices – IRIS Suture Fixation

If the dislocated IOL is in good shape and free of surrounding capsular debris, it can be captured in the pupil and sutured to the iris. This technique only works well for dislocated IOLs that have haptics. There are other types of IOLs, like the crystalens IOL, that do not have haptics and cannot be sutured to the iris. The sutures holding the haptics of the IOL to the iris in the accompanying photograph are blue and can be seen where the arrows are pointing. The optic of the IOL is perfectly centered and not visible.