**8. Iris-fixated intraocular lens**

A secondary IOL can be fixated to iris tissue by suture or iris-claw enclavation. Iris-fixated secondary IOLs have the benefit of sparing scleral/conjunctival surgery in case future glaucoma surgery is needed, however normal iris anatomy is required. Iris fixation can cause iris chafing leading to inflammation and cystoid macular edema. As with all secondary IOL techniques, patient selection and counseling are key for surgical success.

A three-piece IOL can also be sutured to the iris via a variety of techniques. In one technique, the IOL is inserted into the anterior chamber such that the optic is captured by the iris with the haptics located behind the iris. A 10-0 prolene suture on a long-curved needle is used to suture the haptic to the iris with as small a bite as possible and placed as peripherally as possible. Peripheral placement avoids creating an oval iris. The suture is then tied in place and the ends trimmed. A smaller corneal incision can be used as the IOLs for this technique are foldable.

Iris-claw lenses are the most commonly used iris-fixation technique outside of the United States. Several studies have shown the safety and efficacy of this technique [16, 17]. A peripheral iridectomy is required to decrease the risk of pupillary block. Iris-claw lenses need to be carefully centered during enclavation. Studies have shown that if the iris-claw lens undergoes deenclavation, the haptics are irreversibly damaged, and the lens requires explanation [18]. These lenses can be fixated anterior or posterior to the iris. A 5-year follow-up showed no differences in astigmatism, complications or post-operative corneal endothelial cell density between anterior or posterior placement [19]. However, some prefer posterior placement with the theory that deenclavation posteriorly has less risk of corneal endothelial decompensation compared to the anterior approach [20].
