**6. Capsular bag**

Secondary intraocular lens implantation into the capsular bag can only be performed in the early post-operative period before the formation of anterior– posterior capsular adhesions. Typically, this procedure is performed in the early post-cataract surgery period due to incorrect intraocular lens power or patient dissatisfaction with an IOL (i.e., dysphotopsia from a multifocal IOL). Despite advances in IOL power formulas, some of which take into account the effects of prior refractive surgery, patients can still end up with large IOL power errors that may necessitate IOL exchange. Even with small errors, premium lens patients can demand IOL removal due to higher patient expectations in this population. IOL explantation in these cases should ideally be performed within 4–6 weeks of the initial cataract surgery although in-the-bag IOL exchange months to years following cataract surgery has been reported. A needle or cannula with viscoelastic is used to dissect the anterior capsular off the lens with care to avoid damaging zonular fibers and the posterior capsule. Once the lens is mobilized and removed, the capsular stability is assessed. If good anterior and posterior capsular support is noted the capsular bag is inflated with viscoelastic and a new lens can then be placed into the capsular bag.

### **7. Sulcus intraocular lens**

Sulcus intraocular lens implantation is the second-best option if the anterior capsule is intact and in-the-bag implantation cannot be performed. In cases with a single-piece IOL dislocation, the IOL must be removed and replaced with a 3-piece IOL in the sulcus. In cases of 3-piece IOL dislocation, the IOL can be retrieved and repositioned into the ciliary sulcus. If the capsulorhexis is intact, the optic can then be captured by pushing the optic posteriorly through capsulorhexis with the lens haptics remaining in the sulcus. Of note, most three-piece IOLs have an overall haptic to haptic diameter of 13 mm or less, which can be too short especially in long eyes. This can lead to lens decentration and tilt. Three-piece intraocular lenses with larger haptics can fit better in the sulcus and decrease chances of decentration/ tilt. With optic capture, the IOL calculations remain the same as the in-the-bag calculations [10].

Single-piece acrylic IOLs should not be placed in the sulcus [13–15]. Single-piece IOLs have haptics that are as thick as the optic and can chronically chafe the posterior iris causing uveitis-glaucoma-hyphema (UGH) syndrome. Unlike three-piece IOLs, which are posteriorly vaulted, single-piece IOLs are planar in configuration, increasing the potential contact between the optic and the iris. Furthermore, single piece IOLs are shorter in overall length than 3-piece IOLs and thus are not well supported in the sulcus leading to high rates of decentration and tilt.

#### **7.1 Technique**

Viscoelastic is used to create space between the iris and anterior capsular bag. The capsular bag should be evaluated to identify areas with optimal support. Iris mobilization with a Kuglen iris manipulator or expansion with iris hooks may be necessary for adequate visualization of the capsule. The haptics should be placed in areas where the anterior capsular support is greatest. The corneal incision should be planned along the axis where IOL haptic placement is desired. The lens is then inserted with the leading haptic inserted on top of the anterior capsular bag and

**127**

*Secondary Intraocular Lens*

*DOI: http://dx.doi.org/10.5772/intechopen.89569*

**8. Iris-fixated intraocular lens**

key for surgical success.

underneath the iris. However, if the corneal incision is not in the axis of desired haptic placement the lens can be inserted with the haptics on top of the iris. The lens is than rotated to the desired axis on top of the iris. Once in the desired axis the haptics are then placed into the sulcus. The trailing haptic is then rotated into the sulcus with a second instrument. The intraocular lens is then checked for stability and centration. If possible, the optic can be captured into the anterior capsule. There is no indication for peripheral iridotomy with sulcus intraocular lens implantation.

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

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

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

Scleral-fixated intraocular lenses have gained popularity for secondary IOL implantation in patients with aphakia. They are indicated in patients who do not wish to remain aphakic and have no capsular or iris support. However, some surgeons prefer SFIOLs even if there is iris support. In patients where an ACIOL might not be a good option such as in patients with corneal endothelial disease or

Scleral-sutured intraocular lens implantation started in the 1980s with abinterno and ab-externo approaches. Ab-interno approaches utilized suture passes from inside to outside the eye in a blind maneuver. This led to complications with retinal detachment, vitreous hemorrhage, and unpredictable haptic placement. Ab-externo approaches were found to be more promising with sutures passed from outside to inside the eye. This led to more reliable suture placement. Lewis popularized an ab-externo technique in 1991 [21] whereby 10-0 polypropylene

incision can be used as the IOLs for this technique are foldable.

endothelial decompensation compared to the anterior approach [20].

