The use of an intraocular lens (IOL) during cataract surgery allows good postoperative vision for the patient without the need for spectacles. However, in some patients operated years ago, or in the event of unexpected problems during surgery, an IOL may not be implanted or can shift in position after implantation.

In such situations, the patient may need thick, high powered glasses, or may not be able to see well even with such glasses. In other conditions, the altered position of the IOL may result in pain, irritation, light sensitivity, redness, tearing, and damage to other ocular structures. Such situations can be treated by further corrective surgery – termed “secondary IOL implantation”.

Before such surgery, accurate evaluation of the condition of the eye is essential to assess the existing damage and plan for corrective surgery. Tests to precisely estimate the power of the IOL to be used as replacement and the availability of special IOLs ensure the success of the procedure.

Specialized techniques and instrumentation may be needed during surgery to allow successful restoration of vision in these eyes. These include the need to remove any vitreous gel that has migrated to the front of the eye, reconstructing damaged iris tissue, and the use of pharmacological mediators like heparin and triamcinolone to reduce inflammation.

Once favorable conditions have been restored in the eye, the existing IOL can then be repositioned in a more suitable location. Alternatively, it can be removed and a new IOL placed in the eye using existing supports or sutured in place using special sutures.