**9. Scleral-fixated intraocular lens**

glaucoma, SFIOLs or IFIOLs are both viable options.

#### *Secondary Intraocular Lens DOI: http://dx.doi.org/10.5772/intechopen.89569*

*Intraocular Lens*

capsular bag.

calculations [10].

**7.1 Technique**

**7. Sulcus intraocular lens**

**6. Capsular bag**

Secondary intraocular lens implantation into the capsular bag can only be performed in the early post-operative period before the formation of anterior– posterior capsular adhesions. Typically, this procedure is performed in the early post-cataract surgery period due to incorrect intraocular lens power or patient dissatisfaction with an IOL (i.e., dysphotopsia from a multifocal IOL). Despite advances in IOL power formulas, some of which take into account the effects of prior refractive surgery, patients can still end up with large IOL power errors that may necessitate IOL exchange. Even with small errors, premium lens patients can demand IOL removal due to higher patient expectations in this population. IOL explantation in these cases should ideally be performed within 4–6 weeks of the initial cataract surgery although in-the-bag IOL exchange months to years following cataract surgery has been reported. A needle or cannula with viscoelastic is used to dissect the anterior capsular off the lens with care to avoid damaging zonular fibers and the posterior capsule. Once the lens is mobilized and removed, the capsular stability is assessed. If good anterior and posterior capsular support is noted the capsular bag is inflated with viscoelastic and a new lens can then be placed into the

Sulcus intraocular lens implantation is the second-best option if the anterior capsule is intact and in-the-bag implantation cannot be performed. In cases with a single-piece IOL dislocation, the IOL must be removed and replaced with a 3-piece IOL in the sulcus. In cases of 3-piece IOL dislocation, the IOL can be retrieved and repositioned into the ciliary sulcus. If the capsulorhexis is intact, the optic can then be captured by pushing the optic posteriorly through capsulorhexis with the lens haptics remaining in the sulcus. Of note, most three-piece IOLs have an overall haptic to haptic diameter of 13 mm or less, which can be too short especially in long eyes. This can lead to lens decentration and tilt. Three-piece intraocular lenses with larger haptics can fit better in the sulcus and decrease chances of decentration/ tilt. With optic capture, the IOL calculations remain the same as the in-the-bag

Single-piece acrylic IOLs should not be placed in the sulcus [13–15]. Single-piece IOLs have haptics that are as thick as the optic and can chronically chafe the posterior iris causing uveitis-glaucoma-hyphema (UGH) syndrome. Unlike three-piece IOLs, which are posteriorly vaulted, single-piece IOLs are planar in configuration, increasing the potential contact between the optic and the iris. Furthermore, single piece IOLs are shorter in overall length than 3-piece IOLs and thus are not well sup-

Viscoelastic is used to create space between the iris and anterior capsular bag. The capsular bag should be evaluated to identify areas with optimal support. Iris mobilization with a Kuglen iris manipulator or expansion with iris hooks may be necessary for adequate visualization of the capsule. The haptics should be placed in areas where the anterior capsular support is greatest. The corneal incision should be planned along the axis where IOL haptic placement is desired. The lens is then inserted with the leading haptic inserted on top of the anterior capsular bag and

ported in the sulcus leading to high rates of decentration and tilt.

**126**

underneath the iris. However, if the corneal incision is not in the axis of desired haptic placement the lens can be inserted with the haptics on top of the iris. The lens is than rotated to the desired axis on top of the iris. Once in the desired axis the haptics are then placed into the sulcus. The trailing haptic is then rotated into the sulcus with a second instrument. The intraocular lens is then checked for stability and centration. If possible, the optic can be captured into the anterior capsule. There is no indication for peripheral iridotomy with sulcus intraocular lens implantation.
